11 replies to this topic

[Jayz-1]

Does anyone have a 4G92 mivec, 4G93 DOHC, 6A12 Mivec, 6G72 Mivec head apart at the moment that could measure the valve spring for me?
Inner diameter
Outer diameter

I think Im getting valve float and am trying to work out some springs to the pressure I want but need these measurements.
From the workshop manual I know the free height and lbs at seat pressure but just need the actual dimensions and all of my spare parts are in storage

I know the 4G93 springs are shorter but they run the same retainer and spring base (I need to recheck CAPS to confirm but I'm pretty sure I read this ) and have the same seat preasure so I assume they are the same diameters.


Thank you in advance
Jason

[VIN18M]

I have one apart at home, but the springs and retainers are still in. I'll try and give it a measure tomorrow.

[leadfoot]

had i seen this on monday i would have been able to measure my g92 mivec springs od atleast

[evo-gsr]

Shame that he only posted it today hey...would of been hard to see on Monday.

[Jayz-1]

Through googleing, the workshop manual and CAPS I'm under the impression they are the same diameter ID of ~19.7mm and OD of ~27.9mm as an EVO spring.
But now what is confusing is the installed height of the 4G92 mivec springs. Leafoot are you able to measure the installed height of the springs? (Length from spring seat to where the spring sits on the retainer)
I assume yours is a Gen 1 Head?

This would help me out to narrow down a spring without having to pull my car apart.

Thank you
Jason

[Spetz]

I'll be having a 6A12 MIVEC head mostly apart soon enough if you still need those measurements?

Not sure how I'd measure the installed height though, I have vernier calipers but I don't know if they will fit there

[leadfoot]

From my 4g9x manual the value is the same across all 4g9 series motors.

[VIN18M]

Went to measure mine for you today, should have realised how impossible it was going to be with the retainers in. Don't want to pull the head gear apart sorry mate.

Someone must have some 93t springs laying around, all these guys are throwing them away for 63s

[Ian91]

I have a set of the jasma heavy duty valve springs, not installed, I can measure them this week if the uninstalled length helps at all? To suit 93t

[Jayz-1]

That would be good man if you can do that.

The issue I'm having is Mitsubishi list the same part number for the 1.8 4G93 DOHC as the early 4G92 Mivec (it was also superceded to the Gen 2 part number which is different). But then in the workshop manual it shows the free height of 45mm and installed height of 44.5mm for the 4G93 (this can't be right) and the mivec has free length of 51.5mm and installed height of 44.5mm.
I've also found another variation of 4G93 manual that lists the free height of 45mm and installed length of 37.5mm. (This makes more sence especially if people use 4G63 springs)
But I can't work out how there apparently the same part number for the mivec that has a higher free and installed length.

I'm hoping the part number is correct in CAPS and the mivec can share the same as GSR and EVO springs as this will make things easier.

Regards
Jason

[Jayz-1]

Spetz the 6A12 lists the same part number in CAPS and the free length of 51.5mm and installed height of 44.5mm. So would be good if you cold get a measurement. At the moment it doesn't have to be a perfect measurement. Just need to see if the installed height is 44.5mm or 37.5mm. So should be able to get with just a vernier.

Thank you
Jason

[Spetz]

Ok no problem, I should hopefully start pulling it apart this week coming or the weekend and let you know