Pistons

-
DARTLARRY

DARTLARRY

Well-Known Member
Joined
Mar 19, 2007
Messages
578
Reaction score
242
Location
FORT WAYNE IN
If I Use Kb107 Pistons In A 360, With A Stock Rotating Assembly, Will I Need Any Additional Machine Work Done To The Pistons Or Block. Ive Heard Many Different Opinions On This Subject. I Thought I Would Ask The Very Knowledgeable Builders On This Site.
 
Just balance it and make sure the ring gap is correct according to their (kb's) reccomendations and you should be fine.
 
Yes balance for sure. I used KB107's and Eagle SIR rods in my 360 both of which are much lighter than stock. When I had it balanced they removed almost a pound of material from the crank to balnace the assembly.
 
Is there a problem using KB107 pistons on a block that has already been bored? Basically I'm just trying to bump up the compression on a freshly bored, low compression, cast piston block. But I thought I heard that the KB107s needed tighter piston to wall clearances in the machine work? Is this true? It's for a street/strip car.
If it is true about the KB's, do the Speed Pros have the same requirements with clearance?
 
All Hypereutetic Pistons Recommend Tight Clearances (.001-0015). You Dont Have To Fit That Tight They Will Seal But Will Rattle.
 
So if I just swap out the cast pistons and use the hypers I'll have piston slap. Is this just when warming up, or will it be beating the pistons the whole time? I'd hate to go this route and then have problems down the road from damage done from this.
 
I Would Have It Bored. Im No Expert Im Just Repeating What My Machinist Told Me. Mine Was .020 Over, But I Had It Bored To .030 To Be Safe. If You Get On Keith Blacks Website I Beleive There Is A Page That Gives Specific Tolerances On Cylinder Wall To Piston Clearance.
 
Yea, that's the problem, the 360 block was been bored 40 over, so going over that is out of the question, especially since it has never been run.
 
Get a cheap set of forged pistons... They run wider clearances and expand a bit. Hypers dont expand, so they will be noisey, and stay noisey. That's why the tight clearances... They start where the others expand to.
 
You must log in or register to reply here.
-

Back
Top