As you probably know, I'm building all forged 383, but it may
take some time before finances will alow me to gather all
the parts that I want.

Until then, i plan to do a budget rebuild (this winter project) on
my existing engine. I plan to reuse stock crank and rods,
maybe get crank polished, and I'll put in new bearings.

I'm courious about what pistons to get. I'm thinking about this:
Speed Pro hypereutectic H631CP30
Bore : 4.030"
Stroke : 3.48"
Dome Shape : Flat, 2 VR
Dome Volume :-5cc
Comp. Distance : 1.560"
Pin Type : Press or Float
Ring Size : 5/64, 5/64, 3/16
Piston Weight : 567 g. (approx)
Compression (@ .025 deck clearance)
58cc 64cc 68cc 72cc 76cc
10.41 9.73 9.33 8.97 8.63

And for rings:
Sealed Power moly rings
Bore size: 4.030" Top ring: 5/64" moly Second ring: 5/64" cast Oil ring: 3/16" stainless

What I have so far is stock shortblock with LPE 219 cam,
complete superram, 1.6 RR's, LT headers and ported #113's.

Also, while I'm in this rebuild, I plan to go with a little more cam.
here are specs:
Comp Cams XR288HR-10
Hydraulic roller
288 294 advertised duration
236 242 @0.050
520 540 lift
110* lobe separation

What do you think? Are those pistons any good?
I plan to keep revs up to 6500 max.

Thanks

 

I don't trust Hyper pistons.
I broke a piston land on my old 383 with hyper pistons.(KB pistons).

 

can you wait till the 383's done?

I had to make this decision myself recently.

 

I had KB hypereutectics in my 92 camaro 383. I had two pistons disintegrate. If you are running over 350 hp or a 9.8:1 or higher cr DONT DO IT. Spend the money and get some JE srp pistons. They are cheap pistons designed to be used in claimer racing so if your engine gets torn down (which happens frequently) you arent out a lot of money.

I'd rather spend 700 dollars and know its good after blowing one up myself.

 

Use a cheap forged piston and put the rest back together the way you had it, cam and all.
Stepping up to a little better rod bolt is a maybe for peace of mind but if you arent spinning it up high more than liekly dont need it.

 

KB has some forged pistons which we have used a few sets with zero problems.

We have replaced a few sets of of broken Hyper pistons with forged ones that guy have brought in the shop but have never replaced a set of broken forged pistons with HYPERS

 

Ok, after all your posts, and some other infos that I found,
it looks like hypers are definately NOT the way to go.

I'll back up from this for now, and wait a little bit to see
how will things work out for 383!

Thanks to all!