Jorlain

iTrader: (4)

Hey guys,

I'm trying to find some hyper pistons, but it appears that none of the part numbers I have written down are active any longer. After some searching around, I found there were lots of arguments about whether the Sealed Power\Speed Pro $90\set pistons were 1.560 compression height or not (not to mention the posts are years old).

Basically, I'm looking for a standard 4.00\3.48\5.7 1.56x compression height hyper piston set(preferably coated) in the $100-$200 range. I would also like to have the option of using floating pins, but it's not the end all be all.

I appreciate the help!

Thanks,
Mike

sofakingdom

iTrader: (1)

All of the Sterling pistons I've ever used or seen or measured, added the extra .020" of "rebuilder" clearance. (aka, for a 3.48" stroke motor, their ACTUAL REAL AS-MANUFACTURED MEASURED compression height was 1.54" regardless of the ad copy that hinted they were "designed" "to fit" motors that were supposed to have 1.56")

Look at some other brand; Keith Black (Silvolite licensed his name and likeness) for instance.

Jorlain

iTrader: (4)

Is there any particular reason to stay away from claimer pistons (other than them being intended for IMCA use)? I've never used them, and I don't know anyone else that has, either, so I've no experience with them.

These are the ones I was looking at in particular.

http://www.summitracing.com/parts/ue...-std/overview/

Thanks again,
Mike

sofakingdom

iTrader: (1)

No particular reason.

Those are one of the ones I had in mind that you should consider. (not... "you should buy"... consider.)

Do you know what "claimer" means?

Jorlain

iTrader: (4)

I do. Of course, I personally have not seen how claimer pistons last in a street motor, so second opinions are great.

sofakingdom

iTrader: (1)

I don't think you know.

"Claimer" means, there's a price on the {whatever}, and if somebody offers THAT PRICE, you have to sell it. If you don't, you get disqualified.

SO back in the day, I used to build motors. (never for a motor claimer class... those were dominated by the guys w junkyard sponsorships... kinda hard to compete with that) My favorite ones to build for were the carb claimer classes. You had to run a Holley 4412, you could do anything you wanted to it; but the claimer rule was, $250 You couldn't even buy a carb and a set of jets, and not get skinned at that claim. Another one I used to build for was a valve spring class. You had to run 1.25" valve springs; any cam, any heads, any any any any, but with stock dia valve springs, kinda gives you a clear-cut compromise between power and reliability. Another was a "lift rule" class: you had to run a cam that was .390" / .410". Didn't specify the duration: just the lift. Another was the heads class; you had to run 882 heads, and the claimer was $350 the set if memory serves. (I kinda discouraged customers that wanted me to build for that class) And the list goes on.

Anyway... that's what that kind of piston is for. Build a motor cheeeeeeep, run lots of races, win some lose some, but if you're GOOD, you win more than the other guys, and at least FINISH em. Can't finish first unless you first finish. Which is how I got all the business I could stand; you can't win a race of that kind with your motor, but you can SURE AS HELL lose it. Mine, they ran about 25 - 30% more races on average than my competitors, and finished toward the front more often than usual, and just generally DIDN'T LOSE races for motor failure. No oil-downs (dirt tracks mostly... if you've never run one, you have no idea what a PITA an oil-down is... can't just clean it up with kitty litter and a blower) and no shrapnel.

Anyway, that's what a "claimer" part is.

Jorlain

iTrader: (4)

I understand. When I was putting myself through college, I worked at an auto parts store that also had a machine shop. The majority of our customers were circle track guys, so I get the gist of it.

That being said, I suppose I'll just have to drop $250-$300 on a set of KBs and be done with it since information seems so sparse for current part numbers.

Thanks for the help.
Mike

cardo0

I think your reading others finding their new pistons are 0.020" down the hole in the block. So take a look at the math as most stock blocks are 9.025" tall (deck height) from the crank centerline. Subtract rod length of 5.7" leaves 3.325". Then subtract half the stroke 1.74" leaves the piston compressed height of 1.585". So if your compressed height is 1.56" your piston stays 0.025" down the hole. I have never heard of a sbc piston left 0.045" down the hole - where a 1.54" compressed height would leave it. So it sounds like your getting mis-information here. All the hypers i can find are 1.56x" compressed height.

Now have looked for sbc pistons w/compressed height = 1.58" because it makes a much better quench height for a nice composite head gasket. I think 1.58" pistons were available at one time but i cant find them anymore. Have to deck the block now for good quench - "zero deck".

Hope this helps Jorlain.

sofakingdom

iTrader: (1)

1.58" will put the pistons out the top of the block.

No wonder you can't find em any more. Never has been any such thing, off the shelf. (anybody can have anything made "custom"; doesn't count)

A stock SBC block is 9.000" "nominal", 9.025" "production", with a tolerance of - 0.000" + .025" FROM THAT, with a mean of around + .015". A typical rotating assy is 9.000" total, unless of course it has 1.54" pistons; so, a typical production motor is 9.025" - 9.040" on average, with most motors having some close to 9.025" and some closer to 9.040". A typical production short block will therefore have anywhere from .035" to .050" of deck clearance, since crank properties ALSO affect it.

sofakingdom

iTrader: (1)

Did you by any chance click on the gist of the link?

Jorlain

iTrader: (4)

I haven't been able to find any information on that particular part number, so I figured there's probably a reason for that. The other KB claimer pistons I see on Summit are priced $50-$100 higher, so at that point theres really no point in purchasing a claimer piston.

I'm not opposed to paying for a quality piston. However, I don't see the need to pay additional for something just because it looks prettier, either. If paying an extra $150 gives me a better shot at the motor holding together for a long time, it's a small price to pay in the long run.

sofakingdom

iTrader: (1)

Not sure how much info you need... ?

https://www.uempistons.com/index.php...ff4d7909ffd900

Jorlain

iTrader: (4)

Sorry, Sofa, I wasn't very clear. I had meant to say that I hadn't been able to find any information from people who have actually used them, to try and get an idea of longevity and\or reliability. In my experience, buying things blindly will largely cost you more in the long run than doing your research and making a decision from there.

More to the point, with claimer items especially, I see a lot of "Well, it's a claimer part." rather than an actual evaluation of the part itself. I suppose it's entirely possible that I'm just being too picky and so on.

Thanks,
Mike

cardo0

FYI Jorlain, the made in Mexico 350 crate motor in my vette had the pistons 0.025" down the hole at TDC. The original '94 original 350"/LT1 from my camaro thats sitting out in the garage is 0.025" down the hole at TDC.

Hope this helps.

Jorlain

iTrader: (4)

Hi Cardo0.

I appreciate your input, but I've already established that a I need a compression height of 1.560, which hopefully will leave me about .025 down the hole at TDC (since my block has not been decked or resurfaced). Matching this with a Felpro 1094 or similar (with a compressed thickness of .015), should put me at around a .040 quench, which is what I'm shooting for.

Again, I appreciate that you're trying to help, but you're a little late to the party.

Thanks,
Mike