I kinda embarrassed myself with the pics that I posted of my initial clearance testing.. So this morning I'm going to disassemble the cylinders and pistons and clean them up and reassemble.. Wish I had a Trock but then you can't get your valve to valve pocket radius clearance, can you.. So I'll repost later today hopefully.. Thanks for all the help guys, this is the first time I've done this.. Usually when ever I built a motor, I just relied on machine shops advice.. And this time I was told I'd better check it..

 

Quick question while I have this apart.. Should I open the jets for piston oil cooling and if so to what size..I have an S&S oil pump and cam plate so oil pressure shouldn't be an issue.. Thanks..

 

No, never modify the oiling jets. There's a check ball in there that keeps oil from coming out until about 18 PSI. They flow more than enough as is.

 

Another question, I remove O-rings from the cylinder bases and the Cometic are like a quad seal o-ring. Have you ever used them and pros and cons would be appreciated.. I do see that the cases are cleared in the seal areas but was wondering if the quad style seals might be too tall and not squish properly.. I never had any issues with the regular o-ring but these are what came in the Cometic kit.. Also should I put a slight coat of oil on the o-ring on installation.. Thanks..

 

I've not used that style of seal so I can't speak to them. I generally use the OEM gaskets and seals except for MLS head gaskets, those I buy from Cometic.

I run the o-ring through my fingers with a little oil. Just enough so that it has some lubricity.

 

I test fit them and with the cylinder just sitting on the cases in the o-ring in place I have 30,000 clearance so that should compress very nicely.. I like to use train fluid as a lubricant because it's nice and thin...

 

I've not used them. I typically get -155 viton O rings from Mcmaster.

One thing you can try if worried is to slide the cylinder in place, use 2 holded down spacers and tighten the cylinder to the case, It should feel springy then stop when the cylinder touches the case. If it feels smooshy, the seal is holding the cylinder off the case.. Not good..

You could also measure the cross section area of the ring and compare to the measured cross section of the groove. You would like to see the ring have a slightly smaller cross sectional area than the area of the groove. Maybe 5 to 10 percent..

 

Gotcha Max.. The height/width of the seal is .108"/.070 and the machined grove in the case is .080"/.130". So I think there is plenty of squish and room for squish.. thanks..

 

I'm using dusty old memories but I think the square seal is for the 110 cases as they were machined different.

 

Ok, That's good info thank you . I'm sure your not aware but I did go to the 110" kit and that would explain the Cometic 110" top end kit.. Thank you..

Just a note I measured the o-ring for the bases being used for about 4,000 mi it came in at .095".. I should be fine .