Porting the M90

Regul8r

Registered User
My question is this...
Does someone have a template that could be layed on the top of the SC, trace a mark and then port it to that mark?

I would like to open up the 94 SC I have but want to make sure I do it right.
Would be nice if someone had a paper cut out for us to lay inside the top of the blower and then trace it and port.

Maybe the same for the rear intake port, lower intake manifold to heads?

ANYONE?
 
That was a good read.

But seemed to have the same multitude of opinions on it as we do here.

I have seen some on here say fill in the silencer ports, other say don't.
That site had some say you can go wider AND longer on the V but others saying you should only clean up the edges of the V but extend it top and bottom.

Again with ALL the people who have ported SC's here I would think SOMEONE has found the BEST port design with or without the silencer ports blocked off.

Maybe someone has a GOOD ported blower who can take off the SC hat and make a tracing template of it.

Guys on my Intruder sight design things all the time and then send out plans.
I have a template to make a set of forward control plates to move my foot pegs.

SOMEONE????
 
heres the link to my garage. i posted some pics of the case being ported. i did a little extra work after these pics but not much. on the wide end of the V you can even take a lil more out then i did but at this point i was tired of grinding on it. 1 extra thing i did was i polished all the area's that i ported. i dont know if it really helps or not but it sure looks better. to polish start with 600grit, then 800, 1000, 1500, 2000, 2500. you can even go up to 3000 but not needed.

http://www.sccoa.com/forums/garage_vehicle.php?do=view_vehicle&id=112

also being an early model case dont go as far back on the V as i did. keep around 1/2 inch more meat there then mine. keep in mind there is not much point in porting out the V if you dont port the inlet side. you might want to port that to.
 
the one I am porting is a 94/95 so that set up on yours will work!

I can take your pic, print it, and use the copier to blow it up to actual size and mark the blower using your cut out pic as a template.


ANYONE ELSE have pics of their ported blower cases?
Could put together a photo album to get a good idea of what template to use.
 
also on the inlet side of mine, many on this forum and a blower rebuild shop told me i could go alot more on the porting. if you go that much then consider welding in the silencer ports. mine was right on the dot so i decided to fill them in anyways. plus it sounds cool. it gets alot louder
 
You have to be careful on the v because you dont want to take it too big so most guys leave it alone as far as making it any bigger because all it does is loose boost if you take it too far. My silencer ports are closed because I wanted more sc wine, it does not have any other effect than making a louder wine. taking the notches on the h bar out and smoothing the edges seems to be the most effective method.
 
heres the link to my garage. i posted some pics of the case being ported. i did a little extra work after these pics but not much. on the wide end of the V you can even take a lil more out then i did but at this point i was tired of grinding on it. 1 extra thing i did was i polished all the area's that i ported. i dont know if it really helps or not but it sure looks better. to polish start with 600grit, then 800, 1000, 1500, 2000, 2500. you can even go up to 3000 but not needed.

http://www.sccoa.com/forums/garage_vehicle.php?do=view_vehicle&id=112

also being an early model case dont go as far back on the V as i did. keep around 1/2 inch more meat there then mine. keep in mind there is not much point in porting out the V if you dont port the inlet side. you might want to port that to.


Looking at your garage pictures your car looks really nice and I have a question about the intercooler, that one in the picture ( White ) is huge and I am wondering did you make it or what it actually is and how much better than the stock one does this one perform ?
Bill
 
More opinions, Don't do anything but this, don't go too far, other opinions I have heard say you can take it all the way out to the silencers, cut/don't cut the nubs off the fat part of the V, if you port the top you have to port inlet side or it is a waste of time.
SERIOUSLY?
This seems like Republicans vs Democrats, everyone has an opinion but no one is backing anything up with facts.

so can SOMEONE give the masses a reality of what and what not to do?
Not what we CAN do or WOULD/WOULDN'T do.

Enough research has been done on these things that SOMEONE can say, provide pics, flow numbers etc... for WHAT to do.

I can do the work but need a template to scribe/mark to cut and polish to match.

Not sure IF I am pissing anyone off or not but it is frustrating to think that NO ONE has numbers as to what is BEST to do or TOO FAR and you screw it up facts!
 
porting

When I bought my silver '89 it came with an extra supercharger. The guy said it has been ported but since it still needs bearing in the nose section I have not tried it. All other bearings have been replaced. Pay the shipping and you can give it a try. I will try to get some pics of it.
 
More opinions, Don't do anything but this, don't go too far, other opinions I have heard say you can take it all the way out to the silencers, cut/don't cut the nubs off the fat part of the V, if you port the top you have to port inlet side or it is a waste of time.
SERIOUSLY?
This seems like Republicans vs Democrats, everyone has an opinion but no one is backing anything up with facts.

so can SOMEONE give the masses a reality of what and what not to do?
Not what we CAN do or WOULD/WOULDN'T do.

Enough research has been done on these things that SOMEONE can say, provide pics, flow numbers etc... for WHAT to do.

I can do the work but need a template to scribe/mark to cut and polish to match.

Not sure IF I am pissing anyone off or not but it is frustrating to think that NO ONE has numbers as to what is BEST to do or TOO FAR and you screw it up facts!

Yes, plenty of research has been done. I think it's sort of a dead horse at this point. That may be why you aren't getting exactly the info you want.

If you want to know what works with an M90, look at Magnum Powers' MPX. Bear in mind that their port design is intended to work with significantly faster rotation of the blower. Also bear in mind that they cast the blower case from scratch. You can't get the same size or shape inlet port that MP did without lots of welding. So it's not really applicable to you.

To put it in general terms:
You have 3 lobes on each rotor, spaced 120 degrees apart. Focus on one side of the blower and imagine the rotor sweeping down toward the inlet, out to the side, and scooping air up along the outside of the case and exhausting it through the outlet port. In order for the blower to work, the following rotor has to seal the inlet port before the leading rotor opens the outlet port. The inlet and outlet ports can't get too close together or the blower will leak air backwards, and it won't make boost. So the distance that you can widen the outlet port is tied to how far you can widen the inlet port. You can widen one a lot, or both a little.

The amount of extra time that the blower spends with both ports sealed directly affects leakage back to the inlet side. To a point, more sealing is better. The stock setup has ports much more than 120 degrees apart, so it is good in regards to sealing.

However, increased sealing time also means that the inlet and outlet ports of the blower would necessarily be smaller ... because the case is a fixed size, and they can only get so far apart. That reduces the ultimate flow capacity of the blower. Once the blower spins really fast, it becomes hard to fill the chamber between the rotors with air in the short time that the inlet port is open. That means less boost is generated.

If you increase the size of the ports, inadvertently making them closer together (again because of the fixed size of the case), then you reduce the sealing time of the rotors. This hurts low-RPM performance because boost will leak backwards. But it increases high-RPM performance. In order to take advantage of the blower's new strengths, you should increase the overdrive of the blower. That spins it faster and keeps it in its most efficient operating range more of the time.

Since you are talking about porting, not welding, it's safe to assume that the inlet will be the most restrictive part of your blower. You can only widen it a little bit, say 3/32" of an inch, and still maintain a workable sealing flange. You can, however, contour the inside of the case so that the air has a little more time to enter the chamber between the rotors.

However far you take the inlet will dictate how far you can take the outlet. You can move it back to the point where the rotors will still seal both ports, plus a little bit for safety. However, it may not make sense to move the blower outlet back as far as you can, because it may already be big enough to move all the air that the inlet can provide. And moving it beyond that point will yield no gain, reduce sealing time, and wear out your tools.

For an example of what works well with a stock case M90, look at what Magnuson Products did when they turned the 94-95 blower into an S-port. It's really not very radical. I think they had the time to figure out if something else would work better, so I think theirs is a good lead to follow.
 
Guys,

I'm all for doing stuff yourself, but there are some things on these cars that should be left to people who truly know what they are doing. Specing camshaft profiles, porting cylinder heads and porting blowers are all in this category.

I'm not saying it's rocket science, but there is a lot more to it than just making the inlet and outlet bigger. If you want a quality product, send your blower to Magnum Powers, Dave Dalke, High Speed Lab or Steigimer.

David
 
Done the blower porting myself on a late model blower as well as a early blower.

My recomendations:

Early Model: Make sure you have money for or have a replacement incase you screw up. There are many pictures to go by but no real signifcant data to go with.

Late Model: If you have alot of experience doing port work then go to it. Get some pictures of the Magna port and make it match but becareful because there is not alot of room till you cut through the case. If you have never really done any porting (or have do a little from time to time) then put the die grinder down and let the porting to a professional.
 
Thanks for all the replies.

I did some more looking and talking to people.
I got it.

Would be nice to see people's pictures of their inlet and outlet portings in orcer to give others ideas of what and what not to do.

More work to do in the garage I guess! yahoo!
 
Thanks for all the replies.

I did some more looking and talking to people.
I got it.

Would be nice to see people's pictures of their inlet and outlet portings in orcer to give others ideas of what and what not to do.

More work to do in the garage I guess! yahoo!

Go to the search button and than type in S port pictures. I beleive it is at the bottom of the first page. I posted pictures

Ken
 
I was asking the same thing several years ago. I think the answer was 3/4" and no more on the outlet. I initially wanted to stay away from the bolt bosses at the front of the case but can not remember how deep to cut them, but they were no a problem.

SWS
 
I was ADVISED by a VERY reliable source...

1/2" wider on both sides, do not port the point of the V any further than it is stock, clean up between the bolt bosses, bevel the edge under the front edge to let the air flow smoother out from under the bolt boss area, LEAVE the bolt bosses(you CAN take them out and extend the fat part of the V all the way back to the edge) IF you take them out make sure you SEAL the threads of the bolts or you can pressurize the snout area with boost that pushes through the threads.

As for the silencers... you can fill them in all it does is make the blower noisier. ZERO performance gain. When you fill them there are MANY ways to do it. If you use JB-Weld make sure you bevel the edge on the rotor side to keep the JB-Weld from being blown out, can use a piece of aluminum to fill the hole and seal it in place with the JB-Weld. Youcan also take it to a welder and weld in a piece. Your choice.

On the inlet side open the rectangle up a LITTLE leaving enough mating surface to seal up good. Then clean up all the rough edges of the transition into the rotors. Open them up like the S-Port just be careful not to go too far and punch through the case.

I saw a good pic of a Magnuson/Magnum Powers ported 94/95 case that seems to back up the info I got. That's the info I got and going with.

Thanks to all who answered here, PM and phone calls!
 
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