Ok, so what started today as looking at the block to check out some bearings and try to find an ID # on the pistons ended up as tearing every last bit out of the block.

Here is what we found:
Pistons, Bore, Camshaft, Lifters, Block, Look Great!

The pistons, however, are not forged. By the part #S602P, they appear to be:

Piston, 350, hypereutectic, 400 crank / 350 rods, 9.67 CR
Product Details Stock #: H602P
9.67 CR w/ 64cc heads|8.65 CR w/ 76cc heads|.110 dish, 4 reliefs|stock ring widths|press or floating pin

These should handle my hp outputs fine. My question is. What am I looking at for Compression ratio for 58cc heads? Anyone?
Also, how much porting could I do to try to bump them up to 64ccs? Is it possible?

The Crank, however, the bearings (Clevite 77 <standards>) on the underside are pretty worn to the copper. (Mind you, this block should have about 5k miles on it) Taking a micrometer to it we found the rod journels look fine. Its the crank that look a little iffy, so I think we will have to take it down a 10th. (Any ideas on prices???) Especially in the rear of the block the bearings didn't really sit down snug in the caps like they should.

Here are some pics:





Also you can see that the oil holes have been enlarged along the crank (a little racer's advantage I hear) So it isn't as bad as it seems, but we will see what we can do.

I want to thank all of you so far and especially my friend Rob who I don't think gets on her often in his 87 Corvette. He helped me tear it down quick. Hopefully the next update will have the crank being installed in the car. Thanks guys!





[Modified by USAsOnlyWay, 1:37 PM 7/4/2004]

 

You'll have around 10.25:1 Compression, which is FINE. Hyper pistons are ok, just don't put a nitrous kit on em.

 

Excellent!
I also have 0.051" gaskets, which should drop the compression just a bit as well. I think if I can just get this crank business worked out, all should be well.
No nitrous planned, this baby should be just fine N/A!

 

Try a .039 gasket, and ask "how much are in the hole,,, .010" .015" etc.

What is your quench?

 

You think it would work with 0.039...well I geuss it is a good thing I already have the 0.051" gaskets DOH!

 

STL-H602P
$25.99
Specifications:
* Bore: 4.000 in.
* Stroke: 3.750 in.
* Rod length: 5.700 in.
[B]* Compression ratio: 10.16:1 (58cc heads), 9.55:1 (64cc heads), 9.18:1 (68cc heads), 8.85:1 (72cc heads), 8.55:1 (76cc heads)[\B]
* Head type: .110 in. dish with 4-valve reliefs
* Ring size: 5/64 in. top ring, 5/64 in. second ring, 3/16 in. oil control ring
* Pin style: Pressed or floating
* 383 stroker application; 350 engines using a 400 crank
here is the info you want to know about compression...this is the link http://store.summitracing.com/defaul...=H602P&x=8&y=8

Good luck with the crank...
BTW the links u posted may not be working.. takes me to the sign in rather than to the picture......


[Modified by korvette4u, 9:08 AM 7/4/2004]

 

Thanks Korvette4u and Larry!

The pics are up now, any geusses on how bad it is???

I need to find a crank grinder around here, but I don't know if there is one local.
But still, what do you guys think about this.

 

I was going to agree with Korvette4U about the resulting compresion ratio. I have learned through years of catalog dreaming that on a +/- 4" bore, a piston or head 1cc change wll result in a compression change of .1 , although I consider this a ballpark- its very close to what Korvette4U posted.

Find the compressed cc of your head gaskets (both the .39 and the .51) and use it to roughly calculate the change. This info is available if you search the web. Anyone know??


[Modified by SBNova, 4:11 PM 7/4/2004]

 

http://www.rbracing-rsr.com/compstaticcalc.html