I got two sets of 283 pistons the part number is L2302 one set has been fly cut.... My question is what material are they? I believe there forged... Also what kind of compression am I looking at with a 64 cc head? They are a .60 over bore, I would like to build a killer nitrous powered 292 backed up by a t56! Or a TKO600!!! Would be badass!
Someone no doubt has a book that will tell whether they are forged or not. But sometimes you can tell by looking at the inside of them. Your compression is going to be determined by the compression height of the piston, or how far it rides up the cylinder bore. That will be determined two ways either by pre assembly and checking it or by the information we are able to glean from TRW itself. I could throw 9:1 out there and may be real close but it would just be a guess.
The TRW book shows them as 11.42 to 1 with a 1.805 comp. dist. with a 64cc cylinder head. Thay usausaly have a F at the end of the part# that would designate a forged piston.
Yes that and small bore those spects are with a .020 deck clearance and if thay have been flycut it would be less C/R
Those were made to run a hi-comp 292" SB. I believe only available in +060", not 100% certain though! They are 12.1:1 with an .025" deck and an .020" gasket. This is based on a 64 cc head. Specs are: 1.805" C.H., 19.5 cc dome (as forged), and a 1/16"-1/16"-1/8" ring pack. Could be pressed or floated, has lock ring grooves. They weigh (nominal) 630 grams, this is a very heavy piece by today's standards! Uses a .927" x 3.010", 145 gram wrist pin, also somewhat heavy. (Add) These were still available back in 1989, not sure about today! Thanks, Gary in N.Y. P.S. If you're trying to build something decent I would pass on them and choose a longer rod platform!
Longer rod would be ideal, actually bigger cubic inch like the 5.7 rod 406 I'm building would be better. But I figured I got two pairs to mess with thats less money I spend!!! I can have the short block built for less then 500 bucks with all the junk I got laying around, I don't expect to run 9's or 10's I just wanna play around on the street with a nice solid roller, and some cheap camel junk heads and a 150 or 200 shot on top of it! Should be fun! Now on running 2.02 on 283's? Is it possible I've heard you run into clearance problems with the block.
I've had friends that ran 202's on 30 over 283's. If you have any doubts, bolt the heads to a bare block and see where the valves would hit the block. A slight touch up with a tapered sanding cone can make more clearance with not a lot of impact on compression. Just don't grind down to the area where the top ring goes.
It is less a matter of clearance and more a matter of shrouding. We have run 2.02s on bored 283s but the smaller the bore the more you loose on flow because the intake valve is shrouded. With an .060 you are almost halfway there from a stock 283 to a stock 327, bore wise. I am trying to understand if they were a domed piston why you just happened to not mention that. I know the whole idea was to see who owns an old TRW catalog, right? Oh and a 5.7" rod is what a 283 has stock. The compression height is different on the pistons from one stroke to the next; with the exception of the 400 all small blocks had the same length rods.
Yeah I know all sbc Sept for 5.5 rod on the 400 are 5.7. I was just saying I'm using a 5.7 rod on my 400 instead of the stock 5.5. But my idea was just to use the stock 5.7 sj rods with arp bolts, those pistons, and stock steel crank. And see what it would do with some juice. Heads are a set of ported 186 camel humps.
Let me make a suggestion here, those stock rods are not the best to shoot a 200 shot of sauce to. At the very least check the rods for straightness, the ARP bolts, polish the beams, magnafluxed, and very important to have them Shot Peened, and finally resized. This is different from bead blasting OK, shot peening has enough force to bend a rod done incorrectly so find soneone who knows how to do it. Now, compare the cost of that to a new set of 4340 Forged rods. I know Eagle has a small journal set. I build Nitrous engines, and these stock rods if you don't do the mods to them will be the weak point. Stock forged crank and the forged piston OK, but those rods will crumble if not hot rodded for the juice. Also, I like the 1.940"/1.500" valve heads better for these small engines that will be run on the street as well as sprayed. Clean up the bowls, port match them to the intake, and a GOOD set of valve springs are mandatory with the juice. If you have the knowledge to do some mild port work, then do so. Velocity is key in making good power in these little burners. Comp Cams makes some nice Nitrous grinds, I use them quite often, really wakes them up with the kick!!
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