well i am looking at going .030 over. looking for a good piston but not sure what kind to go with. What is the differ between forged and hypereutectic? and ring type any help with this would help thanks mike
Just go with the forged, it's not worth the problems people have been have with hyper. I run file fit moly ring(I thing there speed pro).
Postons are speed pro's. Speed pro or JE would be my best guess. I know you could get them from TA or Poston, and I think PAE sells them too.
called ta today they are pretty broud of there cheep forged pistons. there pistons will cost more then all of my machine work is going to cost me. poston and summit are pretty close.summits are 9.5-1 and poston are 10.25-1. now if i am looking for close to 10.5-1 doe i need to deck the block with the 10.25-1 not sure how all this works. not trying to be a pest just trying to figure all this out thanks
all the replacements are low comp pistons. You have to deck the block to zero deck to get over 10:1. Either the speed pros or the srp's are a good deal. prices from ta Speed pro not sure Speed pro w/notches $455.00 SRP(JE) $585.00
I have used hypereutectics in more engines than I can even remember, I have never had any problems with them. It's a fine choice for a 450 to 500 horse engine. Jim Burek P.A.E. ENTERPRISES
I got my speed pros from Jegs for 360.00. They're the new ones with the coated skirts. 9 to 9.5:1 w/stock deck height depending on the heads used.
ordered the speed pro's from jeg's, summit didn't have them in stock. They were $370 shipped also got file to fit rings. They told me that the piston's are 9to1. How much should i deck the block to get 10.5to1 going to use 67 big port 430 head's and poston intake that came in car thanks for all the insite.
Your gonna need to cc you heads and mock up your short block to determine actually compression ratio, anything else is just a guess.
got my piston's the other day there not notched like they told me they would be. they are dished. now is this a good or bad thing . should i send them back and git notched
If they are forged don't worry about it unless your using a huge cam(check with vender). If there hypers then they sent you the wrong pistons.
So what I can't figure out is, if you are going to rebuild the engine completely, spending thousands of dollars, why would you cheap out on pistons? What are you going to save $150-200o No: Whats the point? Forged are the best, no doubt about it. Piston failure means that you get to do it ALL over again. Seems like forged is pretty cheap insurance to me. I would also have to guess that most of us use these engines in what could be considered "severe" ways. Those forged pistons will save you lots of headaches and damage if you get a bad tank of gas running 10.5:1 compression. I guess I just don't understand, might as well just save even more and run cast stockers, if money is the issue. Why run hypers over cast? I've heard of more problems with hypers than cast too. Anyway, congrats on buying forged.
Maybe Jim B can offer some addtnl info on Hypers---I've heard good and bad...the problem with the "bad" is you, alot of the time, never hear the "full story" as someone mentioned above. Possibly hypers have a problem if they are put in with too little wall clearance? Also--consider what is mentioned above--how accurate is the machine work being done---and the resulting true compression--all this effects the durability of the parts. Finally you have the driver and the way the engine is treated. Jim has seen a number of them used and I know Automotive Machine and Perf in Kentucky has built a LARGE number of BB Buicks with hyper pistons (and I think they still do). Both of these builders (Jim B and AM&P) are LONG TIME BUICK BUILDERS...so you are hearing from two very reputable sources (that have to deal with customers) that they don't have a problem with them. I suspect these things are getting a "bad name" b/c of marginal machining/rebuilding techniques and/or "driver error"("well- it was only a 150 shot of nitrous!") more than being defective parts. I see the point of going to forged pistons for a few bucks more--definitely one way to avoid the issue. Patton
Forged piston notches If you need valve notches, I'm sure your machinest can "fly cut" some notches to your specs, but do this before balancing! Hypers are a very good replacement for the cast. Good to about 500 or less HP, IMO. Not for high RPM or ANY nitrous use, period. Forged, skies the limit..
Mike, The forged speed pros are dished so its OK if that's what you ordered and by the price it sounds like it is. Get a good machinist and talk to him about what you want to do with this motor (mild street, street strip ect.). Check the casting numbers on your heads at the web site below to see what cc chambers your heads are (or have them cc'd). The folks at speed pro told me that with 66cc heads these pistons will yield a 9:1 comp. Once you know this your machinist can help you decide how much you'll need to deck your block to get an acceptable compression fo your application (within reason of coarse). atlantabuick.com/castingnumbers.htm P.S. The part number for the .30 over forged speed pros are L2353F
I got the forged all i was asking was the diff between the two. When i ordered them they told me that they were nocthed but i recived dished and from the sounds of it i will be ok with the dish. My heads are 69cc.The part# for the pistons is L2353F thanks all for the insite.
Hi Guys, The saleman at Jeg's obviously did not check this, I would say he assumed....those Speed Pro pistons are dished but do not come with valve reliefs/notches. TA is the only vendor I know of that sells them with or without reliefs. The reliefs are of course higher cost because TA does them in-house. If I'm not mistaken I think they charge around $75 to do so but you'd have to verify that with them. Hope this helps....
