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skyy406
05-11-2010, 07:20 PM
Hi all

I have a 2004 Galant 3.8 that I am swapping into my Avenger. Picked up a pair of MIVEC heads for $250 because one has 2 bent valves.

I need to know if the internals are identical between the 3.8 from the Galant and the 3.8 MIVEC motor.

Are the heads physically the same size as the NON-Mivec heads?
SPD_FRK
05-11-2010, 07:25 PM
Everything is the same. Though I would suggest ditching the MIVEC and use the Non-Mivec heads. Why? Because there are no aftermarket cams out there for the MIVEC heads. RPW was going to make them but the price and market just would't have played in their favor.

Best bet is to swap in a set of 262s, or 272s from RPW on the Non-MIVEC Heads. You will find them listed under the 6g75, otherwise even a set for the 6g72/74 will work as well
skyy406
05-11-2010, 07:43 PM
I am not sure i'll even go with cams though. I want the extra 30hp the Mivec heads deliver. I will then have them ported and polished.
beam514
05-11-2010, 07:58 PM
How do you plan on using the MIVEC?
skyy406
05-11-2010, 08:04 PM
Megasquirt II
SPD_FRK
05-11-2010, 08:08 PM
I guess if you don't want any other cams then the MIVEC would work for you. The MIVEC is good as long as you control it. A lot of people have messed with the "activation" point of the MIVEC and found the factory set it up right the first time at around 4k rpms.
skyy406
05-11-2010, 08:10 PM
I guess if you don't want any other cams then the MIVEC would work for you. The MIVEC is good as long as you control it. A lot of people have messed with the "activation" point of the MIVEC and found the factory set it up right the first time at around 4k rpms.

yeah I have read that. I think with porting the mivec heads- a good free flowing exhaust- possibly a larger plenum and TB- i'll be happy. :dunno:
Boosted
05-11-2010, 10:33 PM
You could get cams specially produced if you can find a company that would be fine with doing a single order. Most would rather make a batch of these items then just a set for one car.
skyy406
05-12-2010, 10:12 AM
Is the lower intake manifold the same on the 3.8 galant V6 and the MIVEC eclipse 3.8??
SPD_FRK
05-12-2010, 07:33 PM
Ports are larger on the MIVEC heads, thus the lower manifold ports are also
skyy406
05-12-2010, 10:58 PM
Ports are larger on the MIVEC heads, thus the lower manifold ports are also

Ok so is the 3.8L galant lower intake manifold the same as the eclipse 3.8L one but with only larger ports?

Reason i'm asking is because i am going to have both intakes ported while dennis is doing the valve job and port/polish. I don't want to send him a lower intake manifold that is not going to work with these heads.
SPD_FRK
05-12-2010, 11:03 PM
Ok so is the 3.8L galant lower intake manifold the same as the eclipse 3.8L one but with only larger ports?

Reason i'm asking is because i am going to have both intakes ported while dennis is doing the valve job and port/polish. I don't want to send him a lower intake manifold that is not going to work with these heads.


That is correct. Either one will work, and if you are having PnP work done he can certainly port the non-mivec lower to match up