cooters T bucket build
- Thread starter cooter
- Start date
cooter
Well-Known Member
Lol. I don't think this little motor needs a blower. Tryin to figure out what forged pistons to use. It had builder pistons in it. 1.785 compression height best I can tell. If my measurements are right I need a 1.825 CH. She really hum with a good forged piston with the compression up.
fletcherson
Well-Known Member
Ouch! Pistons aren't cheap anymore either...looks like a fresh break too. How's the bore look?
cooter
Well-Known Member
I still need to get that measurement. Cast piston might not like high revs?
fletcherson
Well-Known Member
I've had good luck with hypereutectic pistons. The last time I priced sbc internals, I was shocked how much they went up in price. I rebuilt a basically stock engine and could have bought a crate engine for about the same price.
tdkkart
Member
If it was "rebuilt" in a stock bore that was just honed and put back together it likely has too much bore clearance, which causes piston slap, which knocks the skirt off the piston, especially if driven hard. Under ideal conditions cast pistons are good for at least 6000 rpm, but that number goes down as you get further away from ideals, such as piston slap, high temps and detonation. A lot of builders consider the stock rod bolts to be an issue before the cast pistons.
Hypereutectics are a good a good plan IF you follow the instructions, which most that have problems don't/didn't.
Hyper pistons by design put more heat into the top ring, and then into the cylinder wall. This allows for a stronger-than-cast piston, while
still allowing tight piston to wall clearances so they are quiet and seal up better. BUT, the hotter top ring needs to be gapped slightly wider
or it will but the ring ends and either destroy the cylinder wall, pull the top off the piston, or both.
Check out these folks. I used one of their rebuild kits in my '95 350 truck block with good results!
Northern Auto Parts Warehouse
Northern Auto Parts Warehouse
mountainman
Member
Cooter,
I know this won't help your situation but it may help to know it could be worse.
Bought my car as an unfinished project. Been changing things for over a year and finally got to point of firing engine. Car was bought with "newly built by prominent engine builder in St. Louis" engine that was never fired up. "Has all the "right stuff" on it (new RHS heads, Comp cam, etc, etc)". Was shown an invoice for all parts and labor. Much $$$$$.
Well, last week I got started on it. Wanted to know specs on cam so pulled timing cover.....no name or #'s on that end of cam. Decided to break out the degreeing tools to take measurements. Cam was a stock rebuilder cam for the 1982 smog motor. Now I get leery of entire build. Tear it down and Long story short.....All new parts BUT internals are a cheap rebuilder kit. Has $10 dished pistons that are .060 down in the cylinder, stock cam, worn rockers, non-hardened pushrods (heads have guide plates), stretched head bolts, and a NEW set of RHS heads that are unusable on this engine.....72cc chambers and 235cc intake runners! Compression calculates to 7.88:1.
So...I have a nicely machined block and crank as a base to build from. Ain't life fun?
I know this won't help your situation but it may help to know it could be worse.
Bought my car as an unfinished project. Been changing things for over a year and finally got to point of firing engine. Car was bought with "newly built by prominent engine builder in St. Louis" engine that was never fired up. "Has all the "right stuff" on it (new RHS heads, Comp cam, etc, etc)". Was shown an invoice for all parts and labor. Much $$$$$.
Well, last week I got started on it. Wanted to know specs on cam so pulled timing cover.....no name or #'s on that end of cam. Decided to break out the degreeing tools to take measurements. Cam was a stock rebuilder cam for the 1982 smog motor. Now I get leery of entire build. Tear it down and Long story short.....All new parts BUT internals are a cheap rebuilder kit. Has $10 dished pistons that are .060 down in the cylinder, stock cam, worn rockers, non-hardened pushrods (heads have guide plates), stretched head bolts, and a NEW set of RHS heads that are unusable on this engine.....72cc chambers and 235cc intake runners! Compression calculates to 7.88:1.
So...I have a nicely machined block and crank as a base to build from. Ain't life fun?
cooter
Well-Known Member
Mine are .040 down in the hole. Stock cam. Too bad I can't find a good set of forged flat tops for a .060 283. Think I'll just go back with the piston that came out and just cruise. Jegs has it for 25.00
fletcherson
Well-Known Member
Bummer! Sorry to hear that. What was the invoice for? Bait and switch? It's hard to trust anyone anymore. I hope you bought it right.
SRM1952
Member
Cooter you have some good options with Hypereutectics--keith black has a flat or dome .060 over---the dome piston with a 64 cc combustion chamber head is still appox 9.5 or better--depending on gasket ,deck hgt .-----the flat top w/your 283 head 58cc or so about 9.2 the 64cc gm head you could go to a 1.94 valve mild cam would breath pretty good .
the Hypereutectics pistons are in all the new ls motors with some higher compress ratios---they use less clearance than forged pistons =better ring seal and they are good to 6000-6500 rpm, they are very good for street rods . Price 414.00 is about the same as stock forged pistons the flat top Hypereutectic are 373.00
Just some thoughts, have build a lot of race engine over the years and I would use them in heart beat for street motor .
https://www.summitracing.com/parts/uem-kb166-060/overview/
mountainman
Member
I honestly think the builder screwed him. I bought it right but turned out not as right as I thought.
BTW....Cooter has some of the stuff that I took off this car on his.
cooter
Well-Known Member
Love my fanI honestly think the builder screwed him. I bought it right but turned out not as right as I thought.
BTW....Cooter has some of the stuff that I took off this car on his.
cooter
Well-Known Member
I like all the dimentions except for the domes on those. I looked at KB but got scared due to the top ring issue and popped off heads. Probably due to people running too tight of ring gap. I settled for a single replacement for the broke piston and a set of SCE .015" thick head gaskets to help get closer to the .040" quench. .040" DH. Gasket I pulled off mixed .045". Really low on compression. 60cc chamber power packs
mountainman
Member
Yep...I just looked and yours are harder to find than my .020 oversize ones for an block that has not been decked.
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