I had a '72 Chevy van with the 230 and a 3 speed manual transmission. I contemplated using a 350 cfm Holley 4 barrel and this manifold. I took the dog house off and measured and the carb would have been in my right let. I gave up with this notion. I did a lot of work on that van. It got terrible gas mileage and my goal was to make it economical. I put a posi rear in it for travel to work in the winter snow and changed the gear ratio to I believe a 3:73 ratio. The engine was extremely clean, no sludge. I rebuilt the carb (1 bbl.) and made sure the body was not warped causing a vacuum leak, installed a replacement distributor so the bushings were new, put in a Melling flat tappet cam and lifters (what they considered a 1/2 race cam) which was very mild, timing chain and gears, and nothing improved the gas mileage and it stayed the same. I sold it and ordered a '76 with the options I wanted and the 350 4 bbl. was a 4 mpg improvement over the 230 with identical gearing. Plus, the dog house needed no modification. I would love to own either of them today. They were bullet proof for the most part.
I've been running and Offy Dual Port since the 1980's the they really can hit hard in the low and middle range. They really are two intakes molded together and it's a great idea for torque. If you open that up, you'll ruin that intake and it will NOT flow like a regular one would. If you really want to do that, get any other aluminum intake and cut it in half. Have TWO carbs feeding the front and back. Two small progressive 2 barrels, one front, one rear, will give a lot better response. Even better would be two side draft SU types like the old Jag or Z car used. Great torque from those. You might as well toss that Offy if you're not going to use it as intended because it's not a high CFM intake and you have the split all the way thru the whole system. You can also make and adapter that moves the carb over a few inches. Just drill out a block of aluminum so that it feeds at an angle. If you wanted to get wild, make an adapter so that you have two carbs on that, one for the primary, one for the secondary. If you haven't carved up that Offy, save your money, it won't deliver what you want. Its only game is port speed and it does an amazing job at that. It will give a nice bump in the low in torque and you can really feel the secondaries kick in hard right above the middle because you have two different port speeds and it's the same things as being "on pipe" with a motorcycle, it's like a turbo boost.
This is going to be a interesting build. Love it when people build something different. I'm hunting for a 318 poly to put in my '46 Plymouth instead of a LA series.
We are ready and can handle it! We definitely can make that flow and perform a 100 times better. The question is can the motor keep up with our work?? Lol😁
Why would you destroy the entire purpose of the Dual Port instead of just getting another open plenum intake? And use an AFB/AVS/Edelbrock square bore. Carter used to make 500 cfm carbs commonly for Mopar linkage.
Basically, the purpose of my channel is alot of working with what you have on hand, alot of "what would happen if .." etc. This is going on a Ford 300 in a Ford Econoline Van, and the intake itself physically fits, but the linkage won't become it faces the body/doghouse . Remember ford sixes are opposite of a slant six or Chevy inline as far as intake and exhaust side. Really puts me in a pickle, only way to make it work is put a 4 barrel inline on it. I having a legit company, professionals do the intake. They are also flowbenching it before and after. Im having the plenum milled open, but also some other modifications and a full port job ...stay tuned, you may be impressed. It's very possible that with this intake we make nearly the ideal intake for my application.
They indeed are. But the issue still , is which it's oriented primaries facing the valve cover, the throttle linkage will have to hang from the back of the carburetor and there isn't alot of space for it with only 1 1/4 inches of space and alot of potential for binding.
The intake is currently directional, and with the primaries facing the valve cover I have 1 inch from the edge of the intake to the body , which will make a throttle linkage and kickdown cable absolute hell... I wish they'd have designed the intake for secondary towards valve cover.
I had a '72 Chevy van with the 230 and a 3 speed manual transmission. I contemplated using a 350 cfm Holley 4 barrel and this manifold. I took the dog house off and measured and the carb would have been in my right let. I gave up with this notion. I did a lot of work on that van. It got terrible gas mileage and my goal was to make it economical. I put a posi rear in it for travel to work in the winter snow and changed the gear ratio to I believe a 3:73 ratio. The engine was extremely clean, no sludge. I rebuilt the carb (1 bbl.) and made sure the body was not warped causing a vacuum leak, installed a replacement distributor so the bushings were new, put in a Melling flat tappet cam and lifters (what they considered a 1/2 race cam) which was very mild, timing chain and gears, and nothing improved the gas mileage and it stayed the same. I sold it and ordered a '76 with the options I wanted and the 350 4 bbl. was a 4 mpg improvement over the 230 with identical gearing. Plus, the dog house needed no modification. I would love to own either of them today. They were bullet proof for the most part.
I've been running and Offy Dual Port since the 1980's the they really can hit hard in the low and middle range. They really are two intakes molded together and it's a great idea for torque. If you open that up, you'll ruin that intake and it will NOT flow like a regular one would.
If you really want to do that, get any other aluminum intake and cut it in half. Have TWO carbs feeding the front and back. Two small progressive 2 barrels, one front, one rear, will give a lot better response. Even better would be two side draft SU types like the old Jag or Z car used. Great torque from those.
You might as well toss that Offy if you're not going to use it as intended because it's not a high CFM intake and you have the split all the way thru the whole system.
You can also make and adapter that moves the carb over a few inches. Just drill out a block of aluminum so that it feeds at an angle.
If you wanted to get wild, make an adapter so that you have two carbs on that, one for the primary, one for the secondary.
If you haven't carved up that Offy, save your money, it won't deliver what you want. Its only game is port speed and it does an amazing job at that. It will give a nice bump in the low in torque and you can really feel the secondaries kick in hard right above the middle because you have two different port speeds and it's the same things as being "on pipe" with a motorcycle, it's like a turbo boost.
This is going to be a interesting build. Love it when people build something different. I'm hunting for a 318 poly to put in my '46 Plymouth instead of a LA series.
Adapt....improvise....overcome ! Another problem most likely solved !!
Those Dual Ports are a reminder of the gas rationing days of the '70s.
What about a Quadrajet? Smallish primaries but large secondaries. Be a smaller unit than a Holley at least lengthwise.
We are ready and can handle it! We definitely can make that flow and perform a 100 times better. The question is can the motor keep up with our work?? Lol😁
I'll see what I can do to get this engine to tax the intake.... 😂
Holley Sniper 2!
Have you tried Clifford Performance and see what they have?
Why would you destroy the entire purpose of the Dual Port instead of just getting another open plenum intake? And use an AFB/AVS/Edelbrock square bore. Carter used to make 500 cfm carbs commonly for Mopar linkage.
Basically, the purpose of my channel is alot of working with what you have on hand, alot of "what would happen if .." etc. This is going on a Ford 300 in a Ford Econoline Van, and the intake itself physically fits, but the linkage won't become it faces the body/doghouse . Remember ford sixes are opposite of a slant six or Chevy inline as far as intake and exhaust side. Really puts me in a pickle, only way to make it work is put a 4 barrel inline on it. I having a legit company, professionals do the intake. They are also flowbenching it before and after. Im having the plenum milled open, but also some other modifications and a full port job ...stay tuned, you may be impressed. It's very possible that with this intake we make nearly the ideal intake for my application.
Why not install TBI? Holley makes very good systems, and they are essentially a bolt on with lots of room to spare all around.
I do not care for fuel injection, I can match it or exceed it's power for pennies on the dollar. Nothing wrong with efi, just isn't my thing.
Isn't an Edelbrock a much smaller footprint ? Even though I don't much care for them .
They indeed are. But the issue still , is which it's oriented primaries facing the valve cover, the throttle linkage will have to hang from the back of the carburetor and there isn't alot of space for it with only 1 1/4 inches of space and alot of potential for binding.
How about an edelbrock/afb carb
Still would be an issue making the linkage fit with the carb mounted as specified by offenhauser. I prefer the Autolite 4100 as well
If you are opening up the plenum why not remove as much of the dividers in the runners also? They are just as much of a restriction as the plenum is.
what are the typical HP/TQ gains goin from the stock log manifolds & 1 barrel carb tothe offenhauser and 4 bb setup?
Why don't you just put a 4bbl AVS2 there? Should fit "as is" and has annular boosters too?
The intake is currently directional, and with the primaries facing the valve cover I have 1 inch from the edge of the intake to the body , which will make a throttle linkage and kickdown cable absolute hell... I wish they'd have designed the intake for secondary towards valve cover.
Would converting to a throttle cable instead of linkage help? Or make a linkage to push the butterfly valves, instead of pulling.
@@v6ileib I may have found a solution, video coming tomorrow evening or Tuesday. I can't believe I didn't think of it sooner....