Cylinder/head assembly question.

[edfmaniac]

I have a question that I'd like to see if I can get answered before planning the next stage of my engine work. The 102mm cylinder that I purchased for my Skorpion project came ready to bolt in or so I thought. When checking the top of the cylinder with a straight edge I noticed that the steel sleeve is as much as .0025" or .063mm higher than the surrounding aluminum surface. Is the gasket designed to make up for that difference or do I need to be closer to dead flat?

Thanks,
Victor

[edfmaniac]

After finding a post on a Saturn website, it sounds like you want the sleeve to be even with or slightly higher than deck height to ensure that it is firmly captured. But the spec was in dispute. They couldn't decide if .005" or .0005" was the maximum allowed. The last thing you want to do is to machine or sand the flange on the sleeve down to near zero only to find out that the sleeve isn't pressed in all of the way. Granted, they are talking about a completely different engine. Any thoughts?

[Bill Jurgenson]

It should be even. 6/100mm isn't much. Take a fine emery cloth (280 or so) on a flat surface such as machine table. slide the head back and forth two or three times and check if the score marks are evenly visible all around. If not repeat after rotating 45°. that way the new scores can be distunguished from the previous. Repeat until the the surface is evenly ground. A good head gasket (e. g. Cometic) can easily manage the 6/100mm. Even a copper gasket can, tho I do not recommend those for hobby mechanics.

[edfmaniac]

Thank you sir. I will be using the gaskets that came with my Weisco piston. I thought that they were Cometic but I didn't see anything other than the Weisco name on the package.

[Bill Jurgenson]

they are (or at least used to be) Cometic.

[samandkimberly]

I think Bill is referring to the head and you are referring to the cylinder. Yes, the head should be flat, but having a sleeve that's sticking out by a couple of thou should be fine, in fact it may be like that to ensure a better seal right by the combustion chamber - not at all uncommon practice.

Wouldn't hurt, though, to bring it up with the person who installed the sleeve, if possible.

Sam

[edfmaniac]

I'll check the head when I pull it to make sure it is still flat and I think that the triple layer stamped steel head gasket should make up for that 25 ten thousandths after reading some more. I had no idea that the gasket was triple thick until I pulled it out of the bag.

The vendor that I bought the cylinder from was an ebay seller that evidently sells these in mass. I'm sure it's within spec judging from the opinions here and elsewhere.

[Bill Jurgenson]

no I was referring to the cylinder. Of course you can check a head that way, too.

[DAVID THOMPSON]

not every thing is made in china

that gasket maker Cometic.is located about 100miles north of my home
so in the future if we have trouble finding gasket s
i can ride up and see them in person
dave

but due to the number of raptors made
it may b a while