Getting ready to pull the top end and freshen it up. 96k miles and hearing some piston slap when cold. The plan is to go back with 8.5:1 pistons at .010" over. My question is which top end gaskets to get? Mainly what type of head gaskets and how thick? MLS, teflon, carbon? .030", .040" or .045"?

 

I went with Cometic.

 

I use Cometic's on my Kaw builds. Good gaskets. If I go with the .030" kit, anyone know how much of a CR bump I'll get? Not sure what the stock thickness is.

 

the difference is almost .2 on the 8.5 so maybe 8.7 .042 verses .030 but it depends on deck height and you being stock that is about right with out a cam like EV 27 it causes more strain on the battery and starter


we only use cometic MLS today even if a customer brings us gaskets we throw them away - if you plan on removing the paper ones yourself you will see why we do that -- johnjzjz

 

It has an EV13 in it now.

 

Stock is about .045
Like john said going to a .030 will only bump your cr up about .2, no big deal, but every little bit helps w/ the weenie stock compression. Although your not losing much, if any compression with that EV13.
Cometic MLS is the way to go as far as brand.

 

I just measured the old gaskets that came off my '97 softail and they are .050.
If your deck height is zero or in the hole, which it probably is, you can go with the .030.

 

I used HD head gaskets. Actually, I used HD for everything but the base gasket which was Genuine James.

 

a point of info - short duration cams trap static compression better than long duration cams do - that is the compression that the engine actually compresses after the intake valve closes

lots of other info is also at work but that is the idea - So an EV 3 has more low speed grunt than the 27 but it runs out of breath earlyer in the PRMs - and the 27 make more power higher in the revs < all it really is is an air pump the more you take in the more you get valve opening and length of time open determins how much power