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Old 10-10-2023, 08:45 PM
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old willy old willy is offline
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Join Date: Oct 2017
Location: Baysville, Ont
Cobra Make, Engine: Mine, small block FORD
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Default A tale of tubing......

Hello again to all.

Well another catch up post here. Again some of this to place over a longer time span as I worked on other things while I waited for parts but I thought it best to just edit this all into one section.

So then “out with the bad air” or an exhausting tale of tubing, or …………

So then,

I have been thinking about the exhaust for quite some time. I originally wanted to go with something like the AC factory cast iron Y type manifolds. Not for their amazing flow capabilities but for the correct look and compact size, plus I knew they should fit Ok.
Someone on our little corner of the internet here mentioned the Mike McCluskey had a supply of them available. So I called to inquire, left a message and being the nice guy he is he called me right back to tell me that he did not have them anymore he sold the lot to David Kirkham. So I contacted him and after a couple of messages I was told they would see if they had any left to sell and then the line just sort of went dead, no more replies, so I took that as a no. Hey, I understand they want to take care of their main customers just like Superformance, they want to sell cars not parts, it’s just the way it is.

Another line of inquiry got me to Hawk cars in the UK. I was told they could supply them but Oh wow what a price and then shipping, also from my time on the 289 register it seems they also tend to have some issues with delivering things in a timely manner.
I also considered building some out of precut flanges and heavy wall tubing, it could be done but probably only as a last resort.
I looked at lots of pictures of period correct headers and thought about building something like that. Then I was looking back at some great under hood pictures of CSX2000 when it was sold a few years back and really liked the rough shop made look to the exhaust manifolds on it.
Coincidentally about the same time I came across an excellent deal on a set of Headman block hugger type headers for small block Ford. They were bought for a rod project, painted sliver and never used, the hardware and gaskets were still sealed, Oh, did I mention they were really cheap!

I thought if nothing else they were good parts, flanges, collectors, hardware etc. or they would end up in the collection of parts that I need to pass on to somebody else when this is over.

Of course they will not work for our applications, the exhaust must go outside of the chassis tubes not “hug the block” , bit of test fitting made me think differently about how to do this. If I put the right side one on the left and left on the right It puts the collector in a much better spot. Sort of right in line with the engine mount towers and ahead of the foot boxes, then if I change the angle of the collector to outside the chassis that could work…. maybe

I also decided to swap how the rear primary tube entered the collector moving it from the outside to the inside to give a bit more clearance to the foot box, yes I will be using new space age heat shielding but every bit helps keep those temperatures down.

I also wanted to improve the area where the collector transitions to the exhaust pipes. If I leave the collector as it is I would need to have the tapered attachment flange pipe then immediately a smaller tight 90 bend to turn towards the rear of the car, not so good for flow or clearance around the engine mount area either. So I decided to extend the collector with a full size 90 degree bend and add the mounting flange after that.

I ordered up one U bend for the primary tube reworking and one for after the collector leaving me with this lot of parts.



My original idea had me just making some pie cuts to change the angle but after my decision to swap the rear tube placement there was a lot more cutting leaving only the front 2 tubes still connected for aligning purposes.

And in the end only the second tube was not cut completely apart. After I had the rear tubes sorted and tacked I cut the front tube and inserted a small piece to line things up better. Kind of a mess but they do fit in the space rather nicely.






I then moved on to adding the elbow after the collector and getting the flange where I wanted it. The fit up still looks promising.



So after all that it was time to sit down and do some old school welding. I still enjoy this type of thing; it was the way I first learned way back when.
Also I was always told it is good for exhaust work because it does not tend to get hardened the way a fast electric process like MIG can. It is a slower more controlled way of doing it, adding just as much filler as you need.



My old Henrob / Dillon III torch is still nice to work with as well, I have had it since the early 90’s and it has done a lot of work over the years.

So with them all welded up and the flanges checked and adjusted a bit for straightness I am happy for now. It may not be the most conventional way to build some exhaust but I have hope for them. I am still not sure if I will put the Headman tags back on or not?

They look a bit grotty with the remnants of silver paint and the heat marks from welding but after a quick blast and some high heat paint ( what’s your favorite?) they should do the job just fine. And they certainly have the rough shop made look I liked in CSX2000 . If not there will always be another option….

Also after walking around it for a while I decided I could not abide by my crudely done 1 inch extension of the rear corner tubes and now that other tubes are bracing things I removed the extra tube and angled the rear tube forward to match it. In the end this is under the trunk liner and not seen but the corner tube will visible so better do it now……



I knocked up the rad mounts too…..

So while I was still waiting on seats and things I decided to do the rest of the exhaust

After looking at many options I decided to keep it simple, old school and affordable. So what that really means is I went with 2 inch tubing with classic “cotton reel” type mounts and classic Thrush turbo mufflers.
The last decision was hard, I know the current trend is for the modern chambered exhaust sound but my lovely wife really hates it, one of her requests is that the car is somewhat “quiet” and I want her to enjoy riding in it so I went with the old school Thrush. We all had them back in the day, I know what they sound like and if we are not happy we can look for other options later but I think they should keep most people involved happy enough.
Also the size was very nice for this under car application; I don’t want too much hanging down.
The tubing came from a great suppler here in Ontario called Lyell’s Stainless Exhaust Inc. they have a nice selection of tubing and bends and everything else you need, they even make their own line of B-52 classic mufflers that I did consider but just went with the pipe, U bends and sleeve type clamps from them. Their pricing is good too!

The mounts were added to one of my Moss Motors orders, cotton reel type ( Jaguar? ) for most of the hangers with a single vertical type in the rear that would fit a classic MGB and others.

So the first step was to take the Headman collector mounts and shrink them down to 2 inch. A bit of math told me the difference in circumferences and I made 4 wedge cuts and tapered the tube with a bit of hammer work over a T bar, looks good so far.




So then I needed to decide where the muffler was going to live and clamped it in place.
I haven’t made any exhaust systems in a long, long time and most of them were a lot shorter (VW’s ). I bet there are new fancy tools to do this now but I just made up a cardboard template to show me the angle I am looking for in relation to a straight section of pipe and then a template to mark the U bend from.




So once I figure out the angle and mark it I cut it in the handy shop made metal jigsaw and tack it in place and move on to the next one.



I also marked the pieces I made as I went along because I figured the left side of the car should be about the same ……and I was right.
So front pipe…




For the rear pipe I went with the newer (?) style that bends inwards to the main chassis tubes as it passes the rear suspension arms. I know the crude heat bent straight pipes are more period correct but I am not sure how they would work out with my suspension design and they do seem to hang down a lot t. Also they tend to be a bit on the ugly side of the ledger .

So several bends cut and tack welded later I have a rear exhaust pipe, I then added the mounts, a pair at the front and rear of the muffler, then one on the inside corner of the bend to help with torsion forces and the vertical mount at the rear.





Then I went ahead with the left side and other than a small variation around the pedal box, everything else was a mirror image of the right side, and my markings saved a lot of time.

Then it was time for another classic welding session and reassemble to check the fit.





Everything looks right to me so far, in the future I will blast and paint everything and possibly add the classic chrome tips but perhaps not.

And that’s all for now other than I would like to ask the group…

What is your favorite High heat paint? In the past I have used VHT and Tremclad ? I have been looking at the POR 15 brand stuff but have never tried it, have you?

Let me know your thoughts.

Cheers,
Hudson


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Last edited by old willy; 10-10-2023 at 08:48 PM..
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