CIH Turbo EFI by RallyBob

[RallyBob]

You might be able to use a 3" reducer cone and just cut it short...eventually you'll end up at 2.5" somewhere along the taper.

Regarding the flanges. I'd wait until after they're all put together to have them ground, as they will warp from welding.

Bob

[namba209]

Bob, I was planning on getting two reducers, one from 2 1/2 to 2 and one from 2 to 1 1/2, that way it will be about 6" long , but if I can go from 1 1/2 to 3 like you said, the taper will maybe be shorter, I didn't check the length of that particular reducer. I'll go to their website and check it out. I would like to surface grind the flanges after the welding, but it would be kinda hard to have a magnetic table hold the asssembly flat with the tubes already welded to the flanges. But I'll check with the machine shop and see if it can be done that way. Thanx again for the ideas. Your expertise is outstanding, as usual.

Ron

[gtzero]

Bob,

This might be worth driving cross-country to see.

I wish I had more machine shop experience to try some of the things you do. Looks like a lot of fun.

Manny

[Gary]

Originally posted by gtzero Bob, This might be worth driving cross-country to see. Manny

Gee Manny.... Marty Remier (sp?) from Texas showed up in Carlisle last year.....

[RallyBob]

Originally posted by gtzero Bob, This might be worth driving cross-country to see. I wish I had more machine shop experience to try some of the things you do. Looks like a lot of fun. Manny

Manny, sometimes the only way to get the experience is to just pick up the tools and go for it!

I grew up with parents that weren't particularly helpful or supportive of my automotive habits. Dad never showed me how to change oil, or fix a dent, and not even how to hand-build a rollcage.
I learned how to do everything I do simply by trying to do it. Don't worry, I've left a wake of trashed parts learning how to do custom work. I learn from every mistake though, I seldom make the same one twice. In fact, I'm constantly discovering new ways of making mistakes......

Bob

[72GT]

Originally posted by RallyBob ... I've left a wake of trashed parts learning how to do custom work. I learn from every mistake though, I seldom make the same one twice. In fact, I'm constantly discovering new ways of making mistakes...... Bob

Thanks, these are very inspiring words!

[RallyBob]

Originally posted by 72GT Thanks, these are very inspiring words!

No problem! That's the reason I post my photos and updates here, to inspire. I watch all these new TV shows like American Chopper, American Hotrod, Monster Garage, Rides, etc....because they inspire me to do better. It's also nice to know that even the pros make mistakes!

[RallyBob]

Sorry for the lack of updates here, it's been tough getting anything done other than ordering parts (which has take about 2 hours per day for the past three days!).

I did finish the header flange and finish-welded the fuel rail. I also trimmed the throttle body to clearance the fuel rail.

Here I started to make the header tubes. It's tough to make thick-walled round tubes fit a rectangular port shape. I decided to make the beginning of the header tubes from square tubing, and form them into a round shape to meet the remaining round tubes. I needed to make the tubes 1.25" x 1.50" to fit the header flange. I only had some 1.5" square tube, so I cut the tubing at 3/4", figuring on welding the two 3/4" pieces into one 1.50" piece. Here are the cut pieces before welding...

[RallyBob]

Here the two pieces are welded together to make one piece.

[RallyBob]

Inside the tube....full weld penetration. Damn, I love my TIG welder, don't know how I went without it for so long.....

[RallyBob]

Header flange test-fit to cylinder head with intake manifold. Hoped to finish the header this weekend, but I'm attending a dyno session for my friend's rallycar. That will probably eat up half the day Saturday.

[namba209]

Bob, on my square tubing exhaust manifold, the muffler guy used a tubing expander to open up the square tubing into a semi-round shape. I don't know if he heated it up before expanding it or not, just figured to give you an idea from what I've seen. You've been more than helpful to me and others on the list.

Ron

[RallyBob]

That was my idea too. I'm gonna get me one of those tapered expanders, heat the pipe, and hammer it in to make it round. Should work sweet....

[Old Hippie]

R-bob, I hope I can make a weld half as decent as yours when I get my garage wireing done And after some scrap practice. That is some pretty bead work. Say, ron's right. You have more excellent answers for people here than I can count. Tell me, do you put your pants on one leg at a time?

[namba209]

Bob, I don't know if you'll have to beat the square tube to make it semi round, of course I don't know metallurgy that well or at all actually. There were no hammer marks on the section of square to round tubing on the manifold I got from the welder. I can't take a pic right now, it's back at the shop for tweaking. If I get the fittings Monday, I will end up with two pairs of manifolds, one like yours and the square tubing setup. Oh well, I can always use a spare

Ron

[RallyBob]

Decidedly off-topic, but I attended the dynoing of my friend's rallycar today, and it put down 230 hp to the wheels (about 270 hp @ flywheel) from an internally stock 1.8 litre VW! Just the custom exhaust and bigger IHI turbo (12 psi), a bigger intercooler, and an aftermarket ECU. Almost no lag either, boosting at 2200 rpms....

Man, I love turbos! Can't wait for the Opel turbo to fire up....

[RallyBob]

Not much accomplished today, didn't spend a whole lot of time at the shop. But, the critical tube merge (rectangular to round) was at least completed on the header.

I used a t-dolley clamped in a vise, and then hammered the square tubes into a round shape at one end.

[RallyBob]

Here one side has taken shape. Nothing fancy, just used a ball-peen hammer and hit it for about 2 minutes total per tube.

[RallyBob]

The full rounded tube outlet.

[RallyBob]

You can see how nicely the cast steel 1.25" ID tube bends fit the newly formed outlet.

[RallyBob]

At the inside of the tube where it meets the flange, I tack-welded the corners, then used a small hammer to tap the tubing tight to the inside of the hole in the flange. This will make for a nicer weld later on, and hopefully it will flow better too.