Does any one know the spacing between each of the Stromberg 97's on a 6x2 log manifold setup? Not across but between. I know they are smaller than the Holley 94 but how close can you run them? I am going to try my hand at designing an all aluminum 6x2 for my early Hemi.
Hey man! Which model of 6x2?? Edelbrock, Weiand, and Offenhauser made them. The offy spacing is different than the others, I think. I have an Offy 6x2 I could measure for you. I'm able to fit 94's on it comfortably and still get to the jet access plugs. Let me know what measurements you need. By they way, the 6x2 Offys are still available NOS for around $400. Saltflatmatt is also making U-fab type. (lakeheader)
I found the offy used 4.625 with the Stomberg 97 and 5.125 for the Holley 94. I am assuming they put them together pretty close without hitting. Yes I saw the Lakeheader website which gsve me the idea. I work in a fab shop and wanted to try one in aluminum and blast finish. Besides, I enjoy making things. Thanks
Yeah! Figured that was the case. I get ya' completely! Have something in the works myself right now... Yeah, I think center to center on my Offy was 4.625". Sounds right. I was thinking the Weiand and Edelbrock manifold was spaced a little closer. I don't have one to measure though.
We squeeze them in at 4 1/2" on center. It's close but it works. Just keep in mind what you are using for an air cleaner, that can dictate your spacing also especially if you have a certain piece you want to use. Dashman's Hot Rod & Speed Parts www.dashman.net
Dashman, I should have assumed you were here as well. Thanks for the E-bay response. I didn't give the air cleaner a thought to be quite frank. I was thinking of the little polished aluminum scoops you see all the time on a 6x2. I don't know their proper name but they don't appear to be an issue. Scootermcrad, I will post a hand sketch and you can give me your 2cents.
Here is my first mock up and went with 8 just to see what it would look like. My thought was to give the apperance of a cast piece but this would be a sheet metal fabrication which anyone could do with a laser/mill access with a blasted finish. I don't know what the runner length should be but is about 3.75" with the .5 spacers.
Hmmm... What engine is this going on? What type of driving are you doing? I can't really tell what you have going on INSIDE this manifold, but there's more to making a manifold that will function properly than just making a box and welding it to some flanges. There needs to be pulsation, atomization, some kind of ramming effect would be helpful, etc.. There is a LOT involved with designing an intake manifold. Companies spend years designing manifolds because of how complicated the fluid dynamics are. Not trying to beat up on you here, just saying... Maybe you can tell us more about what you have planned for this project.
It is going on a warmed over 354. The inside is just as you suggested. Open plenum style with no runners to speak of. It will be used strickly for my own use on a hot rod for Sunday afternoons. I know it will not be a big performer with stock Strombergs or even 8 for that matter. This type will have to used with ....(insert dirty word) EFI based Stromberg TB. The design is based on the Offy unit pictured here. I thought they were just open plenums to the intake ports. Am I barking at the moon here? I am open to any input before I dive into this.
They are open plenum. You are correct. However, it's not as simple as just essentially having an open space or "box" welded to a flange that mounts to the heads and a plate for the carbs mounted on top. In addition, adding yet ANOTHER carb to the mix, making it a 8x2 doesn't make it any more efficient. Inside the Offenhauser manifold you show in the picture, there are indeed runners that lead to an open plenum. There are also a series of washboard or baffles that were believed to be in-place to prevent "reversion" (direct from the source) or possibly to help promote atomization of the fuel mix (not sure on that one, though). Interior radius' are super important as well as the shape and length of the runners. Yes! There is a TON involved here! There is a LOT more than meets the eye. I know you say you are just building for the weekend cruises, but just welding up a box and welding it to a flange will not get you anything worth running on an engine I would suspect you have put plenty of time and money into rebuilding. There is a TON of information on the internet that can help point you in the right direction. Your standard "U-fab" type manifold, like Crower made back in the day and like Matt, from Lakesheader is making now, is going to be pretty decent when it comes to overall performance. This design exists for a reason and essentially is mimicking the original Weiand Drag Star and/or Edelbrock style log manifolds. Offenhauser took it a step furter, I believe, by playing with the runner designs and enhancing the open plenum. Again, not trying to beat up on you here, but do some google searches on the topic. I'm designing a manifold right now as well, and I can tell you that it's not as simple as what you are planning on doing. I would use Matt's intake manifolds as a starting point. 20 minutes of research on here and Google will help explain what I'm trying to convey to you. Some big name fabricator guy once said on here, "If it's worth doing, it's worth doing right." Frankly, I agree...
This thread has some pictures of the Offy... http://www.jalopyjournal.com/forum/showthread.php?t=4086&showall=1
More links... http://www.jalopyjournal.com/forum/showthread.php?t=407257&highlight=manifold+design Even though this is about an import O/T car, there are still some good facts here, as well: http://www.physicsforums.com/showthread.php?t=80364 http://www.team-integra.net/sections/articles/showArticle.asp?ArticleID=466 Some of what you see will be for forced induction, so be aware. http://www.amsperformance.com/pdfs/intakemani.pdf
I wasn't taking it the wrong way. I was hung up too much on the looks over the fuctional aspect. I never saw a pic of the inside of the offy to see the runners like you have shown. I thought they were just a box...ok me stupid now. Might be better to work on what I know and just buy a proven unit. Thanks for your insightful remarks.
You're welcome, but if you want to do it, don't give up! There really is a ton of good info out there and the worst that could happen is, you end up buying one anyway. Only time and a bit of money, right? That's what hot rodding is all about! I love the topics associated with building manifolds! So many people have built amazing things, out there! I'm certainly no professional, but I love reading about what makes them work.
I agree with scotter, don't give up..Short runners are better then no runners.. I had a Dodge Hemi intake made 3x2 with short runners to the plenum area andit works great.. Duane..
Here is a picture of the intake..You could build it like this with a bigger plenum area for the 6 or 8 Strombergs..Would work great.. Duane.
Forgot about about these two..The 4x2 staggered is steel with equalizers. Second is Aluminum. Notice the runners.. Duane..
I see I need to do a littler more home work on this one. I have seen the tunnel ram type here before and I understand the reason behind the runner length. I will put it on the back burner for now until my mockup is complete to see if I will have hood clearance for something like that. I love the look but I don't want to run a hood scoop on the old 53 Stude. Thanks to both scooter and Duane for all of the help.
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