1st Post, Want more speed.. HELP

[Chillin The Most]

I need some info. I have a mint 1995 Rinker 236 Captiva Cuddy, about 125 hours on original 454 carb. 300 Hp motor, 21 pitch SS mirage quicksilver prop. It runs 63 mph @ 4600 rpm.It also has Baja SS corsa through hull exhast. I don't need the fastest boat on the river, however what do I need to do without spending a fortune to get this thing running around 72-75 mph. My local Rinker dealer says it can't be done. I told him he must be crazy because HP means speed.
Any suggestions would be greatly appreciated.

[ratso]

Dude...Money=Speed. Make the commitment to the money first...Then you get there.

[Chillin The Most]

I know money = speed. I said 72-75 mph, although 80 mph would be nice as well. Money isn't really a problem, but I don't want to get $20.000.00 tied up in my motor like I've read on some of the other threads where some people have 800-900 HP motors. What I would like is for some of you experts to tell me how much it will cost and what I need to do to achive 72-75 mph & the same to reach 80 mph. Thanks for the reply! Waiting to hear more!
Mike

[Havasu Hangin']

Any other guys going that fast with that hull?
Maybe the dealer was trying to say that your bottom (the boat's, not yours- sorry) was not designed to go that fast. There are alot of boats out there that no matter how much HP you dump in, they still drag like an anchor is out. For example, some boats have a little hook built in the bottom to smooth out the ride...
Also, with boats that wern't meant to go that fast, funny things can happen. Maybe the balance is not set up for the hull to fly. Maybe a chine walk develops.
Either way...I'm assuming that's a fairly heavy boat, so you'll need ALOT of money...er...HP (torque) to get to 75MPH. According to my unscientific intuition, a blower and 150+ ponies are in your future for 10MPH. Also, you may need better steering...
http://www.planetsmilies.com/smilies/happy/happy25.gif

[crmax]

you will need to change your heads from oval port to square new cam intake and carb, 23" or 25" prop should get you close to 70mph however the rods and crank in that motor are not the best and you have to keep your rpms under 5000 for sure. you may need to do some upgrades to your steering. as far as your hull goes it should make it. make sure you dont wax or paint the bottom and adding trim tabs if you dont have the will help. if you do alot of the work yourself it should cost $2000-$3000

[Costello]

Why don't you try just one thing at a time? That way you would know what's really working without the heavy investment. Here's what I would do right away and I think you will be impressed with the gains. Go to an MSD distributor and box, and change the intake and carb. You don't even have to buy these parts new if you want to really keep it on a budget. I would also agree with Crmax on some trim tabs,. In fine, I would agree with Havasu Hardcore on the hull design. If this is the Rinker with a cuddy that I am thinking of, I'm impressed that it does 63 mph right now, that's pretty damn good! Again if this is the style of hull I'm thinking of it was NOT really made with high performance in mind, but rather comfortable pleasure boating. This further supports my "one step at a time" approach and HH's theory about not taking it beyond it's limits, and keeps it pretty affordable at the same time. If you do end up changing the heads later, you'll already have a carb that can run with the bigger heads and the proper ignition.

[Chillin The Most]

Well thanks for the info. I guess I will have to do the old spend and hope theory. As far as the hull design, it is made for high performance. I've seen two of them on the water and a guy on shore with a rader gun clock them at 90 mph, but these guys won't tell you a damn thing. I know they got a ton of money in them but they won't share any info. I don't need to keep up with them though. Just interested in another 10 mph.
Thanks,
Chillin
[This message has been edited by Chillin The Most (edited March 17, 2002).]

[hulshot]

chillen, oval port heads for you will work fine, you wont be spinning over 6000 rpm. Oval heads will work up to 6/6500. They should help by producing low end torque. If I was in your position on a buget, which most of us are anyway, I would sugest cam, carb, intake, ignition and an upgraded exhaust. you dont need to go radical just get some combos that work, ie... MSD, Gil risers or any after market riser and possible manifolds, good aluminum dual plan intake, 750 carb, and maybe a hydrolic roller cam with a mild lift and duration to keep the power where you need it, 2/5000 rpm on a 108 ceterline. One thing is your motor may only have 8.0:1 compression, if so you could opt to bump it to 9.1/9.5:1 and still run mid grade gas if you chose to. all this may cost about 3500, for new stuff if you shop around. just another opinion.

[Chillin The Most]

I don't mind spending 4 or 5 grand. One person says oval port and one says square port heads, hey everyone which is it?
Mike

[hulshot]

chillen, oval port heads generate greater low end torque than rectangle port heads. the ports are smaller so the head can generate more velocity through the ports at a slower speed to help the torque. rectangle ports need some assistance at lower rpms due to their large volume runners, they are great for spnning 6/9000 rpm where an oval cannot get enough air through the smaller ports for high rpm running. Think about this, why does GM put oval and penut port heads on big trucks, To generate the best low end grunt to haul the weight. You dont see them spinning 6000+ rpms they dont need it, they will generate sometimes over 500 ft lbs of torque at about 25/3000 rpms. hope this sheds light on your head delima.

[crmax]

why does gm put square port on 454 mag marine engine? and how much horse power at what rpm does it make?

[Snafu]

I do not believe Rinker made a 236 in 1995!
That would be a 232 or your boat is older.
If you do indeed have the 236. Check the specs for the Land and Sea Stern Jack!!!!
I think the gains were 8 MPH !!!!
I have a 232 and am considering the SJack although I think it is a slower hull than the 236 (Dealer Lied what a surprise)
Rectangular Heads are crap 0-5000 RPM!!!

[Chillin The Most]

Rinker did make a 236 captiva in 1995. I'm glad I have one. I don't know what the difference between the 236 & the 232 is, maybe hull design, but I've raced alot of 232s and beat them really bad with this 310HP motor. I've also raced 25 Outlaw Bajas with 454 EFI, 385 HP, I hole shot them everytime but after 40-45 mph they catch me and pass me, still they only have me on top end by about 5 mph because I'm running a 21 SS Mirage and they are using a 23 SS mirage, but that is all about to end. I don't need to spend $60,000.00 for one of them, when I can build this one to run 75 mph for maybe $3500.00 By the way what is an S-Jack? One more thing, now I'm not knocking your boat but I think the 236 looks like a lot more sleeker Hi-performance boat than the 232, don't take that the wrong way now.
Write me back, Mike

[Havasu Hangin']

Hey Mr. Chillin'...is your speed GPS? Are you running a 1.5 ratio Bravo?
http://www.planetsmilies.com/smilies/happy/happy25.gif

[Chillin The Most]

No GPS, it's from a radar gun. I'm not sure about the ratio, but it is a Bravo 1. Is the ratio stamped on the outdrive? If so I will look in 4 weeks when I get it out of storage.

[Havasu Hangin']

I don't think it's stamped...most are 1.5 ratio from the factory...
The reason I ask...
4,600RPMs x 1.5(ratio drive) x 21"(prop) x 10% slip (average to good) = 54.9MPH
Maybe your tach is off, or maybe that drive is 1.36...even then, it's only 60MPH. Maybe it's a 23" prop...still only 60MPH. If all your variables are correct, you have negative slip (not possible). If so, I'm buyin' a Rinker...
For a point of reference, I spin my 23" SS to 5K RPM's with a 1.6 ratio drive and I'm nowhere near 63MPH...
Might want to check your tach...
http://www.planetsmilies.com/smilies/happy/happy25.gif

[Chillin The Most]

I had a friend of mine check the tach because I thought I was turning more than 4600 rpm. Tach is ok, speedo is exact with radar gun (I know hard to believe). The boat is a 1995 but everyone thinks it is brand new. Not a mark on it inside or out.
I just can't wait to get the motor set up the right way so I can have more rpms where I have to go up to a 23 or 25 prop to bring the rpms back down to 4900-5000. Should notice a big big gain in speed. Any thing over 70 mph, I'll be happy!

[Snafu]

Powerboat did a test on the 236 with a 502 415 HP. It Ran 68.
Your Big Block is basically a stock Motor. Cast pistons etc. Trying to get 70 MPH with that motor is not a wise move.
Once again...Try the Stern Jack for maximim hull efficiency!!!

[Chillin The Most]

Snafu,
What is a stern jack? I know my motor is a stock motor. Why do you say getting to 70 is not a wise move? 500-600 HP is not very hard to get with this motor or even more than that.
I wouldn't want to go over 600 HP because that is about all the bravo 1 will handle.
It all takes money. I've seen two of these 236s with the 502s that were really built, lots of money now & run 90 mph off the radar gun.
Call Randy Rinker at Rinker Boat Co. he will tell you that 70 -75 is not hard to get, and by the way ask him about 90 mph with a 236/502 motor built to run.

[Bondo]

Chillin the most, Snafu just told you why you'll never see 600hp with that motor...about the Only parts Good in that motor is the Block, Maybe the rods,+ that's about it...the Land & Sea Stern Jack is a Big block of aluminum that moves your outdrive back about 10", Just like the outboard guys do.....gives better leverage... they Guarantee 10% more top end....there's one on ebay right now... not a bad reserve either... http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1813325804&r=0&t=0&showTutorial=0&ed=1016669455&indexURL=0&rd=1
i never tried that before, but those 4 lines are a copy,& paste of the address in my browser....
I think

[Chillin The Most]

Thanks for the info on the stern jack! As far as the 500-600 HP I would suggest talking to a engine re-builder. I'm sure their must be some on this forum. It can be done, it would cost some money, but not as much as you would think.
I checked out E-Bay, thanks again!

[crmax]

you could always supercharge

[playdeep]

chillin,A few months back I asked a friend in the boat business (certified Merc station) about stern jacks.He showed me a Mercruiser memo pertaining to the subject.Seeing as how you have a bravo you might want to contact a Merc factory rep.They have some interesting observations about putting one on against thier gimbel housing.just my 02...

[Chillin The Most]

OK, I have some new info. First off I've owned ski boats in the past, this is the first Hi-pro for me. I decided 2 years ago I wanted a loud faster boat, so I bought this one from a one owner.
I contacted him yesterday and asked him why no one believes this thing runs 63 mph. He says it used to run 68, he also says that they don't normally run 63 stock, but the reason it does is because it has a stern jack on it. Lucky me!
He also said when he sold it to me he took off the Mirage 23 prop and the K&N air filter and sold it to someone else. He told me to go borrow a 23 and since I want to build the motor to go buy the K&N filter and try that out. Go figure, I didn't know that was a S-Jack, I just thought it was part of the outdrive.
He says 75 mph is very easy to get. He suggested, MSD..6AL ignition, 750 Holley,108 or 110 centerline cam with a 630 to 650 lift, Dual plane intake, and after market Hi-perf.oval heads, along with 9.5:1 pistons. He thinks that will take it over 75 a little bit. Says I could always upgrade exhaust but would wait and do that last if needed. He thinks I might have to move up to a 25 prop though as to not run motor over 5000 rpms.
Just his thoughts though. This is a good forum, I've gained lots of knowledge here from very good people.
I can't wait to hear what everyone has to say now, but I guess a S-Jack alone would make it run 63mph. Later!

[Racing Ray]

Originally posted by Chillin The Most:
OK, I have some new info.
he also says that they don't normally run 63 stock, but the reason it does is because it has a stern jack on it. Lucky me!
He says 75 mph is very easy to get. He suggested, MSD..6AL ignition, 750 Holley,108 or 110 centerline cam with a 630 to 650 lift, Dual plane intake, and after market Hi-perf.oval heads, along with 9.5:1 pistons. He thinks that will take it over 75 a little bit. Says I could always upgrade exhaust but would wait and do that last if needed.
Chillen the previous owner has given some good info as have many others who posted here. Since your soliciting opinions here is mine.
First you won't need new pistons as the aftermarket oval port heads will probably have 110cc combustion chambers. This will net you about 9.7:1 with the pistons you have.
You will need the aftermarket ignition as you are right against the rev limiter built in to the Thunderbolt V ignition.
The lift he reccomended is a tad high I would look more around .610 and to avoid exhaust reversion I would keep the centerline around 112. A hydraulic roller will reduce oil temps as well.
I seen no mention of a roller rocker set-up but you should include that. This will also reduce oil temps.
I agree with Hulshot get a good dual plane intake such as Edlebrocks Performer RPM. This intake will work good to 6000 RPM and will build more torque which is what you need.
As someone else already stated the Sternjack does add more leverage to your gimbal housing/bearing and it is very expensive to rebuild. Adding this much more power and speed will further stress this situation. You will after these modifications seriously have to look at an external steering system.
A single ram set-up would do for safety concerns but does little to alieveate the wear on the gimbal bearing. A duel ram system will take care of that. So plan on spending another $2500.00 to do it right.

[Chillin The Most]

Ray,
Your sure are right, lots of good advice and options here.
Glad to hear from you, heard quite alot about you on this site (all good)
Ok, I agree about the dual plane edlebrock, but would you use the 750 holley with that or use a Edlebrock carb?
What is your opinion on the edlebrock dominater intake and carb Vs.edlebrock performer rpm

[Racing Ray]

Originally posted by Chillin The Most:
Ray,
Ok, I agree about the dual plane edlebrock, but would you use the 750 holley with that or use a Edlebrock carb?
What is your opinion on the edlebrock dominater intake and carb Vs.edlebrock performer rpm
Chillen
I faced the same situation as you. Mine a 95 Ultra 21'SS. Same engine as you have. My boat topped out at 60 mph (summer 110+ degree heat, winter 65 mph) with a Mirage 23P prop. This is based on speedometer readings because I really don't care how precise it is. Bottom line it was a comfortable ride but didn't get me excited.
I chose to go with the Edlebrock Performer heads (oval port) Part number 61459 (new number) These are the Marine heads and are actually cheaper than the street heads. They are hard anodized for marine use and come with 2.25 intake valves and inconnel exhaust valves for marine severe duty. The street heads are equipped with 2.19 intake valves.
The price is less because they do not include springs retainers and locks. You will want to match these items to your cam anyways.
I went with the Performer RPM Air Gap intake and 750 Edlebrock carb. Holley will work fine they just cost a bit more and in my opinion the Edlebrock/Webber will produce more torque. I never heard of an Edlebrock Dominator Intake. Holley does make a Dominator intake or at least used to.
My first cam choice was the Performer RPM cam and was a bad choice as it went flat during the break-in and deposited metal shavings in the engine. First and last time trying their cams. I say stick with Crane, Comp, Isky, Clay Smith or Lunati.
I chose to replace it with a Crane Hyd. roller .598/.610 226/234@ .050 112 lobe center. While I was at it I had a zz502 shortblock so I switched it as well. However you should do ok with the 454.
I replaced the Mercrusier Thunderbolt V ignition with the MSD 6M marine unit box, distributor and rev limiter.
I also added Imco powerflow exhaust and elimanated the bends in my silent choice by removing it and going straight out the transom with "S" bends
I topped the heads off with Cranes gold rockers and a stud girdle for valve train stability.
I tried several props and chose to go with the Bravo1 4 blade 24P prop. It has that set you back in the seat acceleration and stays glued to the water on high speed turns. I did sacrifice about 4 mph over a Mirage 3 blade 25P prop but well worth it on handling and acceleration.
The speedometer now shows well over 75 (only reads to 75) and squirts water all over the place (gotta get that fixed). The ride is exciting, holeshot much improved.
Probably more than you wanted to know. Hope it helps you make the right decisions.
[This message has been edited by Racing Ray (edited March 20, 2002).]

[Snafu]

Hey Chillin. To increase you marine engine knowledge I highly recomend the Big Block Performance book by Dennis Moore Merc master mechanic. It is $20 WELL SPENT!!! This book will tell you exactly what you have as far cast pistons, cast crank,valve train etc.
Ray, With cast pistons and crank what do you think is wise HP wise???
I read the Stern adds an additional 10% of stress to your outdrive and transom.
I am going to try the Stern Jack this summer on my 232 with 454 Mag. 385 hp. I would like to know what your boat did stock before the S-Jack. Do you have any clearance problems with the swim platform? Have you checked for stress cracks in the transom??
Check out the Website for the Stern Jack. 77 mph with a 502 could be in your future.

[Racing Ray]

BBCs are known to live a long life producing up to 500 hp on cast components if you don't spin them too high and don't put on the squeeze via blowers or NOS. If thinking of mods from 500 and up I would insist on forged internals.

[Chillin The Most]

HI Ray,
Thanks for all the information. My mistake on the carb., your right it is the Holley Dominator I was talking about. I will take your advice Edlebrock/Weber for more torque.
Final question, with all that you've mentioned in your last post can you give me a ballpark $$$$ amount on the cost to do all that you did?
Thanks a million,
Mike

[Chillin The Most]

By the way Ray that is with my buddy doing all the work and me helping and learning!

[Chillin The Most]

Originally posted by Snafu:
Hey Chillin. To increase you marine engine knowledge I highly recomend the Big Block Performance book by Dennis Moore Merc master mechanic. It is $20 WELL SPENT!!! This book will tell you exactly what you have as far cast pistons, cast crank,valve train etc.
Ray, With cast pistons and crank what do you think is wise HP wise???
I read the Stern adds an additional 10% of stress to your outdrive and transom.
I am going to try the Stern Jack this summer on my 232 with 454 Mag. 385 hp. I would like to know what your boat did stock before the S-Jack. Do you have any clearance problems with the swim platform? Have you checked for stress cracks in the transom??
Check out the Website for the Stern Jack. 77 mph with a 502 could be in your future.
Thanks Snafu, Where can I by the book????

[Havasu Hangin']

Originally posted by Chillin The Most:
Where can I by the book?
You could get it here (http://www.amazon.com/exec/obidos/ASIN/1557882975/qid=1016655136/sr=2-2/ref=sr_2_2/103-8909875-4335041).
http://www.planetsmilies.com/smilies/happy/happy25.gif

[Racing Ray]

Ballpark only
Heads 1400
Cam 250
retro-fit lifters 450
Intake 250
Carb 250 Marine 750
Fel Pro Marine head gaskets 65
Crane rockers 250
stud girdle 150
MSD distributor 350 Marine version
Ignition box 250 MSD 6M-2
Rev limiter 150 Marine version
RPM chip set 75 marine
Eddie Marine valve covers to clear stud girdle 180 (includes 2 cast breathers)
Imco exhaust 2500
Total $6570.00
These are based on memory I did not look up these prices. It should be real close.
As you said you can hold off on the exhaust. So your looking close to $4000.00

[Havasu Hangin']

Originally posted by Racing Ray:
As you said you can hold off on the exhaust...
How much for the custom, pharmaceutical-grade stainless "S" pipes?
http://www.planetsmilies.com/smilies/happy/happy25.gif

[Chillin The Most]

Originally posted by Havasu Hangin':
You could get it here (http://www.amazon.com/exec/obidos/ASIN/1557882975/qid=1016655136/sr=2-2/ref=sr_2_2/103-8909875-4335041).
http://www.planetsmilies.com/smilies/happy/happy25.gif Thanks alot.. Just ordered it.

[Chillin The Most]

Hi Ray,
Thanks, that is with in my budget. Any special place to start buying all this?
Like maybe Summit Raceing, Jegs, or look around E-bay? Or somewhere else? I'm in Central Pennsylvania. I really would like to have this done and ready for the water by no later than mid May.
Regards,
Mike

[Racing Ray]

For the most part I used Jegs they had all the items in stock at that time. I did buy what I could locally but delivery was important to me as it was the end of last season and I wanted some time to do a bit of work and testing.

[hulshot]

Chillen I have a set of Gil offshore exhaust that I would sell complete from maniflod to soft pipe to posibly tail pipes, not a scratch on them. If interested lets talk.
As for the buget minded, I just sold a complete 850hp motor for only 11k with all the good stuff. It seems to me you could possibly have Ray cut the valve seats on your heads to accomodate bigger valves and also cut the spring bosses for biger springs. Again after market racing oval ort heads are for just that racing or higher performance. You are just trying to get some extra power out of your existing package without going broke, aren't you?
If you do your research and get parts and peices that will work together you shoud easily obtain your goal for speed and power. ie.. any local swap meet, you should be able to pick up a 750 double pumper for 100/150 that probably still works and then even by a rebuild kit or 25 and now you have a good carb for less. You can buy a complete cam kit with springs, keepers, retainers, lifters, custom made from Herbert Cams for 700/750. I know because I now have two sets. (mine were solid roller sets also) You can call a cam grinder and pick his brain and with the weight and prop and engine combo they can help you design or find the right cam for your motor. This takes the guess work out of the mail order will this, or will this one, or maybe that one work better.
Its not uncommon to see 500/550 hp from a stock casted motor with some bolt ons. The 112 center line might be too much, I dont think you need to retain all that cylinder pressure 110 would probably work better for this motor.
Good luck, hope you get it started soon, its almost boating season.

[Chillin The Most]

Hulshot,
Thanks for the offer on the exhaust, but like I said in an earlier post with Ray, I think I will wait for exhaust as my last investment, since it will be the most costly.
As far as budget I don't mind spending 5 grand, and I think it may be a little less than that to get to 500-550 HP range.
My main objective is to reach at least 75 mph so I do think I will need the Hi-perf. heads, MSD ignition, dual plane intake, and 750 carb. I'd rather spend the few extra bucks and get a new carb. and know what I have.
Picking the right cam, I can see might be a problem. I've seen three different opinions on this board now. The 108,110,112 centerline. I've also seen & heard all kinds of different lift combinations. I'm sure they all worked for everybody with the other combinations they have used.
I believe Ray gave a really good combination of what he used, as well as you did with your complete cam kit. Still not quite sure on which way to go on that cam.
Also I might want to go with the forged pistons since I'm trying to achieve the 500-550 HP range. (maybe not though, not sure)
BOTTOM LINE IS I WANT TO DO IT RIGHT THE FIRST TIME, that's why I've asked so many questions from guys that have been doing it.
Besides 75 mph, I do want that set you back in the seat accleration as well.
Thanks Everyone, (Hope I don't seem like a pain in the ass)
Mike
[This message has been edited by Chillin The Most (edited March 21, 2002).]

[Racing Ray]

Mike
No problem on the questions. You just like myself want to be sure you do it once and right. The cam I reccomended is used in literally hundreds of boats. The centerline is specfically chosen for the cylinder pressure and use in conjunction with lower compression ratios. It will build most power in the 2000- 6000 RPM range. Crane recommends this cam as a marine performance cam.
You can idle all day long without loading up or run it 5100 RPM under load. The best site on the internet for information on making serious power with Mercrusier/Bravo set-up is Offshoreonly.com
The best in the business post there and you will see the cam I mentioned and the next larger one are recommended 10:1.
You have a MarkV block so you will need the retro-fit roller lifter that includes the vertical locking bar. These are very expensive if you look at my list. There are lots of cams that will make power and work for you.
You can save a lot of money with a different choice but you can not get a better cam. I don't like the next bigger cam as you will pick up some top end speed but sacrifice some on planing time and if you pull skiers you will notice it.

[Chillin The Most]

Originally posted by Racing Ray:
Mike
No problem on the questions. You just like myself want to be sure you do it once and right. The cam I reccomended is used in literally hundreds of boats. The centerline is specfically chosen for the cylinder pressure and use in conjunction with lower compression ratios. It will build most power in the 2000- 6000 RPM range. Crane recommends this cam as a marine performance cam.
You can idle all day long without loading up or run it 5100 RPM under load. The best site on the internet for information on making serious power with Mercrusier/Bravo set-up is Offshoreonly.com
The best in the business post there and you will see the cam I mentioned and the next larger one are recommended 10:1.
You have a MarkV block so you will need the retro-fit roller lifter that includes the vertical locking bar. These are very expensive if you look at my list. There are lots of cams that will make power and work for you.
You can save a lot of money with a different choice but you can not get a better cam. I don't like the next bigger cam as you will pick up some top end speed but sacrifice some on planing time and if you pull skiers you will notice it.
Ray,
Thanks Again! By the way I don't pull skiers anymore. Can't stand going that slow.

[Snafu]

The number for Big Block Marine Performance book is.626-6753548. Dennis Moore will usually answer the line and he will answer some questions over the phone. This book is one you can't put down!!! If the terms Quench and scavenge are not in your every day gear head conversation this is a must!!!
Chillin
There is about 10 pages on cam selection. Reversion is a major concern in your selection!!!
Can you find out what your 236 did before the S-jack??? Thanks Rinker Dudes

[BOFH]

The choice in cam is where do you want your power. Low end power means busting out on plane faster. High end power means more top speed. This can be overcome with prop selection, but your will have loading up problems with a long cam.
Heads are nice. The new marinized alluminim ones from Edlebrock look promising, and save a bunch of weight.
As to compression, you have too look at a few things here. High compression means power, and fuel economy, with potential detonation. Low compression means cheap gas, and less power. Two ways to combat detonation are thremal barrier coatings and water injection. Both cool hot spots which lead to detonation. I have run 12.5 to 1 on pump gas with water injection. Both of these systems are hard to find, however. Expertise on them is even harder to find.
Valves. Big is good, but look out for shrouding. If you go with big valves, they can get so close to the cylinder wall that they flow less than smaller valves. Also, high lift can cause a piston to slap a valve. Good builders have play dough in there tool box. Ask why... If they don't answer, get a new engine builder.
As to the carb, if you just want to spend the money, go with fuel injection. A laptop is easier to work than a jet kit. :-) You will have to modiffy the headers for the sensor before the water is injected. Good power gain, and a lot of economy.

[Chillin The Most]

Originally posted by Snafu:
The number for Big Block Marine Performance book is.626-6753548. Dennis Moore will usually answer the line and he will answer some questions over the phone. This book is one you can't put down!!! If the terms Quench and scavenge are not in your every day gear head conversation this is a must!!!
Chillin
There is about 10 pages on cam selection. Reversion is a major concern in your selection!!!
Can you find out what your 236 did before the S-jack??? Thanks Rinker Dudes Snafu,
The original owner says 58 mph with the 21 SS Mirage, with S-Jack 63mph,S-Jack and 23SS Mirage 68MPH.I've never had a 23 on it. A buddy of mine has a 23 and a 25.
When I get my boat out of storage in Mid-April, I'm going straight to the water with that 23 and 25 and see what I get. I think the 25 is just going to slow me down in mph and less RPM. I'm really curious to see if that engine still has enough torque to turn that 23 and give me 5 more mph though.

[Chillin The Most]

Originally posted by BOFH:
The choice in cam is where do you want your power. Low end power means busting out on plane faster. High end power means more top speed. This can be overcome with prop selection, but your will have loading up problems with a long cam.
Heads are nice. The new marinized alluminim ones from Edlebrock look promising, and save a bunch of weight.
As to compression, you have too look at a few things here. High compression means power, and fuel economy, with potential detonation. Low compression means cheap gas, and less power. Two ways to combat detonation are thremal barrier coatings and water injection. Both cool hot spots which lead to detonation. I have run 12.5 to 1 on pump gas with water injection. Both of these systems are hard to find, however. Expertise on them is even harder to find.
Valves. Big is good, but look out for shrouding. If you go with big valves, they can get so close to the cylinder wall that they flow less than smaller valves. Also, high lift can cause a piston to slap a valve. Good builders have play dough in there tool box. Ask why... If they don't answer, get a new engine builder.
As to the carb, if you just want to spend the money, go with fuel injection. A laptop is easier to work than a jet kit. :-) You will have to modiffy the headers for the sensor before the water is injected. Good power gain, and a lot of economy.
BOFH,
Where I want my power is... I want to come out of the hole at a preety good rate and still have a good top end around 75mph. I might have to play around with the 23 and 25 prop to see which is going to work the best.
Here is just a theory >>> Two boats that have about the same top end speed, say 73-75 mph. Boat #1 comes out of the hole much quicker than boat #2. Boat #1 now has a 1-2 second lead over boat #2. Now boat #2 has to play catch up, they reach top speeds of 73-75 mph. Boat #2 now is still behind by 1/2 to 1 second.Everyone one on shore says wow boat #1 is a much faster boat than #2, not knowing they are doing the same speed.
That is why I want it both ways. If someeone takes me out of the hole, I still want that torque to catch them before they get to much of a jump on me.
Did you read Rays earlier posts on cams, heads, and all the other add ons? If so tell me what you think.
EFI is not in my future. If I want to build this motor, then ad EFI, I might as well by one of those crate 502 EFI, 500 hp and go from their.

[Snafu]

Thanks For the info Chillin!
Spoke with Rinker...They said 236 is a little faster hull than 232. I am doing 58 by Radar with 21 Mirage 385 HP. 4850 rpm With my 232.
He said there were about 20 1995 236's. They were actually built in 1994 but were stamped 1995.
Can you hit trailer button all the way up with the S-Jack not hitting swim platform??
Can't wait for the weather to break!

[Racing Ray]

Chillin
Give you an example of out of the hole. My son borrowed my boat for a couple of hours last night.
A 21 foot Carrea pulled along side him equipped with a 454 and jet drive the other fellow was by himself my son had 6 adults and 2 kids in my boat.
Jets are best known for the out of the hole performance my son owns a real fast one himself. So he is thinking he is going to get waxed on the start. They were coming out of a no wake zone.
He told me today how suprized he was the jet had him by 1/2 a boat length until they were planed and he was about 3 boats ahead by the time he was trimmed out and had only reached about 60. Thats what a 4 blade prop can do for you. Thats what you get when you pick the right cam.

[Chillin The Most]

Originally posted by Snafu:
Thanks For the info Chillin!
Spoke with Rinker...They said 236 is a little faster hull than 232. I am doing 58 by Radar with 21 Mirage 385 HP. 4850 rpm With my 232.
He said there were about 20 1995 236's. They were actually built in 1994 but were stamped 1995.
Can you hit trailer button all the way up with the S-Jack not hitting swim platform??
Can't wait for the weather to break!Snafu,
It doesn't hit when all the way up. If I were you I would borrow a 23 Mirage and see what you get. Probably a little slower out of the hole, not that much though, but I bet you still have the torque to see maybe 61 to 63. RPMs will be down a little but who cares , sounds to me like you just want more speed anyway. Try the 23, hell you got 75 more HP than me. You must have the EFI motor.
MIKE

[Chillin The Most]

Originally posted by Racing Ray:
Chillin
Give you an example of out of the hole. My son borrowed my boat for a couple of hours last night.
A 21 foot Carrea pulled along side him equipped with a 454 and jet drive the other fellow was by himself my son had 6 adults and 2 kids in my boat.
Jets are best known for the out of the hole performance my son owns a real fast one himself. So he is thinking he is going to get waxed on the start. They were coming out of a no wake zone.
He told me today how suprized he was the jet had him by 1/2 a boat length until they were planed and he was about 3 boats ahead by the time he was trimmed out and had only reached about 60. Thats what a 4 blade prop can do for you. Thats what you get when you pick the right cam.Hi Ray,
Once again, thanks for the information. That's exactly what I want, I really don't care If someone takes me out of the hole, but when that GRUNT TORQUE starts working thats when I want this thing to pick up and go.
Afterall most of my raceing is when I'm just putin along at 40-45 mph and someone comes up along side and wants to throttle down and go.(Ok everyone, along side means at least 100 ft.to the side. Safety First)
Later,
Mike

[BOFH]

What would I do? Ouch... Tough call... :-)
I am a big fan of thermal barrier coatings. I would start there with TBC on the heads, pistons and exhaust, and raise compression to about 11 or 11.5 to 1. As for cam, I would go middle ground. Something with power from about 2k to 6.5k RPMs. As to roller cam or not, that is a tough call for you to make. Size up the valves, but run stock ratio roller rockers.
With this kind of money, I would go with EFI. It is easier to tune, and runs much more consistantly. Ignition would be a tunable advance MSD with a rev limiter.
As for brands, that will depend on you or your builder. Go with what you know. I like Carter carbs, and others like Holly for example.
Once done, I would start playing with prop sizes. I would try a bunch of cheap ones to get size about right before investing in a good alloy prop. It will end up like swaping rear ends. One will rocket, and one will fly. You may end up with two "real" props depending on your mood. At this point you will just need to feel for your self what you like.

[hulshot]

Chillen you talk about hole shots but then you stated that you cruise at 40 to 45 and race from there. Hole shot is from an idle not 40 mph this is where you need to deceide on how you will pair off with someone. If your at 40 your probalbly at your peak torque already and now you will have to rely on the hp of the motor to stay ahead. the tighter the lobe separation the quicker you can get to a certain point(rpm speed) then the motor lays over and slowly accells to top speed/rpms. the broader the lobe separation the more consistant pull to almost full speed then it sill once again rely on the hp to pull the rest of the way. What I'm tring to point out is that you can get a cam talored for specific duties ie from 40 to 70 has a hard charge, or from 5 to 50 it is strong, or even from 20 to 60. This is all dependant on the installed centerline, lift, separation ect, ect. What ever you chose it is a give and take, you give some low end to have a hard charge at top end and vise versa. Also I stated on a post that compression would have to most likely be bumped up.
One thing to add if you plan on spending this much money to do it right just so you can get about 500 or so hp why not cange to a forged piston select a good hydrolic roller cam that has a very moderate lift and 250ish duration and put a stage 1 or 2 procharger on it. It adds no height to the engine and comes with a carb enclosure case, switch your ignition to MSD put some decent exhaust on it and make 600 or so hp and idle as long as you want and race all you want, the blower will make more torque than almost any cam compression carb ignition combo and you can use your heads with no mods due to the forced induction, sure it would help if you have a bitchen set of heads but why your already ahead of what you were tring to build any way for probably the same price. Now 75 and a good holeshot is a reality and not a hope I can see it situation. Run it by Ray and see what he thinks.
This is just all opinions. You should take all these thoughts all of us have given and put together what you think is best talk it over with Ray (your engine builder) and come up with the best bang for your buck and be relyable. good luck.

[Chillin The Most]

hulshot,
I've enjoyed all the opinions and posts from everyone on this subject. I've printed all these posts and probably will meet with my engine builder on Sunday and see what he thinks.
I kind of like what Ray has told me so far, as well as you, and everyone.
I'm sure Ray will read this and give his opinion. I hope so anyway, because everybody in my area says to stay away from a blower unless you want to blow your engine up.
I have watched a guy here, that has a Baja H2X, blow his motor 3 times a year, for 2 years in a row. He had a blower on it. Last year he ran all year long with no problems, because he took the blower off. Sure he is back down to 70 mph, but he says never again for a blower. Maybe he didn't have the right combinations to run a blower, I don't know. I don't know him personally, just that he would be here, then gone for 3 weeks and be back and blow it again & gone again. I'm not even sure if he had a procharger, 671 or what, but everybody on the water seen him getting towed back in all the time.
Now as far as the 40-45 mph thing. What I meant was, most of the time when just puttin along and a guy comes up along side of you, looks over, or maybe gives the lets go signal and all of a sudden you go. Now with these stock Bajas or even the scarrabs, I can't keep up. I know, I need more HP, but when we race from the hole (idle) when I floor it, my thumb is right on the trim bringing it up as fast as I can because this thing is on plane super fast. Reason being, I"m running a 21 mirage, they have either 23 or 25. Their bow is up in the air alot longer than mine, sure I understand why, bigger prop, stock motor, takes a little longer for their torque to get up to max. After about 40-45 mph I'm looking at the back of their boat. Once again bitin by HP.
Once again great advice from everyone. I'm positive I will come up with a combination that will work for me to run with the BIG DOGS. Your post does sound good. I'll wait and see what everyone else says about it.
Thanks, MIKE

[Racing Ray]

The combination I gave you will work from idle to 6000RPM. In fact when this motor was pulled on the dyno peak torque came in at 1800RPM and did not vary more than 10ft.lbs. to 5900RPM where it began to fall off.
That is why a wide seperation angle is ideal for your application. I chose a roller cam because of the design of the ramp angle and the fact you can run a much wider lobe seperation without the big overlap you would get with a non roller set-up. As hulshot says it has a flat broad torque curve ideal for the RPMs we turn.
The results are when on plane it does not matter if I am running 2500RPM or 4500RPM when I peg it it flys!
If this engine were going in a Jet boat with water injected headers such as Bassetts I would pick a cam closer to 108 centerline to avoid reversion.
With a jacketed exhaust system this is not as critical. There are a lot of combos that will work this is what I did, I am very pleased with the results it is a proven combo not just something I am guessing at or dreaming up.
If I don't respond to any of your questions to quick Mike in the next few days, bear with me. I am letting my son run my Chevelle at the Super Chevy race this weekend so I won't be on the computer much.
One good thing with this set-up unlike pushing the compression limits, if 87 octane is all that is available with the aluminum heads I don't have to worry.
Good luck with your project whatever you choose.
Ray
High Performance Cars.com (http://www.highperformancecars.com)

[hulshot]

RR glad you could understand my jiberjaber, I knew what I was thinking but couldnt quite get my fingers to type what I ment.

[Chillin The Most]

Hi Ray,
I see you made a post about a hour after I did on Friday. I didn't get to read it tll Friday afternoon.
My job called me out to New York City for the weekend and I couldn't respond, even though I read it from NYC.
I didn't get a chance to talk to my engine builder on Sunday, maybe sometime this week.
So how did your son do over the weekend at the race? Is that your car that you hyperlinked to me?
Got to go for now, I'm pooped, been a long weekend.
Later,
Mike

[Racing Ray]

Yes that is a picture of my Chevelle. He did real good. I slowed the car down to run low 10s. First time driving this car he went 5 rounds in Bracket 1. He even managed to put together one pass that was only .002 from a "perfect pass" he missed the light by .001 and the dial in by .001.

[waterbum]

HI Chillin,I just wanted to let you know i'm also from Pa.,Johnstown.Also I just happen to have a 750 Edelbrook carb with electric choke for sale.$200.Carb only has a couple hours on it.I'll also give up the jetting kit with it.Do you boat at Raystown?If so i'll see you before long as long as there's water in the lake,it's still awful low.I,f your interested let me know. Bum
[This message has been edited by waterbum (edited March 25, 2002).]

[Chillin The Most]

Originally posted by waterbum:
HI Chillin,I just wanted to let you know i'm also from Pa.,Johnstown.Also I just happen to have a 750 Edelbrook carb with electric choke for sale.$200.Carb only has a couple hours on it.I'll also give up the jetting kit with it.Do you boat at Raystown?If so i'll see you before long as long as there's water in the lake,it's still awful low.I,f your interested let me know. Bum
[This message has been edited by waterbum (edited March 25, 2002).]
Yeah I've been to Raystown Lake,. I live about 1.5 hours away from the lake. I suppose the carb. is not a Dbl. Pump Marine version?

[Chillin The Most]

Originally posted by Racing Ray:
Yes that is a picture of my Chevelle. He did real good. I slowed the car down to run low 10s. First time driving this car he went 5 rounds in Bracket 1. He even managed to put together one pass that was only .002 from a "perfect pass" he missed the light by .001 and the dial in by .001.Hi Ray,
You slowed it down to run low 10s, I like that. Is that your website?
In earlier post you said you had same 454 mark V motor 310 Hp. Did you ever dyno the motor after you were done with build up?
If not what is your best guess on your HP now?
Also with that parts/price list that you gave me. What do you think (ballpark HP) I would have using that complete combo minus the exhaust?
My brother has a question to anyone that wants to respond. When removing the lower unit from a Bravo 1, after un-bolting it, is their enough room when you start to pull it off to get in and un-hook the shifter/throttle cable or does he have to un-hook it from the motor and pull it down?
Thanks,
Chillin

[Racing Ray]

Originally posted by Chillin The Most:
You slowed it down to run low 10s, I like that. Is that your website?
In earlier post you said you had same 454 mark V motor 310 Hp. Did you ever dyno the motor after you were done with build up?
If not what is your best guess on your HP now?
Also with that parts/price list that you gave me. What do you think (ballpark HP) I would have using that complete combo minus the exhaust?
My brother has a question to anyone that wants to respond. When removing the lower unit from a Bravo 1, after un-bolting it, is their enough room when you start to pull it off to get in and un-hook the shifter/throttle cable or does he have to un-hook it from the motor and pull it down?
Thanks,
Chillin
Mike
Yes that is my site. We closed the throttle blades to about 3/4 throttle and I made the first pass to be sure he did not run under 10.00 you must be licensed to run faster. I still ran 9.25@145 with my small motor. Then I closed them to 1/2 throttle and run a 10.24 @133.
I did not dyno the 454 but an honest estimate would be 425-450 on a stock block. With balancing and blueprinting you can gain another 40-50HP and the exhaust will add about 20-25 more. These are conservitive estimates but real world numbers. A good engine builder through some port blending and gasket matching can probably pick up another 20HP. As I mentioned the torque will be what is impressive about that combo.
Tell your brother after he takes out the 6 bolts holding the drive unit to the gimbal housing to slide it back about 1" just enough to peek around the corner and you will be able to unclip the shift cable.

[Chillin The Most]

Ray,
Thanks for the info. I'll let my brother know. It sounds like a 10 minute job.
Thanks Again,
MIKE

[Racing Ray]

It is about 10 minutes. Lower the front of the trailer as much as you can. Then lower the drive until the skeg almost touches the ground then you can slide it out even by yourself if needed.
Be sure to keep the motor mounts exactly as they are spaced and it should stay in alignment but for extra comfort you might want to beg borrow or steal an alignment tool when you put it back together to be sure. A slight misalignment of the drive will result in wearing out the drive collar.

[waterbum]

Chillin,yes my carb is a model #1410 marine 750cfm electric choke non emission Edelbrock.Price from Summit is currently$264.95 plus handling.Calibration kit is #1480 current price is $45.95.Thats $310.90+ worth of merchandise for $200.00.I had bought it for my 383 stroker but even stroked did not flow enough air to pull open vac. secondaries.It is of no use to me.If your interested I could meet you somwhere at the lake so you could take a look.Raystown is also about an hour from me.Bum

[Racing Ray]

Chillen great deal on the carb! If you don't want it let me know I would like to pick it up.
Waterbum I would like to be second in line if Chillen decides not to take you up.
I will say the Edlebrock does not have vacuum secondaries it has mechanical secondaries. The top set of butterflies are called an air valve and its intended purpose is to give a pressure drop to pull fuel from the auxiliary system this prevents a bog or lean condition when the secondaries open.

[Chillin The Most]

Waterbum,
Sounds like a great deal, but I think I'm going to re jet my Merc, Cruiser Weber carb. and try that.
Mike

[waterbum]

Well Ray,looks like your in.If your still interested let me know.
I will say that although the secondary butterflies open mechanically,fuel will not feed unless enough air flow is present to pull open the air valves which are balanced against a counter weight as was my problem.In light of this i'm not sure calling an Edelbrock carb a mechanical secondary or a vacuum secondary would be correct.How bout calling it a vacuum over mechanical variable venturi motha fooker. http://free.***boat.net/ubb/biggrin.gif http://free.***boat.net/ubb/biggrin.gif Bum

[Cole 383]

Why hasn't anyone considered a 200hp NOS system and a 23prop to see what kind of boat this guy really has. That would tell him a lot about if it will really pick up any speed or not. Plus if it does he will meed the prop anyway and would likely want to keep the NOS on a better motor. Just a thought.
PE383

[Chillin The Most]

Originally posted by Cole 383:
Why hasn't anyone considered a 200hp NOS system and a 23prop to see what kind of boat this guy really has. That would tell him a lot about if it will really pick up any speed or not. Plus if it does he will meed the prop anyway and would likely want to keep the NOS on a better motor. Just a thought.
PE383Sounds like a good theory, BUT is this ok to do with a stock motor?
Chillin