Putting heads back on a 95 SL. Need a clear, definate answer. .

[R1pilot83]

I sent my heads off two months ago and got them re-done completely. Now the heads have been sitting while I take A LOT of time cleaning the old gasket material off of the block. I have been using a razor blade and it seems to work well, but it is time consuming. The machine shop gave me the heads back with the cams out. He told me to tighten down the heads with the cams out. I asked why and he said that you get a better overall fit when the heads are torqued down with the cams out. Is there any truth to this? I am going to install the heads in a day or two, but want to make sure that I am doing this correctly. The paperwork that I have says to torque them down to 90lbs once. Throughout the forum I read to torque them down to 90lbs once, then back them off. Only to re-torque them back down to 90lbs?????? If anybody can clear this up I would be very happy. This is my first big engine job and I am a little nervous about doing it correctly. I have the skills to do it, the problem is that I keep reading different things. Yesterday I ran a tap through all of the head bolt threads on the block. The block is all taped and cleaned ready for the heads. Sooooooo, install with cams, or without???? Also feel free to provide any tips you may know to save me trouble and time.

[benson8277]

I've never heard of it being better to torque heads down with cams out, if your machinest told you that then he may not be the one u needed to use...

[R1pilot83]

Sorry, it was the mechanic that picked them up for me that said that. Either way, install or not to install is the question.

[RealMcCoy]

You can do it either way.... If the block it still in the car, you may find it easier to get the cam seals and plugs in properly with the heads on the bench.

[Beau_Jester]

Yes re-torque heads.

Install heads and tighten in specified order but do not go directly to 90lbs on each bolt.

One technique is to tighten bolts first at 25lbs, then 50lbs, then 90lbs. Next go back around the bolts one at a time in the specified order and loosen one bolt 1/2 to 3/4 turn or until loose and then re-tighten directly to 90lbs. Do this to each bolt one at a time. This equalizes the stress on the heads and bolts.

Put a little bit of oil on the bolt threads before installing and do not use thread locker.

[speedy25]

I recommend ARP fastener lube over oil.

If there is any doubt about how to torque, use the method in the manual. We know that one works.

CLEAN and gouge free makes the best seal.

Good to read you already cleaned out the block threads. I think many failures are fom skipping that step.

Never heard of installing heads without cams. Never did it that way either but have never had a head gasket fail after I replaced it.

-SP

[R1pilot83]

Thank you for the feedback. I think this guy was just being lazy. Either way I guess I will installing the cams out of the car. I think there is a special lube to use when your dry installing cams? Does anyone know the torque specs for the cam bolts?

[RealMcCoy]

Originally Posted by speedy25

I recommend ARP fastener lube over oil.

If there is any doubt about how to torque, use the method in the manual. We know that one works.

-SP

You realize there is a different torque spec for ARP lube VS. motor oil...?

Back to the OP:

If using the factory procedure including the factory torque spec, I would recommend sticking with motor oil.

lightly lube the threads and the bolt heads where they contact the washers... You don't want to overdue it. Too much oil can hydro-lock the bolts and screw up your torque, as well as contaminate the gasket surface.

As far as the cam lube, I use engine assembly lube (usually Sealed Power 55-400), but motor oil will work...

[Forest Gump]

tool access isn't the best with the cams in anyway.

He may have a point though. By torquing down the cam caps after the heads are installed and torqued the cam alignment may be better.

[R1pilot83]

I though it made sense. I wasnt happy with how clean my block was so I took a scotch bright pad to the block. It seems to take off the rest of the residue and made the block shiny again. Has anybody used this method? I sware I worry myself to death that I am not doing the right thing.