Offy Intakes?

[nitroracer]

Does anyone know about offenhauser intake manifolds? I just found a bunch of ford parts listed on craigslist and one of them is an offy 351 intake.

[Blaze86Vic]

Cool ones they are. They were the shit back in the flat head days.

[Pirate]

And 'shit' is the collective word for the most current batch of them. Unless you absolutely need a four-barrel intake, just get an Edelbrock Performer. Those Offy intakes were good thirty years ago, and that is where they remain, stuck in the past. A modern RPM Air Gap pretty much stomps all of them into the ground.

[Nathan in MI]

They oughtta be decent stuff, I should think. Maybe not the be-all-end-all of design, but hey, if you can get it for a decent price, go ahead and use it.

[gadget73]

The split port design looks like it would do well for a lightly used DD, or maybe a truck or something where you want as much low end torque as possible, but are less concerned about high rpm. Having that big divide in there looks like it would choke the airflow. I imagine on just the front half of a 4bbl it would do OK but it really wouldn't move a lot on the top. An AirGap would definitely be better.

[DuceAnAHalf]

that would make one hell of a tourqey manifold. but get a RPM Air-Gap instead, unless you are trying for a 60s style motor

[nitroracer]

I let this one go, still thinking a weiand stealth will be the best.

[turbo2256b]

I have a 351 Edelbrock performer for sale. I think this is a pic of it or the 302 intake I had.

[Archangel]

that would make one hell of a tourqey manifold. but get a RPM Air-Gap instead, unless you are trying for a 60s style motor

That they are, for sure - maybe I shall take a vid of my truck towing the Lincoln with the Townie's parking brakes on and the truck's carb set on fast idle at 1200 rpms and my foot off the gas :evil: Yes, I'm very very easy on the gas when it's rainy, lol Then again what I have is the spreadbore split-port intake, and it's on a Chevy, but 350 is close enough to 351ci, so I think it's a decent comparison. However, I'll have to agree with that not being suitable for yer car, I run out of steam at right around 4000 rpms.

[88Vic]

Then again what I have is the spreadbore split-port intake, and it's on a Chevy, but 350 is close enough to 351ci, so I think it's a decent comparison.

Your truck also doesn't have much weight over the rear wheels. I'm not sure how much is over the rear of a MGM, but I think it's more than your truck.

[Archangel]

Your truck also doesn't have much weight over the rear wheels. I'm not sure how much is over the rear of a MGM, but I think it's more than your truck.

Correct, but what I gain in weight (3700lbs) I lose in tires (33s).

[1987cp]

I don't think I knew you had a Dual-Port on your truck.

I think the Dual-Port is an awfully nifty idea, maybe kind of a precursor of today's variable-length intake designs. Be great for a car with a stock cam and governor, probably have tons of low end - I'd like to try it someday. The Performer 289/351 are still about the best up to maybe 5500 rpm, and of course lots of dyno tests show that the Performer RPM designs are consistently the best overall up to about 6500, gaining top end without giving up much torque compared to the regular Performer. I've got the divided single-plane Equa-Flow on my 306 right now, and while it works pretty well, it seems a tad soft on the low end for the high-lift/short-duration cam I'm running, so I'm thinking on switching to the more modern Edelbrock at some point in the future.

[Pirate]

I don't think I knew you had a Dual-Port on your truck.

I think the Dual-Port is an awfully nifty idea, maybe kind of a precursor of today's variable-length intake designs. Be great for a car with a stock cam and governor, probably have tons of low end - I'd like to try it someday. The Performer 289/351 are still about the best up to maybe 5500 rpm, and of course lots of dyno tests show that the Performer RPM designs are consistently the best overall up to about 6500, gaining top end without giving up much torque compared to the regular Performer. I've got the divided single-plane Equa-Flow on my 306 right now, and while it works pretty well, it seems a tad soft on the low end for the high-lift/short-duration cam I'm running, so I'm thinking on switching to the more modern Edelbrock at some point in the future.

If you will look at the offy, and direct your attention to the intake ports on either side of the intake. What you will see, is that the two middle ports are a lot shorter than the outside ports. What this does is create a tragic mismatch of airflow and fuel distribution between the inside and outside cylinders. Even the basic performer 289 has better airflow and fuel distribution than that piece.
They definitely had some really cool ideas for their time...

[1987cp]

So in other words, the Equa-Flow isn't really equal flow? I guess I could see that. Big open plenum with a "360-degree" design and a partition down the middle, whereas Edelbrock touts their "180-degree" design dual-planes as superior to most. I do have a Performer 289 on my other engine, and it seems to do pretty well. Seems there was a Ford Racing intake that was said to be really strong on the bottom end but give up by about 4500rpm; if I could find one of those, I might want to put one on the weaker engine and swap the Performer 289 over to the 306 with the good cam and heads where it could really do some good.

[Mercracer]

Failed design attempt.......Those are Junk! Run far far away from that intake. An Offenhauser 360 intake (#6150) however is competitive with the Weiand Stealth and the Edelbrock Performer RPM intakes for the 351. I ran one on a Torino a few years ago with excellent results.