I guess My fender flare thread wasn't enough to stir the hornets nest... So to really introduce myself, I'm gonna stuff a 3.8 mivec into the stealth.
I was drinking one night thinking about my first girlfriend back in Jr High school.... Then I grew a wild hair up the butt and said, I'm doing the 75 Full Mivec Engine swap. That ends that love story.
It has been done many ways already and I'll be doing this my way. This time around. I'll post up pics of progress as I go along just like the fender flare thread. I know I'm pushing some kind of limit here but it should be interesting to be 4th or 5th known to have done this swap. So far, its Been Itallo, Bdranck, and MichealMR2 that are known to be running Mivecs.
Yes compreasion does not mean squat. Unlike the evo motor your comparing very thin rods to over engineered stock evo rods.
Not hating, just saying. I really think it could benefit greatly from a grand or so in some bullet proofing.
Not that it matters but youve got full support from me and im sure many others on this.
For the longest time ive been wanting to use the MIVEC heads on a stock 6G72.. Thats where most of the 3.8s power comes from. With bolt ons they uave some crazy power even as a n/a. My bolt on vr4 got pulled on by a 4G eclipse with bolt ons and a tune FROM A DIG. I got him on the launch the launch, then he pulled on me in 2nd hard, and i pulled away in 3rd and 4th. Impressive engines. IMO they are Mitsubishis last Hoorah.
I just love these Mivec threads. Seems the process gets easier over time. Interested what all you come up with. Figure out front and rear motor mounts as well as accessory brackets?
Thought I would share....So I decided to make some mods to the car over the winter and finally got some time to dyno it.. Leonel and I have a good friend who specializes in Ferraris and let us use his Dyno today..The outcome was pretty good..1305 awhp at 40 psi battling through ignition blowout and traction issues. This is on Pump e85
Really just turbos.:suspect: .lol. torque was a little over 1000 then it pegged..must have been a tach issue..it comes on much better then before...yep still same stock 75 crank from the start of this build in 2007.. Also not one drop of coolant with the head studs...
E85 will save the pistons. Nothing will save the puny 75 rods when you add 10.5:1+e85+boost=tq.
I obliterated a stock 74 rod at 500awtq and it is beefier than the 75. Maybe you'll get lucky and it lasts a few miles longer, but it will break. When it does, there is a lot of carnage.
I think a full swap is great. But as soon as you get it running, pull it back out to build the bottom end.
You can use 74 Rods, but not 74 pistons, The difference in the stroke of the 75 (4mm) is compensated by changing the compression height on the 75 piston. The CH on the 72 and 74 is 31.75mm. The CH on the 75 is 29.75mm. As Italo stated, the only difference between the 74 and 75 crank is the stroke. The 74 is a 86mm and the 75 is a 90mm. So, that is an increase in the center offset of the rod journals by 2mm or 0.080".
iirc CP made a set?
it may take some more searching, I didn't find much through a vendor or anything, but some luck on 4G forums about Ross pistons, so it may be your best bet to try contacting Ross or hopping on one of the 4GEclipse forums.
I believe others here, have had Wiseco make a set too. It is not difficult to get a company to make you a set of custom pistons, shit there are even forums you just fill out the info and they do the rest for you. just mic your 75 pistons, and tack down the information on a sheet of paper, and make any changes you want for the sake of compression. I'm sure Ray can point you in the right direction, If I remember right he was involved in both the completed 75/74 builds
also for the sake of information and to show how REALLY thin the 75 rods are vs the already thin and weak 74 rods.
So I'm stepping into my flame suit for this question. But may I ask, besides the Mivec, what would be the difference, if any, between a stroked 3.5 (3.5 block sent to Ray and made into 3.8) and the actual 3.8? I know the 3.8 can be bored out to 4.0 or 4.2 which is insane, but is there any differences between a stroked 3.5 and the actual 3.8. I honestly feel the Stroked 3.5 would be easier to get into our cars.
I plan on taking advantage of the AEM EMS' Vtec controls for progressive application. The OE Mivec ECU has 3 tables for Low, Mid, and High Lift profiles depending on RPM.
Here's a few more updates. A majority of the important bits have been attached and some creative fabrication is clearly needed. Again I'm doing this swap a certain way to show members that the 3.8 mivec can be physically installed with some creativity. Wait until you see what I have in store for the exhaust manifolds... But this thread is worthless with out pics so...
Motor mount, Alternator, Belt tensioner are on. There are a lot of gaps but those will be addressed as necessary. Note all of the bracketry is OE 1G 6G72 equipment. I'll address the Timing belt idler pulley and Power Steering bracketry in my next post.
1G A/C bracket... 3 of 4 holes line right up. The 4th is... missing a boss. 3 out of 4 is good enough for me.
The Belt tensioner is just a hair on the short side, nothing a stack of washers or machined spacer can't fix.
And the Alternator top bracket just isn't gonna jive, Making a new one isn't an issue.
More pics and technical info to come, stay tuned fellas!
Nope. That's why I told him I'm very interested in his solution. The newer SOHC heads use mounting flanges that run more or less parallel to the ground. The housing from the DOHC heads (ours and the 74) are nearly vertical.
When the time comes for the Thermostat housing, there is guaranteed welding involved. The really is no OE solution for making it face the correct direction in a 3/S car.
As promised, Here is the solution for the powersteering pump mounting and Timing belt Idler pully. It is basically a portion of each part from the 75M and the 72, The Idler pulley mount on the 72 places the pulley too far away resulting in a slacked timing belt even with the tensioner pulley and tensioner at full extension... we can't have that at all.
So the Idler pulley mount portion of the 75M's Accesory belt tensioner had to be modified and the 72's Idler pulley bracket basically became a regular bracket so the Power steering bracket had something to bolt on to.
Also for the 72 Accessory belt we had to get creative regarding the Gap between in and the Timing belt tensioner... Simple! Spare A/C compressor bolt to the rescue. It's the same grade, same thread pitch and correct length! Now to make up for the gap.
I gotta wake up at 4:00 Am... Thats it for now fellas.
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