6g75 Dohc?

[GTOJOE]

Just wondering if it exists... I think there was a DOHC MIVEC version.. but is there a non mivec 6G75 DOHC? Or do I need to be looking at the 6G74 DOHC?
Looking at a possible GTO engine upgrade. Maybe rebuild and drop in when complete. Not sure about the strength factors though.

Micheal - You looked at these options... any suggestions?

[inperfectdarkness]

you need to search 3.5L upgrades. save yourself the ass-pain & go with a 6g72 or a 6g74.

there is no such thing as DOHC 6g75, there probably never will be. there will probably never be another non-mivec 6g7x performance engine.

[MichaelMR2]

Originally Posted by inperfectdarkness

you need to search 3.5L upgrades. save yourself the ass-pain & go with a 6g72 or a 6g74.

there is no such thing as DOHC 6g75, there probably never will be. there will probably never be another non-mivec 6g7x performance engine.

half and half...

correct, the 6g75 has a single cam shaft, and this is the only variant it came in, it does still have 4 valves per cylinder however so it's as good as you get.

the 6g75 MIVEC heads will fit on a 6g74 block...give or take a little adjustment

the 75' block is also missing some mount points...

the 74 block IS the way to go...you just need to chose to stuck with the standard crank, or go with a 75 crank and a little overbore to get you up to 3.7L

[inperfectdarkness]

i've yet to hear anyone running mivec heads on a 74/72 block & actually making good boost out of it. yet.

[MichaelMR2]

that's true, but there are 3 people at last check going this direction as we speak, I know of quite a few more that will be there in a few more months.

I'll be another 3-6 months before I start buying the parts for my build.

Good stuff:

MIVEC Build
a 6G75 present for you (ras463us)lol
6G74 performance
MIVEC 6G75 teardown...lots of pics

[GTOJOE]

Originally Posted by inperfectdarkness

you need to search 3.5L upgrades. save yourself the ass-pain & go with a 6g72 or a 6g74.

there is no such thing as DOHC 6g75, there probably never will be. there will probably never be another non-mivec 6g7x performance engine.

Sounds expensive. How strong is the standard 6G74 crank? is it really worth the effort to use the 6G75 one?

[MichaelMR2]

standard 6g74 crank is great, very strong...the journals are wider so you have more surface area if you get me...the 6g75 crank is cool as it's a very cheap drop in upgrade, and it gives you more stroke so you have a considerably larger capacity engine from it, warning on this...alot of australian cranks seem to die so I'm a little concerned purchasing an aussie one. My general plan is buy a whole eclipse motor and ship it over, that way I can swap parts at my leasure etc.

you have spent some time on John's site right?

Monnin Engineering at WrenchMonkey.com


he is the pioneer for alot of this stuf

[GTOJOE]

Originally Posted by MichaelMR2

standard 6g74 crank is great, very strong...the journals are wider so you have more surface area if you get me...the 6g75 crank is cool as it's a very cheap drop in upgrade, and it gives you more stroke so you have a considerably larger capacity engine from it, warning on this...alot of australian cranks seem to die so I'm a little concerned purchasing an aussie one. My general plan is buy a whole eclipse motor and ship it over, that way I can swap parts at my leasure etc.

you have spent some time on John's site right?

Monnin Engineering at WrenchMonkey.com


he is the pioneer for alot of this stuff

I believe I have stumbled across the site some time ago but never read the section regarding the 6G74 conversion. After reading it maybe it's too much work. I'm not after crazy power and this would only be cheap if you have the right place and equipment to work on it yourself. Which I have neither of. I can't believe your working on yours in such tight conditions. Also the inability to fit a strut brace is an issue. I would really like to stiffen up the whole body. Was even looking at a middle strut brace. Front middle and rear. Not sure how legal the middle one is though.
I might purchase a cheap 6G72 and slowly rebuild it. Maybe just forged internals and strengthened crank.
Do you know if the Eclipse engine will fit? or you have to modify everything John did?

[MichaelMR2]

eclipse(75') engine is much worse, all sorts of crap does not even remotely fit, only usefullness is bolting some of it's crap on the 74 block. Unless you want more than 600hp at the wheels honestly, your best sticking with the tried and true 72'

[inperfectdarkness]

you can get 600hp to the wheels--ON PUMP GAS--WITH A 6G72.

ray is the MAN!