I'm building a 302 for my '51 shoebox Ford, and I'd previously purchased a Weiand Stealth manifold for it, on the recommendation of several people. Then, I ended up buying a complete engine with an Offenhauser 360 manifold on it already. I'm just wanting a street car, nothing on the track at all. Whichever one I don't go with I'll sell, just not sure which one to use. I know either will probably work, but which one would be best? Anybody using either of these?
I am a fan of the Weiand intake. I run one on 2 of my Ford's ( a 302 in my 56 vicky and on a 393w in my 52 f1.)
The Stealth is far better than the Offy 360 an extra plus if it is the early Stealth with both front and rear water passages.
I ran a Offy 360 on a 302 for a few years, never had any problems out of it, ran good. Probably not a nickel's worth of difference on a street car.
While I've never been a big fan of Offenhauser intake manifolds I got my Austin with a 350 SBC equipped with an Offy 360 and an Edelbrock 625 4 bbl. The Offy seems to have a bunch more throttle response compared to my other similar 350 with an Edelbrock manifold and the same carb. I recently read an article in an old HRM when the Offy 360 first came out. Offenhauser explained the theory behind the design and it seems very sound, especially for a street car. This may be a good opportunity to do a little home R&D. Put one on, tune it, then some weekend when you feel like getting dirty or the engine needs a major clean up, swap 'em and see what happens.
Offy intakes can confuse folks there is an Offy 360 and then there is the Offy 360 Dual Port which gets put downs because it does not use the same tuning tricks like normal intakes do because of the split port design.
I also have two carbs (a Carter WCFB and a Holley 600cfm) so that may be the approach I take. I'll have to see which one it is, I've seen the same thing. Dual Port seems to have more potential, but has to be tuned right.
You probably will want to go with the Holley, the WCFB won't bolt to either manifold without an adapter.
The Carter was already on the engine with the Offy when I got it, so I guess it's a square-bore manifold as well. A cursory search shows that the 360 dual-port is available as a square-bore, so I assume that's the one I have.
THINK ABOUT THIS FOR JUST A SINGLE SECOND...! It's really not that difficult a situation. Toss a coin for which manifold to...START with. Run it for a while, get everything sorted. Keep an eye on the mileage, and your "butt dyno". THEN...spend an hour or so...and install the OTHER manifold..! Drive it, re-tune if required..! Watch the particulars. Then...either keep the current manifold in place, or swap for the original manifold if IT helped the engine run better, THEN sell the other, unneeded manifold. Was that so freaken difficult ? WHY...cut yourself short using OTHER peoples thoughts, when you actually have the answer in your hot little hands..? Mike
You're right, it's not difficult - but I wanted to see if it was worth even considering both of them. If one is junk and others can tell me that, then asking saves a whole lot of time. This is my first engine build so I'm sorry if my questions are obvious to some who are more experienced. Sent from my iPhone using The H.A.M.B. mobile app
Have absolutely zero experience with the Weiand, thus no comment on the Weiand. Have LOTS of street experience with Offenhauser, and another aftermarket brand. NEVER did a dyno comparison test; but I have NEVER installed an Offenhauser that did not fit perfectly without the need of grinding, shims, etc. Wish I had the hours back wasted on trying to make the other brand fit! Even had one that the cut angle was wrong for the heads, another that came out of the box with a crack in a fuel runner. When one is in business, time matters. Jon.
If you decide to run the Offy Dual Port use the Holley because you can get more parts to tune it with. I've had a few of those and back in the 70's Fred Offenhauser Jr. came to United Speed Wholesalers in Sacramento and I was managing the retail counter which was M&M Speed Engineering and I discussed the Dual Port with him. Putting it simply you will probably run the primaries leaner than normal and usually a smaller power valve and with a Holley vacuum secondary Carb you will want a spring kit to play with. Camshaft should be a on the mild side off idle to 5500 RPM range, I ran the L-79 grind in a 327 & a 350 and it was a good combo.
That's good info, thanks! I'm also running an AOD transmission and I know I can get a throttle valve cable adapter for the Holley, not sure about the Carter. Sent from my iPhone using The H.A.M.B. mobile app
One thing to be aware of if it is a Dual-Port is that you can NEVER use the open plenum style adapter because if kills the Dual-Port feature. I have used several of these intakes over the years and they really do seem to perform better for street use, but do not make as much power at higher RPM's, but how often do you run over 5 grand in normal street driving. Never used one on a Ford, used on AMC, Mopar and Oldsmobile.
I'm an edelbrock fan. Small motor, low revs, street use = performer. I had a stealth on a solid roller 406" SBC street engine, it loved it. It was too big on a mild 350 tho. I have been told the stealth for sbf is not as large as the sbc version.
Yeah the Stealth for a SBF is definitely different than the SBC version. It's highly recommended in the Mustang community, and I actually bought it before I got the engine, I just haven't been able to find much info on the Offy. Sent from my iPhone using The H.A.M.B. mobile app
That reminds me, I still need to make sure it actually is a Dual Port. I'll look tonight. Sent from my iPhone using The H.A.M.B. mobile app
Well, it doesn't say on it if it's a Dual Port or not. Anybody know how to tell? Or do I need to uncover where the carb goes?
After looking for some pictures of the dual port, it appears that it has the words "Dual Port" cast in right in front of the carb mounting surface, since this doesn't have those I guess it's not that unit. I guess the Weiand is the choice then. Anybody interested in this one PM me.
Whenever I see a 'Which Manifold is Best' question, I always remember a manifold shoot-out that Hot Rod or Car Craft did back in the early '70s. They used a 350 Chevy of course, but they tested virtually every aftermarket single-four-barrel intake available at the time except for tunnel rams. This included a couple of stock intakes as well. All they changed between tests was the manifold, everything else was the same, although they did play with timing/jetting. The motor build was a 'middle of the road' package with a 'street' cam and a Holley carb The results? At the end of the test, there wasn't more than about 15HP or Ft-lbs of torque difference between any of them, including the stockers. The ones that made the most power sacrificed something in the low/mid ranges. They admitted that some would have benefitted from a cam and/or carb change with more tuning for best results, but keeping the 'playing field' level was done to show just the manifold difference. The Offys were firmly in the middle, with neither the highest or lowest numbers at any given test RPM, but IIRC they were somewhat impressed with how flat their curves were. Food for thought anyway....
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