jafo

I'm not real familiar with all the tricks in building up a stroker SBC and have a couple of questions for you experts-
Is it possible to stick with a one-piece rear main seal as used with the 1986 and later SBC when building a stroker motor? Does anyone offer a stroker crank that can utilize the one-piece seal?

pullmytrigger

So your going to have strokers and Prochargers or just strokers.

jafo

Thinking of building strokers specifically for WhippleChargers- pull the stock 350MagMPI's out of the AT for resale on down the line.

Where would we be without projects? I've got two empty engine stands since I finished the Formula!

TomZ

iTrader: (2)

A variety of different crankshaft companies make stroker cranks to fit the later model one-piece rear main seal blocks. They are usually a little more expensinve though... definitely available.

I know that Lunati makes a kit for F-body and Corvette LT1 engines... with exception to the reverse flow cooling heads and what-not they still use the same rotating assemblies as the other later model blocks.

Check out Jegs and Summit... I think they are listed online in their catalogs.

jafo

Thanks Tom! I figured it would be step up in price.
Would this allow the use of the original flywheel and coupler assembly? What about internal/external balance of these engines with that crank set-up?

TomZ

iTrader: (2)

It really depends on the rotating assembly that you purchase. If the assembly is internally balanced then you are good. If it's not then it gets just a tad more complicated in the fact that you have to find a flywheel or flexplate that will work with the one-piece crank AND your three-finger coupler. I have the older coupler that bolts to the crank so mine was a no brainer though it didn't matter for me because my rortating assembly was internally balanced already.

Coddigtion

A quick word of advice for you, if you can swing it and want to make tons of power on a SBC sized motor. Look to the LS1, you can stroke these things out the ying yang if you want to and they make all kinds of power, light weight and take boost VERY WELL! I have had a couple BBC corvettes, including one hell of a 502 stuffed into a 85, and nothing competes with the LS1 for reliability and durability. You can easily get a one wire system for one of these where you just give it power, ground, on and off to the computers and you are ready to go. FYI... There is more than one LS1 around with over 600RWHP, these are very reliable, and this would make about 700 Crank HP. If my boat was setup for small block, and I was doing a power conversion this is what I would look into. If you want more information send me a PM, I had a LS1 that was 422 CI, and very streatable, made over 500RWHP, with out a poweradder and did it with 92 Gas. Just some food for thought.

TomZ

iTrader: (2)

Even better yet...

Get the 6.0L LS1 block (iron truck block) and then a set of Z06 heads. Then throw it all together including the stroker stuff (folks are building 420+ CID setups in the Fbody-Vette crowd with cars running damn near 8's in the quarter!) and stick it in the boat. Strictly a FI setup though... you cannot carburate these things successfully as the intake ports are design for a direct spray of fuel at the intake valve.

For what it's worth though... this would be VERY expensive... read five digits to build.... something I've yet to understand (the purchase of a $30k car... fbody ... and then another $12k in engine work alone)... must be nice to have that kind of money (or credit) laying around.

jafo

That LS1 sounds like a killer set-up guys, but is probably more than I want to invest- I've always wanted to do go the supercharger route at least once, and I have to build two of these engines for the 28' AT! I was thinking more of going with two fresh blocks- that would be 377 CID right? By the time you invest in proper bullet-proof internals to handle a well-boosted Whipple set-up, the cost will be high enough.
I was thinking of using the MPI off the stock engines though- reprogrammed of course.

TomZ

iTrader: (2)

I was justgoing on about the LS1 as I have a '00 Formula 6spd running 12.90's with only an aftermarket airbox lid and WS6 cat-back. These things are incredible and give the older muscle cars fits when it's time to get the lead out.

The trouvle with the LS1&6 engines is that they are aluminum and really not suited for a day-to-day type boating environment without taking the precautions to keep them alive in the marine environment (closed cooling, etc). They also ONLY work with FI like I said and that gets REALLY expensive.

With that said, yes those would be 377 CID. I don't know much about the current marine MPI but if it's programmable then you shouldn't have any troubles. They should make some nice power as well over the 5.7L engines.

Good luck!