M1 Tunnel Ram Top Plenum Volume Reduction with Photos

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I need to look into the math on the plenum before I start playing with the TR1 I have for my 340. Nice job. The cutoff disc obviously worked, but I think for jobs like this a slitting saw is the optimum tool to use. Good slitting saws get pretty expensive so I've been using various diameter (3"-7") carbide tipped trim saw blades. Even the cheap thin ones from HF are useful. You can buy cheap arbors but I just make them from scrap on the lathe. In aluminum they go like a hot knife through butter. Cut very well on steel too, but you need to pay attention to rpm and feed rate. Probably set the mill to minimum speed and plenty of lubricant to prevent smoking the teeth.
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Do you have the large or small top tr1
 
Do you have the large or small top tr1
Small top I think. Haven't looked at it in a while but I'd say it is smaller in volume than the one in this thread before he cut it.

Edit...
I may have misspoke. Could be a TR5. I think this is a pic of it before I picked it up but its stashed in the attic at the moment.
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Small top I think. Haven't looked at it in a while but I'd say it is smaller in volume than the one in this thread before he cut it.
Small top is 173 cubic inches. Perfect for a 340. That’s the try1 top same as a Chevy
 
6500 rpm max

Tom
How's the traction/tire/suspension situation? I ask because some folks who have filled the bottom of a traditional "V" TR Plenum to near the runner bottoms, found out they had a problem hooking all of a sudden, lol....
 
I need to look into the math on the plenum before I start playing with the TR1 I have for my 340. Nice job. The cutoff disc obviously worked, but I think for jobs like this a slitting saw is the optimum tool to use. Good slitting saws get pretty expensive so I've been using various diameter (3"-7") carbide tipped trim saw blades. Even the cheap thin ones from HF are useful. You can buy cheap arbors but I just make them from scrap on the lathe. In aluminum they go like a hot knife through butter. Cut very well on steel too, but you need to pay attention to rpm and feed rate. Probably set the mill to minimum speed and plenty of lubricant to prevent smoking the teeth.
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There was no need to use a saw blade. The aluminum is only 3/16" of an inch thick on the sides of the plenum. The cutoff disc only removes .062" and in my opinion a whole lot safer than a toothed blade for my application. It cut super clean, took no time to do it, plus it was a very easy and economical way to do it. Had I felt I needed a toothed blade I would have used one. However aluminum that thin doesn't require over thinking the process.

Tom
 
Yes, exactly and from all the sources I’ve seen it’s pretty darn close. Most sheet metal intakes target the third. However low rpm stuff usually can’t get enough length for third so the fourth is used. Do you happen to know the length on a m1 tunnel ram? Also here is another tech source about taper etc

Swartz Racing Manifolds
That's a great read !
 
I've been really busy the last 5-weeks, but managed to get back on the plenum project a few days ago. Got the edges all beveled and the halves welded back together. Started filing the welds smooth and a little 50-grit sandpaper works wonders on aluminum. Once the filing and sanding is all done I'll make 4 block off plates to cover the machined surfaces and glass bead it all over. When finished I doubt anyone will ever be able to tell it was very shortened. Lots of work, but a really enjoyable project.

Tom

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I've been really busy the last 5-weeks, but managed to get back on the plenum project a few days ago. Got the edges all beveled and the halves welded back together. Started filing the welds smooth and a little 50-grit sandpaper works wonders on aluminum. Once the filing and sanding is all done I'll make 4 block off plates to cover the machined surfaces and glass bead it all over. When finished I doubt anyone will ever be able to tell it was very shortened. Lots of work, but a really enjoyable project.

Tom

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I can't remember but did you say how much you took out, volume wise?
 
I have about 3 hours worth of filing and sanding to be half way finished with blending the weld in at this point.

Now that one side and one end is totally finished I am really happy with the progress so far. I'll do a little more sanding before I glass bead it and no one will ever know.

Tom

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Tom, FWIW, would you do a little detailing of the work you’re currently doing? A short how to in the outside of the manifold?
 
Tom, FWIW, would you do a little detailing of the work you’re currently doing? A short how to in the outside of the manifold?

There's really not much to it. You just need an assortment of files (two rounds, a flat, and a triangle), some 50 & 80 grit sandpaper, and a glove to wear when sanding, so you don't

wear your thumb out (It hurts). The blue handle file is a really coarse and cuts with ease. I find that I've used the edge of it for tight work a lot. You just file in whatever

direction/ angle that works.


Several of my friend have asked why I haven't used power or pneumatic tools and I told them I wanted more control. It's just to easy to make mistakes with fast cutting tools.

If you take one file stroke at a time you can control the removal process and direction much easier.

It's not hard, it just requires time, effort, and attention to detail.

Tom

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Just about finished with only 4-3/4" on the end left to do out of the 41" all the way around, but I need to give my sore thumb a rest for at least a day before I can work on it again.

Fortunately the end is a lot easier to do, so it will go quickly.

Tom

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Good job on a cool project:thumbsup:

That one vs an unmodified one on the dyno would be a fun test.

It's going to do some back to back testing when the time comes. I am also getting ready to cut another top right under the carb pads and weld a plate on that will

accommodate an Enderle Birdcatcher.

Tom
 
The filing of the weld has finally been completed. I might have to do a small touch up here or there, and still have some sanding to do before it's ready for glass beading.

Went ahead and removed the Mopar logo and the part number (something I always strip off of every intake I use) and smoothed that up a bit. Probably make the 4 plywood plates to

cover the machined surfaces in the next few day (when my thumb feels better) and try to get it blasted by the middle of next week.

Tom

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Block off plates made and installed today covering the machined surfaces. There is no point in filling the inside with trash and dust.

Hoping to get it bead blasted tomorrow and call it done.

Tom

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Got the plenum bead blasted today and tomorrow I should have the powder coating done. Need to get this one finished, so I can start another one for the Birdcatcher project.

Tom

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Bird Catcher.jpg
 
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