Stupid question but......

[Tim Baillie]

When you paint an engine block, how do you get it to not crack the paint when your torquing down heads and other fasteners?

I have tried different paints etc, sanded everything, primed it........

Seems like something so simple and stupid but I can't be the only one who runs into these issues........

Thanks

[96z28ss]

where are you cracking paint on the engine block, when you tourque down the heads?

[Vegas69]

The only logical explanation is your cracking the paint on the fasteners. If the block is cracking the paint you have a real problem on your hands.

[BritishGreen68]

make sure you use metal etch on the bare metal block before other topcoats. epoxy doesn't adhere all that great to rough cast metal because you cant really sand it properly for a good mechanical adhesion. Or...Tape the top surface of the block off when you paint so its bare metal out to the edge and the head doesn't contact the paint at all, and deal with a little bare metal area around the head, or assemble it unpainted and do a tight mask job on the heads and spray it with them on. or you could set the head on the block unpainted, spray some paint or something around the OD of the head so you have its exact profile on the block deck, and mask on that line and trim it perfectly on the head line so the head wouldn't touch the paint but it would be up to the edge of the head.. you might also have too thick of a paint build up, and it will be prone to cracking no matter what,.. thats all i got lol..

[Tim Baillie]

With the heads painted, when the head bolts are tightened, not even torque is "twists" the paint off and cracks under the bolt. Have had it happen under like alternator bolts, some intake bolts on my TPI and a few other places

It like the bolt is just twisting off the paint under it and it flakes off....really sucks.....

[96z28ss]

okay.
bolt the heads on first and paint everything all at once.
If that isn't an option. Then try puting some lube on the washer, on the bolt face side. That way the bolt wont twist the washer into the paint.

[DocJr]

I'll honestly admit, I never understood the concept of painting engines anyway.

We painted the engine that's in Dad's Olds black (engine paint), and it dulled up in a matter of a month or two.

I never understood how the pros put on a paint job that looks identical to the car's body, and have it last....what do them guys do?? (Besides not drive them) tehehe.

[J2SpeedandCustom]

You need to use a washer under any bolt head that goes on a painted surface. Check out Radrides and Ring Bros sites, they make special washers just for this. :thumbsup:

[mfain]

Should you even have paint between the bolt and the head surface if you want a truly accurate torque number?

[Bow Tie 67]

No there should be no paint. Paint the head with bolts dropped in the holes, and dont over apply.