High comp pistons.

[Badarse mopar]

Can anybody tell me what pistons can be used to get a closer piston deck clearance in my 318.Engine currently has the standard 8.5 to 1 compression ratio,i would like to raise it to around 9.5 to 1.

[frankwest]

KB 167 http://kb-silvolite.com/performance....tails&P_id=134

[TK]

Yuck.
Hyper pistons.

ROSS!!!!!!!
Why dont you Deck the block?

[rumblefish360]

Ain't nothin wrong with Hyperu pistons. Follow the directions and you'll be fine. Deck the block if needed only if the combo of piston height, cyl. head cc and gasket thickness dosen't make the ratio desired.

[party340]

My friend used to race wing modified and all they ran were KB hyper pistons in there sbc. 7500-8000 rpm with few failures. They dont like to be ran lean, espically in an alky motor.

[jelsr]

Hypers are harder and with that comes brittle. A little pinging can get skirts in the pan. Forged are superior and are not that much more dollar wise considering everything.

[TK]

Originally Posted by jelsr

Hypers are harder and with that comes brittle. A little pinging can get skirts in the pan. Forged are superior and are not that much more dollar wise considering everything.

THANK YOU!
They also don't seem to take high mileage very good, the slap kills them where a stock cast piston just rattles away...............

[dust]

Magnum heads are lesser CC than stock heads, right? I was thinking, Zero-deck the block then install Magnum heads for superior flow and help with compression. ...A little.

[rumblefish360]

Originally Posted by dodgetruckboy

THANK YOU!
They also don't seem to take high mileage very good, the slap kills them where a stock cast piston just rattles away...............

Have you had yourself a set of hyper-u's wear out through age in a engine?
I find the term, "slap" funny. The clearance for there fit is tight since they do not expand alot.

[83Imp]

Originally Posted by rumblefish360

Have you had yourself a set of hyper-u's wear out through age in a engine?
I find the term, "slap" funny. The clearance for there fit is tight since they do not expand alot.

That seems to be a common misconception. All the local gearheads either cringe or talk about "slap" and noises when I mention KB pistons. Evidently, they don't read directions. I'm going to use KB240s (IIRC) in my 400. There isn't jack for 400s unless you want a no-compression stock slug, high-dollar custom jobs, or go with a 451 to open up some options.

[TK]

[Have you had yourself a set of hyper-u's wear out through age in a engine?

Yes, a 400M Ford, lately, and a 350SBC, and a 318 I built when I was 20 or so. All had between 90, and 110 thousand miles on them, about where the bore starts to wear.

[The clearance for there fit is tight since they do not expand alot.

Not after some mileage.

That seems to be a common misconception. All the local gearheads either cringe or talk about "slap" and noises when I mention KB pistons.

I never said they slap, or make noise, they break long before you can hear them. They are brittle, because they are hard, and, IMO, wont take the abuse a stock cast piston will.
About a month ago, I was talking with a buddy, who builds BBC's, and monster trucks. He said his 454 in his truck broke a piston. I asked him if it was a KB, he said, "Yep, that is the last time I buy those".
Cold weather may have something to do with it, but, If my stock pistons will rattle like hell, after 200,000 miles, and not break? I'll go stock or forged.

There isn't jack for 400s unless you want a no-compression stock slug,

That is why most people run them, because they are cheaper. Here's food for thought, I have a set of old, old OLD TRW forgies, they have been in 3 different motors, and are still good to go. The next 318 I build that is standard bore, they are going in, AGAIN.

[rumblefish360]

Post #7

I never said they slap, or make noise,

Post #11

They also don't seem to take high mileage very good, the slap kills them where a stock cast piston just rattles away...............

83imp

All the local gearheads either cringe or talk about "slap" and noises when I mention KB pistons.

I'm to busy to stay in the loop. LOL @ this, 3 weeks to swap an intake. Lifes busy.

I certainly have not put on 90,000 miles on any of my rides ever. I guess that living out of the city and the burbs life for ya. Someone tell me the difference between rattle and slap.

All had between 90, and 110 thousand miles on them, about where the bore starts to wear.

And the pison causewd this to happen? Not the rings?

[TK]

Rattle and slap are the same thing, Or to me they are, I should have called it noise.

As the bore wears, the piston to cylinder clearnace gets bigger, and that is what seems to kill KB's, or at least that is my theory. They are more brittle, so it only makes sense, unless someone has a better idea. The inside of a motor cant stay perfect forever.
(The last 318 work truck engine I built for myself had over 145,000 when I sold it) You are right, most tear they're engine down before it wears out, I guess as long as you do that, KB's are fine. Me? I like to throw a chain and valve job on them at 100,000 and keep on rockin!
KB's dont seem to take pre-ignition very well either.

[rumblefish360]

Originally Posted by dodgetruckboy

Rattle and slap are the same thing, //////////
KB's dont seem to take pre-ignition very well either.

lol, They even tell you that in the instructions and on there web site,
Well, if I ever get to a 100,000 miles on any ride I own..............

[TK]

Nevermind..............KB's are the shit.................

[rumblefish360]

you crack me up.
Heres the ring gap thing; http://kb-silvolite.com/clearance_pop.php
And http://kb-silvolite.com/feature.php?action=read&F_id=47
And; http://kb-silvolite.com/feature.php?action=read&F_id=46

Just keep scrolling down for more interesting stuff

[frankwest]

The facts as I see them , Any internal engine component improperly installed could fail prematurely . Don't expect a performance engine to last like a stock one. The harder you run an engine the shorter life it will have.

Just my $0.02

[TK]

Originally Posted by rumblefish360

you crack me up.
Heres the ring gap thing; http://kb-silvolite.com/clearance_pop.php
And http://kb-silvolite.com/feature.php?action=read&F_id=47
And; http://kb-silvolite.com/feature.php?action=read&F_id=46

Just keep scrolling down for more interesting stuff

Thanks Rumble.

Don't expect a performance engine to last like a stock one.

Really? Why not? I got miles out of a 318, that spent 8,000 in a 12 second duster, then, over 115,000 in a 71 D200, now, it is sitting in my race truck, bottom end is solid, just needs head refreshing. When I was putting it in my racetruck, five years ago, I dropped it on the pan. I pulled a rear main off, damn near perfect! Same with a couple rods................Bore looked good when I blew head gasket between a couple cylinders too, a little ridge, but not bad......................It has TRW's.
It is my prefference to spend the extra 400 and get forged pistons.