hey guys

does anyone have a 6G74 head lying around their garage? I need the fitted height of the valve spring as i want to replace the ones i have in my heads. i would measure them myself but i have already sent the heads away for a service and port job so i can't do it.

if anyone can help it would be really appreciated

cheers guys

When replacing valve springs you are interested in length of uninstalled (free) spring.
Anyway this info is from Gregory's :
Free length - standard: 51.0 mm
Limit: 50.0 mm
Maximum out of square: 4 degrees
Installed height: 44.2 mm

do you happen to have the max OD and ID in the manual?

Sorry, there is no info about diameter of the spring or diameter of the spring wire.
Ring the Mitsubishi Parts&Service around where you live and I believe they will tell you :)

thanks for your help. That info was enough for the guy to get the ball rolling. Just another part knocked out of the way :D

hey guys

does anyone have a 6G74 head lying around their garage? I need the fitted height of the valve spring as i want to replace the ones i have in my heads. i would measure them myself but i have already sent the heads away for a service and port job so i can't do it.

if anyone can help it would be really appreciated

cheers guys

are you changing the cam grind for 10.5 psi

are you changing the cam grind for 10.5 psi
nup, thats just another 1000 bucks i dont want to spend and doubt the gains would be justified. would rather spend the 1000-1200 on water/meth injection to get more power, and safe power

How aggressive will the porting be?

bahh 1k

i was talking to a cyl head guy here in vic builds heaps of HUGE HP heads he said he can re do my cams for under $400 and will garauntee them not to break/suff up

the place he was refering me to has a new 1million dollar machine that does just that, more metal is added to the cam then its re profiled and the surface hardened etc....

just do it! if the heads are off y not get 100% from it not 90%

How aggressive will the porting be?
as much as they think is enough. they have my intake manifold as well to match it all together


bahh 1k

i was talking to a cyl head guy here in vic builds heaps of HUGE HP heads he said he can re do my cams for under $400 and will garauntee them not to break/suff up

the place he was refering me to has a new 1million dollar machine that does just that, more metal is added to the cam then its re profiled and the surface hardened etc....

just do it! if the heads are off y not get 100% from it not 90%
ohh shoosh you!

your heads are off......

it must be very tempting to take the sump off and start on that end.

what are you doin Jase?
I have a 3.5 stripped in garage if you want any dimensions or pics!!!:D

what are you doin Jase?
I have a 3.5 stripped in garage if you want any dimensions or pics!!!:D
cheers chris but i have all the info i need now so its all good.

the guy at a place im dealing with said a set of RB25 or XR6 valve springs (well their specs at least) will do the job, just have to get some shims made to get the right height. Now i dont know a lot in this department but is that a good or bad idea?

It'll have a lot to do with seated pressures and open pressures of your springs. The Ralliart runs dual springs from the factory, due to the higher lift cam, so it's a good indicator that the head can physically handle the spring pressures.

I'd say that they'll shim between the spring seat and the spring, to keep the retainer in the right place up top, but since you're sticking with the original cam there'd be no need to increase the pressure.

Why does the mechanic want to use different springs?

It'll have a lot to do with seated pressures and open pressures of your springs. The Ralliart runs dual springs from the factory, due to the higher lift cam, so it's a good indicator that the head can physically handle the spring pressures.



Just some information for you, the ralliart magna did not run double valve springs from factory. They used a stiffer single spring with a single shim fitted between the spring and the spring seat in the head.

The ralliart valve springs had approximately 15lbs more seat pressure than the stock 3.5L valve springs (for a total seat pressure of around 95-100lbs) . The ralliart cams only had 1.1mm more lift than the stock 3.5 cams and as such did not need extremely heavy valve springs.

your heads are off......

it must be very tempting to take the sump off and start on that end.


he did that too..:P

Just some information for you, the ralliart magna did not run double valve springs from factory. They used a stiffer single spring with a single shim fitted between the spring and the spring seat in the head.

The ralliart valve springs had approximately 15lbs more seat pressure than the stock 3.5L valve springs (for a total seat pressure of around 95-100lbs) . The ralliart cams only had 1.1mm more lift than the stock 3.5 cams and as such did not need extremely heavy valve springs.

My mistake. I've heard from a few people that they did, but researching proves you right. Sorry mate.