Building a tunnel ram

[440Clark]

Just in the planning stage right now so before I reinvent the wheel anybody out there built a tunnel ram for a 302 Ford before? Or anything for that matter? Let's see some pics.

I was thinking of using a bare block and heads I have laying around to mock everything up on. I'd use something like 1/4" plate for the 3 piece bottom ( a large plate to seal the valley and two sides kind of like header flanges) and weld them together while cinched down to the motor. I was thinking of just using exhaust tubing for the runners. Let them be round where they enter the plenum and I'll fit them to the flanges just like building headers. Then I'll build a sheet metal box with a V bottom. It will be set up for one carb. I still have not figured out the plumbing for the coolant yet but I'm just thinking out loud right now.

I know a tunnel ram isn't necessarily the hot set up and we could go on and on about plenum volume, runner length, cross sectional area, Helmholtz waves and blah, blah, blah-BUT the coolness factor is what I am ultimately after!

I was thinking of using steel because I'm just not there yet with the TIG welder however I have a friend who would probably do it for me in aluminum. If I make it out of steel I'm afraid it's gonna weigh a ton, although I had a cast iron six pack intake once that I guarantee weighed more!

What do you guys think?

 

[sawzall]

Go to lakeheaders.com they build great intake manifolds, maybe you could get some ideas there.

 

[rex1927]

Go For It!!!

I like your idea.
I saw a custom intake on BBC engine a few years ago.Runners were built out of tubing.They twisted and twirled around and looked like they were tied in a knot.Needless to say that car was trophy winner.[dr
It cranked up and drove off running just fine.It had 2-4bbls,but one should be fine too.
If I could weld thin stuff good enough, I would build one myself.
Go for it.Better to try and possibly fail than wonder "what if ".[S
Please post pictures when you are finished.

 

[rainman]

I've often thought about trying it, never done it though!!
Seems like it would be time consuming, and think of how many
other cool parts you could make with that time!!
If you do it, please document it on here!!![P

 

[Torch]

watched an episode on cable where they were making headers. the gasket flange had opening larger than the exhaust port to allow for the thickness of the tubing. they also has a tool made that was like a chisel but it was a spreader ground out to fit perfectly in the port opening. they drove it into the end of a round tube to shape it to match the port.
then they put the tube in the flange ran the tool in again.. then welded the tubes to the flange and ground the welds flush with the flange on a large belt sander.
Doing it this way you would not have any visible welds once your intake was mounted if you used this method to make your manifold from round tube.

 

[rainman]

Saw that too T-Man, was very educational!! Kept that in my head in case I make my own headers for my Gasser!!

 

[440Clark]

I've made zoomie-type headers using basically the same procedure that's what gave me the inclining to try building the intake. I will play around with it this week and try to get some pics up. BTW sawzall, thanks for the link, that's probably how I'm gonna do it.

 

[phitter67]

Years ago I worked as a toolmaker, and I made the flanges so a guy could build one for a 460 Ford. I used aluminum and he made the rest from aluminum tubing and plate. He is a heck of a welder and it came out nice. I used 1/2 inch, if you use steel 3/8 would probably be fine. He used a mock up engine to build his also.

 

[Neverdone]

If you want something different......... and tuneable......

Years ago a place by me called Ramchargers had car with a custom tuneable high rise intake. It was kind of funny actually. They made the bottom plate and top box, then to get the right height for the most performance they used radiator tubing for the runners. That way they could run it, if they didn't like it they would cut the tubes down and shorten it. If this is for a rat, maybe that might be they way to go anyway!!!

In any case, this is something I always wanted to do to, so if you build one, keep us posted! [P

 

[440Clark]

If you are referring to the old High and Mighty car, Yeah I dig it. But thats just a little bit sleazier than I wanted to go. Oh pictures just loaded yeah that's the one.

 

[Neverdone]

was just a thought.

 

[440Clark]

It was a great thought, I didn't mean to belittle it in any way. I love sleazy (especially on women). The High and Mighty was cutting edge racing technology in it's day. I dig the way you were so casual about referring to a car Mopar guy's like me hold in such high esteem and I envy you for being anywhere around it when it was going down.

 

[klink]

After welding the tube into the flange fill the joint with braze. It'll make a nice strong joint, we do this when we build headers.

 

[440Clark]

Ended up cheating a bit. I took the bottom off of an old 5.0 FI intake. Made 2flanges like the gasket on the cnc plasma cutter, cut 8 4" pieces of 1 1/2" tubing. Cut up a 4" x 4" square tube and cut a flange for a Holley. It's not done yet but here is where I'm at so far. I know the plenum volume is large and the runners are a little small, but like I said, I'm doing it for the "how crazy is that?" factor.

 

[Neverdone]

I REALLY like that idea. Its a shame I already sold off my fuel injection junk for my 302. I bought a torker intake for it and got rid of the old stuff.

Let us know how it turns out. [P

 

[440Clark]

Here is what I ended up doing. I knew from the git-go the plenum volume looked too big so I took two sticks of 2 1/2" stainless exhaust and welded them in to the corners. Hopefully in addition to removing volume, it'll create a venturi effect and speed up the velocity, (this is where you put your boots on, it's gonna really get deep) oh and don't dismiss the intercooling effect that the air flowing through the tubes as you drive down the road will create! At first I let them stick out about 4" in front and back, but it looked too much like the a robot so I cut them almost flush with the plenum box. All that remains is powdercoating. I'll post one more pic after that.

 

[jakas66]

Your idea looks very interesting. Have given thought to making one for a BB Mopar for years, has yet to be tried out. Curious to know how well it performs.
BTW Klink, I too have brazed the gaps on some block hugger type headers I've built, works very well. I also use 5/16 or 3/8 plate for the mount flange.

 

[JeremyL]

Oh man, this just gave me an idea. I've always loved the look of the Mopar 413 cross ram intake. It'd be easy to do the same type thing on a Ford using the lower EFI intake & fabbing up the cross rams to put the carbs over the valve covers.

 

[440Clark]

You know, the real way to go on a project like this would be to retain the STOCK fuel injection set up (I tossed mine years ago) then you could put the throttle body wherever you want, the air will do virtually whatever you want. I definitly here you big block MoPar guys out there. The next one I make will be tunnel ram six pack!

 

[Sunnybeach]

I think you have achieved the "how crazy is that?" factor you were after. As long as it goes half as good as it looks, things will be fine.