I'm laying plans for a new exhaust later this summer. As I try to decide what to keep, what to buy and what to build, I'd really like to see pictures of a complete stock downpipe for a '70-72 240Z. Mine has been modified and I need to decide how (or if) that affects my plans.

Does anyone have one off the car that they can take pictures of, and maybe a measurement or two?

Arne,

I had an entire NOS exhaust system put on #237 last year. Here are some pics of the parts before installation. I have another complete used OEM exhaust that I saved from a parts car. I can take some pictures and measurements from that tomorrow if you want.

-Mike

That would be great, Mike. I'd like to know how long the pipe is after the Y, the OD at the end, and perhaps the approximate amount that the pipe offsets to the center of the car after the Y. Any of this you can provide will help.

Here are some measurements and pictures Arne.

I'd like to know how long the pipe is after the Y

Using a straight line, it is about 18" to 19". The end goes under the joint for the middle section, so it is hard to know exactly where it ends. Using a tape measure to follow the curve, it is about 1" longer.

the OD at the end

The OD looks to be 1 5/8" for the entire length of the downpipe.

the approximate amount that the pipe offsets to the center of the car after the Y

It is difficult to measure (and even more difficult to photograph accurately, but I think it is about 4".

Hope this helps. Let me know if you need anything else.

-Mike

Great info! Thanks Mike

Thanks, Mike. Useful info, but opens a whole new question.

I'm looking at the construction method of both the new one you put on #137 and to old one above, and they aren't the same as mine, which I would have thought was original.

In both of the ones you pictured, it looks like the forward manifold outlet is one long pipe all the way back to the center muffler joint, and the other manifold outlet is cut and welded into the first to create the Y.

Mine on the other hand, both manifold outlets feed into similar length tubes, which are both welded into a Y adapter, and the single tube to the center muffler is welded into that. Dang hard to get pictures with the car on the ground in the garage, but hopefully this shows what I'm talking about.

Was the new downpipe you pictured only used on really early cars? I can't believe that mine has been replaced, but it's not similar in construction to the ones you have/had.

Hmm. The image on the parts CD is pretty much what mine looks like. It lists the same downpipe through 8/71, and a different number for 9/71 - 6/72. I've seen other so-called 8/71 parts on my 7/71 car, so I wonder if my downpipe is actually a '72-style?

Don't know if it's relevent in this case but there was a difference between an automatic transmission and a manual transmission exhaust system. According to this the difference was $6.49.

Here is a picture of 6/70 down pipe when it was out.

Notice the z welded on the down pipe.

The measurements matched what Mike showed above.

Was the new downpipe you pictured only used on really early cars?

I'm not sure Arne. The used exhaust I attached pictures of was from a 3/71 car. The pre-muffler and rear muffler are OEM and I assume the downpipe is too. I just checked #32 and #210 and both have the same style downpipe that I posted pictures of. The entire exhaust system on #32 looks to be original. At least the rear muffler on #210 has been changed to aftermarket. I don't have my 5/72 at the house right now, so I can't comment on what it has.

-Mike

Notice the z welded on the down pipe.

That is an interesting Z on the down pipe Jim. I don't think I have seen that before.

-Mike

Thanks, Mike. Useful info, but opens a whole new question.

I'm looking at the construction method of both the new one you put on #137 and to old one above, and they aren't the same as mine, which I would have thought was original.

In both of the ones you pictured, it looks like the forward manifold outlet is one long pipe all the way back to the center muffler joint, and the other manifold outlet is cut and welded into the first to create the Y.

Mine on the other hand, both manifold outlets feed into similar length tubes, which are both welded into a Y adapter, and the single tube to the center muffler is welded into that. Dang hard to get pictures with the car on the ground in the garage, but hopefully this shows what I'm talking about.

Was the new downpipe you pictured only used on really early cars? I can't believe that mine has been replaced, but it's not similar in construction to the ones you have/had.

Arne,

Take a look at Kats web sight, go to "Original Detail" and scroll down to a picture of the "cast junction" on his down pipe. It has always been my understanding that this style of downpipe is the early part number, while the down pipe with one pipe welded into another is the later redition.

Dan

That is an interesting Z on the down pipe Jim. I don't think I have seen that before.

-Mike

how do you know its not an 'N'