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weiand accelerator vs offenhauser 360
I currently have the weiand on my mild sbc i was wondering if it would be worth my time swapping it out with the offy? My sbc is built for more low end to midrange power so i know the single plane isn't helping it very much.
Does anybody have any info on the offy i've looked around and can't find hardly anything about them. |
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Offy intakes are hard to find because nobody uses them for years. They were obsolete in the '70s.
IMO, the best intake for your purpose would be Edelbrock "Performer". One thing not comonly known is Edelbrock wears engines out testing. Most other manifold makers (not high-end) simply make their intakes LOOK like Edelbrocks. No substitute for the real thing! Edelbrock isn't a 'buzz word", it's the BEST. Jim |
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You can check here: Phethean Racing Products - Offenhauser
And go to intake manifolds. |
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i had an edelbrock performer intake but i sold it.
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weiand accelerator vs offenhauser 360
If you have you engine built for low end and mid range power then these two intakes are your best choice. Edelbrock Performer or Weiand Street Warrior.
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The weiand is a 7546 and i'm not sure on the offy a guy told me it was a dual plane high rise he wants $50 for it. Its goin on a 350 that has a elgin cam with 228 duration at .50 with .480 lift
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assuming you have the compresion, tuning, and exhaust worked out the performer RPM will be an almost perfect match for that cam.
There are several Offy 360 intake styles, so a picture or at least apart number would help. It probably won't be as good as an RPM but it may not be a bad move depending on what it is exactly. |
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Based on the lower rev desired, RPM may take away too much velocity at lower engine speeds and hurt low-end torque.
Offy "Dual Port 360" is possibly the worst intake ever made by anyone... It's a good idea, it just doesn't work. Wieand intakes have been around forever. I'm not versed in their part numbers. We've had far more success with Edelbrock than the others combined. Some of the old Wieabnds were cast at the Winters foundry (the little "star" with a "W" in the middle is seen on them, where GM's factory aliminum intakes were cast). There has been speculation that some of the Wieand and Chevrolet offerings were the same, only part numbers being different. The "key" to a torque engine is smaller runners and lower revs. FWIW Jim |
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Offenhauser Dual Port
"Back in the Day" I was a manager here (see Pic Below) around 1976 I had the pleasure of talking with Fred Offenhauser Jr. for a while and we talked about the Dual-Port it is and was a much better intake than many give it credit for,tuning it is where the problem lies.Offy claimed the Dual-Port primary runners which are smaller increased the speed through the runners to a much higher speed and velocity this was to provide increased fuel economy and low end performance then when the Carbs secondaries opened the primaries velocity would suck the secondary flow along for the ride.The trick was finding a leaner jetting and correct power valve with a Holley and playing with the jets and rods in an AFB Carter or Quadrajet for the primaries.The higher velocity primaries changed the amount of vacuum reading you would get.I have used them on SBC's and they can work well,the manifolds with the spreadbore base for some reason worked better than the square bore intakes.The Weiand Accelerator you have is actually a good match for your cam and stock heads as the ports are not overly large,for a dual plane with your setup the Weiand 8004 would be OK a cam swap to a Comp Cams CL12-231-2 would up that low end and mid range over what you have,it all gets down to budget.
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Quote:
That single plane manifold is hurting your power at RPMs up to 4500 or even higher. The problem is all 8 intake valves are exposed to each other. That means, for example, while piston #1 is half way down the intake stroke, cylinder #8's intake and exhaust valves are both open (during overlap). This means some of cylinder #8's exhaust gasses are sucked through the intake plenum and into cylinder #1. And this is repeated on every intake stroke of every cylinder. The larger the cam, the more the overlap, the bigger the problem -- at least at low-mid RPMs. Last edited by 55_327; 09-14-2012 at 10:12 PM. |
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Quote:
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Quote:
![]() An RPM manifold will walk all over it. |
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Doug Flynn at Holley told me their dual plane Stealth (now Speed Warrior) manifold makes better power than the X-CELerator up to almost 6000 RPM. So, unless your engine spends most of its time above 6000 RPM, a dual plane is the way to go. The Street Warrior places an emphasis on low-mid range torque, but even it probably kicks the X-CELerator's butt up to 4500 RPM or so.
Just because the engine will run at 1500 RPM with an X-CELerator doesn't mean the power band goes anywhere near that low. Being required for a certain racing class is the ONLY reason to use one. Jeff, I love the old school stuff, even some GM 283/327/350 cams. But this manifold is a relic. |
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