3.1 head spacer

[geoffinbc]

They may look bronze in colour but it is most likely oil staining. All the aluminum heads used iron guides.

[walterdude]

Those guides look like steel. Bronze is golden in color,,, a little darker than brass..
Also X2 on the "bronze is not magnetic...
Hope this helps,,
Tom...

[pocket-rocket]

Bronze is not magnetic.

[fastback4]

He said guides. I'll ask again today when i pick the heads up. I'll take some pics of what he shows me to be bronze.....Tom
P/S going to the scrape yard to look at 2 3.4 engines out of the car. Does not know what they came out of. Where are the numbers to check for engine size accuracy and year of engines.

I picked up the heads from the shop and asked the owner " Where are the bronze guides you told me where uncommon to see as in never before seen by your shop of 40 years. He showed me and i took some pics of what he pointed to. My magnet stuck to them like glue. Is bronze magnetic?...Was i wearing my " I'll believe anything" t-shirt today?........Tom

[fastback4]

guides or guide liners?

He said guides. I'll ask again today when i pick the heads up. I'll take some pics of what he shows me to be bronze.....Tom
P/S going to the scrape yard to look at 2 3.4 engines out of the car. Does not know what they came out of. Where are the numbers to check for engine size accuracy and year of engines.

[pocket-rocket]

GM would at times install bronze guides to "save" a head rather than scrap it.

It's also why there were .005 overbored engines with pistons you can't buy.

Chrysler was famous for that on 340's and Hemi's.

Usually late in a production run to get stuff out the door.

The engine out of my wifes Daewoo has oversized rod journals from the factory. DOHC 2.2l built by GM.

[SappySE107]

guides or guide liners?

[asylummotorsports]

GM would at times install bronze guides to "save" a head rather than scrap it.

It's also why there were .005 overbored engines with pistons you can't buy.

Chrysler was famous for that on 340's and Hemi's.

Usually late in a production run to get stuff out the door.

[fastback4]

If you mean pics of the heads valve guides, sure....as soon as i go get the heads back from the shop.....

[SappySE107]

Can you get some pics?

[fastback4]

3.1 head shim

Check this out. The owner of this machine shop (40 years experience) also told me my head had been worked on before because i have bronze valve guides. Says he's never seen bronze used before in the 90's 3.1/3.4 GM. Problem is i told him this car was bought new by me in 1997 and had 3 miles when purchased and never out of my sight. So he say's, "Well then it's a test car!!! HuH!

[fastback4]

Shorter is right..not longer

Longer pushrods for milling heads? Maybe shorter, but not likely. They do not make head spacers but they do make rocker arm shims to lift them up .010 or .020".

Shorter is right..not longer

[Superdave]

so you are looking at a max of .017" milled then?

People have been running .020 thinner gaskets on gen2 3.1's forever without issues. I doubt you'll have any. Your compression will be higher of course so you may gain a little power.

[geoffinbc]

Thats a lot of milling for stock aluminum heads. Some shops have machines to twist aluminum heads back into shape or at least get them within .005" and then you can mill them. I would just get some used heads that are not warped and rebuild them.

[pocket-rocket]

97 3100.

http://60degreev6.com/forum/f97/1997...results-t45929