When Dick explained to me what he could do with the Bridgeport CNC vertical mill, I was amazed. Basically he mounts the pulley, then locates the center hole and the existing bolt pattern and then tells the mill what he wants done and it does the functions as instructed. I'm sure there is 40 years of knowledge that goes along with this, but I WANT ONE SANTA!!
I expected minor adjustments but the pulley simply bolted on. Remember the center hole is enlarged to .980" diameter and the new 2.25" four bolt pattern is offset 45 degrees and drilled to .259". With the 1/8" spacer, the new pulley fits over the existing cast iron pulley on the pump (1" grade 8 bolts required-original fan blade). This moves the fan forward 3/8".
We are now at 1.14 times the crankshaft speed instead of 1.59 times using the original 4.25" water pump pulley. Big difference!
This would offer a 1.01 pulley ratio if the stock damper was used.
Now if I wing'er up a wee bit in the garage, my organs don't cramp from terror and the spectators and my hood are safer on launch (kinda sporty looking too).
The speed and efficiency of the water pump are a factor here and I will report if any problems crop up.
I received the invoice from Rich Tool but there was evidently an Inkjet cartridge malfunction. I penciled the corrected amounts in prior to submitting it to Corporate.
Thanks once again Dick!!!!!
Took the 34' for a 10 mile ride this morning, no cooling problems indicated and so nice and quiet. Previous fan noise was terrible, even at normal driving RPM.
This modification is a big plus in my situation.
Back from Dick's shop, the pulley is perfect!!
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| BBFL1WP |
The pulley with internal spacer should mount on the existing water pump pulley and slow the the fan to a reasonable speed that will prevent damage should I have to wind'er up a little. This is a CVF Racing part
# BBFL1WP pulley that has the center hole bored to .980" and the 54' bolt pattern (2.25") added to the mounting flange. The spacer is installed internally between the new pulley and the existing pressed on 54' water pump pulley.
This is going to require a little time to install, and I will report back on the operation.
Thanks again, Dick.
These two were probably my closest friends during my teen years and the renewal of that friendship after 45 years has been great. All of us went our separate ways during that time and ended up a little beat up but still kickin'.
Dick is the tall good looking stud and Tom is the Italian weight lifter to the right.
Now the hard part.......
Both are standing in front of Dick's VERY NICE '57 Chevy.
The '57 has a recent paint upgrade, wheels, Discs, and it looks like new pinstriping!
I always felt that the '57 was Chevy's best 50's year and Dick's has all the goodies and upgrades. The dash has an absolute mirror finish in black that is hard to believe. he's got a beautiful early Mustang that sits in the garage next to the '57.
I shouldn't post Tom's '32 'cause it probably needs work....
1932 Chevrolet four door 350/350 and
a magnificent vintage lacquer candy apple red paint job on a flawless body. This car has more chrome underneath that mine has in total. To
give you an idea of this car, there is no dust on the lug nuts under the hubcaps.
As you can see, it's probably a good thing that I live 300 miles away from these two. I would not be allowed to park in the same lot for morning coffee.
Beautiful cars. Just click on the pictures for enlarged view.
At the age of 16 years, I learned the hard way (twice) about fan blades. Coming home from work one night, I wound up Dad's '51 Henry J six in the middle of Coyote pass leaving East L.A. One of the four blades of the fan broke off and came through the hood......started shaking like hell. Back to Ford Blvd. on the way to work for a hood and another fan. Cost me a weeks pay and he was more than upset.
THEN, maybe eight months later, in the same place, I was copilot in Dad's other chopped and channeled '51 Henry J when HE wound that little hot rod flathead four up and did the same thing except this time it sliced a hole in the top tank of the radiator. He detonated on me even though I tactfully pointed out that HE was driving, not me. I still had to remove the HOT blade right there in the dark while he stomped around looking at his custom Henry J hood with the '50 Merc nose leaded in. Lessons.........
The '54 vintage Chevy six has a stock water pump/fan ratio of 1.41. The fan runs faster than the crankshaft. 4000 rpm crank = 5640 fan rpm.
On my 235, I needed a later Chevy Harmonic balancer (6.75" instead of the 6.0" original) to bolt the serpentine drive pulley onto. Now the ratio changes to 1.59. 4000 crank rpm = 6352 fan rpm (Scary!!)
The answer is a larger water pump pulley, but which one? Evidently the dimensions of the multitude of water pump pulleys is classified space shuttle technology. No one wants to share this information, nor is it listed anywhere that I could find.
I finally got a response from a very courteous gentleman at CVF Racing who took the time to sell me a pulley that is close enough to modify and mount on the original '54 Chevy water pump pulley (part # BBFL1WP).
Three modifications are required, bore the center hole to .980, redrill the bolt pattern to 4 on 2.25" bolt circle, and add a 1/8" spacer between the water pump pulley and the new aluminum pulley. This pulley moves the fan forward 3/8" which I need to clear the serpentine idler.
This new pulley is 5.9" in diameter and will result in a pulley ratio of 1.14.
4000 rpm crank = 4560 fan rpm. Much improvement!
As soon as the pulley is back from Dick's machine shop I will summarize the results.
There are several references on supercharger design and all contain various formulae and discussions on the superchargers and related design criteria....read'em, done that.
Of particular interest is your individual application (engine size and type, supercharger size and type, and intended use) in order to correctly determine the speed (flow/boost) of the unit. The MagnaCharger is a roots design and boost is closely related to RPM. A number of variables come in to play and all must be considered regardless of the formulae.
I sized the drive components according to the references for the 90 cubic inch 4th generation MP90 by Magnuson at a pulley diameter of 4.1" for 1.5 lb. of boost. The calculations did not factor in the volumetric efficiency of the MP90 (.74) in the 6000 rpm range and the calculated and measured boost at .74% is actually 0.0 lbs.
Changed the supercharger pulley to 3.8 in. from 4.1 in. (1.513 pulley ratio) and observed an increased boost to 1.0 lb. This is fine for a street vehicle used only for crusin'.
At my age, it's not the launch from the stoplight that's important........
It's how cool you THINK you look when the light turns green!!
Now the supercharger is turning
almost as fast as the fan blade which is
turning way too fast..... 6352 rpm at 4000 rpm engine speed. Imagine a Star Wars light saber, thats my fan.
The answer is on its way to Dicks Tool and Die shop for slight machining (new fan pulley) and will post the results as soon as I get it installed.
This is the new 3.8" pulley, I found a 3.4" pulley on Ebay last night.....
2.9 lbs. of boost. I'm thinking .........
