I must say that is some great and HELPFUL info. You may have just helped this guy do a quick fix which most people would over look. That is what I love about the boards and I missed it a lot over the last 9 months.

St,
Best of luck on getting your truck going again. -Mat-

 

Here's a little input on the blowers. The Eaton is actually a Magnuson blower. From the outside it has three major pieces, the snout, gear housing and main case. The snout has the pulley on the front and inside the snout are bearings to carry the tension load of the belt and support the main shaft. When you look at the blower, you'll see that the snout tapers back into a housing which is about 5/8 thick and the same shape as the blower case. Inside that housing are a pair of gears. The rotors are actually driven by those gears. It may look like the shaft just turns one rotor and that rotor turns the other one, but each rotor has a gear that drives it and keeps the rotors timed. One gear is fixed to the main or input shaft and drives just that one rotor. The other gear is driven by the input shaft gear and drives the second rotor. Ideally, the rotors never touch each other. The far end of the rotors have a turned end or diameter on them that are supported by bearings in the back of the main case right below where the plenum feeds the air into the blower. That's it - no magic, no miracle parts, just a pulley, two gears and two rotors spinning in a housing. As such, the blower is a pretty simple device. All of the porting work is done on the main case, not on the snout/gear and rotor assembly.

When the blower is being ported, the first thing they do is to unbolt and remove the entire snout, housing and rotor assembly as a unit. Here's how its done. Remove the bolts (8 of 'em) that hold the entire snout and gear case assembly to the the main case. Pull the entire snout, housing and rotor assembly out of the main case. It comes out in one big piece. No oil need to be drained and you never see the bearings or gears. Put that assembly aside and you are now left with just the main case. There are two bearings in the main case that support the back end of the rotors, so they have to be covered with tape while the porting is done, so no grit gets in them.

Once the porting work is done on the main case, it is cleaned and the snout, housing and rotor assembly is dropped back in and the bolts re-installed. The porting shop has no reason or cause to open, inspect or do anything with the actual drive portions of the blower. When I sent a unit in to be done for that same September special, I asked why I needed to send the rotor, snout and drive assembly and was told that I'd save on UPS by not sending them - and that I was better off, since they are subject to damage in shipping.

So here's the summary: The porting folks are most likely not responsible for the problem. The bearings in the snout are decent, but they are not the best money can buy. You can check to see where the problem is yourself. Take the bolts out and remove the snout, gear housing and rotor assembly. The split line for that assembly is at the main case, not about 5/8 inch forward wher the gear case meets the snout. Once it is out, see if the pulley and rotors will turn. If not, the problem is in the drive end. If they do turn, look at the two bearings in the back of the case. I hope the information helps.

 

wish i had thought about pulling the snout and rotors, oh well
that makes me think
would KB rotors fit in to a eaton case????

 

Mondo1, you are giving me hope that I can have this supercharger fixed.

kerno, thanks for the supercharger 101 class. The way you explain it, the supercharger doesn't seem so complicated.

Also, thanks to everyone else for your input.

I should have the supercharger off tonight or tomorrow. I'll update asap.



-Mike

 

The K-B blower has more volume (or displacement) than the Eaton, so the rotors are quite a bit different. The K-B also has higher helix rotors, so they have a faster twist to them. If you look at the bottom of the Eaton, you'll notice that the sides of the triangular opening (the discharge port) match the angle of the rotors. Since the K-B has higher helix rotors, the shape of the discharge port in the K-B is also different.

Mike: If your blower is history, I do have a spare, so e-mail me if required. You can also go to www.magnusonproducts.com

 

Update: I pulled the blower off tonight, and it appears to be a rear bearing failure (my uneducated guess). You can see where the rear of the rotors have made contact. It also looks like the rotors made contact with the upper rear of the blower housing.

There is some minor teflon flaking on the intercooler. But, not as bad as I have seen on some stock blowers. I'm going to pull the intercooler and clean it before I put the blower back on.

I'm going to drop the blower off at Stegemieres (Aptens porters) tomorrow or Saturday, and see what they say.

 

i thought the KB was also a 112ci
it would make a sweet upgrade tho, dont you think

 

It looks like something similar to this happened to my blower. The front snout is fine, andd the rear bearings are fine with semi fresh grease still on them. It appears the rotors expanded and hit the top rear fourth of the housing. We checked 5 other Lightning blowers and each had small scaring marks in the rear from the rotors.

The shop is going to try to smooth out the scaring and rotor damage, They couldn't guarantee how well it will make boost. But, I really can't afford to pay $800 for another ported blower right now.

 

You are probably on to something. When I pulled my blower to be ported the rear of the rotors had some very minor contact scratches on them. Hopefully the shop will be able to fix it up for you.

 

Yea, it should be an easy fix. Let me know how you make out.