A post yesterday about a supercharged 58 Packard Hawk got me to thinkin about this. What types of superchargers were available back then and what applications were there? I've seen the Stude setups, 57 t-birds and fairlanes, and a couple of lathams. I even have a pic of a 57 Dodge Royale 2dr hdtp that sat in a local mans front yard for years that had, I believe, a Paxton setup on it. So what could be had?
All those centrifugals were around, plus some early GMC Roots types. The hot rodded Roots blowers I've seen from the early days used multiple V-belts to drive them, which didn't work too great once some real boost was being made. Naturally, the drive systems were home-brewed, as no "kits" existed to mate a Roots blower to a V-8 automotive engine. The modern BDS, Dyer, Kuhl, Weiand, etc. kits and cog belts are the result of this need for reliable well-engineered Roots blower kits. That, and the need for well-engineered rebuilt 6-71 (and similar) superchargers for automotive-type applications. I have seen pictures of early chain-driven setups too. I wouldn't want one, but they looked mean as hell. Most had chain guards engineered around them, but that wouldn't be enough to make me comfy. Beyond the centrifugals, Roots, and Lathams, I don't know of any other belt-driven superchargers from back in the day. Turbochargers were certainly around (since like 1903), but they were not common on hot rods. Nitrous came around in WWII, but wasn't commonly adapted to hot rods until the '70s or so. ~Scotch~
Latham, S.CO.T, GMC, Judson, and McCulloch were the primary supercharger manufacturers of the period. Best link for educational purposes: http://www.vs57.com I had originally planned on placing one of these on a car I'm building, but passed on the idea, as the drive system (planetary ball type) limits the application to *about* 300 cubic inches or 300 HP, whichever comes first. After you reach this threshold, the fan affinity laws state that you're gonna attempt to move eith too much air - or try to move it at too high a static pressure for the drive system to hold up. The balls start to slip on their races, and the unit eats its drive system in fairly short order. It's one of the reasons there aren't that many of these around - and the few that are probably need rebuilding, as the drive system has to be in *perfect* working order to function - or the unit grenades... Literally. I have a very detailed article at home which goes into the design limits of the VS57 - and how to modify the unit for more HP; it's very involved, requiring special German drive balls, recontoured races, and a conversion to full-flow engine oiling. Without this, a VS57 is limited to about 5# of boost. S.CO.T.s were neat blowers, but suffered from build quality issues which resulted in short operating lives. Some US based company (S.CO.T. was based in Northern Italy) picked up the tooling and did a run of them afterwards which was more reliable - I forget the name. Lathams were interesting - a multistage centrifugal, if I recall correctly. Expensive as hell, and not many out there, period. NetNet: Early blower systems were good for *about* a half atmosphere, or 5-6#. This represented a 30-40% increase in power, no small potatoes, but about as much as a carefully modded motor.
To add to Scotch's comments: The way drag racers got around the drive limitations of Rootes type blowers was to direct-rive them off the crank by using a flex coupling. The drive ran at the crank centerline, with a mass of plumbing on the high sice of the blower to route it to the intake side of the motor. Low side of the blower received either side-draft carbs, or more likely - a Hilborn fuelie setup. These systems went away in the mid 60's - about the same time the cog belt systems began to show up. Cog belts allowed racers to overdrive the blower - and a whole new method of grenading motors was born!
I run a 471 roots type on a slant six--225ci, and according to the dyers blower web site, a 225 with no modifications will handle 17 lbs of boost. I have run mine up to 15 lbs. with a single v-belt on it. The belt is only good for about a year and I buy one that is actually to short and remove the bolts from the blower, tilt the front end down, install the belt and tighten it back up. So far there has ben no damage to the motor or bearings from doing this. If I run the proper size belt, it will only last a couple of months before I lose all of my adjustment. The motor is bone stock except for some port work on the head. As soon as I am through building the HA/Gr that i am working on, I plan on installing a different cam that is more suited to a blower and see what happens.
The amount of boost is a function of the volume of the motor, the speed of the blower, the static pressure, and the belt drive system used. The bigger the motor - the lower the static pressure that can be made before belt slippage. You're 'cheating' a bit by forcing the belt deeper into the sheave, thus improving the grip of the belt. It's cool that it works!
I agree 100%! I have an electronic tach and have used it to determine that the blower is 10% overdriven on the 225. The reason for the other cam is more duration to hold the valves open longer and shove more through it.
Hey Chuckspeed " have a very detailed article at home which goes into the design limits of the VS57 - and how to modify the unit for more HP; it's very involved, requiring special German drive balls, recontoured races, and a conversion to full-flow engine oiling. Without this, a VS57 is limited to about 5# of boost." Would love to see a copy of that article. Jim
I have to find it - I've sold off most of the mags I had to raise jing for the next project. I'll look for it this weekend and will scan/post if it turns up.
I dont get all the nervousness about chain drives, your SBC timing chain is under a tin cover and I have NEVER seen one escape, and bikes ran chains for decades, some with stupid horsepower levels blowers and nitrous with just a tin guard. What am I missing, other than the fact that some manufacturer discovered that people will pay $1500 for 3 pulleys and a belt?
"Lathams were interesting - a multistage centrifugal, if I recall correctly. Expensive as hell, and not many out there, period." ..................................................Lathams are axial flow. same as the compressor section on a jet engine.
I have seen a chain for a blower drive break at high RPM's and it flew over a hundred yards--- pretty scary!!
had originally planned on placing one of these on a car I'm building, but passed on the idea, as the drive system (planetary ball type) limits the application to *about* 300 cubic inches or 300 HP, whichever comes first. After you reach this threshold, the fan affinity laws state that you're gonna attempt to move eith too much air - or try to move it at too high a static pressure for the drive system to hold up. The balls start to slip on their races, and the unit eats its drive system in fairly short order. It's one of the reasons there aren't that many of these around - and the few that are probably need rebuilding, as the drive system has to be in *perfect* working order to function - or the unit grenades... I knew a guy in about 1959 or so that put 2 Paxtons on a 57 300C , worked pretty well on those 392 cubes.
I may be wrong here and if so please tell me the right story. But i was under the impression that Paxton blowers were McCulloch blowers with the variable drive system replaced with a solid hook up. Yes? No?
I am not sure of the changes made but they were pretty much the same blower except for the name . Seems to me I remember that McCuloloch started out making lawnmower engines in Arizona.
Here is a bit more info about MCCulloch/Paxton. McCulloch Motors Corporation is a manufacturer of chainsaws. The company was founded in Milwaukee, Wisconsin, in 1943 by Robert Paxton McCulloch as a manufacturer of small two-stroke gasoline engines and introduced its first chainsaw in 1948, the Model 5-49.<SUP id=cite_ref-0 class=reference jQuery182027632058811611215="13">[1]</SUP> McCulloch moved its operation to California in 1946. In the 1950s, McCulloch manufactured target drone engines, which were sold to RadioPlane in the 1970s. These McCulloch 4318 small four cylinder horizontally opposed two-stroke engines were also popular for use in various small autogyros, such as the Bensen B-8M and Wallis WA-116. Bob McCulloch also started Paxton Automotive, manufacturing McCulloch-labeled superchargers like the one fitted to the Kaiser Manhattan, the 1957 Studebaker Golden Hawk, and Ford Thunderbird.
Robert McCulloch started making centrifugal blowers for Ford V8s in about 1937. Made them for a few years before WW2. After the war he made chain saws in California, then in 1953 introduced an improved centrifugal blower with variable belt drive and ball bearing planetary drive to the impeller.The first one was the VS57, thousands were sold as aftermarket accessories and more thousands offered as factory equipment by Kaiser, Ford and Studebaker. He made several models, the Paxton came out about 1960 and was the old VS57 without the variable speed drive. Then there was the well known GMC series adapted from GMC 2 stroke diesel engines. SCOTT and Italmechanica blowers which were Roots type like the GMC. The Judson from England for small cars like the MG and VW. This was a positive displacement vane pump. Latham axial flow, like a jet engine, a series of hand made fan blades, very complex and costly to make but very efficient. Turbonique from Florida made some wild blowers, centrifugal type like a turbocharger but driven by their own hydrazine rocket fuel motor.
Attached is a photo of a crank driven P1SC Procharger centrifugal supercharger on my 392 Hemi. The intermediate gearbox from The Supercharger Store steps up the engine RPM thru a set of gears to spin the supercharger to the RPM speed needed for the design boost. On the 392 the boost at WOT with the engine under load is 6 psi. The carb is a blow thru 4150 Holley rated at 750 CFM.
Here's a VS57 on my 1954 Kaiser Manhattan...factory installed and boosts horsepower to about 140. Not alot by today's standards, but enough to keep up with the Twin-H Hornets back in the day.
Here's an aftermarket supercharger other than Mcullogh/Paxton from a 1950 Hot Rod mag: ...I sent my $.25, but Piston Displacement Chart hasn't yet arrived Have Fun
""The Judson from England for small cars like the MG and VW. This was a positive displacement vane pump."" The one I have is for a 40hp VW...The tag on it says "Judson Res. & Mfg Co., Conshohocken, PA.." In reasonable shape I may put it on my Crosley..
A few more not previously mentioned are the English Wade superchargers as originally fitted to the Commer "Knocker" Diesel engines in the UK. See link below. http://www.britishv8.org/articles/roversupercharger.htm Another type of blower adapted for use as a supercharger over the years is the Godfrey cabin blower.These were used originally in aircraft to pressurise cabins in flight. http://www.ozrodders.com/forum/viewtopic.php?f=1&t=38433
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