Down Pipe?

[Rush]

I bought a lovely stock exhaust manifold from a member quite a while back but didn't realize I'd need another pipe (2 to 1 collector) to use it or I'd have asked if he had that as well. Does anyone have any idea where would I find one of these?

Thanks!

[datzenmike]

You'll have to make or have one made. Muffler shop?

I swapped an L16 4 into 2 exhaust manifold onto my 710 which had the terrible 4 into one L20B manifold. I modified a 240sx exhaust down pipe (free) by cutting the flange away, slitting both pipes and squeezing the pipes down to 1 1/2" diameter (or what ever the 510 down pipes are) and slipping on a pre-made 510 flange (thanks once again Mklotz70) and welding it all up.







Above. The two pipes clear beautifully and join far down and under the car where I joined to the stock system. From exhaust valve to 'collector' is over 32". Those tabs are for a heat shield I removed.

The original pipes

[Rush]

Thanks! I'll have to trailer the car to the exhaust shop (IF I can find one competent enough to do this). It looks like the flange is the crux of the thing.

[datzenmike]

Mklotz70 on Ratsun had a bunch cut with water jet. He may have the file so you can cut your own.

[Rush]

Thanks! I appreciate the info! I'll see if I can get in touch.

[datzenmike]

You could buy a gasket and trace that out on 1/4" steel and cut out your own with hand tools. The pipes should match the inside of the manifold and stick out 1/8" or so, so that they stick up inside the manifold for better exhaust seal. I was talking to Mike at Canby one year and he showed me one and then gave it to me. I had it for about 8 years before having any use for it.

[Rush]

That's great info! Thanks!

[yenpit]

FYI if you can find a decent stock downpipe, they are the same 1968-1973 510 2dr 4dr Wagon. The Wagon pipe, AFTER it turns down under the car is different, but if you find a Wagon downpipe, grab it, cuz all you would do is cut off the pipe AFTER it turns under the car & then have a competent muffler shop bend up an exhaust pipe from there to out the back. Sorry, I do not have any more good USED downpipes!

[Rush]

Thanks for the info! If I ever find one I'm sure I'd be wondering about that.

[Pjackb]

did you get this done ?

[Rush]

No, not yet.

[Pjackb]

We just did mine last week with long tubes it really wasn’t that hard and I’m pretty sure you can do it yourself, I’ve seen your work
I can’t add pictures right now they’re too large but follow my build thread I’ll post more details and pictures soon

[Rush]

I'll take a look! Thanks!

[Pjackb]

Here you go

Started working on my exhaust system , since the primary focus for this car is relaxed cruising I want to have a relatively quiet system without compromising too much on performance .

To that end I selected to go with a stock 4-2-1 Manifold , 2” pipes into a Vibrant resonator and Magnaflow Turbo muffler.
I have read multiple time that the stock manifold is good for up to 150hp only but to be honest I think it should be more than that when you consider that the primaries are at least 1.5” and the secondaries are 1 5/8” most exhaust shops I’ve talked to say they should support past 200hp with properly configured system and they all recommended longer than stock secondaries. This was ok with as the down pipe on the car was shot and needed replacing,

We started by taking some measurement and had 2 lengths of 36” pipe bent to the angles we needed, the originals are 1 5/8 but I bought 1.75” since 1 5/8 is almost impossible to find and the bends would crush the pipes some anyways



At first I had planed to use the flange from my originals but in speaking with a few people I found an already made flange that we used to mount them

Started by tacking one on to get our measures and final angles




Made some adjustment cut to the second tube.



Once the two tube were set to the right angles time to join them






And test fit everything.



We added a piece of 2” pipe to weld in the O2 bung and do final fit test.



I added a 2-bolt flange and sent everything to get ceramic coated.

[datzenmike]

I left about 3/16th of pipe sticking up out of the flange so it fit tightly into the manifold on mine for a better seal. I must have climbed under and tacked that flange a half dozen times to get the fit position just right but it paid off in the end.