Hey guys I'm rebuilding the bottom-end and want opinions on the 355 w/D-1SC twin 12#. Here's the deal: Forged pistons, h-rods, splayed 4-bolt mains, stock turned crank (maybe new forged...), new bearings, pins, etc. Looking at 9.2-9.5 CR. and going to run Alky/water 50-50. I'm using 64cc CNC heads with the following flow numbers:

> > > > > I E
> > > > > .100 60.5 58.8
> > > > > .200 124.3 111.5
> > > > > .300 185.8 147.8
> > > > > .350 210.7 166.4
> > > > > .400 233.3 180.7
> > > > > .450 249.7 189.3
> > > > > .500 260.4 195.4
> > > > > .550 255.5 198.5
> > > > > .600 256.1 201.7
> > > > > .650 260 203.4
> > > > >

Race-built A4 & 12 bolt. I'm looking for around 500 at the wheels. Realistic? What do you think of the 355 vs. the 383?

Oh, I'm also doing the hydra-rev kit to push around 6500 and will probably push more boost...

Thanks, TJ

 

I think 500 rwhp is capable with your proposed setup. As far as a 383 vs a 355. The biggest difference you will see is the torque gain on a 383.

 

if your going to spend all that money on parts i would build a 383. specially if your going to buy a forged crank. good luck.

 

Personally I think you'll be pushing way more than 500rw, mor elike 550+. Only reason I say this is because I know of setups with a 224/236 cam and 1.6rr and long tubes and a p-600b procharger with the 12# pulley and he pulled 525rw. So I think you'll be more than that.

 

The question is really WHY a 383? If I can reach my goal with the 355 why worry with the extra machining/cost? I'm going to try to use the stock crank if it is in good shape. My builder thinks the stock crank is fine up to 700 hp. With the fluid damper and 4 bolt mains, probably more.

I think tons of torque on a 300hp engine is great. But how in the hell do you hook up 700ft lbs on a 500hp engine? I want to get the setup as consistent in the quarter as I can, and hooking up is a big key. Convince me...

 

Personally just to be on the safe side I would throw in a GM Forged Crank.

 

I just pulled my 355 out and had a stock crank with 500 rwhp. The crankshaft was cracked from the twisting action which was chewing up my bearings, mains and rod. The rods were also twisting.I would not use a stock crank or rods. If you are building a motor a forged 383 crank is easier to find and the cost is not much more. In my opinion why bother with the 355

 

How many miles on the motor and how hard did you run it?
Ed

 

Thanks, guys. I'm trying to get the most bang for the buck I can and keep everything together. I just bought the SC and heads and then discovered the bottom needed a redo, so I'm dropping a big pile of dough in a short time frame. Deciding where to compromise is the trick. I'm trying to be goal oriented and not get too self-indulgent. When I first started looking at blowers, I was reading the 1000hp posts and getting star-struck thinking about 9 sec. street cars... Very cool, but probably not the level I care to play. If I can get my car to the point where it can thrash most Vipers, then I'll be pretty happy...

Realistically, about 700 hp at the crank is the max I want. I'd be happy with 600. When I've had a better taste of the game, my goals will probably change. Who knows?

I like the idea of building a stout, rebuildable engine and building power with a blower that I can put on anything I want. It really makes for a long-term, fun solution. Hell, the whole setup might come out of the Z someday and drop into a streetrod... who knows... But for now, I'd like to see low 11s at altitude.

 

EDSZ28, I had abouth 25,000 miles on the motor with 8lbs of boost. The forged pistons and rings were fine but that was about all that held up. I never took the car to the track and it was always maintained. I ran hard once in a while on the street. I'm in the process of building an all forged 383

 

A 383 is going to be my next engine if this one ever lets go. So far, everything is holding up just fine. What brand of parts are you going to use in your 383?

 

EDSZ28, I'm using a Callies Dragonslayer 4340 crank, Eagle 4340 H-beam rods, JE dished pistons, C/A Zero gap rings, C/A Main,rod & cam bearings, Custom blower grind Cam, Comp pushrods, lifters, & springs. I'm also boring to .040 over (385 C.I.) square deck block and convert to 4 bolt mains and balance & blueprint. The heads are being ported and polished and will hopefully flow 285 cfm @ .500. I also am using enconel valves 2.02 intake, 1.625 exhaust for the heat and teflon coating pistons, combustion chambers and valves. Plus alot of other misc. stuff

 

I have a GM Steel one-piece rear seal crank sitting in the shop. I had it turned to a 3.50" stroke for the extra 2 cid. It came out of a ZZ3 crate motor and will fit LT-1's.

Let me know if you're interested.

Mike

 

stock rods and crank will take a good bit. I know of guys running 10's with stock crank and rods with no trouble. I'm running 12#s with that set up. You don't have to do a 383 to make real high #'s. AFR heads with a decent cam and you will put down massive numbers for sure. In a issue of GM hightech, a guy is running an ATI with 12#s on stock crank and rods. GTP heads and a cam has allowed him to run a traction limited 11.01 at 132mph. All though I have yet to dyno my car, I can say that it runs stronger than anything I've ever owned. I even have a hotcam in which is not the best blower cam. 355 is less expensive to build because of not needing machining. Obviously I would build a mean 355 and have some fun!

 

That's pretty close to what I'm doing now. H-beam rods and blower pistons, 4 bolt mains with custom cam and CNC heads. Add the hydra-rev kit and it should be a little fun...