Will 92-99 3.1LHeads Work on a 2000 3.4L

[SLPGAGT1]

Will the heads from a 3.1L 96 Grand Prix fir on my 3.4L 2000 GrandAmGT?

Will other 3.1L Heads fit on my 3.4L? I guess what I am getting at is a pair of stock 3.1L heads that I want to buy in order to have them Ported, etc.

Which ones will work and which ones won't. Thanks.

[bszopi]

The heads for the 96 3100 (3.1L) will work on the 2000 3400, but the intake valves are smaller (1.72" vs 1.76"). In order to get the larger intake valves, you need to either get heads from a 3400 or a 00+ 3100.

[SLPGAGT1]

Thanks for the Info.

Where can I get the correct valves? Does J-Body Performance have them? How hard are they to replace?

[SLPGAGT1]

Not Thinking

I could just remove the 1.76 valves from my 2000 3.4L heads and put them in the used ported head correct? I have never removed valves before, so other than assuming they s;lide in and out I know nothing about them. Can you tell me how they are removed?

[firechiken]

No. Bigger valves=bigger valve seats.

[SLPGAGT1]

3.1 to 3.4

That sucks. So in order for me to use 3.1 heads on my 3.4 I need new valves, valve seals, need to change the rockers out. I need to match the porting of the 3.1L head to the lower intake manifold of my 3.4L. Christ, I should just look for 3.4 heads! Anything else that I am not considering?

[firechiken]

Or, as stated above, 00+ 3100 heads, if you want the bigger valves. Besides that, they will work.

[Corpse]

The port of the 3100 pre-00 head is only 1mm smaller on the port I believe. Which means it will line up pretty well still. You don't have to change the vlaves out, and also, .04 in valve size is extremely negligible as it will not really make a noticeable difference.

"so other than assuming they s;lide in and out I know nothing about them" - "valves, valve seals, need to change the rockers out" - Ok. The rocker arm is never effected by the valve unless the valve stem face is changed in height (The end of the valve). The Valve stem seals can be reused but, are probably worn a bit, those are the same size between the two head types aswell.

The only actual valve difference you are looking at is, the size of the valve and the valve seat. While you can swap the valves, it would be useless and, would require the seats to be machined a little for proper fitment, although, it is very close as-is. Any-time you change a valve though, it needs to be lapped to the seat and such.

So, changing valves would require you to have a valve job done. Along with possibly needing to change seats.

If you do not mess with the vavles and keep the ones in the head, you will only have to worry about the 1MM gap in ports, whereas, you said the heads would be ported anyhow. So, realistically, that is unimportant. The only real factor at hand is a 1.72" vs. 1.76" Valve. But, 4/100th's of an inch isn't going to be something you will even be able to see with your eye very well.

What I am saying is, figure that the valves are the same size, they aren't much larger at all.

I would go the 3x00 head route..

-Dave

[ikessky]

Re: 3.1 to 3.4

I should just look for 3.4 heads!

That was my first thought..........

[SLPGAGT1]

3400 Heads

I decided to go with a used pair of 1999 Alero heads and then have them machined the way I want them. Thanks for all of your input, I learned a lot!

[SLPGAGT1]

99' Alero Heads

So on Saturday I bought a pair of heads from a 1999 Alero and I have a question. There is one valve (Exhaust) #1 cylinder position that is not closed all the way. It is not seated correctly along the edge like the other valves. It may be bent. I just want to know if one of them is supposed to be like that or what. All the valves are closed tight except one. I was thinking maybe it is supposed to slightly open for startup, or it's bent. What do you guys think?

[bszopi]

They should all be closed.

[SLPGAGT1]

Need One Valve

Thanks Brad. So where is a good source for (1) Exhaust valve? J-Body Performance sells them for the 2.8 and 3.1 and I emailed them about a 1.76 3.4 Valve. Anybody else I could ask?

[bszopi]

I'm sure someone around here has one... The exhaust valves stayed the same size in all the 3x00 heads, so it should be pretty easy to find one.

[SLPGAGT1]

Bent Valve

How does a valve get bent anyway? The valve springs are all in place, so the valve itself would be hard to damage in this state. Must have been while the heads were still in use. What might cause this? Is it common?

Also, do you recommend posting a wanted thread for the valve?