I dug this up from another forum he posted it on, hope you enjoy.




ere's a rundown on what's required and what it all costs (roughly as I scored some stuff REALLY cheap)

This conversion is possible with ANY second generation Magna that had the SOHC 12v 6G72 3.0l V6 from the factory.

The motor, DOHC 24v 6G72 (from now on will just be referred to as DOHC) shares the same block as the SOHC 12v 6G72 (referred to as SOHC from now on). The starter motor and gearbox bolt onto the DOHC block from the SOHC. So you owners of 5 speed manual V6's can have a manual DOHC.

http://home.swiftdsl.com.au/~monstr/monstr/images/conversion/sohcin.jpg
http://home.swiftdsl.com.au/~monstr/monstr/images/conversion/dohcleft.jpg

Now, as far as fitment is concerned, the N/A DOHC is a direct bolt in proposition. The 5 speed manual (or the auto - why you would is beyond me however!) bolts onto the block with no modifications required. The block is the same (however I believe the holes for the heads may be different, not 100% sure on that).

You can use the SOHC flywheel and clutch if you've gotten an auto diamante front cut/motor.

A DOHC 6G72 24v 3.0l V6 N/A will set you back about $1200-$1600 depending on condition. You would be FAR better off getting a front cut off a N/A GTO/3000GT which will be about $2000-$3000 that way you have all the wiring and everything you'll need. I scored mine for $650, pure luck lol

Things that need to be made up/replaced:

Power steering hoses - The power steering pump is located at the back of the motor instead of the top like the SOHC. These cost me nothing as my dad works in hydraulics and could make them up. He told me that it'd be about $70-80 to have them made up. Though, the actual 3000gt ones could be available from Auto One or something for less.

Air con hoses - The a/c compressor is in the same area as the SOHC but the pipes attach on differently. You'll need to get the new hoses made up and then the a/c rebuilt and re-gassed. We all know that is expensive lol, I'm guessing about $800...but feel free to correct if anyone knows different

ECU/Wiring loom - I used the factory wiring loom and ECU from a US 1994 LS Diamante, the loom was then spliced into the original TR loom and plugs were swapped as necessary. The traction control was wired out as well as any unnecessary ancillaries. This cost me $827 if I remember rightly. If you have a front cut then you don't have to worry about this.

The ECU/wiring loom is what cause a major headache for me. Here's why:

There are two generations of DOHC in both turbo and N/A form. From 1990-1993 is the first generation and 94+ is the second. In N/A form the 90-93 had 202hp, 94+ had 220. I'm pretty sure the difference was just from ECU work. AFAIK the cam profiles and physical specifications of the two generations are exactly the same.

Now, the wiring loom from the Diamante is designed to have the ECU in a different spot to the TR/TS Magna (cant remember exactly but I think it's in the passenger side of the D's, our driver's side). Now this meant that some wires were too short, too long etc. And finding someone to do this work was a major hassle. Took me 2 months to find someone, when I did find them, it took 2 weeks to get it done (only because for the first week the guy was in hospital, workplace accident of all things! His hand was pretty messed up!)

Anyway, he did the work and it was then running and running sweet.

Extractors were custom made by Windsor Exhaust Centre in Richmond, NSW. They cost $900. Bloody well made too.

Things I would recommend that be done before dropping the motor in:

If you can afford it, complete rebuild.
Change all belts, timing fan etc.
Replace all gaskets
Reverse flush the motor
Get the injectors ultra sonically cleaned
Clean out air intake

I'd also recommend looking at your suspension, strut brace and a rear sway bar. The power that it has now makes a big difference to it's handling. The strut brace practically eliminated torque steer and I don't have an LSD.

http://home.swiftdsl.com.au/~monstr/strutbrace.jpg

Also be sure to check out your engine mounts before putting the motor in, change as necessary. Probably a good bet just to change them anyway considering the age of TR/TS's now. And get poly ones if you can.

Cheers guys! Again, my apologies for forgetting about this site and not passing on the info about it!!!!!

Oh and just quickly my 1/4 mile results, this was before I got the new suspension and still had issues with launching and stuff (tacho still doesnt work, have to drive by ear and speedo lol)

1/4 mile: 14.806@153.22km/h



Dyno: 165hp at the wheels, not sure of rpm as it wasn't a dyno run for power, they just printed it out when searching for a high end ignition problem...you can still see the problem in the top end there. I will get it dyno'd again one day.

http://home.swiftdsl.com.au/~monstr/dyno.jpg

Quick 7 sec video of it on the mountain:
http://home.swiftdsl.com.au/~monstr/Corkscrew.wmv

If anyone has any questions feel free to PM me or email me at killbilly1982@swiftdsl.com.au, I'll be coming here more often now that I'm not going to hang around Aussie Magna anymore as I'm getting a new car.

-Paul

I think this deserves a sticky. It just explained everything I needed to know for my conversion :D

Cheers for the post up

No worries mate, thought you might like it.

i have looked into this option as an upgrade on my KR, the only problem i have come across is finding a front cut or complete engine in vic or infact trying to find a importers or wreakers that knows what i am talking about. i think i am looking in the wrong places. Is there anywhere in Vic than can get me one?

i have looked into this option as an upgrade on my KR, the only problem i have come across is finding a front cut or complete engine in vic or infact trying to find a importers or wreakers that knows what i am talking about. i think i am looking in the wrong places. Is there anywhere in Vic than can get me one?

having the same problem here mate...
But as soon as the tax return comes in, i'll start looking deeper lol

hey, i haven't read any on the previous thread, but what is the difference in fuel economy between the sohc and the dohc?

cheers

Good question dean. I'd like to know this as well. I believe it would be similar under normal driving. But if you are to drive hard, it would definitely take up more fuel.

Also wondering what kind of power figures people are getting through 98 octane on the quad cam? I'm estimating around 170kw at the fly?

Good question dean. I'd like to know this as well. I believe it would be similar under normal driving. But if you are to drive hard, it would definitely take up more fuel.

Also wondering what kind of power figures people are getting through 98 octane on the quad cam? I'm estimating around 170kw at the fly?

JET BLK has one in his car (down in vic) And his fuel economy is about the same as a SOHC, so not much difference at all..

I was wonderin, is it all basically the same if doin the DOHC TT conversion?

More things would have to be considered, intercooler, piping, gearbox, room under the hood for the snails.

Also see http://www.aussiemagna.com/forums/showthread.php?t=49671

thanx info is all good

I was wonderin, is it all basically the same if doin the DOHC TT conversion?

Nope, The TT Conversion will set you back to over $7K, The N/A will cost you far less.

Yeah the N/A can be very cheap and the engine has a lot potential for power upgrades. Easy to achieve 200kw atw N/A if you've got the spare cash to mod it as the quad cam has a strong foundation for upgrades and many parts available.

Yeah the N/A can be very cheap and the engine has a lot potential for power upgrades. Easy to achieve 200kw atw N/A if you've got the spare cash to mod it as the quad cam has a strong foundation for upgrades and many parts available.

NA is cheaper initially, but I can see the cost quickly rising as you start chasing more power.

Yeah that's true. But a great start if you want to start building power and you don't have the time and money to spend on a full TT conversion.

DOHC has 165.5kw stock on 91 ULP.
I'm guessing around 170kw on 98 Octane. What you reckon guys?

untrue.

DO NOT use 91ulp with the dohc engine.

Yeah? Only premium?

untrue.

DO NOT use 91ulp with the dohc engine.


Why, it's got a knock sensor, it will retard the timing to suit the fuel so no detonation will occur. But Being Japan its probably designed for 102ron fuel lol

Yeah that's true. But a great start if you want to start building power and you don't have the time and money to spend on a full TT conversion.

I'm not arguing, this conversion is awesome. :P Personally I wouldn't push too much power in a FWD, It's not much fun if you can't make full use of it everywhere.:D

But Being JapanESE its probably designed for 102ron fuel lol


That's right....these engines were built with better fuel in mind.

I once put in 91 by accident and my car ran ****. Wont do that again.

And to answer your question Dimi....them power rating you're stating are with japanese fuels...not our 91...

hmm, sum1 metioned sumthin about firewall surgery (think it was TuffTR), how much firewall surgery would be needed? and would u need a new ecu or could u use the magna one with a piggyback?

hmm, sum1 metioned sumthin about firewall surgery (think it was TuffTR), how much firewall surgery would be needed? and would u need a new ecu or could u use the magna one with a piggyback?

All i know is mate, your gonna be sore in the pockets After putting the TT motor in, I would use the GTOTT One, and then you could use a piggyback on that..

ah kz, cheers for the info.

Any idea if this ECU will work? I assume this would be the 220hp version ECu as it is from a post 1994 model.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=270088169450&fromMakeTrack=true&ssPageName=VIP:watchlink:middle:us