Was perusing the Clifford catalog the other day, and happened across an IR design three two-barrel intake for the Chevrolet 235 / 261 inline six. Part number C-4750 Has anyone used one of these intakes? Jon
Never did personally, but I sold one to a guy who ran it on a 261 powered stock car. He used small base 2GCs from a 283, and eventually got it dialed in, after much trial and error.
Lots of pre-EFI I-6 engines ran triple carbs, Jags, Healeys, Datsun Z cars, perhaps even BMWs, etc. They just have to be the right size and jetted correctly for the build.
Well, I may need to start reading with a magnifying glass! There was a list of applications, but then reading the fine print, it stated that the manifold was designed for 3 of the 500 CFM Holleys EXCEPT for the Chevrolet models which were drilled for single barrel carbs. The three single barrels make a lot more sense than three two-barrels for a 235 / 261 Jon
The intake I had was definitely for three two barrels, and was alleged to be a Clifford product. It was rather high rise.
I've run 3 1bbls on a 235. I'm currently experimenting with 2 350 cfy Holleys on a 261. Some of my race buddies run 3 Holleys, but thery're on the later 6. 292. I have an old Clifford catalog but don't have with me to look up the number. The Corvette manifold used Carter YH carbs.
If anyone has one of the Clifford C4750 intakes that is available, I would be interested. This thing sufficiently intrigues me to build even though I don't have an engine to put it on. Bet if I built the unit, I could find a volunteer to test it for me. Jon
I was at a local car show a couple years ago when a survivor '39 Chev coupe pulled in with a rowdy sounding 6 cylinder in it. Of course I had to go see it, and ask the owner about what was in his Chev. He opened the hood to reveal a big 301 c.i. GMC six and it had an old period correct intake that had 5 carb mounting plates! Two of them were blanked off and he was running the two outside carbs, and center carb locations. He said for the street it was too hard to tune it with 5 carbs, so he built blankoff plates.
They were Rochester 2 bbl side draft carbs! I believe the Wayne and Arias 12 port heads both ran 3 2-bbl carbs as well.
I also think 3 Rochester YH single barrel carbs were correct for the C1 Corvette 6 cylinder. Like the one used on the Turbo Corvair out in the field. Corvettes might have had bigger venturis, or maybe not. As I recall the Corvair one had a surprising number of chrome doo-dads like fuel lines etc. Also not sure if the bling was a carry over from Corvette or not. https://images.squarespace-cdn.com/...19991219319-CYJUX9OLB2AZGJ3DTN6U/DSC_7671.jpg
The YH is a great carburetor, with a horrible reputation! Carter released a spring-loaded fuel valve for off-road and marine use in the 1930's. The YH carbs came with this valve. The common aftermarket kit had a conventional solid valve, and when used in marine applications, the bouncing of the waves caused the carbs to leak. Leaking carbs are definately undesirable on marine applications. The problem was not the carb, but the cheapsters that used the cheap aftermarket kits; but the carburetors got the blame. Jon
I used to use the spring loaded inlet valves from Jeep YLs to help the issues with the YHs on Corvettes.
I had a intake and the YH's that came off a Gray Marine Y block Ford. Found a pair of YH carburetor's in a box at an auction. They were off of a old Nash wrecker that was there. If I had enough money I would have bought that old wrecker.
I’ve got a Y marine intake with a pair of carbs. Was almost thinking about using them on a 235 I’ve got a 235 updraft intake similar to this gmc set up would be simple to add whatever to this and block off the bottom
I have a 2G TriPower on my 270 GMC. I've run the engine for cam break in only at this time. It's not idling well yet but sounds great when I open it up. Lots of things to check before I run it again, but that will be after I finish the rest of the driveline and fit the body. I have access to a dyno. Soon, I hope.
Here’s one I would like to try on my 261. But will have to clearance the firewall. Three Zenith 810’s
An inline six needs three Weber/Dellorto/Solex on individual runner intake. Choose carb size and chokes to match the power output. I could agree with someone having a different opinion, but then we'd both be wrong.
G_son, you're right for an IR-type manifold, but these chev-heads have siamesed ports. 3 inlet ports, for 6 intake valves. IR won't work w/this head, so old-style is the better way to go. 3-2's should work, but it'd probably work best if each 2bbl could be altered so's the throttle plates were separated on the shaft. Have them linked for each carb to open 1 throttle plate simultaneously, & use the other side as secondaries. Cool, but some trickery involved. Marcus...
1961 Car and Driver 1961 XKE road test https://www.caranddriver.com/reviews/a15112090/1961-jaguar-e-type-road-test-review/ "Our gas mileage was impressive. An overall average, including testing and very hard driving, of 22 mpg was realized. 1965 Motorsport road test of a 4.2 XKE - https://www.motorsportmagazine.com/...-1965/23/a-lengthy-road-test-of-the-42-litre/ "Motorway cruising at over the ton, allied to traffic work and a little pass-storming in Lakeland, failed to undermine the notable economy of the E-type, fuel consumption averaging a creditable 18.7 m.p.g. "
The Jalopy Journal
