rebuilding after the crash

A brief intermission today. My grandson hanging out with crazy grandpa getting some culture. Ziggy zagga. Ziggy zagga oi oi oi. It's time for German fest at the Summerfest grounds. Prost. We will be in lannon wi for the big car show tomorrow. Eight nitro cars firing up on main St. Come out and smell the nitro.

 

To get to 200 mph I need to tune up the blower. This involves taking it apart and restripping the Teflon strips.
The blower has two very different styles of strips. The black strips are very hard. They seal to the case. The case needs to be measured first. New black strips are installed. The rotors are put in a lathe then cut to fit the case. It's a involved process to get it right. It doesn't need to be done very often.
The white strips are teflon. They seal rotor to rotor. There's two per rotor. This is were the magic happens. A good street blower will have the black. The problem with whites on the street is it creates alot of heat compressing air. The other issue is it wears out fast. A few street miles and it's done. Big show nitro cars restrip every pass. A crew guy is dedicated to the blower. As the whites wear the tune up changes going richer due to less air. After a restrip the tune up is richened do to more air. On my car after a few passes it will wear a little and maintain a max boost. When the boost starts to drop it will get restripped.
To do the work a special gear puller is used. The gears rotate as they are pulled. Before disassemble the rotors are marked rt and lt. Punch marks are made on the gears so it's timed correctly.
The screws on each end are removed. A small screw driver flips up the strip. A pliers grabs the strip and it's pulled out.
Wd-40 is sprayed in the groove after cleaning. Putting the rotor in a lathe set in neutral goes a long way to get this done. They don't just slide in. A new strip is pulled into the groove. It's cut off leaving a extra inch on each end. The strips stretch. They sit for a while then a soft mallet is used to tap them in a little more. The screws are put back in. Then a razor blade cuts them off perfectly even with the end of the rotor.
I stopped at nitro dragster driver Tony Zizzos shop. Tony drives the Rustolium sponsored car. I was there to borrow his puller. I didn't need my own because I would send my blower back to Littlefield every two years. That's going to change. Next week we will be making our own. A rotory table is needed. A print has been made. This is hot rod stuff here. I will cover the machining process next week. I talked to Littlefieldyears ago about the rub marks on the rotors. They say its onlya cosmetic thing. It makes no difference. The strips are doing the sealing not the rotor.

 

Something that the casual fan and/or hot rodder may not know, is that the rotors spin away from each other, moving the air around the outside, not down the center of the two rotors. In the photo of the top of Brian's supercharger, you will notice a screen. OEM supercharged Detroit engines used those for many reasons. Not many hot rods or inexperienced racers use them. That is asking for trouble. In the photo below is the result of a mounting bolt backing out of the inside of an Enderle Birdcatcher, and that team was not using the supercharger screen. The result was the bolt getting pinched between the rotor and the case, and the rotor won. What results next is a massive intake leak, which sends the RPMs to the moon, and the engine doesn't want to shut off. There was an instance like this recently that happened to a funny car backing up from a burnout. The result was a fatality. Brian immediately installed a screen to his supercharger after it was known what had happened. At the end of the day, you don't know what you don't know, and sometimes that gets people hurt.

 

These things can be very dangerous. I know the family very well that suffered a loss of life. The driver was my sons collage room mate. I'm very surprised this is not a nhra rule yet. Everyone should run a screen. Thanks Justin for bringing that up. Some guys use the reasoning that the screen causes a slight restrictions in air flow so they won't run it. Its not worth the risk.

 

When I bought my first blower set up from Gene Mooneyham years ago, I asked him about the screen. He said it was a good idea and I've never run a blower without one. That photo above should be enough to convince most people. That's expensive. Sorry about your friend.

 

Very good points made here on the all important screen. I have always run one on my blower since day one. Gary Dyer supplied the screen when he built my blower. Thanks for sharing the blower tech Brian. Interesting stuff.

 

I’ve always run a screen on mine, even though it’s a street car with air cleaners. Better safe than sorry. I think it was Austin Coil that sat down and computed the area of the screen wire to see how much it reduced the inlet opening.

 

Been using a Screen Since early 80s ,
To me Not Using One Is like not useing
A Fuel Filter , Just Extra insurance,,
I guess my way of thinking comes from Many years to this day @ National events @ times Standing between the Zoomies , All pro classes , National tracks 15 -20 feet between cars ,,,
Out law Tracks 8-10 feet between Fenders , & Pullers ,
If Not running a containment ballistic bag , Then definitely screen should be used street or strip/Race ,,,

I'm surprised Brian Not running a
Diffrent Case design and rotors,,
More efficient, ( I started off small & worked up Many Hand me down parts)
Yes you can get there with the case design model / rotors you have,
But a different case and rotors would make it easier, But $$$$,

I'm surprised that many that run Hot set ups, Race set ups do not service their own supercharged /blowers instead of sending them off,
I do not have a fancy
Shop , Im not that Old but remember taken a part Engines , Transmissions etc.
In parking Lots , side of road ,
( Like road Kill) Taken butane torch
beaten in wrist pins Brass hammer ,
Before having Clips & Buttons ,
Polishing cranks with emery cloth and shoe strings,
Back in 80s around 15, Wilma @ BDS
& Littlefield teaching me over the phone before Internet and all there was ,was national dragster Yellow pages of drag racing,,,
Sticking rags in between rotors to brake / toque gear bolts, setting Gear & timing, clearances..
For those who do not Know , wants
Restripped 3-4 foot Braker bar needed to rotate Blower / supercharger
Best mounted to an engine or Too heavy table, plenty of WD-40, once started it will loosen up but still be very tight

 

This Pic I took between 98 to 2004 IHRA Fuel event I was @ ,
This is type of low Budget Thinking to full-blown sponsorships I was around,
Modern at the time TF/D

 

If I understand correctly, the black strips are removed, new ones put in, then the rotor assembly is machined down in a lathe, cutting back the black plastic until it is a tight clearance to the case. I assume the case is measured beforehand, with the rotor in place, using a vernier (?) between the rotor face and casing bore. How tight a clearance is aimed for?

The white strips get pulled out, and new ones tapped in. Do they get machined down too, or are they "close enough" and get clearanced by wearing in?

Cheers,
Harv

 

Don Gartlets said that he found pennies on top of the screen.

 

Sounds like someone thought it was a wishing well.........wishing they could beat Garlits.

 

Harv you got it.

 

Something else to look at is the end plates. If they get scored from the rotors they both need to be machined. The end plates will need to be re hard anodized. The end plate/rotor mating is a big part of sealing up the blower.
13Eddy30 my blower starred out as a retro case gas street blower. The retro case has the small pie opening in for the rear exhaust port. This provides more stability for the rotors in the rear. It also decreases the exhaust area increasing the pressure. Last year I added the white strips. The only thing left to do is add high helix rotors. I'm holding off on doing that because if I go back to street driving they will create too much heat. My blower when fresh creates 35 lbs of boost driven 20 percent over. That's all I need.

 

Seeing that we are in pretty deep on the blower rebuild let's go a few steps further. The gears and rotor shafts can only go on one way. The splines dictate this. Before disassemble I punched the gears two/one for easy retiming. I'm just waiting on the strips to show up next week. The first rotor is in the lathe ready to go.
I mentioned the bottom of my case. This is referred to as a retro case. More pressure. More support.
The manifold has a extra pattern drilled into it. I use the rear pattern. By doing this the distribution is cleaned up. The front cylinders get more air than the rear. To straighten that out the front nozzles are richer. Moving the blower back decreases the stagger so all eight are running closer to the same power output. Look at a modern top fuel car. They are really set back. My buddy Roger that I go see in Iowa invented this idea years ago. It took a long time for other teams to catch on.
The manifold uses a o ring to seal. There are three patterns to allow for different size blowers.

 

Very cool that you are going to do your own blower servicing. Thanks for taking us along, good stuff.

 

This is stuff you dont normally see. Its hard core hot rodding. It keeps things fresh and interesting.

 

Blower rotor timing is very important to have it set correctly I see your blower has the steel gear set as I expected it would most old gmc blowers used cast gears and tend to wear some so servicing the blower regularly is also important on a old street blower I know Brian makes it look like it’s real easy but it takes time and experience to tear one apart like this and reassemble it properly as the rotor timing is achieved by shimming the gears at least on a street blower the more expensive high performance blowers are machined to a spec to eliminate the thin shims that can escape under the extreme conditions and high rpm the blower is spinning remember if the engine is running 8000 rpm and the blower overdrive is 35% the blower is spinning 10,800 rpm Brian thanks for taking the time to post this info

 

Very well stated Jackson. Most of the inexperienced guys do not really think about what is happening with the blower to crank effect in rpm and boost. Thanks for posting .

 

My blower does not use shims.
If I keep racing it I might put hi helix rotors in it next year.
For those that don't know what that is the rotors have a extra 15 percent more twist. It makes alot more air.

 

Just a few pics of othere case designs and rotors there's several more for full out race,,some maynot seen or had hands on

 

Tonight's fun. Building a mount for the starter. Not only does the mount hold the starter stable so it won't fall out while driving. It has a lock hole. These starters cost 3500 each. They could easily be stolen. The design works so another will be made for the spare starter. You always need two. If one goes bad at the starting line the spare comes out.

 

Hmmm, is this to say we shouldn’t get you started @racer-x ? Hehe.

 

$3,500! X2! Holy Crap!

 

That's without the 1200 dollar 48 volt battery and charger. Of course the cable is extra. I'm fortunate I only had to buy one. A friend passed away recently and had a brand new one. The guy running his estate is a racing friend of mine and ex top fuel driver. The spare is his on loan as long as I want it.

 

I sure admire what you've accomplished, Brian, if it was easy, everyone would be doing it. My KB Hemi sits under a blanket, awaiting my attention. I had to turn the Hemi spend-fest off for awhile. One thing I've learned, it doesn't pay to have some quality parts mixed with some questionable parts. Just blows up in your face.

 

Or worse.

 

Never would thought That !!!
Would be Pretty Balls Z to steal a Starter
Drive , Walking Up to some ones tow rig
& grabbing,,, as we know that a pretty&
Unique item!!
I know some things that would Happen if Spotted some one doing

There was a Pretty well known Female FunnyCar driver pass in last few years
Local to me ,, Her Team /Crew Pretty Wild Crew , especially after the race or they were eliminated from a around,
It was pretty rowdy afterwards..
& still when they Bring car out,
But in last year Her husband also has passed so I don't know if the car will be out anymore

 

I learned from a friend's mistake. He had one stolen without a backup. Mine is engraved with my name in a few places. Thieves are opportunist. When they see a chance they take it.
We have a few things around that identify as manual hole punchers but I won't get into that. Life can get real out on the road. I have been there a few times.

 

Lead can cause Poisoning
So Be aware !!