Budget Blower Build

[jrork]

Okay, here’s something I’ve been thinking of posting up and thought I’d follow Tims advice and attempt to get rekindle some activity here.
For some background, we’ve had this boat for about 6 years. It’s a 78 18’ full stringered Brendella. We’ve run the heck out of this boat for years.
The motor is;
2 bolt 454 bored .060 over
Stock cast crank
Stock rods with ARP bolts
SpeedPro Hyper pistons 8.00/1 with 119cc chambers
Clevite bearings
The heads are stock 049 large oval ports with a 3 angle valve job
Compcams springs, retainers and locks
CompCams 3/8 pushrods
Crane pushrod guides
ARP studs
Compcam longslot stamped steel rockers
ARP rocker nuts
CompCam Xtreme Marine Hydraulic flat tappet cam and lifters
Lift .544 & .547 and Duration .270 & .286 with a Lobe Sep of 112
ARP head bolts
Double Roller timing set
MSD billet dizzy and 6AL box with MSD wires and Blaster coil
Bassett twisty headers (ran dry)
10 quart pan with Mellings HV pump and ARP pump driveshaft.
We ran this set up for approx 3 years with great success but then I got the wild hair to totally redo the boat.
I’ve wanted to go with a blower motor for this boat for years and figured that since I had blown the boat completely apart, now was as good of a time as any.
Like so many projects, when I estimated the costs, I shouldn’t have doubled it. I should have TRIPLED it!!!!
Once we were done with the fiberglass work and supplies, paint and clear, new interior, steering, gauges, wiring and controls, I was coming to the realization that money doesn’t grow on trees.
It became clear my idea of a great big motor wasn’t going to happen but I looked at it in a positive light. Since I’ve never had a twin carbed motor let alone a blower motor, I’d rather use this setup as a guinea pig rather than mess something up and grenade/melt down a good motor.
So, I used this always faithful motor to work on refining the plumbing, rail kit, ignition, and carburetion.
We went with an 8-71 Weiand non stripped blower. I’m running a 61t on top and a 54t on the bottom so I’m hardly even working the blower
Two 850cfm DP Holleys with Proform mainbodies, Trick Flow slabbed throttle assembly on a progressive linkage. Primarys are 82 and secondaries are 88s with a 6.5 PV. I’m not boost referenced (I know) so I figured I’d run it fat for protection over the Labor Day weekend coming up and take it easy on it.
Carter 170gph mechanical fuel pump.
Fuel lines are -8AN tee’ing into a fuel/water separator with ½ fittings. From the filter I ran -10AN into the pump and -8AN to the BlowerShop fuel hardline kit. Fuel pressure is a consistent 7lbs (over the winter, I'm going to increase the pickups in the tanks)
A blower balancer with an extra ¼ keyway cut 180 from the stock keyway.
We completed the boat just in time for the end of the season blast over Labor Day and even though it hadn’t ran at all with no shake down runs, all in all we had a great time for 3 days till I lost a head gasket between #4 & #6.
Best we turned was 5400 but no speed numbers at the time spinning an A impeller.
The next day a buddy showed up with a Radar gun and even though we lost the head gasket and a header gasket, we still ran 74.5 at 4800 rpm on a gun the next day and finished the weekend (and maiden voyage) with no major damage, so I’m thrilled.
Now, we primarily use this boat for a motorized air mattress and frankly, I don’t have any desire to go 100 mph in this boat. A solid 80mph boat would be great and frankly, given some time with setup and a healthy head gasket, we’re probably getting close to 80. If I was to describe my driving style in the past, I probably run it wide open for 500 feet and for the rest of the 99.999% time, I'm running it at about 3800 to 4000 rpm. Not a racer by any means (too fat and old)
Given all that, I know this motor is not the perfect candidate for a blower but I’ve got a little money left and am curious what would be all your thoughts assuming that the economy is going to continue the path it’s chosen and my money tree is not leafing out like it normally is?
Let’s say I have between 0 and $2,000 for the winter.
So come on guys, let’s spend my money (wisely) and see what folks think would be a good direction.
Forged pistons?
Forged Rotating assembly (probably not gonna find one for less than $2K)?
Increase the valves to 2.19 and 1.88s?
Different heads altogether? (I have a set of 990s but I dropped a seat on one of them and it’s hard to say what it would cost to save it)
New cam that is more blower friendly (remember, a roller cam, lifters, valvesprings and rocker arms, pushrods are gonna shoot the wad)?
Maybe a good old fashion flat tappet blower grind
ARP head studs?
Stud the mains, convert to 4 bolt or leave it alone with some new ARP main bolts (already have a new set from a previous build that I never used)
Remember, I’m not looking to light the world on fire………….john
Here's the project......
http://i63.photobucket.com/albums/h157/jrork/DSCN0267.jpg
PS.... the pump is a fresh Panther Energizer from Jet Boat Performance with a A impeller and Place Diverter. Stock Ride plate with skags added for stability. I didnt even have time to check what angle I bolted it to but it appears to be pretty close to 0 degrees.....

[jetboatperformance]

Nice work John Good post ! JBP

[TIMINATOR]

Weiand blowers aren't noted for making a lot of boost. Swap the top/bottom pulleys to overdrive the blower. A BDS 8-71 (like I used) made 5 lbs at one to one ratio. I have over-driven it on the Nova by 24% and made 16 lbs, thats when it kicked out the headgasket.... I ran the fel-pro 1017s. TIMINATOR

[rat tuned]

although i just lurk here and i have very little to no knowledge i would appreciate it that this post will stay. i did not read into this post that tim was in any way insulting anyone. i appreciate that anyone withy tims knowledge will come on here and share his experience. i don't even own a boat (but have a 69 chevelle ss) and i check this forum daily. i have a 8-71 bds stage 1 that when finances allow i,m dying to install. too bad i live on the wrong coast!! thanx mike

[TIMINATOR]

I'll still be here to answer questions, no matter what coast anybodys on. TIMINATOR

[TIMINATOR]

I re-read your last post and we did have some miscommunication, I drew conclusions based on what I read. I recomend that once you build a purpose built engine(I will be here or on the phone for answers), experiment with your current "mule motor" to learn how to tune a blower deal. They ARE different. At this point I think we are all good.... Let the info flow...... Also,I have in the works, an internet/***boat website article to help us ALL understand what we are actually saying, and how to get the most from this site. TIMINATOR

[jrork]

I re-read your last post and we did have some miscommunication, I drew conclusions based on what I read. I recomend that once you build a purpose built engine(I will be here or on the phone for answers), experiment with your current "mule motor" to learn how to tune a blower deal. They ARE different. At this point I think we are all good.... Let the info flow...... Also,I have in the works, an internet/***boat website article to help us ALL understand what we are actually saying, and how to get the most from this site. TIMINATOR
Sounds good Timm, with luck maybe HB will start running coverage on lil boats like it use to. Take care...........john

[Blue Thunder]

I hate to interupt a good pissing match, but here is what I would do jrork with the 2gs;
> Buy some alum edelbrock marine heads with inconnel exhaust valves, oval ports.
> Buy a set of ARP head bolts
> Install a set of good quality roller rockers, I like Pro Magnums myself but you have to watch for cheapo knockoffs these days.
> Replace head gaskets with Cometic MLS gaskets sized to acheive a .038 quench area.
> Size the blower drive to achieve 12.5:1 effective compression with your pistons and use 93 octane.
> Set timing between 28 and 30 all in.
BT :cool:

[BoostDaddy871]

I would upgrade the pistons to forged. The hypereutectic pistons are not going to live very long in a supercharged marine application. I would then spend the balance of available funds on the cylinder heads. I would then look at why the head gasket checked out. The timing is the first thing to look at, as too much advance will cause problems. The next thing is fuel. It sounds like the system is sound as far as line size & GPH. Many marine engine have problems due to lean conditions at crusing speeds.
Good luck!

[bigkatboat]

Since you're all still here, let me say this..... I would spend the money on a crank, rods, and good pistons. I would use a more "forgiving cam" with 108 lobe centers. This will soften the powerband down low (so the pump don't skip) and put the 'boost load' easily onto the rods and bearings. You don't need to POUND the motor bearings and pump at 2K RPMs, so why use a cam that does? Hold boost ONLY when you can use it! Cometic or SCE head gaskets, and port matched/big valve ovals or just some nice factory (cheap) big port heads. Look at Isky #Z77 flat tappet cam, I have used that cam in a number of NDBA and IHBA class winning BUDGET boats. "It's easy to make power, but it's not easy to make POWER THAT LASTS"

[jrork]

Folks, thanks for the tips. I appreciate it and I'm glad to see this thread back on track as it was ultimately planned to be just something to get some discussion going here.
Blue, Boost & Bigkat,
Thanks very much for the tips, tricks and advice. I'm kinda leaning towards swapping out the rotating assembly first as I'm afraid if something there let go in the interim, they could probably do the greatest damage (i.e. heads, block, ect).
I've typically used FelPro 1017's with good success till now. Could somebody explain the differences in the "Cometic or SCE" gaskets as I see they are typically highly regarded?
BigKat, once again I really appreciate the post and suggestion. In your opinion, would the 108 be a concern if I have to run water through my Bassetts?
Thanks again........john

[jetboatperformance]

John we've been using Cometics for years after encountering problems with dead softs and orings , My Buddy Hals BGF motor and Joshs both have them and Hals has 4 seasons ,They're laminate type gaskets similar to those even used on a lat of late model production stuff ,They(Cometic) have even made gaskets one off for us for special applications, kind of spendy but well worth the investment , I'm with the rest here re the Rot assy, go for the Steel,Forged,good rod & bolts etc delio and check out Summits (Dart) Iron rec port heads (smokin prices) It will all give you the confidence , I bought a couple of new Howards steel cranks a year or so back for a buck and a half each, ones still running in an 8.0 Alchy flat . Lots of good deals on rods and Pistons out there too ,if you just scout around ,let me know whats on your wish list we'll sick the kid on it ! Tommy
(re the "water" ,creat a positive shut off , it will be a non issue ,i'll explain)
(Cometic dealer:D )
http://www.cometic.com/gaskethome.aspx

[jrork]

Thanks Tommy, I'll check it out. Say hi to Rhonda and Josh for me

[TIMINATOR]

With flat machined decks and heads, (CBN head/deck MILL, NOT a low speed broach), with studs, Fel-pro 1017s will reliably work at 15 lbs. If you detonate the motor and use coppers and o-rings the gaskets will hold, but you will kill the bearings or split the cylinders! TIMINATOR

[jrork]

Thanks a bunch Timm. I pretty damn sure I'll never see 10 lbs of boost let alone 15 :D .
In your experiance, have you found studs that much better than good (ARP) bolts for more mild builds?
Thanks again.........john

[TIMINATOR]

Studs over 8-9 lbs, good, new, bolts, below that. TIMINATOR

[jrork]

Okay, we're definately back on track. Many thanks to all.
Just for the sake of discussion, a good friend just gave me a 990 head I can use instead of seeing whether the one that dropped the seat can be fixed.
So things are looking up. Also, the way better half has implied there may be more in the piggy bank that I realized so figure a good rotating assemble, a cool flat tappet cam like that has been recommended by BigKat and Timm, think these 990 heads are worth spending some $$ on versus running my 049s?
If so, let's build these up too. Iconel valves or just severe duty (remember, we're on a budget and Iconels must be half gold), stem size, spring recommendations and something that I've always wanted to ask:
Everbody runs roller rockers but are they really needed on what I still view is a very mild build or are they just sexy as hell and really needed for bigger and better types of builds?
Thanks again everybody. I really appreciate it.

[bigkatboat]

Don't ever run water thru the exhaust below 2000 RPMs, automatic valve (with 7/32" restrictor at T valve inlet) Drill the 'weep holes' larger in the pipe bottoms. This will work for blown or unblown motors. Inconel exhaust, standard stem and length. "No monster cams, no push rod or guide plate problems". 125/135 lbs on the seat and AT LEAST 350lbs 'over the nose'. (in case you ZING it) 3/8" push rods, and regular solid lifters. If manifold is big, port match heads to it. (just roll the corners!) Drill and tap the rear water passages of the intake. Install a #6 hose line from each side to a "T" and then overboard. This will prevent (idling to quick short WOT) 'air pockets' in the heads and make the head gaskets, valve guides and valve springs last longer. Save money, use an "SFI" flexplate, it just needs to have teeth on it for the starter. No balancer, FRONT HUB. Spark must be at least 40,000 volts, and around (with 108 cam) 12 to 18 degrees cranking and 32 degrees all in at 1200 RPMs. "Locked out stuff" is not good for PLAY BOATS, that need to crank at hotter engine temps. (no starter drag) OK, I'll breath now. YES roller rockers.

[jrork]

Awesome info George. Thanks a bunch. Now take a breath. :D That's info that anybody can use.
Thanks again........john

[blownt]

Fairly new on here. Been lurkin the last several months ever since I bought a 460 jetboat and been upgrading it. Just bought a super deal on a new BDS blower kit and Edelbrock heads still in boxes for $3500 for a winter project on the boat.
I have had a 6-71 blown T bucket for years. I question why using a 108 lobe center cam? When I first installed the blower on the bucket I had 10 1/2 hypert. pistons and kept the 108 cam to help blow the charge out the exhaust (as well as running underdriven). But once I rebuilt the motor with the good stuff I went with a good 114 cam and I am 12% overdriven. Been running that for many years now and man is it fun. The blower really tames down a 108 cam, while a 114 cam sounds and lopes great. Personally I would not go back to a 108 cam.
BT

[bigkatboat]

Fairly new on here. Been lurkin the last several months ever since I bought a 460 jetboat and been upgrading it. Just bought a super deal on a new BDS blower kit and Edelbrock heads still in boxes for $3500 for a winter project on the boat.
I have had a 6-71 blown T bucket for years. I question why using a 108 lobe center cam? When I first installed the blower on the bucket I had 10 1/2 hypert. pistons and kept the 108 cam to help blow the charge out the exhaust (as well as running underdriven). But once I rebuilt the motor with the good stuff I went with a good 114 cam and I am 12% overdriven. Been running that for many years now and man is it fun. The blower really tames down a 108 cam, while a 114 cam sounds and lopes great. Personally I would not go back to a 108 cam.
BT
The 108 cam is for a JET BOAT, not a street rod. Close lobe centers narrows the power band and PEAKS the power in a specific RPM range. The jet drive does not need blower power at 2000 RPMs, so why have the rod bearings get pounded at low RPMs? I think YOU called it right when you pointed out "10 1/2 pistons/108 cam." (underdriven ???) Then you go on to say, the 114 cam sounds and lopes great. (that's what you really wanted, right?) I'm glad that you have what you want! BUT, this jet boat motor isn't anywhere near a street rod motor. He is asking for a motor that "runs well and LASTS !" 108 centers will treat the rod and main bearings with respect while giving MAXIMUM POWER where the pump needs it. Lastly, 12% overdriven would be too much for this "pump gas blower motor", considering it needs about 8.00 to 1 static compression. A 'reasonable' 6-71 @ 5% over should give about 6lbs max boost. (with correct carb sizing) The motor should see that boost from 3000 RPMs thru 7000 RPMs and @ 32 degrees of spark timing, do it on 91 PUMP GAS. If he can keep the water temps under 180 (F) and the oil temps under 240 (F), this motor should last 3 seasons. After the third season it will need #1, 16 new valve springs. #2, reset/replace timing chain (stretch). #3, inspect bearings. #4 new gaskets/seals. #5, carb rebuilds. I know these things to be true from my experience. PS if you want the "blower surge" at idle, just turn the idle mix screws out 1/2 turn (all the way around) it'll SURGE then!

[blownt]

thanks for the explanation. Wasn't tryin to give ya a hard time. Just curious why a 108 and not a 112 or 114? I figured it had sumptin to do with being in a jetboat and not on da street.
This new blower deal I happened to run into I just could not pass up on for the price. I plan on keeping the motor fairly stock and the blower at 1 to 1 or underdriven. Besides I can always stick the blower on my 29 sedan BBC project with another intake if need be.
BT

[bigkatboat]

This is an open forum, as I post, you ask and so on. You stated facts (as I did) and so we exchange ideas/experiences. I have no problem going deeper into what I think works in these motors. Let's keep the dialog going.

[jrork]

Let's keep the dialog going.
Yah, what George said. Let's keep this going.
How bout this one,
I understand how they work and the benefit of cooling the charge after you've heated the heck out of it by building boost, but for your run of the mill blown jet that limits it's hard charges to short distances (think drag races), is there that big of a benefit to an intercooler or are they really for those guys that stay in it for long distances (building tons of engine heat)......?
Sorry for the silly question....john

[bigkatboat]

I just typed out a big long 'deal' (BTU's, inlet temps VS EGT's) on this subject and it "fell off the planet". This happens (to me) on this site all the time. NEVER anywhere else, just here. Sorry, I don't want to waste any more time here. I'm over on V-driveboat.com (with a lot of very smart people) and I never have trouble posting there. "jrork" you know where I'll be. SORRY

[TIMINATOR]

Longer runs are benified more by intercooling than short bursts. Some cars and boats benefit more than others. In the case of my 25 daytona, I am able to run 11-12 lbs boost on 87 octane pump gas. Before the intercooler I needed 91 with a splash of av-gas. My street/strip Nova runs no cooler and likes 1/3 av to 2/3 pump gas, but I burn much less fuel in it than the boat. TIMINATOR