Board question/advice…
 

I have an IA2 and will require a deck clean up that will likely put my piston up to +.010 out-of-the-hole.

My current piston is a Ross with a 2cc dome. Piston to cylinder wall is the nominal suggested spec of .005 (validated by my machinist).

Bore size is 4.310.

I have (3) Cometic 4.350 MLS gaskets that are .040 compressed thickness. They are all identical and brand new.

My question is this:

Can I remove the rivets from the (3) gaskets I have and use the third (extra) gasket to add a layer or two to the other (2) gaskets that will be used - to add compressed thickness - giving me another +.010 for a total of .050 or thereabouts?

Scat 6.8 steel rod.

My machinist is advising having a deck steel shim built (another $200-$250) that would work with my existing gaskets.

Does my question make sense? Thoughts?

Cometic can make you a gasket any thickness you need and that’s the way to go.

Why is this the case that the block needs to be cut .010”, as that’s a lot to need to get taken off it would seem?

is your current piston set as run out of the hole .005”

Purchased used. Has a deck issue.

Zero deck currently, max clean up would be .010 and a WORST case scenario.

I know Cometic can build any gasket I need.

Was just asking the board…

I had pistons rods and crank for an MR1 that had issues so put it all in an IA2 and was 0.010 out. Got Cometic 0.050 head gaskets.
Had to do the same when the machine shop that supposedly mocked up my 409 decked it but they were 0.010 out.

Thank you for the replies so far.

If your machinist has a piston vise, and I bet he does. You can just take the desired amount off each piston head. That's a pretty quick and easy operation with a good piston vise.

Just wondering, all these "fixes", why not just by a gasket that's thicker? .060 or so and sell the .040 gaskets you have? Are your .040 gaskets new in the box?

Yes, NIB.

Added the extra cooling hole (known best as ‘421’ hole) in the gaskets with a 1/4 bit to match block.

I guess I could sell them.

Thank you.

Wouldn’t I have to rebalance my rotating assembly? Purchased everything as a complete motor.

I did that with a set of cometics, Haven't fired the motor yet will let you know.
I don't see any problem though

Thank you Blueghoast.

Bought .080" Cometics for the ability to select the desired stack. Well, sold em before using em.

Yes, replacement gaskets would be a easy fix for this situation. only suggesting another option because the OP already has a set of what I assume are custom Cometic gaskets that probably cost over $300.00 a pair. And he modified them so they won't exchange them.

Yes. the balance would be effected, slightly, based on the piston head configuration. Probably 2-5 grams. That is within the tolerance range of most balance jobs unless the shop has a really accurate, newer machine. Our Sunnen balancer can balance a crank +- 3 grams. That's the best it can do.

Thank you for the replies/advice folks.

I would get the correct gaskets and sell the ones you have. I normally get 4 gaskets at a time so I have a second set and avoid price increases also double shipping later on