Intercooling the 4.0 ohv/sohc with Ford Supercouper M90

I figured I better start a new thread, as my old thread goes on forever detailing my 4.0 ohv M90 install, motor rebuild (Funny thing about that), etc. Here's the original thread that brought me to this point: http://www.explorerforum.com/forums/showthread.php?t=345617

The issue I am currently having with my M90 install is that I am attempting to increase boost, but cant get the intake charge cool enough. I tried water/meth and had limited results. James with Henson performance just cant do anything more with the tuning till iat's come down.

So, Ron at RPCaster (Building an intercooler for me), and Tim (Vroomzoomboom) who is going to perform some magic on a hood cowl (It was either that, or a body lift to get the additional height for the intercooler). These are the two components I am not able to do myself.

I have detailed logs of my iat's, and am going to do a dyno session before and after install. This will give some great real world numbers.

I'll detail the whole thing as I go (The good, the bad, and the ugly).

For starters. Here is what Just came in the mail.

 

[Dono]

I don't know....
I just told the guy to stop the run at 5500 rpm. Ive never 'looked' for the rev limiter limit.

I wish there was a way to advance cam timing on our ohv's.
But, then again, street driving is really about the lower rpm grunt. Its racing that the higher rpm stuff is best.

 

[jd4242]

I don't know....
I just told the guy to stop the run at 5500 rpm. Ive never 'looked' for the rev limiter limit.

I wish there was a way to advance cam timing on our ohv's.
But, then again, street driving is really about the lower rpm grunt. Its racing that the higher rpm stuff is best.

Ok was just wonding.your probably don't need to go any higher than that.around 3, 000 seems to be peak

 

[jd4242]

I don't know....
I just told the guy to stop the run at 5500 rpm. Ive never 'looked' for the rev limiter limit.

I wish there was a way to advance cam timing on our ohv's.
But, then again, street driving is really about the lower rpm grunt. Its racing that the higher rpm stuff is best.

Ok was just wonding.your probably don't need to go any higher than that.around 3, 000 seems to be peak

 

[CDW6212R]

That torque is very good early in the band because of the positive displacement blower. If you consider the potential results of high IAT's, plus the small blower displacement itself, and the small exhaust, those results look to be accurate. I'd say the curve is very good at low rpm, when the blower is generally efficient and the IAT's haven't spiked yet.

I forgot the rule of thumb for selecting a blower to produce 14.7psi of boost(1 atmosphere), but I think it's about half of the engine's displacement. That's about the blower internal ratio, the blower displacement, and good IAT's. I know very little about blower guidelines, just the small amount I have begun to learn.

That being said, you should begin seeing better power figures when the IAT's drop. The transmission is a weak link, so be sure to give the trans all of your best efforts to keep it alive. That means great clean fluid, a good cooler, external filter, and a VB kit(including all Sonnax upgrades available), finished with a good PCM tuning of it.

Hopefully you will begin to push the trans to its limits, like James and Jake etc.

 

[Dono]

The trans has a rebuilt valve body with all sonnax mods. Tim has a trans cooler for me. I'll order up the external trans filter kit from summit when I do the trans cooler.

Being that my M90 was originally on a Ford Supercoupe 3.8 I would have thought it would mate pretty good to my motor. I guess it does, but makes its power down low.

Breathing is key to high rpm power, of course. Unfortunately the ohv is not a great breathing motor, even with a higher lift cam.

 

[R1dd1cK]

How many psi are you running on your supercharger? It can't be what the Tbird SC makes. When my Supercoupe was stock it would make 12 psi. After a few mods and an overdrive pulley it was able to push it to 17.5. I can't see you running more then what 5 or 6?

 

[Dono]

Right now, I'm around 10. That's the need for the ic, right there.

 

[CDW6212R]

I think that the M90 is around a 1 liter or so blower, so it is small for a 3.8 engine, though I didn't know that was the size on the Super Coupe. I have two IC's from those, and the boost gauge, somewhere.

That should be a reliable blower though. A good one can make more boost at higher speeds even though it reduces efficiency, if the IAT's are kept low. So concentrate on the IC system, that's your best chance to optimize the current combination. Hopefully that will allow the engine to move a lot more air at higher rpm's.

 

[R1dd1cK]

O cool. That is not a bad amount of boost. Have you been to www.magnumpowers.com?
They make some aftermarket stuff for the M90 off the super coupe. One of the things they have going right now is a redesigned bearing plate. It was able to increase boost and lower IAC. I know it is a little costly but if your inter cooler is not enough it might be worth while to get in contact with Charles at www.magnumpowers.com/

 

[jd4242]

How many psi are you running on your supercharger? It can't be what the Tbird SC makes. When my Supercoupe was stock it would make 12 psi. After a few mods and an overdrive pulley it was able to push it to 17.5. I can't see you running more then what 5 or 6?

The supercoupe has a larger crank pulley and is a smaller motor.why it makes more boost stock.

 

[jd4242]

I think that the M90 is around a 1 liter or so blower, so it is small for a 3.8 engine, though I didn't know that was the size on the Super Coupe. I have two IC's from those, and the boost gauge, somewhere.

That should be a reliable blower though. A good one can make more boost at higher speeds even though it reduces efficiency, if the IAT's are kept low. So concentrate on the IC system, that's your best chance to optimize the current combination. Hopefully that will allow the engine to move a lot more air at higher rpm's.

M90=1.47 liters

 

[CDW6212R]

M90=1.47 liters

Is that what it is, 1.5 liters really? I was thinking maybe 1.3, I couldn't remember what I had run across in other research I was doing about the Mustang stuff.

That might be just right with the best supporting items(IAT/boost/exhaust etc).

 

[jd4242]

Is that what it is, 1.5 liters really? I was thinking maybe 1.3, I couldn't remember what I had run across in other research I was doing about the Mustang stuff.

That might be just right with the best supporting items(IAT/boost/exhaust etc).

Its close, especially with the ohv not being a high rpm motors.ported and polished it can move little more or atleast more efficient. m112 would be much better tho

 

[R1dd1cK]

The supercoupe has a larger crank pulley and is a smaller motor.why it makes more boost stock.

Well simple it has a jack shaft. To drive a super charger on a super coupe it takes 2 belts. Crank to jack shaft then one from the jack shaft to the super charger. The jack shaft multiples the speed of the crank pulley. That is the easy way of saying it.

 

[Dono]

My M90 had the rotors coated, and new bearings and seals installed in the plate. The housing was also ported.
I just received an email from him asking me to send the rotor pack back to him for further modifications. He thinks he can increase the overall efficiency of it. Pretty good customer service, Id say.

I guess I'll be installing my backup M90 while this rotor pack goes for a tour to the USA and back.

 

[vroomzoomboom]

don, where is it going? if its not too far out of the way, i can take it with me when i go to the u.s. in june

 

[Dono]

don, where is it going? if its not too far out of the way, i can take it with me when i go to the u.s. in june

Plant City, Florida. I'm guessing that's out of the way.

 

[jd4242]

My M90 had the rotors coated, and new bearings and seals installed in the plate. The housing was also ported.
I just received an email from him asking me to send the rotor pack back to him for further modifications. He thinks he can increase the overall efficiency of it. Pretty good customer service, Id say.

I guess I'll be installing my backup M90 while this rotor pack goes for a tour to the USA and back.

Is he paying for shipping? Hmm I wonder what else he is going to do?maybe changing the coating. Was this the one with the silencers filled?

 

[Dono]

yup, that's the one, silencers filled.

The issue was staring at me, but I didn't see it.
http://www.explorerforum.com/forums/showthread.php?t=345617&page=67
have a look at the rotors. Notice the rotor edges don't line up parallel with the case?

 

[Dono]

I'm not too happy about the grief in pulling my sc off, apart, then cost of shipping and time to fix the error of installing the rotors bvackwards. I am impressed that he contacted me and came clean without disapearing in to the darkness of the internet. I havnt discussed shipping with Logan yet, but will hope he will at least pay shipping to get it back.
Another real cost will be the cost of new snout oil and sealant.

I went with a less expensive solution, and its costing me. Ill just get it done, and press on with life. We all make mistakes from time to time.

I'm thinking of installing my ic when I pull my m90 oFf to send away. Then I'll go for a drive to see Tim to measure up for the hood. I see no reason why after measuring I couldn't just set the ic to the side, un-pug the pump, and put the sc and hood back on.

The only real mechanical unknown is belt length.