stormbauer

I am pulling my motors over the off season to go thru them and possibly looking to increase HP from 900 to around 1050-1100! The current set up is 540 cu in tall deck with 1471 Littlefield Blowers. Thoughts were to increase Bore and Stroke a bit and tweak Boost to achieve end results. I have been doing alot of reasearch on various engine builders and there is not much consistancy shop to shop on what CU's (565, 572, 598, 632) that are used to achieve this range of HP. So I would appreciate any comments on what people are running in this range. My first though was to go with 4.600 Bore and increase stroke to either 4.375 or 4.500????

jeffswav

I am not a engine builder. It seems what you have is good. I have a 489 stroker. I have heard of guys using longer strokes with the tall blocks. Some say it is to aggressive of a rod angle.

FIXX

iTrader: (2)

Put it this way, i know this is not boat engines but back in the day when i use to work on alcohol and nitro drag cars the most power was from a 500 cid engine with 35psi of boost..if it were mine i would use what you have and up grade the engine components to a bryant crankshaft and a bullet proof set of rods..upgrade to bigger blowers,cooler's and carbs and call it a day


if you want to really go big i know a guy that has 3 donovin aluminum 11.100 blocks with crower 5' cranks, rods and pistons for 7k obo each and a ton of other stuff,, i know he wants to move this stuff.. their some where around 650 cid.

pm me if interested.

Young Performance

Probably 95% of what I build are 598's (4.600 bore and 4.500 stroke). They make a truck load of torque and still leave quite a bit of meat in the block for future rebuilds. I do not like to, nor will I, put a 4 3/4" crank in a 10.200 block. The rod angle is not worth a damn, nor is the piston acceleration. With a good crank and rods, you should have no problems making your target power.
Eddie

smcclay

If you go to Eagle's website they have a calculator that you can use to determine rod ratio, rod angle, acceleration etc. It seems like the best ratio I could come up with was with a tall deck, long rod, 4.25 stroke and a 4.56 bore that was 555 or 556 ci. Anyway, a fun exercise.

Young Performance

That would be about all I would use Eagle for!!!

FIXX

iTrader: (2)

+1

stormbauer

598 was my original thought. Seems like it would be a fairly simply conversion. I like the current Lunati crank & rods I have so would probably get another from them. Currently have WP Steel heads and was considering switching to aluminum? Any thoughts on if it would be worth while or just leave alone?

Young Performance

I agree on the Lunati crank. That is my choice for the majority of the engines I build.
The aluminum heads will definitely be worth it if you increase the compression. That is the whole reason for the aluminum heads. They dissipate heat much faster than the steel heads, so you can run much more compression. Give me a shout if I can help you out.
Eddie

skaterdave

eddie, i got a ? about blowers vs na motors. i'm a sbc guy thats gotten into offshore boats and stayed with bbc n/a engines.

my question is how does the blower setup work to make so much more power than a n/a engine. i understand the basics of how they work i'm interested why with the added cylinder pressure doesn't cause denotation .

for instance, to get 1000 hp out of a n/a 565 motor you would need alot of compression, say more than 13 to 1 and an agressive cam plus high octane fuel.

same size motor add a blower and it seems you could use pump gas. but if all your doing is adding air which increases cylinder pressure, how come no denotation?