Engine Rebuild Specs

[48Chrashler]

Just got the call from the shop rebuilding my 25 inch block flatty. They need to go 40 over on the cylinders and said the rod/main are 10/10. They questioned the head milling dimension. They need seats for exhaust valves and 2 sleeves.

I recall and have read I can go 60 over with a new set of pistons/rings and the head can go to .0072 (per George Ashe) although others have gone to .0050.

He also asked about getting a harmonic balancer.

Does all this sound like I am on the right track? Any other suggestions??

Thanks...JC (learning new things every day!)

[daddyo23]

Just got my 218 back. They went .060 over and took off .050 between the block and head. He double-checked for clearance and it spec'd o.k.

[greg g]

I would also recommed splitting the difference on the head and block. I beleive I went .010, and .040 for the .050 total (larger off the head) The extra compression really helps. Usually the piston size is related to getting rid of the tapered wear in the cylinders, 40 sounds reasonable unles you are building a hot rod motor.

As far as the vibration damper, was your not equiped with one or is it delaminating??? If coming apart check the Damper Doctor site. they do repairs on dampers and may have rebuild old ones available.

[daddyo23]

I would also recommed splitting the difference on the head and block. I beleive I went .010, and .040 for the .050 total (larger off the head) The extra compression really helps. Usually the piston size is related to getting rid of the tapered wear in the cylinders, 40 sounds reasonable unles you are building a hot rod motor.

As far as the vibration damper, was your not equiped with one or is it delaminating??? If coming apart check the Damper Doctor site. they do repairs on dampers and may have rebuild old ones available.

That's what they did with mine. Bit more off the head. Just got it back together. Hopefully, I'll be able to get pics up soon. Wayne P.

[Joe Flanagan]

My machinist took .060 off the cylinder walls. I believe that's the max.

[martybose]

My machinist took .060 off the cylinder walls. I believe that's the max.

Not necessarily. My 230 block was a worn out .060" over when we took it apart. We took ultrasonic readings of all of the cylinders at 12 points per cylinder, and found good thickness, so we wound up boring it .072" over (after we found a Toyota metric ring set the right size). I had Venolia make me a set of custom pistons for the metric ring set.

Marty

[Don Coatney]

They need seats for exhaust valves and 2 sleeves.

..JC (learning new things every day!)

Are you talking cylinder sleeves?

[Fluid drive]

You guys probably already know that it is a very good idea to install hardened washers under those cylinder head nuts or capscrews. I usually buy at least grade 8 washers the O.D. of the head pad, and chuck them in the lathe to bore the I.D. the slight amount required to be a free fit on the capscrews/studs. If you do not use washers you can really wind up with a false torque reading and head gasket failure. Take it from a student of the university of the thin , flat head!

[Don Coatney]

You guys probably already know that it is a very good idea to install hardened washers under those cylinder head nuts or capscrews. I usually buy at least grade 8 washers the O.D. of the head pad, and chuck them in the lathe to bore the I.D. the slight amount required to be a free fit on the capscrews/studs. If you do not use washers you can really wind up with a false torque reading and head gasket failure. Take it from a student of the university of the thin , flat head!

I disagree. The factory did not use washers. They are not required.

[grey beard]

Don,

Factory wasn't dealing with the larger bore, higher compression, thinner cylinder heads of a well blueprinted engine. Besides, the facrory couldn't decide whether they wanted to use studs and nuts or bolts - I've seen both methods of fastening on many engines and you have, too. Besides, hardened flat washers can't HURT anything, now can they?

[Don Coatney]

Don,

Factory wasn't dealing with the larger bore, higher compression, thinner cylinder heads of a well blueprinted engine. Besides, the facrory couldn't decide whether they wanted to use studs and nuts or bolts - I've seen both methods of fastening on many engines and you have, too. Besides, hardened flat washers can't HURT anything, now can they?

Dave;

One of the reasons I elected to not use washers on my head replacement was the advice you gave me on 9-9-2007. Follow this link.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=5328&highlight=washers

[James_Douglas]

I used ARP studs, hardened washers, and nuts. I also used their thread lube on the tops of the studs and nuts.

They specify washers and lube in their literature. I used their Teflon thread sealant on the bottom of the studs and water crept up the studs to the top of the threads. I used the thick Teflon tape and it stopped.

James

[Frank Elder]

Plumbers tape, same as you would use on LP or N gas, seals a lot better than the std teflon.

[Don Coatney]

Plumbers tape, same as you would use on LP or N gas, seals a lot better than the std teflon.

Plumbers tape is steel tape with holes in it used to hang pipe. Teflon tape is a thread sealent. Google it.

[martybose]

I also originally used teflon tape on my ARP studs, and they leaked. Someone else here had mentioned Permatex aviation form-a-gasket liquid sealant, which I found on the shelf at the local auto parts store. It's a dark brown liquid, and sealed everything perfectly this time.

I also converted the waterpump to studs, and sealed them with this stuff as well. So far so good!

Marty