I want to build a motor for my '89. Didn't want to use my engine in the car so I can still drive it while I build this motor. I have been looking at a bare 350 block from GM Part # 10105123 they have them in Summit. I'm looking to build a stroker.
Eagle forged assembly(help with piston selection?)\
AFR 195's(help with combustion chamber size?) / To determine CR
Super ram set up 58 mm TB
accel 36lb injectors
Edelbrock TES with y-pipe and 3"flowmaster exhaust
Scorpion 1.5 RR or Crane golds
Usual clearing of the block, pan rails etc...
Haven't decided on a cam yet but as you can see by the forged set up I want to put my "baby" on the bottle 100-150 shot. With tuning I'm told that this motor alone could easily push 400HP. With a 100-150 shot,can the block handle it?

 

a stock GM 4-bolt block is usually tapped out at around 500hp. Now noboday can tell you exactly what its going to handle, some may blow apart at 300hp some may last up to 800hp. But you should be fine on a 4bolt for what your doing.


As for the piston and CC size, that all depends on what you want to put in it at the pump. if you want to run 87 your going to need a low CR (dish pistons and large chamber, if your ok with dumping 91+ in it you can go with flat tops and a small chamber which is going to also help alot for power.

 

How high a CR before I can stop using 91 and have to use a race fuel?

 

i believe about 12:1 without some sort of cylinder coolant injection(water injection systems)

 

12:1 is pushing it even with methanol injection IMO. But it all depends on the cam your using, you might even be able to run 12:1 on 87!

 

The eagle forged assy is a good value for the buck, IMO. The H-beam rods help a lot for clearence on the cam and lower cyl walls.

I'd go with JE pistons if the funds are avail.

On my 383, I'm running factory (but modified) 64cc heads with flat-tops (4 valve reliefs) and a std deck height. It's about 9.5:1. I record eng data a lot and I've seen very few knock signals, even on 87 octane.
I wouldn't go over 11.5 to 1 (w/alum heads) running 91-92 octane.

36 lb injs seem a little large unless your planning on using them for the N02.
(as opposed to spraying the fuel with a dedicated N02 nozzle at throttle body)

I prefer the Comp pro mags rockers, but I've heard good things abt the Cranes too.

Can't go wrong with a LPE cam (part# 74219 I think). It was designed specifically for that intake.

You'll definately want to upgrade your fuel delivery system. Bigger pump, larger fuel lines, etc. You don't wanna go lean while on the bottle!!

From what I've heard, a splayed 2 bolt main is stronger than a 4 bolt, but I don't know that for a fact. Might wanna look into that before you make a decision. With the juice, you'll need everything you can get.

 

the block itself is usually very strong, i'd say you're fine up to 800HP pretty easy. good ARP main bolts/studs, a good forged crank, and good rods with bolts is what you need. you seem to have a handle on that, so I wouldn't worry about it.
FWIW, the people who REALLY know what they're doing, and worry about block failures, usually use a beefy aftermarket block with thicker walls, and or put filler in the blocks water jackets. any of the big drag racers here know how much HP you would be at when they use fill? (hint, I think it's really high, much more then 500HP)

i'd stay conservative on the CR. you only gain a tad bit more power by going up a point, like 4% or something, and the hassles you have with it (more expensive fuel, closer to the danger zone of detonation, which is more expensive, etc...), aren't worth it. I don't think you'll have trouble going over the 400HP mark (like, easily).

 

remltr I think youll want to read thru theCHEVY SUGGESTED SPECS/LIMITS on that GM Part # 10105123 block

Sallee Chevrolet - Performance Parts Catalog

Sallee Chevrolet - 1986 to 1999 350ci 4-Bolt Main Bare Block

NOTICE

Intended Max. Hp @ RPM:350 @ 5700rpm
Intended Usage: Street
one peice rear seal

 

Might be better off investing in the block you have now with splayed caps or just spend a little more for a dart block. Even a junkyard 4 bolt would be better since if it fails you wont have dumped that much into it. Im using a 4 bolt block for a 383 but I only paid $50 for the block so no loss if it fails.

 

wow, that's pretty dismal...

however, they all have pretty lame limits there, and I don't think they're any weaker then a production block.... In fact most are described as having thicker this and that, bla bla, meant to sound really beefy.... then they say max 400HP...?

I'm not sure on the price, but if you're paying high prices for a GM block, and aftermarket one like a Dart or something might be worth while.

 

It all depends on how your bottom end is set up. I have a 350ci 2-BOLT main with an Eagle rotating assembly(crank rods forged pistons ) and ARP main and head studs. I'm running a Power Plus Intake similar to a Holley Srtip Dominator, A Holley 850 Double Pumper, A Comp Cams Custom Grind .630int .655ex solid roller with World Pruducts 220 heads. The big roller and intake runners let me shift at 6800rpm and the motor still pulls past that but I really don't want to risk it. Now I've never dynoed my car but my car runs consistant 11.48 passes at 126.7mph. By the way I drive 18 miles to and from work every day for the past 3 years, so yeah I think it should hold up.
As far as gas 87 octane really makes my motor ping BAD, but 93 octane really helps it out not to. Aviation fuel helped even more but that's only like once every 3 months.


Eric......

 

HMM,Look at the fastburn 385 same block just alittle over 350hp. 425 with a cam
According to Sallee the 383 short block stroker kit is the 350 horse block but machined to 383 specs. If you look at the block part # used in the 383 Gm just changed the PN for the 383 block.

 

GM under rates the specs on all of their blocks in the GMPP catalog. The P/N 10105123 bock was clearanced for the 383 crankshaft and GM changed the part number to 88962516. The chart in the GMPP 2006 catalog says that the P/N 88962516 block can handle 450 HP which is still low. This is the same block that is used on all ZZ4 partial engine based engines with the 383 only having the block clearanced. If you take a look at our ZZ383-500 page: Sallee Chevrolet - ZZ383-500 500 HP 383 CI Stroker Crate Engine you will see that this block can handle 500 HP without any problems.