The beloved 318

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Illahe

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For what its worth, some of us are stuck with oem cylinder heads and nostalgia. I just spoke with DSS pistons and they said that they could manufacture a quench head piston up to +.200" off the deck, but do not make domed pistons.

318 blocks are plentiful, but no quality pistons for a performance build. That being said, I am going to see if I can make a chamber mold for 587 iron head and send it to them. 3 sets + will get them to discount. Hopefully they will be able to manufacture a quench piston capable of over 10.5:1.
 
oldkimmer said:
I thought KB had a piston for the teener. Kim
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I won’t run the hypereutectic garbage again.These are H116CP. Last set was a KB that shattered in my HD. Saving money on pistons cost a block and cylnder head repair.

To each their own…

IMG_3295.jpeg


IMG_3293.jpeg
 
oldkimmer said:
I thought KB had a piston for the teener. Kim
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KB has some, They are all Hypereutectic I believe. Icon has forged flat top's with valve reliefs. Diamond has some listed. I'm sure they are forged. Quite a few cast pistons if you choose. That's is all on the first page of Summit's site.
 
toolmanmike said:
KB has some, They are all Hypereutectic I believe. Icon has forged flat top's with valve reliefs. Diamond has some listed. I'm sure they are forged. Quite a few cast pistons if you choose. That's is all on the first page of Summit's site.
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The flat tops don’t have quench, and the KB piston is prone to shattering. I’m looking for other options.
 
toolmanmike said:
Go for it. What head are you using?
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587. I like the 318 police head too, 345 casting I believe. I’m a hobbyist, and want a scan for 318/360 oem cylnder head builds. My 69 has +10 or 11.5 cc Ross pistons with a mild solid and its street-able with Iron heads but about 3/4 point of compression too high.
 
I installed KB107 Hypers in my HO 367, back in 1999.
I used to shift that thing at 7200 all the time.
Engine now has over 100,000 on it.
The trick with hypers is to run extra top gap, and mine are a lil loose in the holes.
KB107s are 502 grams for my 360.
You think a 273 revs fast?
EDIT;
{I ran these at between 11.1 to 11.3 Scr and CCP of 185 to near 200, depending on the combo. I ran a Power-Timing of, UP TO 34*, and from day one, on 87E10. The Q was held to .028 to .032.
Top gap filed to .034, Second to .030, skirts around .0040
Jus saying.}

IIRC KB has 2 or 3 offerings for 318s.
Plus, they say older 318s can be bored to 4.04, without consequences. Then you can put a stroker kit into it, lol.

Badmouthing hypers because you had a bad experience, IMO, is not fair.
 
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So what caused the damage in post#3? I recall the 318 should only be over bored by .040" or something like that it isn't much. I know people say otherwise but. That would give a 318 a max bore of 3.95.
 
AJ/FormS said:
I installed KB107 Hypers in my HO 367, back in 1999.
I used to shift that thing at 7200 all the time.
Engine now has over 100,000 on it.
The trick with hypers is to run extra top gap, and mine are a lil loose in the holes.
KB107s are 502 grams for my 360.
You think a 273 revs fast?

IIRC KB has 2 or 3 offerings for 318s.
Plus, they say older 318s can be bored to 4.04, without consequences. Then you can put a stroker kit into it, lol.

Badmouthing hypers because you had a bad experience, IMO, is not fair.
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Glad you had had good luck.

I have two reputable machine shops near me and they refuse to build engines with K.B.'s Hypereutectic line, and as stated the piston that failed was a H116CP Speed Pro. I’m done with Hypereutectic pistons as well.

Happy trails…
 
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This has been a minute ago but Campbell used to source forged 318 pistons for Wiseco but they may have been flat tops. TRW used to make forged flat top, high dome well actually pretty much whatever you wanted...also sourced thru Campbell...Am I too old now? LOL
 
jeff alder said:
This has been a minute ago but Campbell used to source forged 318 pistons for Wiseco but they may have been flat tops. TRW used to make forged flat top, high dome well actually pretty much whatever you wanted...also sourced thru Campbell...Am I too old now? LOL
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Thanks for the information.
 
Illahe said:
The flat tops don’t have quench, and the KB piston is prone to shattering. I’m looking for other options.
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Yeah, when the ring gaps are too tight, they certainly will.
 
Dartswinger70 said:
So what caused the damage in post#3? I recall the 318 should only be over bored by .040" or something like that it isn't much. I know people say otherwise but. That would give a 318 a max bore of 3.95.
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The picture is from my .03 over 360, La. The piston is a Speed Pro H116CP hyper… Let go on the top end.

I purposely ran the speed pro’s cause we had good luck with the 9:1 in several motors, but the machine shop said they were maid in India, with a frown…
 
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Illahe said:
I don’t believe the rings butted, there are no scores in the surviving 7 cylinders,Lol. They shatter like glass.
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Correct. I've seen it a lot and in every case there wasn't enough ring gap. The other way is if the mixture is leaned out and you get detonation. You don't always hear it. In the end, Hyper pistons are still cast. So if it's a really heavy duty application or race, forged is the way. They're good pistons, IMO. I think a lot of the failures are from people either setting them up wrong, or using them in an application they are not really intended for.
 

RustyRatRod said:
Correct. I've seen it a lot and in every case there wasn't enough ring gap. The other way is if the mixture is leaned out and you get detonation. You don't always hear it. In the end, Hyper pistons are still cast. So if it's a really heavy duty application or race, forged is the way. They're good pistons, IMO. I think a lot of the failures are from people either setting them up wrong, or using them in an application they are not really intended for.
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Yep, using a cast piston where it's not intended to be...At 34 degrees total timing and 100 octane my confidence was up! The $300 bucks I saved on cheap pistons cost me a lower end and possibly my favorite Schneider grind.
 
Illahe said:
The flat tops don’t have quench, and the KB piston is prone to shattering. I’m looking for other options.
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Incorrect. And your definitely wrong about hyper pistons "shattering" they only do that due to improper piston to wall clearance (typically from old school machine shops who are to stubborn to read) not following ring gap requirements (see above) I've built HUNDREDS of engines with hyper pistons with ZERO failures.
 
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