More timing cover info 3.1-2.8

[trotterlg]

This 3.1 Aluminum head conversion to the 2.8 iron head front timing cover and water pump is being amazingly painful. Even though the holes for the timing cover line up between the S-10 type cover and the modern type cover with the high water pump, it is not a direct swap out. Seems the holes on the left side (three of them) are M-12's on the new engine while they were M-8 and M-10's on the older engines. Not a show stopper, but the covers will not directly swap. My solution was to drill the mount holes out to 1/2 inch, this left enough sealing thickness and aluminum around the hole for a good mount, however I think if I did it again I would make up some studs with a M-12 thred into the block and a reduced shank of like 3/8 to hold down the pump and cover. The cover/pump assembly ends up with M-6, M-8, M-10 and M-12 bolts in it. Because of the thread pitch differences, the torque applied to the bolts are 35 ft pounds, 25 foot pounds, 16 foot pounds and 7 1/2 foot pounds, lots of socket swaping. Guess no one said this would be easy. All this to get a low alternator mount and be rid of ideler pulleys to fit in a Fiero. Larry

[Superdave]

same as i did.. just drilled the 3 holes out to 1/2" and they've been fine since... 2.8 RWD cover on a 3500.

[trotterlg]

Then confidence is high! I have Feldpro gaskets, punched the holes out to clear the bolts, what type of gasket cement did you use? Larry

[CNCguy]

We have had good luck using M12 to M8 threaded inserts from McMaster. This leaves plenty of stock and gasket around the holes. And you won't have to drill the holes out on a replacement water pump should you need to change it.

In the front cover, did you plug the unused hole just below the left coolant port?

[trotterlg]

I do have an unused (M6) hole but it does not go through. If it did it would enter the timing chain cover. Is that the one you are talking about? I do have some spare bolts I could put in it. Larry

[CNCguy]

Larry... it's a coolant hole that is used on RWD block but missing on the FWD blocks. If you don't plug it, your coolant will pour out. See picture below.

[trotterlg]

You saved me great pain and suffering! Should I just put an expansion (freeze) plug in it? Larry

[trotterlg]

And why do you cut the top ear off? Larry

[CNCguy]

An expansion plug would probably work fine. I usually weld a plug in the hole.

Cutting the top ear off will let you rotate the lower intake 180 degrees so the T-stat is in the front for RWD applications.

[trotterlg]

I may do that, it is going into a Fiero, so it would work either way, but the stock engine has the water in and out on the same end, so this is probalby better to swap it. Larry