I have my engine block and head at the machine shop getting cleaned up so I can assemble my chevy 261 inline 6. at some point later in its life, hopefully sooner than later, I plan to add the mccullough vs57 supercharger onto it. my issue is getting the carburetors to work with the blow through set up. does anyone on here have the knowledge I need to obtain? i plan to use dual carter w1s on my mcgurk intake. here's some pictures of my stuff to entice you to add knowledge to my post. thank you.
That’s way cool, especially your “inspiration”. The bracket and pulley look to be in pristine condition. I’ve run VS, SN and VR units. I’ve still got a VR on my F code clone, and an SN with brackets in storage. But mine are all Y block Fords, so that’s not much help. I suspect there was at least 1, maybe 2, metal strap brackets to go from the cast bracket to another mounting point or 2. At least the very similar Y block bracket was that way. Since John Erb passed away I don’t know who does full rebuilds. Craig Conley at Paradise Wheels in San Marcos CA. might still be doing those. He’s an expert. I don’t think Pat Fleishman (sp) in Texas does, but you can track him down and ask. But you really want someone to look at that unit before you run it. If they’re not right, the damage will be real quick and not cheap. The carbs you have are something I know nothing about. Doesn’t mean they can’t be used as a blow thru, but most I’ve seen are 2 or 4 barrels. Meyers Studebaker probably knows as much about those as anyone, they’d be worth a phone call. They’ve got parts and experience, and o lot of that goes beyond Stude’s. https://www.myersstudebakerparts.com/ https://paradisewheels.biz/super-chargers Those units don’t make a lot of boost and it doesn’t come on until 3000 rpm or so. Pulley size will bring it in sooner. But overspeed for more boost will destroy a stock unit. How you actuate the split pulley drive can be done a number of way (and has been) from a simple throttle switch to more complicated set ups with Hobbs switches. One last link, not updated for years. Still lots of info there. It won’t work for me right now, let’s hope it’s not gone. http://vs57.y-block.com/
Yes, Jon or Mike can help you w/both carb & fuelpump setup info(although they may suggest different from what you have - the basic theory still applies), & *correctly* rebuilding the McCullough blowers. Both dad & son are not only very knowledgeable but also nice folks & won't lie to you. I've known & dealt w/them for years, still do on occasion, & reco them highly. Marcus...
How about building a box for carburetors and pressurize the box? Might have to increase fuel pressure to compensate. Terry aka dirt t
The easiest way to get where you want to go is to find a '57-'58 Studebaker Golden Hawk, '57-'58 Packard sedan or Hawk take-off. They came with an air box and a calibrated Stromberg WW 2-bbl and a boost-referenced fuel pump. With those pieces, you're good to go. Trying to modify the two 1-bbls, you're on your own. jack vines
W/all due respect to some posters, but: If you really want the headaches of a carb box, have at it. They aren't needed & Stude did away w/them by the 60's using a carb hat. There are better designs these days than back then, but if the old look is what you need, well... it is your choice. I guess they do look rather neat... & Ford used them, on 50's y-blocks, by the 60's mostly sold thru Shelby - & those are *expensive*. Kaiser used the system. & I think one other oem which I can't remember right now. To run w/o a carb-box & use carb hats, some carb & fuel pump mods will be needed(some of which you'll need to do anyways if you run a carb-box). Sadly, a couple of DIY sites are no longer "alive", but there should be others out there. Haven't looked lately. & ~ 4->5 (older)books on the subject too(think: blowthrough turbo). & w/o searching the HAMB, I'd bet it's been discussed to death. Also consider if you use 1bbl, or std 2bbl carbs, how will you control the enriching circuits when under boost? IIRC, the carb-box Stude 2bbl stuff ran larger main jets to compensate. You could mimic a 4bbl circuitry w/a progressive 2bbl, or I suppose iffen you want to get real crafty, 4 1bbls, w/2 of the 1bbls coming in like secondaries & jetted/modified as needed/wanted. Would make for an interesting manifold-carb layout, but should work if done correctly. I suppose you'll get ~5psi boost, maybe in the manifold, but the carbs are capable of withstanding much more. A couple of decades ago a fellow w/a national newsletter went thru a lot of testing, & found that carb-boxes weren't worth the trouble, although he was after high-pressure enclosures, & just did the carb hats. Marcus...
Bought this intake at an estate sale.Pretty sure it was a Chevy 6 but never knew for sure what it was made for.Sold it about 5 years ago to a HAMB person on west coast. Had the makings of a blower intake but blower would have to have been pretty small.
I’d like to see a pic of your intake. I had a McGurk intake, dual carb, for an inline 6. Traded to to a fella in So Cal for something, many years ago. I recall seeing if it would work on my 235, but something didn’t line up right.
the mcgurk intake hits on fenton headers so I went with the stock exhaust manifold. I got the mcgurk valve cover so I'm kinda married to using the mcgurk intake, although I have options.
I have an Edelbrock intake on my 261, it hit the Fentons as well. I very lightly clearenced the intake with a 4” grinder.
Carter W-1's are excellent carbs for a normally aspirated multiple carb set-up. For a blow-through application??? Probable necessary modifications: (1) Idle mixture screw seal (2) Throttle shaft seal (3) Accelerator pump seal (4) Metering rod seal (5) Boost reference (6) Possible float mods ( I think the smooth float would take maybe 4 psi, and the ribbed float maybe 5 psi) (1) is easy, (2) would require machine work on the throttle shaft(s), (5) is easy, (6) has a precedent on how to procede with modification. (3) and especially (4) are going to require some major thought and fabrication. Depending on your machining and fabrication skills, could be a fun project! Please keep us informed! Jon
The Tattersfield intake I used also hit the Fenton headers. I found that if I spaced the intake out from the head 1/4” it would clear without having to grind on the manifold. Since the intake was for a 216 head, I machined one side for the 216 diameter and the other side for the 235 head diameter.
Not this one, sorry. Quit rebuilding due to time constraints several years ago. Will be happy to discuss the mods for which precedent exists (573) 392-7378 (9-12, 1-4 Mon-Tues). Sealing the metering rods is going to challenging! Jon
Actually, with the Carter W-1's, this would be absolutely no problem. The W-1 has a mechanical power circuit. Would simply need to calculate the fuel required under boost, and cut metering rods with the appropriate power step. Could always check for a "stock" rod from a different W-1, but doubt one could be found with the proper steps. Not a problem to cut rods with different calibrations. The mechanical power circuit is one of many reasons the W-1 is our absolute favorite for in-line normally aspirated multi-carb single barrel set-ups. None of the calibrations would be an issue (no pressed-in jets, all are removable/replacable); the big issue is sealing all of the places where the internal pressure could eject jets of fuel all over the engine! A secondary issue, depending on boost, is keeping the floats from collapsing. The Studebaker Avanti with a "converted" AFB would collapse the floats at 7 psi if the brass floats were not modified (6 if the non-ribbed floats were used), and the foam floats were worse! The precedure is to disassemble the floats, fabricate a "brace" from expanded aluminum sheet, install these in the floats, and reassemble the floats. Jon
Hey, Gassersteve; posts 10 & 14 are a very good idea to emulate. Hotrodworks; idea & example is good thinking. Thanks for posting it. Hey, carbking; The Q wasn't rhetorical, as I really didn't know the answer, as I don't know those carbs & their details. Thanks for the info. If Steve requests, I'd appreciate you posting the info on those carbs here. Good stuff to know. IIRC, 57/58 Stude blown engine ran fat. OK then, not now. But 3-5psi isn't much, but sure feels good... . I doubt he'll see more than 5psi at the carbs, more like ~3-4, as iirc, McCullough measured the boost# at the blower outlet only. & the lit claimed ~5psi. Yah, most everyone else measures inside the manifold. Boost is nothing more than a measure of resistance to flow(thru the valves) anyways... For the floats, hopefully they're brass, drill a small hole(on top, thankyou) & fill 'em w/(low)expanding foam(2-part), just enough to fill, not damage the float. To seal, use a touch of solder, or fuel-proof epoxy.(think gas-powered model airplanes, or maybe por15 or jb-weld[supposedly gas/alky-resistant]. IDK about the last 2, as I haven't looked hard at those for this situation). Will have to check/reset float level anyways. The other vents/opening/etc, I don't know about. & while it may be a "dirty" word to some, there is good benefit to running late-model "emissions" carbs - as they're already pretty much sealed. & I'd grab one to copy the sealing if needed. For the oldies I'd seal one up & run a vent tube thru the throat into the float chamber, if one isn't there. For the shafts, if he wants to get trick, sealed bearings on each side of the butterflies would work(think Weber/Dellorto here), or a small tube from airhorn to the outside casting edge of the throttle plates.(Cheap n crummy way is to hand drill in correct places, epoxy a small dia brass tube into the holes, & connect w/short length of vac line. Crude, but works.). Even slightly worn shafts holes will seal mostly ok w/this. This'd take care of the outside & throttle plates. From what I remember from putzing w/old carbs, they only needed all the outside-venting because they didn't have internal vents to the throat or even to the aircleaner. Miserable late70s->80's images coming back... ;( . The late-model Stude carb-hat had a small device to vent under normal needs, close under boost. However: "the big issue is sealing all of the places where the internal pressure could eject jets of fuel all over the engine!" . Please elaborate. ??? As I said, I'm not familiar w/these carbs, sounds like they'd be worth learning about. Are the metering rods & lever inside the airhorn or outside? Why would inside be an issue? I'd look at making a cover of them if they're outside. I should find a pic/diagram I guess. . I'm thinking the whole inside of the carb needs pressurizing, so's it just thinks it's in a much denser atmosphere. If this can't work, then neither will an airbox. TIA. Marcus...
Marcus - going back to my previous answer: (1) mill a shallow hole in the casting around the idle mixture screw, insert an O-ring that stands proud of the casting, then a washer to retain the O-ring. The idle mixture screw spring will retain the washer. (2) Carter AFB's and Holley 4000's both used a vacuum seal, but there is no place in the W-1 to acquire vacuum that would be less than the pressure at the throttle shafts. I think machining grooves at each end of the throttle shaft to accept the Holley Teflon strips would do the trick. (3) I don't know, some thought would be necessary to figure out a seal for the pump shaft. The shaft is rectangular rather than round, and projects into the bowl from the outside of the bowl cover. Not a lot of room either above or below the bowl cover for mods. (4) This was not an issue with the AFB's, as the step-up rods and controls were located under the "cap". This is not true with the W-1, as the metering rod is inserted through the bowl cover from the outside of the carb into the bowl. First thought was to machine a "grommet" seal from Teflon to fit the bowl cover at the entrance of the metering rod; but the metering rod must "float" in the jet. So the second thought was to machine "guided jets" similar in design to those used by Carter in the early BBS and BBD carbs (also one smog application of the AFB) where the jet is significantly taller than otherwise necessary, and a "guide" is machined in the top of the jet above the metering orifice that would locate the rod. (5) Drill hole and insert fitting in bowl cover. (6) Not going to argue about the foam, because I have not tried the expanding foam. We did try the aftermarket foam floats when playing with high boost Studebaker Avanti applications with less than desirable results. I would use the method I outlined above disassembly of the float, fabrication of a baffle, and reassembly of the float with the baffle. This was the Carter solution. I have used it, and I know it works. Obviously, the expanding foam would be easier; but us old geezers tend to use solutions we have previously successfully used. Something about the old dog and new tricks cliche. The W-1 is a great carburetor for multiple inline normally aspirated applications. We have sold more than a hundred for multiples, probably many more than that, but too lazy to check the files for a moot point. I don't know of a better single barrel for that type of application. Jon
Just a thin film of sealant. No gasket on the intake ports, but I did use a gasket on the exhaust ports.
I've heard not so good things about paradise wheels rebuilds but I have no personal experience so I cannot say for sure. I'm researching VS57 stuff now so when I actually get my hands on one . . . . These guys might be worth a phone call: CUNDN Racing
I used the methods shown in this article to modify my 4150 Holley. I don't know if you could get a Holley that would work for your 6. https://www.hangar18fabrication.com/blowthru.html Ask for Cliff at CUNDN. They rebuilt the VS-57 unit that I purchased from someone else that never used it. Cliff is very knowledgeable and helped me out a lot. My VS-57 works great. https://www.jalopyjournal.com/forum/threads/mcculloch-vs-57-supercharger.1251165/#post-14555790 https://www.theturboforums.com/threads/need-help-on-initial-pvcr-sizing.387868/ Glenn
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