Sohc to dohc

[warren]

I have a 7 bolt 4g64 sohc but i was wondering can i do a dohc from a 4g63t .
can i boosylt the motor without blowing up thr tranny?

 

[knochgoon24]

You can put the DOHC head on the 4g64 block.

There are a few oil passages that need blocked with freeze plugs, but it's doable.

 

[cagleje]

Short and simple. Yes and yes. There is work that will need to be done to be done to run the head properly. How you drive is gonna factor the transmission more than how much boost.

 

[bradselph]

I ran 16 psi for 6-8 months on the stock trans and never had a problem.

The stock trans is stronger than you think. I would still be running it if a friend of mine didn't go awd and gave a really good deal on his trans.

 

[mchustle]

Here is a link to a thread I made awhile back when I was thinking about doing it, post #8 has some good info. http://www.dsmtuners.com/forums/cylinder-head-short-block/414030-should-i-4g64-4g63-just-4g63.html

 

[warren]

Short and simple. Yes and yes. There is work that will need to be done to be done to run the head properly. How you drive is gonna factor the transmission more than how much boost.

So your staying in dohc on a oem tranny is better. But if i go dohc with full bolt wont blow my tranny?

 

[bradselph]

depends what one you have?

f5m31 or 33?

 

[warren]

depends what one you have?

f5m31 or 33?

Im not sure its a 98 galant with a 4g64 2.4 . tranny is manuel.

 

[bradselph]

According to google its the same as the spyder trans so it should be a f5m31 trans, It should handle 300ft/lbs of torque but im not gonna guarantee that of course.

So with that i would say yes you can keep the stock trans, swap to dohc, and boost the engine to about 16 psi before the trans may become a issue.

But with boosting a n/t engine without forged internals is gambling all the time.

 

[WES_393]

4g64 DOHC swap.

2G Turbo Head Swap on a 4G64

This site has everything you can think of for the 4g64. ECU swap, turbocharging, etc.

4G64 Performance - Mitsubishi Eclipse Spyder GS

 

[warren]

why you laughing about my tranny
So it will be better to go dohc and full bolt and cams

 

[bradselph]

why you laughing about my tranny
So it will be better to go dohc and full bolt and cams

Depends on what your goals are.

If you want a torquey daily driver then leave it sohc and boost it

 

[GST2012GSX]

You dont need to do the head swap, but is up to You! You will need to block oil passages on the surface block, to be correct there will be 5 that needs to be block. Also You will need the head gasket, timing belt, cam gears from the 94 galant dohc, You can use the cam gears from the 4g63 but You have to advanced both gears. If You stay sohc thats will be cheaper and easier.

 

[WES_393]

Depends on what your goals are.

If you want a torquey daily driver then leave it sohc and boost it

+1 Swapping to DOHC will take away a bit of your low end torque (whihc is where the 4g64 shines). The SOHC is 16 valves anyways so it's not like your completely choking the engine. But SOHC swap will allow you to use all of the 4g63t parts such as intake manifold, exhaust manifold, etc. So it's truly up to you. I plan to DOHC swap my 4g64 Spyder before I boost it that way I can hook up all the 4g63 stock parts.

 

[GST2012GSX]

You are limited on timing belts and head gasket when you do a sohc to dohc, best head gasket will be a cometic. And for the timing belt your best option it will be oem. Im in the same process, one more thing dont forget to put your knock sensor on the 4g64 block.

 

[warren]

So i think im going dohc but do i need a nw fuel pump

 

[bradselph]

No you don't need a new fuel pump for the DOHC swap only if you boost it past 12 psi will you need a new fuel pump.