6G72 DOHC 2/4 bolt 3.0 with 6G75 3.8 SOHC MIVEC heads.

[Blackmount]

Me and a few people have been talking about this so i want to try and gather more data on it. Ive got a few word files on my computer but i want more

So far im pretty sure it will work. 75 heads bolt on 74 block and 74 heads bolt onto 72 block. So 75 heads should drop on 72 no problem. I know there is a select few who have a 74 stroker with these heads. I want 72 for maybe a pretty much bolt on upgrade. As the the 75 mivec heads are some of the best flowing heads out there (or so im told) and have some great cam options (again so i am told) plus it would just be badass. U can get a new set of these heads for a pretty decent price in relation to new TT heads/major machine work on stock heads

As far as controlling mivec im sure a 99 flash ecu could do the job if not AEM. There are also Mivec/vtec/vvti piggy back controllers

My snag is the timing components and related on the block. Would one use a 72 water, oil pump, tensioner crank pulley etc with a 75 timing belt? Is it that simple?

Now that i am working 50+ hours aweek again and have decent income im going to pick up a 2nd motor and maybe try some of this stuff to figure it out myself. But i thought itd make a good thread

[MR2]

Been a while since I've played with the crap in my garage, keep in mind when I say parts fit, I mean the Gen 2 upwards parts. Itallo would have more info.

the 72 water pump fits
72 water neck does NOT fit
I doubt the 72 upper intake will fit
From memory you NEED the 74 lower intake with the 75 heads to allow the 72 Upper to bolt on, but seeing as the 75 heads have massive PCV I assume this was necessary to comply with emissions, you may fine the Pajero MIVEC heads are lower.
the 74 lower also allows you to use 72 spec injectors as opposed to having to have them angled as per the 75 one
I can't see why you need to do anything special with timing, just use the 75 timing belt you will however need to grind down the front mount and come up with some engine covers since none of the stock stuff will fit without leaving gaps. as per the 74 heads you will need to make power steering and alternator brackets, cannot remember but I'm pretty sure the 74 ones are not high enough (and the engine is reversed in the 380/Eclipse/Pajero).
probably the most expensive adjustment will be the exhaust headers, the 75 heads use round ports and the bolt pattern is upside down compared to 74/2
the 75 uses coil on plug so it's up to you if you keep that or just throw some wires on the stock stuff
From what Itallo said in the past the timing from a Gen 2 car plugs right into the sensor on the 75 or he adjusted the harness or something he made sound easy

here is me attempting to fit 72/4 accessory brackets on to the 75 heads

http://3000gt.com.au/car/74%20vs%2075/Accessories/

[Blackmount]

Thanks for the info. Im gonna post what info i have in a organized fashion to my best ability when i get home and can get on my laptop.


Biggest thing im focusing on is the initial engine assembly.. 75 heads on to stock 72 shortblock (to see how simple the process can be) and get all the timing and much needdd companants such as WP and OP installrd and everything together perfectly. Im not worried about the alternator and pws that stuff will be the easy part.

[mehrshadvr4]

you can't bolt 75 head on 72 block. you need 74 block because the block are a little taller and farther apart and the heads need modifying to fit on 74 block, but you need 75 lower manifold and upper manifold. the lower 72 won't work because it's too narrow and 74 won't work because the porting are different. same with upper manifold. i tried to buy 75 manifold for my car and later i found out the lower is different than dohc engines.

[Blackmount]

why wouldn't it work? if 74 heads bolt onto a 72 block then why won't 75 heads bolt onto a 72 block but they will a 74?? that makes no sense. and Yes I am aware of a light modification to get them to work but it was very minor iirc.

[Blackmount]

Most of what I had is about doing a 74/75 SOHC MIVEC Stroker, so it's missing some of the more relevant info but it can be a good source.

Just some things I pulled from my Notes, some of it may need correction, but if claimed false please provide a reliable source that says so.




6G75 Deck height 228
6G74 Deck height 228
6G72 Deck height XXX (?)

6G75 Bore 95
6G74 Bore 93
6G72 Bore 91

6G75 Main journals 64
6G74 Main journals 64
6g72 Main Journals XX (?)

6G75 Rod Journals 55
6G74 Rod journals 55
6G72 Rod Journals XX (?)

6G75 Stroke 90
6G74 Stroke 86
6g72 Stroke 76

6G75 Pin downset is 29.75
6G74 Pin downset is 31.75
6G72 Pin Downset is XX.XX

Custom 3.8 Stroker

Parts
6G74 Block
6G74 Rods
6G75 3.8L Crank
6G75 Pistons or Lower/Higher Compression Custom Pistons.
Bore Block to 95mm
CUstom Upper Intake Plenum
6G74 Oil Pump
6G74 Water Pump

NOTE:

*3.8L Crank is a direct drop in replacement into the 74

*When the custom pistons are built for this application, the pin downset will need to be changed from 31.75 to 29.75 if we are basing it off of a stock 93mm 6G74 piston.

*Heads: Mivec Heads are a direct bolt on and just need a switching system to activate them

*Aftermarket cam gears: These are the same part # being used on 6G72/74/75

*Custom/Modified Waterneck needed

*Custom Headers/Turbo/Exhaust manifolds needed (Modified Stock 72 manifolds will work)

* 74/75 Connecting Rods are the same
* 74 lower plenum will bolt to 75 heads allowing use of 72 TT plenum (maybe)

MYTH?
Supposedly they outflow LS7 heads...I think it was Matt or Ray that mentioned that once.

Flow data pulled from Sources

http://sphotos-a.xx.fbcdn.net/hphotos-prn1/14003_616972384997710_770060808_n.jpg

http://sphotos-b.xx.fbcdn.net/hphotos-frc1/399902_616972388331043_1242566479_n.jpg

Other semi-important shit for reference.

Exhaust ports

http://sphotos-b.xx.fbcdn.net/hphotos-prn1/603814_616975951664020_1257392677_n.jpg

Timing Set up and components.

http://sphotos-a.xx.fbcdn.net/hphotos-ash4/310748_616976248330657_1792605528_n.jpg

Intake ports

http://sphotos-b.xx.fbcdn.net/hphotos-ash3/536947_616976311663984_1319861937_n.jpg

Lower plenum Intake ports (Upper plenum side)

http://sphotos-b.xx.fbcdn.net/hphotos-ash3/601754_616976388330643_1990380485_n.jpg

[mehrshadvr4]

you can put the head on but you won't be able to bolt the lower intake manifold because the heads are closer together. you are going to need a totally redesigned manifold.

[Greg E]

Cam and Crank sensors absolutely will NOT work with a flash/stock ECU. Writing the code to control the MIVEC isn't difficult though.

72 pistons will not work with the 75 head valves. Custom pistons are needed too.

[MR2]

good point on the heads being closer, forgot that one :p maybe you can use the 72 lower intake then? seeing as the intake ports on the 74 and 75 ports are the same?

I assume you already realise that the 75 heads have a 65cc chamber and the 74/2 have a 43, so you'd need to re-work your compression numbers..

when you say "good cam's" available, the only people I've seen to do them are RPW, and when a few people who know a lot more than me looked at they they did not seem convinced as to their suggested numbers etc.

[mehrshadvr4]

are you sure the ports are the same? i'm sure the 75 has bigger ports and probably different shape and angle too.

[Unlogic]

Subscribed.

[Blackmount]

Unlike all the other threads on this site. I want to actually get ahold of a set of heads and find a 72 shortblock and try to assemble itm no one is providing anything more then just words on it not working.

[TUFFTR]

Right.
72/74/75 NON MIVEC upper intake's, all bolt onto 74/74 lower intakes. - NON MIVEC!
MIVEC has the larger manifold upper and lower.

I dont think anyone has played with making the MIVEC manifolds work on NON MIVEC heads. I wouldn't even know on where to begin, may be easy? Might be a PITA.

[mehrshadvr4]

Why would anyone go for a non mivec 75 heads? that must be a down grade if the ports are the same.

[Blackmount]

MIVEC heads only! Lol

[IPD]

as posted above, i don't see how it's going to work on a 72...but subscribed for results.

[familyMAN]

There are 6g72 mivecs on eBay. I know nothing about them but maybe the heads will work. Block looks backwards. Also no idea if they flow as well as the mivec heads you are talking about.

[Italo Grasso]

The MIVEC heads do not just bold on to either a 74 or 72. The coolant ports and oil ports need to be modified on the head to work with the blocks (the 75 block/heads are different). To put the heads on a 72 you would need to fab up a lower plenum or maybe look into some of the older 72 SOHC lower plenums they might work. The timing belt you would need would be from a 72 SOHC.

[futurevr4man]

didnt see this until now. yeah the 75 heads oil ports dont line up as italo said. the coolant passages can be iffy as well depending on which heads you get. the largest benefit of the 75 heads is the flow you get, but you can also bore out the block past 94mm. you are stuck at 94 with 72 heads due to the coolant passages on the heads running into the bore on the block.

there is also the wiring side of things. i know michael said it sounded easy, but i have to disagree. i considered these heads when i was building my engine, and the wiring is significantly more difficult than desired. so much so that it was the nail in the coffin for me. but back then, flashable wasnt out too...

if you gave greg a nice donation and sweet talked him a bit, im sure he could write some code for this application, however due to the fact that there is like 1 person with a running mivec setup currently, its not really in high demand and thus will not be a priority of his. i think if you wired some of the mivec stuff to some of the custom pinouts that it could be controlled without too much hassle. i remember leonel or italo or whichever one of those guys had the mivec stuff saying he has to make a bunch of relays and switches to control mivec because the ecu isnt setup to do it from factory.

my utltimate build would be my bottom end plus the mivec heads. you could bore it out a bit more (95 or 96mm, maybe more... idk what the limit is) and with the extra flow, the numbers you would make would be massive. the crank would quickly become the weak point, but i would haven no doubt that 700+ on pump with some moderately sized turbos (still full boost by 3500) would be extremely doable. especially if you ported/polished the heads. too bad you will be looking at probably 15k into the engine to do that though. and im not even sure which lower intake would work anymore at that point, maybe the 75? you also have hood clearance issues too though...

[Greg E]

If I were going to run this in my car, I would use the eclipse GT ECU. The sensors on this motor are all different.

[futurevr4man]

i think they are wanting to try and retain most of the factory sensors. i dont think they realize how different the castings are though. ill bet nothing (or VERY little) lines up correctly.

[Greg E]

Look at the crank sensor in the picture above. No way that is gonna work with the 72 crank sensor. Same with the CAS. Same with the TPS... Etc... Already looked into that.

The other show stopper is the 75 motor is a coil on plug. Not a wasted spark setup like our cars.

[futurevr4man]

Look at the crank sensor in the picture above. No way that is gonna work with the 72 crank sensor. Same with the CAS. Same with the TPS... Etc... Already looked into that.

The other show stopper is the 75 motor is a coil on plug. Not a wasted spark setup like our cars.

people have gotten COP setups to work before though. i think T4 had a COP setup didnt it? the crank and cam sensor can have bracketry made for it, and you could probably get away with it. im sure there is a ton of fab time to put into it though... not worth it to me.

[Greg E]

people have gotten COP setups to work before though. i think T4 had a COP setup didnt it? the crank and cam sensor can have bracketry made for it, and you could probably get away with it. im sure there is a ton of fab time to put into it though... not worth it to me.

You lose the tach signal with most COP setups.

The only setup I can imagine *might* work would be to setup a 91/92 CAS.

[Blackmount]

This has been done before more then once (it was on a 74 not a 72) but essentially the rest, or at least most of what you guys are complaining about is the same between the engines.

[Greg E]

This has been done before more then once (it was on a 74 not a 72) but essentially the rest, or at least most of what you guys are complaining about is the same between the engines.

Those cars are running AEM which give you much more flexibility to the various inputs. The flash ECU is stuck with stock hall sensors for now. Getting around that is beyond me right now. :(

Little progress has been made at disassembling the eclipse GT ECU. Thinking about jumping in on it and that ECU would be better suited for this swap.

[MR2]

now that I know other people are posting in this...let me get my gasket pictures

[MR2]

http://3000gt.com.au/car/74%20vs%2075/6g75/My%20V77W6g75/gaskets%20(1).JPG

http://3000gt.com.au/car/74%20vs%2075/6g75/My%20V77W6g75/gaskets%20(2).JPG

74 gasket right, 75 left (Smooth one)

notice how there is very little difference, pretty sure everything just bolts up, about the only differences is that they squished the channels near the cylinders in order to make the cylinders bigger

[Blackmount]

Now 72 gaskets lol. And AEM was one of the options in my original post. Honestly i would prefer it.

[MR2]

yeah I think I might have 72 gaskets, I cannot see myself bothering to go into the garage too soon though, it's like a hoarders house :(

[GTOJOE]

The vipec ecu I am running will run the mivec and any sensor. As for COP I'm sure it's possible as well but why bother with it? Just run standard universal leads using the stock system.

Sent from my GT-I9300 using Tapatalk 2

[MR2]

The vipec ecu I am running will run the mivec and any sensor. As for COP I'm sure it's possible as well but why bother with it? Just run standard universal leads using the stock system.

Sent from my GT-I9300 using Tapatalk 2

I've said all this, only thing that needs to match is the CAM wheel, we need Bdrank to talk about this one but I believe he found it was very similar

[ChargerX3]

Thread ive been waiting to see come up. Been looking at doing this swap for some time now. Have a 3.8 Mivec out of a Galant ive been wanting jump on to cannibalize.

http://sphotos-b.xx.fbcdn.net/hphotos-ash3/64990_10100174064132814_1893575284_n.jpg

[Blackmount]

yeah I think I might have 72 gaskets, I cannot see myself bothering to go into the garage too soon though, it's like a hoarders house :(

Get off your ass!! lol


Thread ive been waiting to see come up. Been looking at doing this swap for some time now. Have a 3.8 Mivec out of a Galant ive been wanting jump on to cannibalize.

http://sphotos-b.xx.fbcdn.net/hphotos-ash3/64990_10100174064132814_1893575284_n.jpg

May I has??

[Greg E]

If I were going to run this in my car, I would use the eclipse GT ECU. The sensors on this motor are all different.

Take this back... Upon further research the engine ECU is too tied into the Eclipse ETACS ecu. No good way to run it independently. :(

[MR2]

Bdrank & Itallo have the info, it's not as hard as it looks

[Greg E]

Bdrank & Itallo have the info, it's not as hard as it looks

They're running AEM. I'm trying to figure out how to setup this motor to run with our ECUs.

[GTOJOE]

The infamous Steve aka magnit is running 72 mivec heads on his gto. Is there any data on flow rates between the 72 and 75 heads?

Sent from my GT-I9300 using Tapatalk 2

[GTOJOE]

Also to add to this the cam is simply moved by a solenoid so all you need to do is set a trigger at a certain rpm that triggers/activates the solenoid. I believe this is also how Steve has done it.

Sent from my GT-I9300 using Tapatalk 2

[MR2]

actually a point on this...

the 72 heads are pretty old Tech, the 74 stuff is essentially identical, it was only when it came to the 75 that Mitsu re-worked most of it, why people are saying they would prefer to run the mivec vs the non-mivec version of the heads is beyond me, considering the improvements in head design are shared between the mivec and non-mivec heads, I have as set of each and they are identical.

here's a flow test, the 380 is the 75 non-mivec head, see how it smash's the 72/4 design.

http://3000gt.com.au/car/74%20vs%2075/Bigheadcomparo.pdf

from memory the only sensor on the heads is the one at the back, and again from faint memory/recollection Itallo or Bdrank found that the GTO gen 2+ sensor wheel could be re-used on it (or something like that)

[Greg E]

why people are saying they would prefer to run the mivec vs the non-mivec version of the heads is beyond me

Smooth/stock like idle and huge improvement to mid-range power.


from memory the only sensor on the heads is the one at the back, and again from faint memory/recollection Itallo or Bdrank found that the GTO gen 2+ sensor wheel could be re-used on it (or something like that)

Would like to see more data on this.

[MR2]

with the amount of winging about having to run a RPM 12v switch you'd think MIVEC was the bane of everyone's existence :) I guess a better way of saying it is if you wish to avoid the mivec side of it you can get the non-mivec heads :)


I'll dig through my old emails from both of those guys and see if I can find the info.

[Greg E]

with the amount of winging about having to run a RPM 12v switch you'd think MIVEC was the bane of everyone's existence :)

Its actually a PWM output much like the purge, EGR or boost control solenoids.

[MR2]

maybe this will help

e420c in V6 Magna - COP Conversion and MIVEC solenoid duty cycling (http://adaptronic.com.au/forum/index.php?topic=5175.0)

keep in mind that thread says that the 75 mivec is on/off not fully modulated, the thing about the duty cycle is an interesting one, I have the MIVEC solenoids in the garage lol can take pics if you wish

[MR2]

and here is the full service manual for the Eclipse: Index of /car/74 vs 75/6g75/2006+ Eclipse Service Manual (http://3000gt.com.au/car/74%20vs%2075/6g75/2006+%20Eclipse%20Service%20Manual/)


another guy put a 75 into the 72 spot...

http://www.club3g.com/forum/members-rides/126575-silversides-02-gt-6g75.html

note how he deals with the camshaft position sensor

[Greg E]

Had a feeling the 72 hall sensor blades would swap over! Even still, with a 74 bottom end, this shouldn't be an issue using the stock 72 crank sensor anyway. Looks like we'd have to use a 91/92 CAS for the cam angle sensor. No biggie.

Great find on the MIVEC! Answers a lot of questions I had about the duty cycle operation.

[sergechronos]

Out of curiosity, what's the rough approximation on cost at this point? Provided we can make the flash ECU work, and we assume that anybody doing the swap would have one, as opposed to having to go AEM. Assume motor is what, 1k-1.5k? Between that and the 6g72, you have like 90% of the parts? Sell what you don't need and end up into it for maybe a grand?

[MR2]

Happy to help, just a bit irritated (it probably shows in my posts) that I no longer have money to work on my car :p sorry about that

I wonder if we could get a Gen 2 sensor to work... will have to look at what the gen 2 even has, and I wonder if the signal returned is the same even if the sensor design and attachment is different.

[MR2]

Out of curiosity, what's the rough approximation on cost at this point? Provided we can make the flash ECU work, and we assume that anybody doing the swap would have one, as opposed to having to go AEM. Assume motor is what, 1k-1.5k? Between that and the 6g72, you have like 90% of the parts? Sell what you don't need and end up into it for maybe a grand?

My used MIVEC heads complete with all the sensors & actuators were $300 each... that was a few years ago now, on top of that you need to change the flanges on your manifolds and probably modify the brackets that hold the alternator and power steering on, then your wiring for the solenoids and covers slicing the bit out of the front mount (maybe you could use a SOHC front engine mount if the belt routing is the same?

hard to say on a total project price... plenty of adjustments and custom odds and ends

[Blackmount]

actually a point on this...

the 72 heads are pretty old Tech, the 74 stuff is essentially identical, it was only when it came to the 75 that Mitsu re-worked most of it, why people are saying they would prefer to run the mivec vs the non-mivec version of the heads is beyond me, considering the improvements in head design are shared between the mivec and non-mivec heads, I have as set of each and they are identical.

here's a flow test, the 380 is the 75 non-mivec head, see how it smash's the 72/4 design.

http://3000gt.com.au/car/74%20vs%2075/Bigheadcomparo.pdf

from memory the only sensor on the heads is the one at the back, and again from faint memory/recollection Itallo or Bdrank found that the GTO gen 2+ sensor wheel could be re-used on it (or something like that)

http://sphotos-a.xx.fbcdn.net/hphotos-prn1/14003_616972384997710_770060808_n.jpg

compare @ .500 lift stock non mivec = 277.8

@ .500 lift stock mivec = 322.0

(@ .700 lift = 352.0)

also Italo says:


You can use the 3.8L MIVEC heads on a 72 block, but you would have to fabricate a lower intake becasue the ports are totaly different. My build requires a 201 tooth timing belt, i'm thinking you would need a 195 tooth belt to work with the lower 72 deck. I will be using the AEM to control the MIVEC solenoids.


Out of curiosity, what's the rough approximation on cost at this point? Provided we can make the flash ECU work, and we assume that anybody doing the swap would have one, as opposed to having to go AEM. Assume motor is what, 1k-1.5k? Between that and the 6g72, you have like 90% of the parts? Sell what you don't need and end up into it for maybe a grand?

Ideally I would like to see the heads bolted on and ready to go for less then 2K or at least in that range You can get new heads for a fairly decent price (price obviously excludes tuning software)

Despite the nay saying, I'm fairly confident they will work, and can be bolted on no problem. The lower plenum maybe an issue but we will cross that bridge when the time comes!

Edit: let me correct myself, on what I said. that graph I compared to yours was NOT stock heads. I went back and looked, Stock MIVEC heads DO flow the same, the bigger number I got was from Port and Polish + 1mm oversize. My bad on that one!

Details found here! http://www.3si.org/forum/5902211-post165.html

so yeah, may be easier to run Non, since they flow about the same...but how will the mivec effect power vs not having it is the question.

[Greg E]

Smooth/stock like idle and huge improvement to mid-range power.

Chris

[MR2]

Chris

Putting a bit more detail on this... and I'm not sure how much of this is followed in the non-mivec..

Taken from RPW who, to my knowledge are the only guys making cam's from this: http://www.rpw.com.au/shop/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=2627&category_id=282&option=com_virtuemart&Itemid=1


The 6G75 Mivec camshaft runs a single lobe for the exhaust camshaft, and runs two different intake lobes, one for low and one for high rpm, The factory set-up runs a very conservative intake low rpm profile, and a more aggressive high rpm profile, Additionally, the factory set-up is hydraulic on the exhaust profile, and solid tappet on the intake making it a confusing one to set-up. The intake lobe low rpm profile is further complicated, by actually running two different lobes, The second low rpm lobe runs half the lift of its matching partner.

the theory is, that with Mivec you do get a bit more mid-range and the ability to run a very large opening on the exhaust without ending up with the lumpy idle, I would propose that the non-mivec heads if peeps were worried about the mivec complicating things, would provide a considerable improvement and be very close to the performance of the MIVEC version

[MR2]

on the topic of the lower intake's being the different, I would like to see someone test this, I don't think I have a lower intake hanging around to play with, and the 72 engine I had to play with is also now gone

part of the problem is with quoting these guys threads is some of the information we found to be incorrect (in later threads or in PM's), cases where the builder says that does not fit, but when the guys actually tested it it does

[futurevr4man]

i will be interested to see this actually done, however... with the risk of sounding like a negative nancy, i DO NOT think the heads will simply "bolt on". and if you disagree, prove me wrong. this will be one of the few times i will be happier if you can prove me wrong.

[MR2]

I'm a fan of being Cynical till it works :)

Hope this helps... in this pic 72 gaskets in middle, 75 next and 74 outer pairs..

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03848.JPG

Showing 75 sitting on the 72 gaskets, now notice how all the ports overlap to a certain degree? notice how the ports on the block itself are far larger than the holes cut out of the gaskets? bet the 75 heads sit straight on no worries or stuffing with ports.

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03849.JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03851.JPG


now this one gets a bit more interesting, here's an overlap of the 75 non mivec gasket over a 74 upper intake, what the camera is not having such a good time showing is that it actually fits and would seal against it, the only bolts that don't line up are the end ones, you may have to adjust the holes BUT...

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03853.JPG

I think the lower intake that bob modified was actually a 74, not a 75 as it actually match's the port holes on the 75 MIVEC heads better than those on the 75 non mivec (contrary to the information TuffTR is giving us) notice how on this next pic the holes on the right head (non-mivec Pajero 75) are more rounded than the head on the right (Mivec from Eclipse)

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03863.JPG

showing bob's art work sitting on the Mivec head:

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03860.JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03861.JPG

so I highly suspect you could use the 72 upper and lower on the mivec heads, you may just need a gasket so the upper clears the rear head... or throw the 72 lower in with the 75 upper, looks like it'd seal just fine... plenty of overlap

on the Topic of belts I can't see why a SOHC would not work, keep in mind Itallo's was a 74 block so he has more deck height, not sure why he did not just use a 75 stock belt :| info smells weird.

[Greg E]

Lets talk thermostat housings.

If you put these heads onto a 72 block, will the 72 housing bolt up?

[MR2]

No, it's the one thing that will need serious fabrication...

here's what you need to make

http://3000gt.com.au/car/74%20vs%2075/6g75/img1725.jpg
http://3000gt.com.au/car/74%20vs%2075/6g75/img1726.jpg

note how the flanges the water housing mount to are rotated?

http://3000gt.com.au/car/74%20vs%2075/6g75/My%20V77W6g75/teardown%20(36).JPG

you know, I just dug up the pics I have from Bdranks 75 teardown... and his lower intake match's mine, so maybe it is the 75 lower I have, and those that have the rounder holed intake are from something else? will have to try a stock 72 upper and confirm it bolts, but I'm sure it's a straight fit no overlapping etc...

http://3000gt.com.au/car/74%20vs%2075/bdranck/Block/IMG_1064-1.jpg

and for reference here's the lower intake for the 75 from a Pajero

http://3000gt.com.au/car/74%20vs%2075/6g75/My%20V77W6g75/teardown%20(29).JPG

note how they are round? I wonder if the 380 has the round ports as well (the engine that TuffTR would be taking his info from is a 380.. Galant 9th gen for you Americans)

Side by Side....
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/DSC03859.JPG

[Greg E]

No, it's the one thing that will need serious fabrication...

here's what you need to make

http://3000gt.com.au/car/74%20vs%2075/6g75/img1725.jpg
http://3000gt.com.au/car/74%20vs%2075/6g75/img1726.jpg

note how the flanges the water housing mount to are rotated?

$hit! Yeah I see that now.

It shouldn't be too hard to hybrid the two. They are aluminum right?

[MR2]

Correct, Bob (OohNoo) went to a fair amount of work to make it just right, as the valley pipe has to be spaced just right, which mean he had to use the 75 pipe bits, but with spacers (or whatever you call them) on them

[MR2]

on the topic of the sensor, I was hoping we could just re-use the 75 one... but it looks like the output signal would be different...

taken from here: MS2-Extra Mitsubishi 6g72 Manual (http://www.msextra.com/doc/ms2extra/MS2-Extra_Mits6g72.htm)

the Mitsu Cam sensor looks? like a 4 lobed plate, the one for the 75 appears only 3, which would be a little far for the miracles your working on the ECU's Greg?

[Greg E]

on the topic of the sensor, I was hoping we could just re-use the 75 one... but it looks like the output signal would be different...

taken from here: MS2-Extra Mitsubishi 6g72 Manual (http://www.msextra.com/doc/ms2extra/MS2-Extra_Mits6g72.htm)

the Mitsu Cam sensor looks? like a 4 lobed plate, the one for the 75 appears only 3, which would be a little far for the miracles your working on the ECU's Greg?

Yes. When it comes to signal timing, that's still beyond me.

I keep staring at that 75 timing belt picture wondering how I could mount the hall plates and sensor to that rear head cam gear.

[MR2]

that would be a good question, since I somehow got motivated to go down and take pics of the heat stuff I might see if I can throw the oil feeder control on there and show you the space (tomorrow)

here's some stuff in the manual about it...

the document I'm in is GR00005900E-13B in that link I sent earlier, page 180.

Location:
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor.jpg

Output, now I'm not sure if this an ECU adjusted output, or raw output from the sensor itself:

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20output.jpg

[Greg E]

that would be a good question, since I somehow got motivated to go down and take pics of the heat stuff I might see if I can throw the oil feeder control on there and show you the space (tomorrow)

here's some stuff in the manual about it...

the document I'm in is GR00005900E-13B in that link I sent earlier, page 180.

Location:
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor.jpg

Output, now I'm not sure if this an ECU adjusted output, or raw output from the sensor itself:

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20output.jpg

Yeah I was looking that manual over and found this. That's the raw sensor output wave form.

Its how signal timing looks in machine code. That's what's still beyond me. Believe it or not, there is still a great deal about the ROM I still don't understand. :(

The 1G DSM disassembly taught me much of what I know now. Signal timers function differently in the H8 code.

[MR2]

ahhh right :)

in other news, I had a look through what I have and while I have the feeder control valves, I'm not sure I have the cam sensor the mivec came with :| Judging by the below picture however, the pajero 75 I grabbed has a similar one so I'll have to see if I still have it!

See on left head

http://3000gt.com.au/car/74%20vs%2075/6g75/My%20V77W6g75/teardown%20(36).JPG

looking at the manual the design of the wheel looks very different:

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20better.jpg
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Camshaft%20sensor%20wheel.jpg

I'm pretty sure all it is though is a hall effect sensor, so if we were to get a replacement wheel made up we could probably just use that to get the exact same signal to the ECU, without making ugly plates and mounting the Gen 1 CPS on there :p

[Greg E]

I'm pretty sure all it is though is a hall effect sensor, so if we were to get a replacement wheel made up we could probably just use that to get the exact same signal to the ECU, without making ugly plates and mounting the Gen 1 CPS on there :p

Both you and Jeff read my mind! Crazy.

It's more like a photo sensor. Think of it like our ABS sensors. Now, where is Dave Broomfield....? :chin:

[Blackmount]

so what about us with just 1g cas?

[Greg E]

so what about us with just 1g cas?

In your car, the cam and crank sensor are built inside that sensor housing. I don't know if the crank signal will match up but it'll work for the cam signal.

[MR2]

fwiw here's Bob's water housing he made... as per usual with Bob, it's Art.

http://3000gt.com.au/car/74%20vs%2075/6g75/Waterneck/2011-06-04%2014.34.16.jpg

I notice on that left head there is the sensor, so I should have it somewhere :| maybe I'll go hunting after I finish my coffee

[MR2]

low and behold:

http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20pics%20(1).JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20pics%20(2).JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20pics%20(3).JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20pics%20(4).JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20pics%20(5).JPG
http://3000gt.com.au/car/74%20vs%2075/MIVEC%20Project/Cam%20Sensor%20pics%20(6).JPG


AND when I put something near the end of the sensor it gets drawn to it.... so it's magnetic.

should anyone decide to make direct plug and play wheels, I'll happily buy one immediately, will save hours programming the ECU I have.

[Greg E]

I'm gonna pick up one of these sensors to take some measurements. Not promising anything as I don't have the equipment to make a custom piece like this BUT I will ask around.

[MR2]

no rush, no pressure :) I'm over a year away from even thinking about putting the 75 together, whenever you may be read with the part, assuming it can be made and work with just an adapter harness for your stock ecu's, I will have the money for you.

I have a caliper if you need anything, pretty sure you're better off with the unit in your hot hands though.

[Jeff V.]

I'm gonna pick up one of these sensors to take some measurements. Not promising anything as I don't have the equipment to make a custom piece like this BUT I will ask around.

There are some 3D printers that can used powdered, ferrous metals now. Find someone to knock out the design in a CAD program and then email it off to have a few pieces made.

[Blackmount]

this thread holds alot of potential for great things to come out of it I feel.

[TUFFTR]

Interesting that the Paj uses a different shaped port system...

[Blackmount]

I want to make this happen so bad, I'm not in the best financial situation for it to happen so I am watching the web for the right deals... Also I am buying a TIG welder, not cheap which is almost taking priority over the vr4, which is where most of my savings has gone. I am already creeping 2K in parts/mods/repairs on this beast.


it'll get done sooner then later.

[MR2]

Interesting that the Paj uses a different shaped port system...

is this the same port system you said was on the 380? keep in mind the Paj had a massive intake thing that had a valve allowing the air to double it's intake length, so it was very odd!

[MR2]

Yeah the intake I have bolts right up to a stock 72/73/74 DOHC lower intake manifold. So the round ported upper you show the gasket from there Michael, what car is that off? 380/8th gen Galant 100% bolts up, Looks like the Pajero is using a different intake manifold port design though.....very interesting...

the rounded ports are off the V77W Pajero, I figured the Eclipse had this until I looked closely.

[TUFFTR]

the rounded ports are off the V77W Pajero, I figured the Eclipse had this until I looked closely.

Interesting...
Nope, 380 motor has all the same ports like a magna/GTO/3000GT/Stealth etc. I've noticed on my mates pajero (older 3.5L SOHC) the same thing, the intake is HUGEEEEE, all for that low down torque though.

[sketch]

subbed.

[Blackmount]

Well Hans says he bolted on a set of 6g75 heads on a 72 no problem... He did not do the timing or anything tho. Comfirmed the snag on the lower intake manifold...

In theory for the timing.

75 belt, everything else 72 parts, and I think a solid tensioner should be in order, since the difference in deck height using the 75 belt, a hydraulic tensioner might not take up enough slack and do a good job holding the belt tight. solid tensioner has more adjustment.

also use 1G CAS supposevly for us 91-92 guys.

Things that will need actually modified are the flanges of the Turbo headers, and the lower intake manifold.... everything else should bolt on no problem. I think these heads could make good power improvement over stock ones, even if anything else is the same, and yield more power with mods and added boost later on...

[hotflarexxx]

How is this looking lol any progress?

[MR2]

I think you don't want the 75 belt...if possible figure out how many more CM the 75 heads have the cam's pushed back over the 72 SOHC and go from there....

get the 72 SOHC belt length vs the 75 belt length... if your lucky the 72 belt length will be 72mm shorter and should just bolt up perfectly

[Greg E]

How is this looking lol any progress?

He's banned. Doubt you'll be seeing any updates. :lol:

[familyMAN]

^interesting. When and why did that happen? Not that I'm complaining.

[stealthee]

He's been gone for over a month now for not knowing when to shut his mouth.