Alright, I got me some crazy (yet cool) idea in my head, and thought about it all day. Here's the thing, since I have a ticking lifter, I need to remove the intake manifold (to clean or change the lifter). And that got me thinking 'why not go 4-barrel'? :laugh: I can put a 4-barrel intake on it (and a 4-barrel carb). I found out Offenhauser makes a few 4-barrel intakes for 231's. But I don't really know for sure wich one to get. Summit offers two Offenhauser intakes for 1975 engines: Offenhauser 360 Degree Single Quad V6 #7513 Offenhauser Dual Port #6035DP At the moment there is also one listed on Ebay. But does not say a part number (already contacted the seller). But it does say it's a '360 Degree' intake. On the pics I could see that this one is square bore. From those '360 Degree' series Summits lists 2 wich are square bore. So, it's most likely one of these two. The parts number are: #7513 (yep same one as above) #6169 What is the differance? Well, the #7513 should fit a '75. But the #6169 says it only fits 76-78 and 'Will not fit tall port heads due to port size'. Now my main question is, what kind of ports do the '75 231's have? Do these have tall ports? It might be stupid and time consuming to question all these things and just go with the information given and be on the safe side. But I just can't seem to believe this one is so different and would not fit a 1975 engine. Oh, and the note for that other intake says 'Will not work with large HEI-style ignition cap'. I thought I had a fairly big cap (and I have HEI ignition). Were they even bigger in 1976? I just hope the one on Ebay is #7513. But I also hope someone could tell me a bit more on those ports. Maybe the other will fit also.
edelbrock makes a 4 barrel intake manifold that makes power from o to 5500rpm and weiand makes a single plane for 0 to 6000 rpm the offy stuff is outdated:Smarty:
TA makes an alum 4 bb intake for the odd fire 231. I'd be hesitant to throw too much money into that V6 though. I rsuggest a stock 231 intake unless you can find a cheep used one. A Q-jet would be the best bet for you! Is finding and building up a Buick 350 out of the question? I understand that fuel prices may eliminate this option. oh, and I agree that the Offy stuff is outdated.
How come the Offenhauser stuff is outdated? The only Edelbrock I can find is for '79 and up. The one from Weiand is a high performance intake. Best suited for engines with aggresive cams and stuff. And hight compression ratio. I'm not sure if that one is well suited for my bone stock 231. Sean, I get what you're saying. I'm not going to put too much money into this engine. Right now I'm just trying to find out what's out there on the market. And I hope to maybe buy some stuff cheap on Ebay (used). But I think I'll try to fix that lifter issue soon, and just put the stock intake and carb back on. The engine is running great, good throttle response and still enough power. I was going to buy/rebuild a Buick 350 yeah, but so far I haven't bought one of those blocks. I haven't really looked for them either the last couple of months. The gas prices sure is an issue. But also because I couldn't find a good one. Only engines that could use a major rebuild. For now, I going to fix that lifter issue and put it back together. And in the mean time I will keep my eyes out for interesting performance stuff. And I will collects more info and parts. And do the job some other time, when I have all the parts that I wanted. You should not hurry these things and accidently buy stuff that won't fit or won't work.
yeah, that is all true and I think you'd get better fuel milage with the 4brl carb and intake. I still say search for a 4brl stocker but also a used odd fire alum would be good. Keep an eye out for Buick 350s and collect parts like you said because they are only going to get harder to find.
I'm not sure now that I think about it more.... search in the parts for sale section and see if "the waterbox guy" still has the 231 odd fire that he suped up. Maybe he has the motor still and you could get parts from him?
If I remember, the non-turbo four barrel even-fire engines were all 4.1L. As far as two vs. four barrel economy, it's the same as long as you keep your foot out of it. That 2bbl carb is simply the primary section of a quadrajet. Devon
The 6035DP Should fit , It is what was ued on My T/A Perf. built V6 odd fire. Yea ,it is not a newer desgin, but it works well on a street application. I have a Holley 390cfm 4bl on it with Vac. Sec. The instruction that came with the 6035DP says its fits all V6 odd fires 64 to 75. I do not use HEI , but it will fit on this manifold.
the odd fires do not have tall port heads and dont swap over easily as coolant ports dont always line up 79 and up have tall port heads stock 4 barrel intakes are tall port so stick with the offy or a small port flange
> Now my main question is, what kind of ports do the '75 231's have? > Do these have tall ports? No. The tall ports came later. My even fire '79 had them and I think late odd-fires did too. > TA makes an alum 4 bb intake for the odd fire 231. TA doesn't make their own V6 intake but they do carry the Offy Dual Port for odd-fire intakes and the Edelbrock Performer dual plane for even-fire V6's with the tall port heads. > The only Edelbrock I can find is for '79 and up. That is correct. The Edelbrock is for tall port heads only. > The one from Weiand is a high performance intake. Best suited for > engines with aggresive cams and stuff. And high compression ratio. > I'm not sure if that one is well suited for my bone stock 231. The Kenne Bell Number 1 intake is a single plane similar to the Weiand but has a smaller port design that fits either the early or late heads. KB claims it works fine on a stock or modified engines. I have a Kenne Bell, Weiand and Buick 4.1L V6 intakes here that I intend to sell (along with other Buick V6 stuff like cast aluminum valve covers, Holley 390 carb, etc.) as soon I unpack from my recent move. BTW, the 4.1L Buick V6 intake is a split plenum single plane. The Buick V6 doesn't have the adjacent firing cylinder reversion problem common to 90 degree V8's with non-flat cranks so there is less of a reason to use a dual plane. > Has there ever been any 4-bbl 231's? I think the early carb Turbo V6's used a 4 barrel intake, likely that used by the 4.1L Buick V6's. > The 6035DP Should fit, It is what was ued on My T/A Perf. built > V6 odd fire. Yea ,it is not a newer desgin, but it works well > on a street application. The dual port design has the runners split into top and bottom sections with the plenum split fore and aft (rather than the usual side-to-side like the Equa-Flow 360). It's essentially two single planes stacked on top of each other with the primaries feeding the longer path lower runners and the secondaries feeding the shorter path upper runners. When cruising, the manifold operates on the smaller diameter, longer path, runners. This provides high velocity flow for good fuel economy and throttle response. Under high demand the secondaries open and provide additional flow through the larger top runner portion. It's an interesting approach but the packaging required to fit within a carb intake envelope does compromise the design. By reputation, it's a good fuel economy, low end response type intake. David Vizard did a big intake comparison on a 350 Chevy whih may or may not apply to the Buick V6. Basically, the Dual Port was near the bottom of the list when comparing peak horsepower but had decent area under the curve and was the only intake with better fuel consumption than the stock Qjet intake. I have a Dual Port on my Buick/Rover aluminum V8. It's smooth and seems to run well at low and mid but becomes restrictive at higher RPM. BTW, externally, the Dual Port and Equa-Flow 360 intakes look similar but the 360 is a split plenum (left/right) single plane intake with a notch in the center divider. The Dual Port is the one with the ports divided top and bottom and the plenum divided fore and aft. > How come the Offenhauser stuff is outdated? The 360 was never that great an intake. I'd wager the Kenne Bell Number 1 and Weiand single planes are better for higher RPM applications. Dan Jones
Actually, two barrel carbs have bigger jets than the primary side of the 4-barrel, so 4-barrel economy would be better though not substantialy. Just my 2 cents. -Cort:idea2:
Thanks for all the replys! Very interesting stuff! @ Dan Jones, thanks for your 'review' or certain intakes. If I would buy an Offenhauser intake it would be the 6035DP. But you're saying that you have a few intakes for sale soon? The Kenne Bell intake sounds interesting. Do 4.1L intakes work an a 231 (3.8L)? Or how bout the Holley 300-22? I found out it fits the odd fire 231's. There's on Ebay right now. I think it won't go for that much. So I'm kinda interested in that one. Item number: 270135643174 What is the best way to go, spreadbore or squarebore? I always thought spreadbore was better for fuel economy. The Holley intake is squarebore. But I could go with a Qjet carb (spreadbore) along with an squarebore-to-spreadbore adapter. Or should I just go with..say a squarebore Holley carb? First I was thinking of a Holley 4160. But the cfm of those things are 600-625 cfm. That is too big for a V6 ain't it? What would be good carb for a V6?
> If I would buy an Offenhauser intake it would be the 6035DP. > But you're saying that you have a few intakes for sale soon? > The Kenne Bell intake sounds interesting. Yes it'll probably be three weeks or so before I get around to unpacking them. > Do 4.1L intakes work an a 231 (3.8L)? Yes but only the 1979 and later 231's with tall port heads. I ran one on a '79 even-fire with a Qjet. > Or how bout the Holley 300-22? I found out it fits the odd fire 231's. > There's on Ebay right now. I think it won't go for that much. So I'm > kinda interested in that one. Item number: 270135643174 I think the Holley is like the Kenne Bell intake in that it has an intermediate port design that fits both early and later tall port heads. Come to think of it, the Weaind may be that way too. I'll have to check. I've got the Buick Free Spirit V6 Performance Guide, the Ruggles Buick V6 Guide and the V6 Performance Book and I'm pretty sure the Holley is one of them. > What is the best way to go, spreadbore or squarebore? I always > thought spreadbore was better for fuel economy. The Holley intake > is squarebore. Spreadbore is typically better for throttle response and fuel econamy. Squarebore typically makes more power by giving a better mixture distribution at wide open throttle. > But I could go with a Qjet carb (spreadbore) along with an > squarebore-to-spreadbore adapter. Yes. Not sure how those affect mixture distribution, though. > Or should I just go with..say a squarebore Holley carb? > First I was thinking of a Holley 4160. But the cfm of those > things are 600-625 cfm. That is too big for a V6 ain't it? > What would be good carb for a V6? The Holley 390, Carter 400 CFM AFB (rare) and the Edelbrock/Carter AFB 500 CFM carbs are the usual choices. Be aware that Holley mades at least 3 different 390 CFM carbs. List number 8007 is meant for small displacement, street driven engines and has an electric choke. The 8007 is a 4160 Holley which means it has a plate with fixed size orifices for metering. These plates are replaceable but cost much more than jets. If you plan on doing any tuning (and you should), you may want to convert to the 4150 secondary metering block which has removable jets. List number 6299 is meant for 4 and 6 cylinder applications. I checked my listings and the jetting doesn't look much different from the 8007 but the 6299 doesn't show a power valve. That may mean it has no power enrichment which would be surprising. I also checked the Holley site and it also lists no power valve: LIST # CFM STOCK JETTING POWER VALVE TYPE 6299-1 390 (F)50, (R)plate 134-34 N/A 4160 8007 390 (F)51, (R)plate 134-34 6.5 4160 80507 390 (F)65,(R)65 3.5,3.5 4150HP If that's really the case, I'd bet the metering is quite different in the 6299 than in the 8007. List number 80507 is meant for carb-restricted racing applications, typically on larger displacement engines. 80507 is an HP Series carb and has no choke tower, mechanical secondaries, a streamlined venturi inlet, high flow metering blocks, non-stick gaskets, a four-corner idle system, stainless steel throttle plates, button head throttle plate screws, center hung dominator style fuel bowls with notched floats and jet extensions, spun-in (conventional) boosters, power valve blow-out protection, screw-in air bleeds and double 30cc accelerator pumps. The Carter 400 CFM is a really nice carb for what you want to do but are no longer made so are rare to find. The 500 CFM AFB's usually work just fine when jetted properly. I'm currently running an Edelbrock 500 CFM on my 215 V8 and it works great after some tuning with a wide band O2 sensor. Dan Jones
Great info Dan!!! The q-jet works good on various cid motors and will not "overcarb" a motor the way most other carbs will. If economy is an issue then a Q jet is the ticket for sure.
Thanks for that information Dan! I really appreciate it! Sean, I was kinda thinking of a Qjet, because I like spreadbore. Fuel economy is not really a big issue, but it would be real nice if I can improve it. Holley 390 sounds interesting too by the way, but those are squarebore. Most Qjets that I find on Ebay are usually 650 cfm. You're saying that could work on a V6? I though that was too much.
> Most Qjets that I find on Ebay are usually 650 cfm. You're saying that could > work on a V6? I though that was too much. They will work but be aware that Buick used a specific Qjet for the Buick V6. They were calibrated differently (might have had a secondary stop as well but I'll have to check). There are several different types of Qjets. You'll want a later one with side fuel entry (the front entry version fouls the Buick V6 thermostat housing). You'll need the Edelbrock Qjet tuning kit unless you can find one of the V6 Qjets. Those are kind of rare as Buick switched to electronic Qjets on the later 4.1L Buick V6's. Dan Jones
Thanks for the heads up Dan! I didn't know that about the thermostat housing. But if I recall correctly my current stock 2-bbl carb that's on it now also has a front fuel inlet. The more I think of it, I begin to realize that it's probably a lot easier to go with a Holey 390 for example. Dan, you have one of those right? If you are thinking of selling it, just shoot me a PM (that also goes for the Kenne Bell intake). Did you ran a Buick V6 with that carb? I'd like to know what kind of fuel mileage you got out of it. The only reason I'd like to go with spreadbore is because of fuel economy. But a squarebore might not be so bad either. Is there a big diffence in fuel economy between spreadbore and squarebore? I have no idea what the mileage is right now, with the engine just bone stock. But when I put on a 4-bbl intake and a 4-bbl Holley 390, the mileage will get slightly worse, right?
Roger that... I found out the hard way with my quadrajet 78 turbo carb ou: . I'm going with a holley because I don't have enough hood clearance to use a carb spacer for the quatrajet. I'd given a little thought to using a remote filter and a right angle adapter at the carb. Fate was working against that option though. Btw, my holley street dominator manifold had to be opened up quite a bit on the top of the ports to match my ported 8445 heads. I'm pretty sure that the manifold part number is for the later tall port heads too.
> Thanks for the heads up Dan! I didn't know that about the thermostat > housing. But if I recall correctly my current stock 2-bbl carb that's > on it now also has a front fuel inlet. My car was a '79 Buick Regal and I was running a Qjet on the 4.1L Buick V6 4 barrel intake. Different cars may have different angle thermostat housings. > The more I think of it, I begin to realize that it's probably a lot > easier to go with a Holey 390 for example. Dan, you have one of those > right? If you are thinking of selling it, just shoot me a PM (that > also goes for the Kenne Bell intake). Yes I have a Holley 390. Let me get unpacked and check things out. Shoot me a message in a week or two. > Did you ran a Buick V6 with that carb? I'd like to know what kind of > fuel mileage you got out of it. The only reason I'd like to go with > spreadbore is because of fuel economy. But a squarebore might not be > so bad either. Is there a big diffence in fuel economy between spreadbore > and squarebore? I have no idea what the mileage is right now, with > the engine just bone stock. But when I put on a 4-bbl intake and a > 4-bbl Holley 390, the mileage will get slightly worse, right? I did not run the V6 with the Holley. I ran it with the Qjet and got similar mileage but better power. In my experience, if you take the time to tune the carb (most do not), you can get as good or even better fuel economy with a 4 barrel than a 2 barrel. > I'm going with a holley because I don't have enough hood clearance to > use a carb spacer for the quatrajet. That brings up a good point. The Kenne Bell is taller than the stock intake. What sort of hood clearance do you have to work with? > Btw, my holley street dominator manifold had to be opened up quite > a bit on the top of the ports to match my ported 8445 heads. I'm > pretty sure that the manifold part number is for the later tall port > heads too. In the Buick V6 stuff I referenced last night it said the Holley Street Dominator was for the early heads. The Kenne Bell and Weiand are both intermediate port manifolds and the Edelbrock and Buick 4.1L are for tall port heads. The Offy catalog listed also listed a "C-series" single plane intake similar to the Kenne Bell and Weiand intakes, in addition to the dual port and Equa Flow intakes. Dan Jones
