I am very happy with my BBC engine built by Eric Weingartner. The best dyno run resulted in 810hp with only 666tq. I was looking for high hp motor with lower tq. The short stroke of the motor yielded positive results. The T56 and the irs should live with this amount of tq, hopefully.

Components:

Dart Little M with 3.75 x 4.5 bore and stroke.
AFR 305 heads ported by Eric to 400+cfm at .600 lift
454R intake custom ported
Rotating assembly was extremely lightweight, with a Callies magnum crank and sbc rods.

Eric built this motor for the 2014 EMC challenge. I purchased the parts and he did hours of custom assembly at no charge. The engine for example is using piston guided rods, something out of Nascar, lol. The Afr 305s had countless hours of custom porting and the dyno numbers show the results.

This is not a high rpm screamer as the best run went to 7000rpm. This engine really has me thinking of doing a large bore short stroke SBC to see if it yields similar results.

 

Man that is good 810 hp out of only 477 cu. at only 7000 rpm. Now if i just knew what a piston guided rod is ?

 

Like the bigpower without having to have some crazy rod angle and piston speed. Should be a hell of a lot of fun thats for sure
Nice work, Eric.

Can we see some closeups of your intake handiwork?

 

Eric has a detailed build thread on the Chevelle Forum titled the 2014 EMC Challenge. There are a lot of head photos and flow numbers on his thread. Im just the happy customer, lol.

After the EMC competition, we may consider re-camming the motor to increase the rpm range and kill off some additional tq. The EMC challenge measures the highest average tq and hp from 3500-6500 rpm divided by the cubic inches of the engine.

 

Killer numbers! Eric really knows his stuff. (Although I'm not sure what's up with his facination with yellow paint ) That's solid low 9 sec power there..

That's gonna be a lot of fun, I hope you have a killer drivetrain in that thing.

 

Appreciate the kind words. I'll post the competition results when they happen. Eric is also entering his 540 from last year. On the same dyno his 540 made 806hp. When he ran it at the competition last year, it hit 866hp. The 477 may hit 850 at this year's competition.

I havnt started on the car for this motor yet. Im about 90% done with my SBC 427 powered C2. When that is finished, I will slowly build an SRIII framed 68 Coupe as an updated L88. Getting this engine built at the cost of the parts, is why I the engine was built far in advance of the car.

 

That sounds like an incredible combo and perfectly suited for a manual/irs vette! I can't believe only a few have posted responses...? So much cooler than an LS something or other...

 

Love the combo, hope to have the cojones to pull the trigger with mine as soon as it's finished. I'm starting with a 4.625" bore, should end up around 507 or so cubes when honed out, already have the TKO-600 for it.
You should really be able to give the Z06 boys a run for their money, most of those guys think our rides are like most of us - old and slow.

 

We didn't know what kind of numbers this combo would yield until it went to the dyno. I asked Eric for a prediction and he finally said 650-800hp, lol.

L88 Plus - Eric said and ordinary 477 build would yield about 750hp without the custom work and trick parts. I would expect your 507 to easily break 800hp and then some.

What heads are you thinking about?

 

Since mine isn't max performance, I'm using some rectangle port Bowties that I got a good deal on. Since my block has a bowtie on it, I want the heads and intake to as well. I'll have these ported a bit by a good friend who did a good bit of head work for Sunset Racecraft (R.I.P. Tracy) just to get decent flow. My block had already been fitted with bronze bushings for .903 lifters, which I have. I'm confident it'll make enough power to scare hell out of me and any sucker...er...passenger I might have.
I had everything gathered a few years back to do this but backed out since it was going to be a cruiser for my sweetheart and myself. I kicked myself every day until I figured out the solution: buy her a cruiser, then build this monster any way I wanted. I found her a 1985 Mercedes 280SL that we both love, now I can do this one the way I want without as much guilt.
I picked the combo based on 1) nostalgia of the 3.766" stroke crank - who wouldn't want a Corvette with the heart of an L88, and 2) Jim Moore's many comments on having an engine that pulled hard to 7500 rather than a truck motor that had to be shifted at 6 grand.
Thanks for the posts here and Eric's on TC!
I am going to hopefully knock the pistons out of a 409 at my shop today. Although it's an off-the-wall designed engine, it's another big bore/short stroke combo that I'm hoping will be a candidate for a build (3.50" stroke x 4.3125" bore).

 

Now that there is an aftermarket for W409 parts they are getting popular. Good luck with your 507, it sounds like it will be a lot of fun.

 

Gotta love those "short" stroke BBCs.

 

holy moly.... thats some hp outta 477..... the old sbc 377 guys spray them like mad and seem to dominate at the track.....so not too surprising that a short stroke bbc screams too...

 

I am surprised by the results. This is a little more power than I expected. I may switch to a milder cam.

Im also accumulating parts to try a Short stroke large bore SBC. I have a set of AFR 245 heads that flow 350cfm at .700 or so. A 377 or 388 making 700hp would be interesting, lol.

 

I think you could eclipse 700 with max compression and cam, unless a "reasonably easy" 700 is what you're after.

 

I am trying to get hp without unnecessary torque. In the case of the 477, the competition needed torque to compete. I am hoping a different cam will reduce the torque to 500 or below. I am willing to give up some hp to do so, as I don't really need to drive around with 800hp, lol.

What I am really trying to do is get power within the constraints of a reasonably built irs and manual transmission. If I can get the hp at higher rpms and enough tq to putter around town, Ill be happy.

The plan is to efi the 477 when finances become available.

 

I have a friend that built a smallblock Olds 350 gas block 4.155 X 3.50 (offset ground factory steel crank) = 380 ci. 600 hp and 500 ft lbs with factory iron smallblock heads fully ported (2.10" intake valves ).

Your 245's should be fine

 

Sounds like you need to find a 409! Smallblock stroke at 3.5", big-inch big block bore of 4.3125! I have one in my shop, trying to figure out how to finish getting the rusty booger disassembled.
I wonder why GM gave up on the short stroke/big bore engines?

Getting rid of the unnecessary torque is exactly what drew me to the big bore/short stroke engines. Well, that and Jim Moore constantly talking about how much fun it is to row through the gears and shift at 7K+

 

Part of the drawback for a short stroke motor is cost. You give up a lot of free cubic inches because rotating assemblies cost the same. Also the smaller crank shafts cost more due to lack of demand. Additionally if an engine builder warranties his engines, he would not want to warranty a higher rpm motor. Most crate motors have peak hp around 6200rpm. A short stroke motor will be maybe 7000rpm. More chances for a part to fail.

 

Emissions.
Smaller chambers and a cleaner burn.