454 build-up questions...

[MOBrien]

2000 bone stock 7.4MPI (160 hrs) on a 24' tunnel................
I'm thinking of putting some beef to it and am looking for advice on which heads to look at, pistons (comp/shape/mfg), cam, etc.... Keeping in mind I may Whipple or Procharge it next winter....but may not. Looking to make this put out 425-475hp or so pre-sc.
Also, anyone have any knowledge of aftermarket exhaust systems from Revolution Marine? Manifold & Riser combo's for $995...
Thanks,
MOBrien :clover:

[cstraub]

Are you keeping the MPI?
Chris

[MOBrien]

Keeping the MPI was the plan....at least right now anyway. I'm a motor dummy and have not idea where to begin and don't want to be taken for a ride at a local speed shop because of my lack of knowledge. Just know I don't want to start from scratch with an entirely new motor if I don't have to.
Any thoughts?
Thanks,
MOB

[djunkie]

I've never heard of that exhaust. I replaced my stock exhaust with Imco powerflows and I couldn't be happier. I feel they are definately worth the money.

[hulshot]

Mobrien, I have a set of iron merlin D port heads that will fit what you need, they are complete and ready to bolt on. If your plan is to eventually to put a wipple on it, these will wake it up alot. With a cam, pistons, and heads, with the same intake system, bump up the fuel preesure some, you should add a noticable amoutnt of power. next year add a wipple only and hang on.... :cool:

[Dimarco21]

Will you need a outdrive up grade after the motor up grade?

[MOBrien]

...replaced my stock exhaust with Imco powerflows and I couldn't be happier.
where'd you end up buying them and what'd they set you back?
I have a set of iron merlin D port heads that will fit what you need, they are complete and ready to bolt on. If your plan is to eventually to put a wipple on it, these will wake it up alot. With a cam, pistons, and heads, with the same intake system, bump up the fuel preesure some, you should add a noticable amount of power. next year add a wipple only and hang on....
With those changes (heads/pistons/cam/higher fuel press), what kind of noticable increase could I expect...pre sc? Still stud the motor if it turns out to be a 2-bolter right? How the hell do I find that out BTW...2B or 4B main on this thing? Also, what's the diff between aluminum & iron heads...is it merely a weight thing? Only reason I ask is because all advice has veered toward aluminum and I'm not sure why exactly.
Will you need a outdrive up grade after the motor up grade?
from what I've been told......
unsupercharged and under 500hp = go easy out of the hole and no problems with the B1 drive.
supercharged and well over 500hp = need to upgrate the B1 and add hyd steering
Thanks guys, I appreciate the responses.
-MOB

[Dimarco21]

Still stud the motor if it turns out to be a 2-bolter right? How the hell do I find that out BTW...2B or 4B main on this thing? Also, what's the diff between aluminum & iron heads...is it merely a weight thing? Only reason I ask is because all advice has veered toward aluminum and I'm not sure why exactly.-MOB
MOB, Check the block P/N to tell if it's a 2 or 4 bolt. The motor I have in my boat was a 2 bolt and I converted it over to a 4 bolt. I have all the tooling I made for it (drill and tap guides) let me know if you need them, it only took about an hour to do.

[djunkie]

[QUOTE=MOBrien]where'd you end up buying them and what'd they set you back?
I ordered them from teague. I think they were aroung 2k shipped. Its been a couple years so I don't exactly remember. I was looking at the EMI's and some others but after doing some research it looked like the IMCO's were the best.

[djunkie]

Heres what the imco's look like.
http://www.hotboatpics.com/pics/data/500/6749jims_river_house_011-med.jpg

[MOBrien]

OK, so I figure I should start with the heads.......
But should I bore this thing 30 or 60 over first? WHAT THE???
Then,
for heads I've seen 310, 325, 335, 345, 355, and other cc sizes..........
what the hell am I supposed to look for and what do these numbers mean in lehman's terms? Why go with one over the other? Oval, square, Brodix, Dart, Pro-File, Merlin???? WHAT THE???
Then,
What pistons to match up? I think something that ends up between 8.5:1 and 10:1??? Cast, forged, flat-top, dome...... WHAT THE???
Then,
How do I pick the cam? Lift, duration, lobe separation.... WHAT THE??? Comp cams, Isky cams, Crane cams, etc... WHAT THE???
Focken-A I feel stupid not having a clue about this stuff. :220v: :hammerhea :220v:
A little more advice for a drunken Irishman? :clover: :D :clover: :D

[wrenchdaddy]

You shouldn't have to bore it out any if your just adding heads or bolt on stuff. Besides the only way to bore it is to completely strip the block down. Unless it has a ton of hours on it and has a pretty thick ridge at the top of the cylinders then you should be ok. Im not real clear on the rest of the stuff, i know it all depends on what you want to do to it and how much you want to spend, all the parts of an engine go hand in hand pretty much. Hopefully some of the other more knowledgeable guys around here will put some of their .02 in.

[ECeptor]

MOBrien, you need to go to the local bookstore and get a book written by David Vizzard called something like "Making Horsepower" or something like that. It's the first in a series and is an excellent overview of performance V-8 engine. In it you will find the answer to all the questions you posted here.
OR just buy a complete engine from a shop and forget about it and leave how it all works a mystery.

[djunkie]

I have done some research myself on upgrading my motor. Not knowing how many hours you have, you might be better off building a new motor or buying a package type motor from a known builder. Since you plan on buying heads, cam, etc. it might be better to just buy a complete motor. Also keep in mind that with the increased horsepower you are going to add you may need some outdrive upgrades.,

[hulshot]

Sorry My heads just sold last knight. Neighbor walked in and said he wanted them for a flatbottom. took the deposit.
usually the smaller the intake volumne the more low end to midrange torque can be made and they are not designed for high rpms and large displacment motors. you can still run superchargers on them but midrange to upper rpm power will not be as much as the larger flowing heads.
aluminum heads are lighter and easier to modify and repair. They also have a big selection of intake runner volumns and exhaut runners because of the ease of molding them and modifing them. The Steel heads heavier, Harder to work on, port ect, but retain an even heat throughout the head and have the better ability to make a more consitant power because of the heat and can stand up to more abuse, more forgiving. thats my .01. maybe I dont know what I am talking about either, who knows. :confused:

[Rexx]

I'm a newbie myself but have just recently built some mild 454s for my Baja.
Horsepower is in the cam and everything else has to follow. Definitely consider the IMCO header manifolds. Give Crane a call, www.cranecams.com
Tell them what you have and what you want to do. A blower cam will have a different duration than a Naturally Aspirated cam, but proper selection will give you a cam to work in both scenarios. Keep in mind, an aggressive cam will lend itself to water reversion problems. I've seen many numbers thrown around for duration/lobe separation/lift specs that affect the scavenging relationship of the exhaust which causes reversion at idle, so I can't give you a specific recommendation. Again, Crane or a cam manufacturer of marine cams should know the cam specs to avoid water reversion in the exhaust back into the pistons. Just be cognizant and ask the question. Using the IMCOs will help alleviate water reversion over stock manifolds.
If your motor has rectangular port heads, these are probably the best you can get without the need for porting. Large oval ports are another option. I'm not sure what intake you will need to keep the MPI, but see if Edlebrock has something for your application. :notam:
Without doing a major engine teardown, concentrate on the top end for horsepower: Intake manifold, heads (good flowing valves), cam and then finally the exhaust. 425 hp for a pre-blower motor will be easy. But achieving 475 naturally aspirated without too much changes for a blower motor gets difficult. If you plan to run a high boost blower motor, you will need to take the motor all the way down and replace the pistons with forged and then build with 4 bolt mains, forged crank, high flow oil pump, shot peened rods, etc..go through everything or it will get very expensive when a rod shoots out the side of your block. With mild boost, you can get by with stock engine components (I believe your motor should be a full roller motor). :squiggle:
As for the outdrives, I've heard a 600 hp maximum number on the Bravo 1s in "good" condition. This is somewhat deceiving as a high torque motor with low horsepower will chew up an outdrive. The input bearings seem to be the first to go. Atleast, this was the case for both my outdrives. The gears were fine, but the input bearings of one were trashed and the input bearing of the second outdrive was on its way. Consider a drive shower to keep the oil temps down and be sure the drive oil reservoir is topped off. The older bravo ones didn't have an oil reservoir, but the newer ones do (I have one of each :messedup: ) Basically, the oil reservoir feeds a relief valve...after the drive comes up to temp, a vacuum will occur as it cools down drawing oil from the reservoir to keep the drive constantly topped off with oil.
Hope that helps a bit.. :mix:

[Shallow Minded]

I've got the Revolution Marine exhaust system on my blown 454. Although it was tough to determine exactly how much they helped (I made several changes to the motor...), I'm sure it's breathing a little easier now. I haven't had any problems with the exhaust. Hope that helps.
SM

[cstraub]

MO,
What is your current speed on the boat and what is your goal?
The MPI will work with mild mods and will support "bolt on components" to get you in the 450HP range. After that the ECU will need some "tweaking" and injectors may have to be changed to support more power. You may want to consider selling the EFI and going carb and intake.
If you stay a base of 454CID, you want look at oval port heads. The larger square ports are just too large for a NA boat application based on rpm max of around 5500. Good ovals can support a 454 to 7500 rpm and make excellent power, so the 5500 mark is no sweat.
Alum heads are a good investment if you are planning on a blower or going larger in the future. They give you more room to grow. Neg is the cost and you really need to look at something hard anodized to protect you from corrosion.
Iron, best bang for the buck. Won't give you an weight reduction in the stern but is easy bolt on power. Neg is if you do go blower and the a head gets torched, you have a boat anchor because good cast iron welders are few and far between and the repair will cost you more then new heads.
Budget. What will the wallet support. You need to think about how much you want to spend and give yourself a fudge factor for the extras.
Build Recipe. Plan the combo then build it to reach the goal. Once decided don't second guess or ask any questions. Everyone out there is a closet "Grumpy Jenkins" and will tell you that it won't work and their idea is the best. Align yourself with a "mentor" then go with his/her plan.
Any questions you can PM me.
Chris

[ECeptor]

If you stay a base of 454CID, you want look at oval port heads. The larger square ports are just too large for a NA boat application based on rpm max of around 5500. Good ovals can support a 454 to 7500 rpm and make excellent power, so the 5500 mark is no sweat.
This is what I've read/heard also. On a 454 the ovals will give more power everywhere from idle to at least 6000rpm.
cstraub69, at what CID do you recommend changing over to the rectangular port heads?

[MOBrien]

MO,
What is your current speed on the boat and what is your goal?..
Current speed is about 60/61 trimmed at about 4650rpm. Being this is a tunnel and will start to pack a lot of air, it should get to around 80 with 450hp. Know a guy running a 24' tunnel (nearly same hull), VERY mild 454MAG and was gps'd at over 80. I think he's got about 390/400hp. I should easily pass him with 450. :D
The MPI will work with mild mods and will support "bolt on components" to get you in the 450HP range. After that the ECU will need some "tweaking" and injectors may have to be changed to support more power. You may want to consider selling the EFI and going carb and intake.
That would be the plan...chip would get reflashed by either AZ Speed or Boostpower....
If you stay a base of 454CID, you want look at oval port heads. The larger square ports are just too large for a NA boat application based on rpm max of around 5500. Good ovals can support a 454 to 7500 rpm and make excellent power, so the 5500 mark is no sweat..
Staying with 454CID is the initial plan. If I don't have to machine it, I don't want to. Not sure if a crank replacement is in the budget and don't know if going into the high5's and low 6K rpm range is necessary for this build. I'm on the fence with a crank replacement simply due to the additional $500 or so for a forged one. If it's not a necessity item, probably not going to.
Alum heads are a good investment if you are planning on a blower or going larger in the future. They give you more room to grow. Neg is the cost and you really need to look at something hard anodized to protect you from corrosion...
no "real" plan at this point to put a blower/sc on it, but may try to find a used pair of alum heads anyway to help with weight reduc.
Budget. What will the wallet support. You need to think about how much you want to spend and give yourself a fudge factor for the extras....
Ah ha, the all-important question. Shoestring budget that's for sure. If I can get in and out for a few thousand and end up with 450hp or so, I'd be extrememly happy.
Build Recipe. Plan the combo then build it to reach the goal. Once decided don't second guess or ask any questions. Everyone out there is a closet "Grumpy Jenkins" and will tell you that it won't work and their idea is the best. Align yourself with a "mentor" then go with his/her plan.....
That's what I've been realizing. Talked with many, many people so far and now my head's swimming with information overload. It gets hard to discern between what's experienced & legitimate advice and who's trying to get my wallet and take advantage of my lack of knowledge to sell me stuff I don't need. I've got a friend with an engine builder that "mentored" him, and my next call about this stuff will be to him to see if he'll mentor me through the process of a mild build. Bottom line, my goal is a fairly mild hp/tq increase and not have to continually wrench on it and throw $$ at it to keep it in the water.
Thanks for the info!

[MOBrien]

I've got the Revolution Marine exhaust system on my blown 454. Although it was tough to determine exactly how much they helped (I made several changes to the motor...), I'm sure it's breathing a little easier now. I haven't had any problems with the exhaust. Hope that helps.
SM
For the price, I think it's really hard to beat. Thanks for the input.

[MOBrien]

If your motor has rectangular port heads, these are probably the best you can get without the need for porting. Large oval ports are another option. I'm not sure what intake you will need to keep the MPI, but see if Edlebrock has something for your application.
Was hoping to keep the MPI and the intake....just work on it a bit. And looking to find some aluminum oval ports if possible.
Without doing a major engine teardown, concentrate on the top end for horsepower: Intake manifold, heads (good flowing valves), cam and then finally the exhaust. 425 hp for a pre-blower motor will be easy. But achieving 475 naturally aspirated without too much changes for a blower motor gets difficult. If you plan to run a high boost blower motor, you will need to take the motor all the way down and replace the pistons with forged and then build with 4 bolt mains, forged crank, high flow oil pump, shot peened rods, etc..go through everything or it will get very expensive when a rod shoots out the side of your block. With mild boost, you can get by with stock engine components (I believe your motor should be a full roller motor). :squiggle: .
No "plan" for a blower at this point....at least not for a long while. SHould still replace the pistons regardless thought right? I'm thinking heads, pistons, cam, exhaust, rework the intake, and a reflash of the chip...done.
As for the outdrives, I've heard a 600 hp maximum number on the Bravo 1s in "good" condition. This is somewhat deceiving as a high torque motor with low horsepower will chew up an outdrive. The input bearings seem to be the first to go. Atleast, this was the case for both my outdrives. The gears were fine, but the input bearings of one were trashed and the input bearing of the second outdrive was on its way. Consider a drive shower to keep the oil temps down and be sure the drive oil reservoir is topped off. The older bravo ones didn't have an oil reservoir, but the newer ones do (I have one of each :messedup: ) Basically, the oil reservoir feeds a relief valve...after the drive comes up to temp, a vacuum will occur as it cools down drawing oil from the reservoir to keep the drive constantly topped off with oil.
I've heard relatively the same. This drive is a yr 2000 and whole boat has about 160hrs on it. Drive should be fine and does have a shower & oil reservoir.
Thanks for your post.
-MOB

[cstraub]

Eceptor,
Square ports in the 300 plus CC intake range should not even be considered until you have around 500 inches with an I/O boat. Jets and flats that can run some rpm in the high 6's can use them.
MO,
I would stroke the bottom end then. For your power "wants" you can build a 489 to 496CID engine and not touch the upper half and accomplish your goals. Also don't get caught up in this steel crank 4340 BS. For your power wants, a good Nodular Cast crank will work just find. I have had customers successfully bracket race and truck pull with these cranks in engines making 700HP. A nodular cast crank will do just fine. It will be my choice when I do my 330HP. You should be able to get crank/rods/pistons/rings/and bearings for around $1000 to $1400 depending on type of rod and piston you go with.
With boats the old saying "no replacement for displacement is very true. This will give you a "500" incher that will make dependable power, match your budget, and reach your goal.
If you have any questions drop me a PM.
Chris

[MOBrien]

So, being that my hp goals are around 450 I should be able to go with heads, cam, pistons, and exhaust.....am I understanding this correctly?...and not worry about the crank, rods, and bottom end?
Thanks again everyone for your input....it is very helpful and I feel like I'm learning a lot that will help tremendously on my wallet and when it's tear-down time.
Cheers.
-MOB

[ECeptor]

So, being that my hp goals are around 450 I should be able to go with heads, cam, pistons, and exhaust.....am I understanding this correctly?...and not worry about the crank, rods, and bottom end?
Thanks again everyone for your input....it is very helpful and I feel like I'm learning a lot that will help tremendously on my wallet and when it's tear-down time.
Cheers.
-MOB
When I redo my 454, I'll take the bottom end apart and make sure everything is up to spec. May as well check while it's apart.
Then its:
forged flat top pistions for a 9:1 compression ratio
oval port heads
cam - 236/246 @.050" on a 114LS
single plane intake
holley 850 or 950 carb
I'm going to try to keep the stock Mercury thru hull exhaust and save some bucks. If it doesn't work as I'd like, it's an easy upgrade later. I just can't believe the aftermarket stuff would flow that much better than what's essentially a completely open exhaust.

[cstraub]

MO,
No. Put crank/rods/pistons in the bottom end which will give you 496CID out of your 454. This CID can better use the runner volume of the big heads you have now and will make reliable power.
Chris

[ECeptor]

MO,
No. Put crank/rods/pistons in the bottom end which will give you 496CID out of your 454. This CID can better use the runner volume of the big heads you have now and will make reliable power.
Chris
What heads are on a stock 2000 454?

[djunkie]

I'm going to try to keep the stock Mercury thru hull exhaust and save some bucks. If it doesn't work as I'd like, it's an easy upgrade later. I just can't believe the aftermarket stuff would flow that much better than what's essentially a completely open exhaust.
A good exhaust will make a big diiference. When I put the Imcos on my 454 it really woke it up. I only gained about 4 or 5 MPH but I ran out of prop. So with the new prop hopefully I will get a little more. It was really noticeable in the time to plane frame though. It used to be sluggish out of the hole but now it comes on plane fast and accelerates to top speed a lot faster.

[MOBrien]

What heads are on a stock 2000 454?
From what I've been told they're often referred to a "peanut port" heads. My first thought comingg from that statement is that they are relatively small in chamber size and don't have the flow capabilities needed to produce good power.
Am I correct in reading its nickname this way??? cstraub, check your email & whaddya know about these peanut heads?? Also, what do you folks think about these heads...ever heard of them?? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7948385987&sspagename=ADME%3AB%3AWN%3AMT%3A2 If they can be had fully prepped for $1500, wouldn;'t this be a good deal considering other mfgs like Dart, Brodix, etc... are more like $2000?
Hmmmmmmmmmmmmmmmmmm.
-MOB

[cstraub]

You don't need heads. You need inches!!!
Read your e-mail.
Chris

[ECeptor]

My '89 454 has peanut port heads. They and the cast pistons are the limiting factors for my engine. I've been told that the peanut port heads simply will not flow enough air for decent power - irreguardless of what cam, intake or exhaust is used.
Along those lines, wouldn't better heads (good set of oval port) be a better route to more power than a stroker crank with the peanut port heads?

[MOBrien]

.........I've been told that the peanut port heads simply will not flow enough air for decent power - irreguardless of what cam, intake or exhaust is used.
Along those lines, wouldn't better heads (good set of oval port) be a better route to more power than a stroker crank with the peanut port heads?
ECep, you hit the nail on the head----------
That's exactly what I've been told.....I've got the peanut ports (due to being a non-MAG motor) and simply cannot flow enough air. That's why I've been thinking of new heads, cam, pistons, and exhaust to accomplish solid gains.
That's the big dilemna.....

[ECeptor]

ECep, you hit the nail on the head----------
That's exactly what I've been told.....I've got the peanut ports (due to being a non-MAG motor) and simply cannot flow enough air. That's why I've been thinking of new heads, cam, pistons, and exhaust to accomplish solid gains.
That's the big dilemna.....
OK, so you and I are in the same boat (pun intended).

[cstraub]

Now it comes down to budget. Best bang for the buck. I would still go with rotating kits. A .250" more arm is going to broaden the powerband out greatly. The peanut's out of the box flow enough air on the intake side to make 470HP. Both of you sound like the "magic" number is around this number, so the heads and MPI, although not ideal, will work. Years ago I made rockers for Fueling R&D on a head project for BBC's. The ports were smaller then what GM's are and those heads bolted on a stock GM 454 gave the engines another 100#/ft of torque.
Keeping MPI: For what you will spend on large oval heads/port work to match intake to head which in any case will not be optimal the bang for you buck will not be optimal.
Going Carb: Then yes, go with the heads, a nice E-brock airgap intake and put some cubes under it also. For what you can get for the MPI sold, it will help with the budget on this build.
Chris