Engine: Supercharger mounting bolt threads stripped

[tim333]

I want to install heli coil inserts to repair the threads for the supercharger mounting bolts. The hole goes all the way through, I'm concerned about shavings and the tangs from the insert falling into the chamber inside. Is that a sealed chamber or part of the inner workings of the supercharger? ?

[SN-60]

Off the top of my head...I think bits of aluminum from the drilling would indeed fall inside...I can check for sure tomorrow if you want.

[tim333]

That's my concern. Inside, is that area separate from the inner workings of the unit?

[64V-K7]

The bolts around the perimeter of the supercharger body, which are the same ones that rest in the mounting cradle or the ones you'd remove to "clock" the unit, do not penetrate the inside "oiled" chamber....

Here's a partial pic...

[tim333]

Hmm, on second thought, your cut-away doesn't look like my Paxton unit.

[63 R2 Hawk]

Cutaway is of an SN 57, yours looks like an SN 60. Probably, the bolt holes in question are the same.

[tim333]

The cutaway in post #4 looks like it says McCullough Supercharger when I enlarge it.

[bezhawk]

Robert Paxton McCulloch was the guys name that owned the company. After the company sold to Studebaker, and Andy took over, it became Paxton. They are pretty much one and the same, except for the variable rate drive pulley.

[52 Ragtop]

They are "basically" the same unit. To convert a VS-57 to a SN-60, the front housing needs to be machined down. and the pulley changed. I did that for the blower on my Avanti.

Jim

[DEEPNHOCK]

Robert Paxton McCulloch was the guys name that owned the company. After the company sold to Studebaker, and Andy took over, it became Paxton. They are pretty much one and the same, except for the variable rate drive pulley.

The history is quite interesting (see Paxton history copy below) http://www.paxtonauto.com/article.php?id=3
The history is quite interesting (see VS57 history copy below the Paxton copy) http://vs57.y-block.info/history.htm
McCulloch also was good at developing real estate and moving bridges...
(Like The London Bridge to Lake havasu, Arizona). http://www.citylab.com/design/2013/10/how-original-london-bridge-ended-arizona/7200/

================================================================================ ================
The History of Paxton Automotive
McCulloch Supercharger History

90 HP 60 Cubic Inch Engine (courtesy of Richard McCulloch)
The first product of the McCulloch Engineering Company was a 2 stroke 60 cubic inch 90 HP racing engine developed by Robert P McCulloch, Gerald C Robechaud and Milton Hoeppner. Another product developed at McCulloch Engineering by Francis L. Colburn was a centrifugal supercharger for the flathead Ford V8. The flathead Ford V8 was an enormously popular powerplant at the time, and a low cost centrifugal supercharger developed for this engine had potential for high sales. The resultant supercharger was belt driven, was horizontally mounted between the standard intake manifold and carburetor, and may well have been one of the first aftermarket blower systems produced.

The 1937 McCulloch Supercharger
McCulloch Engineering Company was based in Milwaukee, Wisconsin and the flathead supercharger unit was manufactured and sold between 1937 and 1940, and was significantly different to the later McCulloch blow through centrifugal superchargers in that it was an inline unit, which compressed and mixed the fuel/air charge. It consisted of an impellor, which turned at six times the engine speed in the impellor housing, and was driven by a set of worm gears mounted on the drive shaft and rotor shaft. The worm gears were driven by a triple pulley mounted an input drive shaft driven from the crankshaft pulley using several belts and were initially lubricated using engine oil under pressure from the engines oil system. By revolving at high speed the impellor caused the fuel/air mixture to build up pressure, up to a maximum of four pounds, within the impellor housing as a result of centrifugal force, and the pressurized mixture was discharged into the inlet manifold. There appears to have been two versions, one without a water jacket, and the other with a water jacket around the impellor housing which was used to warm the air/fuel mixture and was purported to aid low speed performance. A special three/four belt crank pulley was furnished for the Ford crankshaft, two new water pumps with three belt pulleys, as well as a set of matched V belts, a belt idler pulley and a special air cleaner which was required due to the reduced clearance added by the supercharger. The initial units, manufactured in 1937 and retailing for around $85, were designed to bolt onto the existing Ford and Mercury V8's which had the water pumps attached to the cylinder heads. Continuous improvement by the McCulloch engineers resulted in a modified version being introduced in 1938, retailing for $125, and which was also engine oil lubricated via a supplied intake manifold, which contained all the necessary link ups required for the engine oil lubrication. These also appear to have been offered with in water jacketed and non water jacketed versions. In 1939/40 thermostatic control of the exhaust gas through the impellor housing was introduced, in order to promote a rapid warm up of the fuel/air charge output from the blower. These flathead superchargers were designated with a model number that correlated the year of manufacture against the intended application vehicle (M for Mercury and F for Ford). Hence 38F refers to a 1938 model intended for a Ford.

The later 30's McCullochsVS57

The move was made in 1946, and Los Angeles was picked due to low manufacturing costs and the availability of skilled mechanics. A fifteen acre piece of land was purchased opposite the airport and some old barracks set up to serve as offices and plant buildings. As well as Bob McCulloch and his family, a further 33 families of McCulloch Aviation employees made the move to Los Angeles, and as a part of the relocation Bob McCulloch bought 13 houses and 16 apartments to house these employees. Initially during 1946, whilst the 80,000 square foot factory was being built, old barracks buildings were used to house the offices and plant. Many of these had leaky roofs and probably did not create a very good impression when Henry Kaiser arrived with his retinue to enquire about a two cycle automobile motor, however they did serve the purpose and within 60 days of setting up the first engines (lawn mower and chain saw) were being produced out of these buildings, along with other staple items such as die-cast gas heaters.

The new McCulloch Motors Inc. factory in Los AngelesBob Paxton McCulloch demonstrates a Chain Saw.

McCulloch Motors Inc. Vice-Presidents and President: (L to R) Gerald Robechaud (Tools and Methods), Fred Breer (Sales), Sherwood Egbert (Production), Robert Paxton McCulloch, Secretary-Treasurer Joseph Hegener, John Ryde (Engineering) outside the new factory.
This expansion led to McCulloch Motors producing helicopters and gyro-copters, as well as more interestingly setting up Paxton Engineering on May 1st 1950 to research new product lines which would allow the continuous expansion of McCulloch Motors. Initial projects for Paxton Engineering were the MI-15 portable pump and subsequently a series of smaller pumps, although by mid 1951 Paxton Engineering was tackling the design of a new and improved supercharger.

Paxton Engineering chiefs. Manager John Thompson and Director of Research Austin Gudmundsen


The concept of a cheap, bolt on aftermarket supercharger for the general public was never dropped by Bob McCulloch and extensive research was carried out by Paxton Engineering (who changed fairly quickly to Paxton Products) to produce a system which would deliver a significant amount of boost at low engine rpm without subsequent high impellor speeds at high engine rpm. The system was required to have the service requirements of the automobiles it was to be fitted on, and should to be quiet in operation and retailed at low cost. Manufacturing and installation requirements specified that one supercharger model could be fitted to a variety of vehicles, and that lubrication was internal to minimize contamination.

The VS57
The VS57 was the result of over $700,000 being spent in research and development in an effort to meet these requirements, and was made possible by the elaborate multi-section magnesium die casting production methods developed by Gerald Robechaud . The VS57 was first produced in 1951 in limited numbers, and was extensively road tested in California for two years before being marketed to the public in 1953. The VS57 was driven using a V shaped belt and used a unique Variable Speed (VS) drive pulley in conjunction with an idler arm to generate high boost at low engine rpm. The flanges of the supercharger pulley were designed to have a variable separation, which was used cleverly in conjunction with input shaft speed multiplication via a planetary ball drive, to vary the impellor speed across the engine rpm range. At low engine rpm belt tension separates the flanges of the input shaft pulley and drives the input shaft at a 1:23 ratio to the crankshaft pulley. At high engine rpm the boost produced is regulated to 5 pounds and boost is used to force the input shaft pulley flanges together, causing the belt to rise, and the input shaft to be driven at a ratio of 1:13 to the crankshaft pulley. The actual input shaft ratio changes gradually between 1:23 and 1:13 as the closing flanges overcome the tension of the idler pulley. The planetary ball drive multiplies the input shaft speed by 4.4 to 1 to produce high impellor speeds, thus producing boost. A kick down set up is incorporated which forces the blower into high boost when there is a sudden power demand, and this is governed by a solenoid switched via inlet manifold vacuum, which drops on high acceleration. Lubrication was achieved by a cam driven oil pump mounted on the ball driver shaft which was immersed in an internal oil reservoir.

McCulloch engineers Ben Parsons, Jack Dilworth, Harold Moore and Walt Deacon inspect a cutaway model in January 1954.
The VS57 met all the requirements that were initially specified. It could produce high boost at low rpm due to the kick down setup and speed multiplication achieved by the planetary ball drive. The planetary ball drive was quiet in operation and lubricated using an internal oil supply of automatic transmission fluid. It was designed to blow boost through carburetors in place of the existing air filter, and could therefore be bolted on any engine, providing there was sufficient room underneath the hood. Manufacturing costs, and subsequent retail prices, were relatively cheap due to the use of die cast stampings, and the fact that it was a single reusable product line.

Assembly line January 1954 and Open day visitors October 1953
The VS57 was officially unveiled to the Motoring press in September 1953 via a conference at the McCulloch Motors site. McCulloch vice president C. Fred Breer briefed representatives of the press and national magazines on the design and performance capabilities of the supercharger. After the briefing they were allowed to conduct test drives of a range of McCulloch equipped vehicles. The press response was favourable and many magazines subsequently reported on the supercharger, with the Los Angeles dailies leading the way with reports the day after the conference.

Fred Breer presents to press representatives and press representatives inspect test vehicles.

The attractive side of press conferences
Initially the supercharger was only available for 1950 through 1953 Ford cars, although fast gearing up of mass production in October 1953 resulted in the kit range being extended to cover very nearly every commercially available V8 and straight 6 engine in early 1954. As well as manufacturing the supercharger McCulloch Motors also set up an installation shop so that initial owners would benefit from proper factory installations and consequently avoid bad early publicity whilst the dealer network was being established and trained up. McCulloch employees were given a 35% discount off the price of the supercharger kits, although the discount did not include the installation cost.

Paxton installation shop
The lack of the dealer network in the early days meant that most publicity, apart from the initial press launch, was concentrated on the Los Angeles area. The new supercharger was lavishly displayed at the October 1953 PanPacific Motorama in Los Angeles using a 40 foot long stand. Three cars were displayed at the Motorama, a Ford, Mercury and a Cadillac engined Allard and the stand was staffed using an alternating pool of 35 McCulloch staff with actress Jane Easton (RKO and TV) recruited to front the stand. As a further publicity stunt by special arrangement the shows Miss Motorama was also crowned Miss Supercharger and in personal appearances at the show and on television she wore a crown topped with a rotating replica of the VS57.

Westchester Sports Car club members inspect the McCulloch.
The VS57 supercharger was formally presented to the SAE on January 15 1954 at Detroits Sheraton-Cadillaac hotel to a convention audience of some 500 automotive engineers. The presentation was by John W Oehrli and consisted of prepared text, coloured movies and slides followed by a brief question and answer session. Earlier demonstrations to the Kaiser-Willys corporation had sufficiently impressed them with the VS57 supercharger to cause them to shift it as standard on the Kaiser Manhattan installation of their 6 cylinder 226 cid engine in 1954, albeit labelled as a Kaiser supercharger. This was publicly announced in late January 1954 in the wake of the SAE meeting and its debatable that the Kaiser-Willys adoption of the supercharger effectively killed off any interest by the majors.

The Supercharged Kaiser ManhattenThe Packard Panther
Given the performance nature of the supercharger and its possible appeal to motorsport enthusiasts McCulloch also actively promoted the VS57 at Carrel Speedway at the Memorial Day meeting on May 30 1954. A supercharged Kaiser was entered in the 250 mile endurance run and it qualified 12^th in the 33 car field. A crash with another car resulting in engine damage resulted in an early retirement for the Kaiser after 55 laps however. More positive publicity was achieved via a static display of a MG TD equipped with a McCulloch supercharger, the pace car for the race being garnished with McCulloch supercharger banners and the winner of the 500 lap stock car classic, John Torres driving a Dodge, being presented with a VS57 supercharger.

John Torres is presented with his supercharger by John Thompson, and the MG displayed at the speedway with stock car driver Bill Cantrell.

The Carrell Speedway pace car for the Memorial Day meetingwww.vs57.com/mcculloch tips.htm

1957 Studebaker Golden HawkVR57McCulloch Roots Blower on a 55 ChevroletPhase I VR57 (Ford Motor Co.)The Phase II VR57 (Ford Motor Co.)
With the homologation requirements met, further supercharged Ford production was not scheduled until later in 1957 when the Phase II VR57, a which produced nearly the same boost levels as the slightly larger Phase I units, were used. These were nearly as potent as the earlier Phase I units, and proved to be a lot easier to maintain and repair. The actual number of supercharged Fords produced in the Phase II production runs, are unknown, although between 208 and 211 of this production is believed to have been in the form of Thunderbirds, and a similar number (maybe as many as 300) were produced as Fords. All of the Phase II VR57 equipped Ford engines were designated as F code engines, and power outputs were 325 Hp @ 4,800 rpm or 340 Hp @ 5,300 rpm dependant upon the installed cam (256 or 290 degree duration), although Ford conservatively claimed only 300 Hp. Interestingly Paxton Products claimed that the output was actually 360 hp with the hotter cam.

^stVR58 Unit for Chevrolet and CorvetteDO-VS59The DO-VS59SN60 and BeyondAndy Granatelli proudly displays the new SN60 unit alongside an old VS unit.The SN60VR70 Industrial/Marine Blower

[SN-60]

Good read!....Notice our old friend Sherwood Egbert in the middle of a group of McCulloch execs in one of the photos.

One boo-boo,.....The author gives us the impression that the blower used on the NOVI V8 Indy engine is basically the same unit as the newer Paxton gear drive 'street' unit.....It isn't!!

[DEEPNHOCK]

I agree that this was a tortured sentence/paragraph. It does differentiate the difference, though, so I wouldn't call it a 100% boo-boo.

Of interest is that you can still buy a CNC reproduction of that supercharger today from Uncommon Engineering.

http://www.uncommonengineering.com/catalog.html

(copy)

Miller style finned centrifugal blowers
Totally unique and totally exclusive ! From in-house design through aluminum foundry pattern making and machining, the new line of Classical Forced Induction for Ford V-8's is the nostalgia look sensation!

Miller Finned Centrifugal Blower
The Miller "style" centrifugal blowers were all the rage in the 30's, adorning various Miller and Duesenberg race cars and highest end passenger cars of the Era. These blowers have not been produced since the Deco Era. Finally, Uncommon Engineering recaptures the Classic Look and Spirit of the 30's with this incredible centrifugal supercharger. Hardened and ground Class 10 gearing, modern impeller design, slipper bearings, pressure oiling, while retaining the Classic appearance of Harry Miller's artistic finned centrifugal superchargers add incredible panache to your powerplant!

Miller centrifugal

Good read!....Notice our old friend Sherwood Egbert in the middle of a group of McCulloch execs in one of the photos.

One boo-boo,.....The author gives us the impression that the blower used on the NOVI V8 Indy engine is basically the same unit as the newer Paxton gear drive 'street' unit.....It isn't!!

[SN-60]

I agree that this was a tortured sentence/paragraph. It does differentiate the difference, though, so I wouldn't call it a 100% boo-boo.

Of interest is that you can still buy a CNC reproduction of that supercharger today from Uncommon Engineering.

http://www.uncommonengineering.com/catalog.html

(copy)

Miller style finned centrifugal blowers
Totally unique and totally exclusive ! From in-house design through aluminum foundry pattern making and machining, the new line of Classical Forced Induction for Ford V-8's is the nostalgia look sensation!

Miller Finned Centrifugal Blower
The Miller "style" centrifugal blowers were all the rage in the 30's, adorning various Miller and Duesenberg race cars and highest end passenger cars of the Era. These blowers have not been produced since the Deco Era. Finally, Uncommon Engineering recaptures the Classic Look and Spirit of the 30's with this incredible centrifugal supercharger. Hardened and ground Class 10 gearing, modern impeller design, slipper bearings, pressure oiling, while retaining the Classic appearance of Harry Miller's artistic finned centrifugal superchargers add incredible panache to your powerplant!

Miller centrifugal

That IS interesting!

[tim333]

Update: Did the heli coil repair and installed the supercharger today, all went well. Now I can properly position the correct fuel filter in the small space between the supercharger and valve cover.