853 Head gasket ? - Ducati.ms

sb748 · Feb 4th, 2012, 8:13 am

About to do an 853 kit on my 748, trying to assemble what I need, question is what do I use for the head gasket, since stock 748 will be to small? 916 or 888? Thanks Fran

CrimsonCloak · Feb 4th, 2012, 8:30 am

916. All the gaskets supercede to a laminated steel from Ducati. So if your 748 has the thicker fiber gaskets like some early models did you may have to get creative in order to end up with proper squish values. Make sure you get the squish right because it was oftwn too great from the factory. Some were off enough that correcting it would get you several hp itself. The other good reason to measure squish is so your pistons dont hit your valves, which is a pretty good motivation too.

sb748 · Feb 4th, 2012, 8:35 am

Its a 2002 so I may be in good shape, thanks for the informative answer. Fran

Austin748 · Feb 4th, 2012, 8:44 am

Just went through this myself...

Search for 94mm head gaskets

Short version is order ST4 (916cc so 94mm) head gaskets part# 78610543A, $66 @ Ducati Omaha.
Or call Cometic Gasket Inc. Cometic (440) 354-0777. They don't list them on their website (or didn't when I looked), but they should be able to supply them if you call.

My 748 is in the midst of an 853 giddy-up as we speak!!

sb748 · Feb 4th, 2012, 9:04 am

Thanks for all your hard work Austin, made it easy for me, appreciate it. Fran

DUC1198S · Feb 4th, 2012, 2:20 pm

I put an 853 kit in my 748. It was a great mod. I did wreck one head gasket in it right after I had the kit put in. I had that fixed and the bike never gave me any more trouble after that. You'll like it when it's done. Enjoy it!

Bat Fink · Feb 5th, 2012, 4:30 am

Quote:

Originally Posted by CrimsonCloak

916. All the gaskets supercede to a laminated steel from Ducati. So if your 748 has the thicker fiber gaskets like some early models did you may have to get creative in order to end up with proper squish values. Make sure you get the squish right because it was oftwn too great from the factory. Some were off enough that correcting it would get you several hp itself. The other good reason to measure squish is so your pistons dont hit your valves, which is a pretty good motivation too.

+1 on checking the squish. When I did my conversion (2002 engine, ST4 cylinders, DP pistons) I measured the squish and the gap was so big it didn't even squash the solder. IIRC I had to remove about 1.2mm from the base of each cylinder to set the squish at 1mm.

Whilst your at it I would check the valve timing, mine had never been touched and was a country mile out on the horizontal cylinder.

Booster · Feb 5th, 2012, 4:32 pm

We just did a refresh on a early 853 and it had the old fiber head gaskets. We added base gaskets to make up the difference from the new thinner head gaskets.
++1 for degreeing the cams.

Austin748 · Feb 5th, 2012, 8:23 pm

+ another 1 for degreeing the cams. Just checked the stock timing of my 748 before ripping it apart and found the the vertical intake at 123 degrees. Bikeboy's chart here has stock set at 119.5 (still very high! I'm after 108 centers for mine.) I checked at 1.0 mm and 1.4 mm lift and was within 0.5 degrees.
Do not rely on factory timing!!! Haven't set squish yet, but I do not rely on factory settings for those either!!!