Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[98fxstc]

Split my cases to get the crank 'darkhorsed' and fitting different pistons .
A trial fit up shows both pistons proud of the cylinders.
I want to use cometic SLS base gaskets to adjust the deck height of my cylinders.
I will use the quad ring and o ring with them.
Do the cometic gaskets go on with the ridge up or down ?
No problems with gaskets deforming o rings ?

[Steve Cole]

While not your answer, how proud are the pistons, as it might be much easier to just adjust with the various different thickness head gaskets that are out there. Then you don't have to worry about base leaks.

[98fxstc]

Thanks Steve

I had 002" and 007".
I made up a base gasket from 005" brass sheet and ran them both at 002"
with 030" cometic head gasket
I'm back in there again due to damaged piston
Swapping +005 " SE pistons for +010" SE pistons but I expect the measrements to be about the same
Was looking to use 010" base gaskets and mill the cylinders to give zero deck height
and use 030" head gasket

I take your point with different thickness head gaskets
I could go 035" on one
Compression would still be the same
Squish ?

[prodrag1320]

with the paper S&S gaskets,i use the O-rings,

[98fxstc]

Thanks Kirby
I'll check them out

[98fxstc]

with the paper S&S gaskets,i use the O-rings,

Had a look at them Kirby
I havnt used S&S gaskets before
I looked at 93-1050-S
graphite 018"
How much do they compress ?
Is 018" thickness before or after ?

Thanks

[HILLSIDECYCLE.COM]

If the dome thickness of the piston allows, it can machined in order to run a conventional gasket/o-ring set-up, and set "O" deck, in one fell swoop.
We use .190" as the threshold number.
Always set piston/cyl wall clearence AFTER any piston machining is established.
Scott

[98fxstc]

Not keen on shaving the top
This is the last one

[HILLSIDECYCLE.COM]

That photo has absolutely nothing to do with piston machining there.
Looks like severe detonation was the cause.
Scott

[prodrag1320]

That photo has absolutely nothing to do with piston machining there.
Looks like severe detonation was the cause.
Scott

I agree

[98fxstc]

Piston was not machined
Just making the point there is not a lot of meat above the top ring at the valve relief
Dont think there was detonation ( could be wrong ) didn't hear anything
bike was on the dyno
But was hot
Wonder if an intake leak caused it to run lean

[sadunbar]

Piston was not machined
Just making the point there is not a lot of meat above the top ring at the valve relief
Dont think there was detonation ( could be wrong ) didn't hear anything
bike was on the dyno
But was hot
Wonder if an intake leak caused it to run lean

Lean can cause heat and burn a piston, or hole a piston, but not cause what your picture shows.  Your picture would indicate detonation occurred...

[98fxstc]

OK
Thanks Scott , Kirby and Scott
Now I know a little bit more about detonation
Time for research   

[HILLSIDECYCLE.COM]

It'll always lift the top of the intake side.
Scott

[HILLSIDECYCLE.COM]

................and chances are VERY good that at LEAST the exhaust valve(if not both valves) is buggered......
Scott