Author Topic: 302 engine build piston recomendations  (Read 7730 times)

zman1969

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Re: 302 engine build piston recomendations
« Reply #15 on: September 17, 2012, 12:39:13 PM »
after thinking more about the use this 302 will get I am thinking more about the Ricks pistons - correct dome , tighter fit, less oil consumption - who has used these? what ring thgicknesses? 3/32 or 1/16" ? I really cant find any more specs on them but I did find that Summit Racing carries them
Rich

69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

69Z28-RS

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Re: 302 engine build piston recomendations
« Reply #16 on: September 17, 2012, 05:47:54 PM »
tighter fit = more friction, lower horsepower, lower RPM... 
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

zman1969

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Re: 302 engine build piston recomendations
« Reply #17 on: September 17, 2012, 10:09:37 PM »
tighter fit = more friction, lower horsepower, lower RPM... 
this is going to be a driver,   I'd really like to see that comparison on a dyno LOL less clearance than forged yes but there is still clearance - more friction from the rings than the piston
Rich

69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

Stingr69

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Re: 302 engine build piston recomendations
« Reply #18 on: September 18, 2012, 03:37:40 PM »
Hypereutectic pistons do not tolerate detonation or high RPM very well. Lots of pictures on the net of top ring grooves blowing out when used hard. You will find plenty of people blaming the installer not opening up the ring gap like they were advised when they bought the Hypereutectics but even with that, there are too many broken high performance hypereutectic pistons out there.  The castings do not behave the same as a forging when subject to hard use.  High heat causes the top ring gap to close up and butt and then the piston blows out at the top ring with a big chunk of aluminum flying aound causing all kinds of damge. That is why you pay more for forgings.  In a "driver" L48 type stock application they make a lot of sense and yes I would use them there but I can't see puting them in a 302 that will be driven like it was intended. Too much RPM's, and potential for detonation.    JMO.

-Mark.

69Z28-RS

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Re: 302 engine build piston recomendations
« Reply #19 on: September 18, 2012, 04:43:41 PM »
and WHY have a Z28/302... unless you're going to build it and drive it as it was designed??...
If you want a 'daily driver' with 'Z28 emblems'...then pull the original 302 (store it away for *resale day*), and stick a stock 350 or 307 in it...

...the 302 (as designed) was classified by Chevy as a SHP (special high performance) engine....  not very many got that classification.
without the full gamut of factory parts, it ain't special...  (it's not the DZ stamp on the block that made it special)... :)

  :)     Just One Man's Opinion..  :)
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

zman1969

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Re: 302 engine build piston recomendations
« Reply #20 on: September 19, 2012, 05:57:57 PM »
and WHY have a Z28/302... unless you're going to build it and drive it as it was designed??...
If you want a 'daily driver' with 'Z28 emblems'...then pull the original 302 (store it away for *resale day*), and stick a stock 350 or 307 in it...

...the 302 (as designed) was classified by Chevy as a SHP (special high performance) engine....  not very many got that classification.
without the full gamut of factory parts, it ain't special...  (it's not the DZ stamp on the block that made it special)... :)

  :)     Just One Man's Opinion..  :)
well your right i should sell it and buy a 307 car
in the past my Z has had a 327 in it, a 396 a 427 and a 350 now I want the real 302 in it. with exhaust manifolds whats so wrong with having this as a driver? no more str$$t racing, no track time so I dont need a $1200 set of JE pistons... yes i will spin it up  and have some fun. after looking at all the options- Speed Pro, SRP, KB, Ricks, Wiseco its amazing that for whatever reason they are all different in compression and dome heights, rings, compositions
Rich

69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

Jerry@CHP

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Re: 302 engine build piston recomendations
« Reply #21 on: September 20, 2012, 06:40:52 PM »
The J&E's are about $650-700.00.  Not $1200.00, this is what I use in all the engines that we build.......

Jerry


zman1969

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Re: 302 engine build piston recomendations
« Reply #22 on: September 21, 2012, 05:00:01 AM »
The J&E's are about $650-700.00.  Not $1200.00, this is what I use in all the engines that we build.......

Jerry


Jerry, after we spoke that's what they quoted me maybe I should try another vendor?
Rich

69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

Jerry@CHP

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Re: 302 engine build piston recomendations
« Reply #23 on: September 22, 2012, 02:11:32 AM »
You should.  The J&E's will make more power too.  I've been getting 365-4000hp with a stock rebuild now using the 30-30 cam.  Stock Eliminator ring combination and some other tricks that pick up the power band.  The heads is where the vary so much.  Core shift, etc.  No two head flow the same. 

Jerry

zman1969

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Re: 302 engine build piston recomendations
« Reply #24 on: September 23, 2012, 04:36:10 PM »
JE piston # 123567 and I cannot find any one that prices them online - any suggestions where to try?
Rich

69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

Jerry@CHP

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Re: 302 engine build piston recomendations
« Reply #25 on: September 24, 2012, 02:44:29 PM »
Yes, call Burtonsville Machine and ask for Bub.

301-490-3131,

Good luck,

Jerry

zman1969

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Re: 302 engine build piston recomendations
« Reply #26 on: September 24, 2012, 04:47:38 PM »
I spoke to Bub he suggested the JE/SRP piston 202890(for .030) he said this is what you use in your rebuilds and the 123567 was a custom built piston we didnt talk $ he suggested Jegs $832 for a set of those SRP are around $563 any issues with the SRPs?
Rich

69 RS/Z DZ302 Daytona bumble bee
69 T/A clone LS6/6sp
69 Nova SS 396

Jerry@CHP

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Re: 302 engine build piston recomendations
« Reply #27 on: September 25, 2012, 01:08:31 AM »
You can use them.  We have in the past when cost is an issue with a customer.  Dome configuration is slightly different but very close to the NHRA Stocker pistons. 

lynnbilodeau

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Re: 302 engine build piston recomendations
« Reply #28 on: September 25, 2012, 05:53:58 PM »
Only slightly off topic.

Jerry, are you using the comp cams 12-107-3 camshaft in stock z28 builds?  Do you consider it a dead on match for the original 30 30?

I know JohnZ recommends the Federal Mogul.  Quote:  "Don't know offhand if the Comp cam is a dead-on duplicate or not, but the Federal-Mogul/Speed-Pro/Sealed Power cam is - their #CS-118R (cam only) or #KC-118R (cam and lifters)."


One more questions, as I am getting ready to put together a couple 302's:  what valve springs are you using?  Thanks.

Lynn

JohnZ

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Re: 302 engine build piston recomendations
« Reply #29 on: September 26, 2012, 03:51:55 PM »

One more questions, as I am getting ready to put together a couple 302's:  what valve springs are you using?  Thanks.

Lynn

The original springs were GM #3911068, same as used in all other small-blocks. They're still available from GM, but the same spring is available from Federal-Mogul for about 1/3 of the GM price as their #VS-677 (F-M makes them for GM - it's the same spring). "Improved" non-FM aftermarket versions of the "30-30" cam may require different springs - the originals were 90# closed, 190# open.
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