Another OHV M90 build

[jd4242]

Here's an interesting read:
http://www.grandprixforums.net/i-rebuilt-my-m90-rotors-home-20356.html
The guy did this in Australia. I'd expect there to be a place that does the same thing in NorthAmerica. Interesting how he said rotor timing was not an issue for him during re-assembly. I'm not sure I'd be so brave.

Yea I've read that.was about to tell you that you can coat them at home and back them.i was going to buy a powder coating kit to do some parts and try and do it myself but like you i didnt want to take them apart or over port anything.you can get gen 3 blades with gen 5 coating pretty cheap and yea the tip coating is the most important .the gen 5 coating is made to wear onto the case making a perfect seal,mine was so tight you could feel the resistance from it.after spinning it by hand a lot before install it got easier and i could see where it was wearing onto the case wall

 

[Dono]

So, following that line of thinking, used rotors are not that good unless they are re-coated.

Probably help with temps a bit, but I cant see more boost happening.

Can you remember where you have seen gen 3 coated rotors?

 

[jd4242]

So, following that line of thinking, used rotors are not that good unless they are re-coated.

Probably help with temps a bit, but I cant see more boost happening.

Can you remember where you have seen gen 3 coated rotors?

man i swear that zz sold them but all i see now is the rebuilt chargers.swear they was $250 but they dont list them,maybe they told me that in one of our conversations these guys do it but they rebuild the blade parts,strip the blades and inside case and then coat all of it(blades,blade bore and inside case)but its over $400 but i hear they claim a 1.5-2lbs of boost gains and over 30* cooler.i dont see it listed on there page but read they do just those services without the whole charge being rebuilt
http://www.embreemachine.com/index.html

 

[Dono]

I'll give zz a call tomorrow. It's worth asking. Thanks JD.

 

[jd4242]

I'll give zz a call tomorrow. It's worth asking. Thanks JD.

May wanna give those other guys a call too and see if they will just rebuild and coat the blades only

 

[jd4242]

Any news?get that belt yet?

 

[Dono]

Nope, No belt.

I did get my brown wire mod completed though. Nice on/off rocker switch on the dash beside the 4x4 auto switch.
I'm all ready for the dyno, except for that new steel pulley....

My new steel 2.7 (or 2.8) pulley hasn't shown up (Im starting to wonder where it is).

What did show up is another complete supercharger. Its off of a 1993, and the blades look all but new.
So, what to do with these parts?
I think I'll rebuild the SC that just showed up over time, and do it very nicely. I might even see if I can find a place locally that can polish the case and snout for a reasonable price.
Then, a set of new coated rotors would be awesome. I'll have to call around and find out who will accept just the case and rotors to do some coating and get really tight tolerances.

Pretty slow going right now.

 

[jd4242]

Nope, No belt.

I did get my brown wire mod completed though. Nice on/off rocker switch on the dash beside the 4x4 auto switch.
I'm all ready for the dyno, except for that new steel pulley....

My new steel 2.7 (or 2.8) pulley hasn't shown up (Im starting to wonder where it is).

What did show up is another complete supercharger. Its off of a 1993, and the blades look all but new.
So, what to do with these parts?
I think I'll rebuild the SC that just showed up over time, and do it very nicely. I might even see if I can find a place locally that can polish the case and snout for a reasonable price.
Then, a set of new coated rotors would be awesome. I'll have to call around and find out who will accept just the case and rotors to do some coating and get really tight tolerances.

Pretty slow going right now.

Hell yea that sounds like a plan.cant wait to see the dyno numbers.you still have pretty much stock tires on there right?im guessing 220-250ish hell maybe more

 

[Dono]

Yup, stock rubber.
I'm pretty curious on what numbers come back also

I do know the smaller pulley makes a pretty noticeable difference. I don't want to bother with the dyno till I get that new pulley.

Also, it's amazing how hot the egr tube gets. It sucked all the solder out of my copper pipe joints. I tried again with jb weld on the joints instead.

 

[jd4242]

Yup, stock rubber.
I'm pretty curious on what numbers come back also

I do know the smaller pulley makes a pretty noticeable difference. I don't want to bother with the dyno till I get that new pulley.

Also, it's amazing how hot the egr tube gets. It sucked all the solder out of my copper pipe joints. I tried again with jb weld on the joints instead.

I bet.thats why i cant see how it helps to lower tempsyea its night and day when i switch pulleys

 

[Dono]

Well, I had my new smaller pulley chromed before installing it. I'm running in to an issue where the pulley slides even further back on the M90 shaft, causing even more of a belt allignment issue. As a result, my belt exploded on me today. I had another belt and a ratchet with me, thank god.

The right way to fix this would be to pull the m90 mount off, cut the welds on the tup plate, and have it re-welded a quarter of an inch forward. That would get the belt riding on the idler pulley properly. :-( The mount is aluminum, so its going to cost me.

 

[jd4242]

Being you have extra ribs on that pulley i take it your using the outside most of the pulley?so are you saying even on the outer side your still a 1/4"off.so your really like a 1/2" off from the belt riding in the center of the 8 rib pulley?

 

[Dono]

Yup, you summed it up pretty good.
I have to be careful with moving too far forward though. My fuel line and water neck will end up being in the way again.

 

[Dono]

On the bright side, I'm ready for a dyno, and a tear down a 1/4 mile track.
We have a track not too far from here, so I'll wait for an evening that is set aside for street cars and go for a tear.

 

[jd4242]

Yup, you summed it up pretty good.
I have to be careful with moving too far forward though. My fuel line and water neck will end up being in the way again.

Aww that sucks

 

[Dono]

Ya, ill snap a pic tomorrow. I eally need to get this smaller pulley sorted out. I love the extra power.

 

[RangerSVT]

Check and see if you can mount the pulley backwards. When I measured my m90's pulley I could gain a 1/4" by reversing the pulley, could be a temporary fix, then have either a spacer made between the pulley and housing or a custom pulley machined 1/2" further out (might be cheaper than moving the plate)...

SVT

 

[Dono]

I tried flipping the pulley already. The shaft and the pulley hole is tapered, for a tight press fit. That's the big issue. When I reverse the pulley, I can't slide it on far enough and its a bad fit on the shaft.

I don't even know how I could get a custom pulley made with the correct taper in the hole, and just the hole a few thousands smaller. I'd even be guessing how much smaller the pulley hole would need to be.

Keep the suggestions coming. There might be an easy answe I havn't thought of.
....I wonder if I reversed the pulley and took it to a machine shop if they could match the taper and make the pulley slide on the shaft to the correct depth? Might be worth taking it to them for an opinion.

 

[jd4242]

I tried flipping the pulley already. The shaft and the pulley hole is tapered, for a tight press fit. That's the big issue. When I reverse the pulley, I can't slide it on far enough and its a bad fit on the shaft.

I don't even know how I could get a custom pulley made with the correct taper in the hole, and just the hole a few thousands smaller. I'd even be guessing how much smaller the pulley hole would need to be.

Keep the suggestions coming. There might be an easy answe I havn't thought of.
....I wonder if I reversed the pulley and took it to a machine shop if they could match the taper and make the pulley slide on the shaft to the correct depth? Might be worth taking it to them for an opinion.

You could go with a quick swap system.its two piece,you could use a washer or even have a machine shop make a new hub.that would be pretty simple to make,i have that spare one but the holes are drilled wrong.

 

[vroomzoomboom]

hey don

http://www.interlakedragway.com/