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Crack in exhaust header...

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M

Midget78

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Hey to all of my addicts out there. I got to say Im getting a bit worried about my use of these forums. Im somewhat of a new member and I can't keep myself from logging on and watching the time go by on these forums. This thing is very informative and addicting. Anyway, and on to my question: I have my mechanic re-installing my Weber DGV conversion due to an intake air leak and upon disassembly he found a crack in the exhaust manifold. It's about an inch long and runs from the edge where the rear mounting stud is. Immediately he asked to buy a new header from Moss and I agreed but after seeing the crack I start to wonder if it was necessary to blow the extra cash on a header and rather weld up the crack or just leave it alone and wkeep an eye on it. This whole header issue is attaching an extra $300 onto the project. Any thoughts?
 
If the header, and I assume we are definately talking about a header and not a factory cast iron exhaust manifold, if the header is otherwise in good shape, not eat up with rust, you wouldn't be the first or last person to braze or mig up a crack in a header, normally this is the case though, when it already gone too far, and you'd be better off just replacing it. You need to look at the overall condition of it and make a judgement call. I will say this though, since you mentioned "the mechanic", don't ask him to do a chicken crap repair, then when it fails, think badly of him (I've been there plenty of times), maybe if he thinks it needs replacing, then it does.
 
Headers are cool... :wink:

Hey, you said: "Any thoughts?"
 
Headers ARE cool (I have one on my BE!), but if cost is an issue, a stock manifold may be more cost-effective, and used ones can be found on ebay etc. at reasonable prices (I even have a couple I could be talked out of! :wink: )!!
 
Won't a header from a Mini fit or austin Metro, there's plenty of them in scrappies (well over here in UK).
"or braze it"
 
Hairyone said:
Won't a header from a Mini fit or austin Metro, there's plenty of them in scrappies (well over here in UK).
"or braze it"
Click to expand...

No.

A '78 Midget uses the 1500 engine (like Spitfire).

It is very common for the 1500 cast iron exhaust manifold to crack. The catalytic converter is attached to it and I guess excess heat and weight really causes extra stress. I've seen several cracked exhaust manifolds on 1500 parts engines that I've had.

Typically, when the exhaust manifold is replaced with a tubular exhaust header, the catalytic converter is eliminated.
 
Thanks guys for the feedback. "aeronca65t" hit the nail on the head when it comes to what the mechanic said about the converter putting a bit of stress on the manifold and creating problems with cracking later on. Now I will have another component from the emissions controls removed and put in my storage box. I cant really see any negative to going to a tubular exhaust header except for the cost. I just joined the union of unemployed workers so spending is now a bit more of a concern. I just hope she runs for a good while with no troubles. It just seems like these little old cars always can have a surprise for you when you least expect it.
 
You can get off cheap buying a Pacesetter header on eBay... but you very much get what you pay for on that one. And it is definitely not plug and play. You will have to modify a few things to get it to fit properly. If you are paying someone else to do the work it will add up fast.

The 4-2-1 header Moss offers (part# 452-070) is probably a much better item, though I have no personal experience with it.

Also, if you are going to install headers, I highly recommend you wrap them with header wraps (you can get them cheap at summitracing.com) or have the header ceramic coated (which is very $$).

BCF member Tony barnhill may have a used stock manifold he can sell you. He told me he had some a while back. If $$ is your main consideration, this may be the way to go. If you decide to buy the Moss header, Tony will give you a 20% discount if you buy from him.
 
I do recall an earlier conversation that favoured one brand of header over another. Someone else wade in here but I seem to recall that Maniflow was the preferred brand and Pace Setter was not
 
My 1500 race-Spridget has a Pacesetter tubular header.

It was a mess and I had to do quite a bit of grinding and re-welding to get it to fit properly.

I would have sent it back, but I had a race to get to and I was running short on time.
 
I too had a cracked exhaust manifold on my 79 1500. I had no choice but to replace it as the car needed to pass CA smog. I picked up a used one from a junk yard for $200 shipped. I know I paid too much, but it was the fastest and easiest way to do it.

I've since seen them on Ebay for a lot less money. Considering that they are a weak point in the system, I'm considering getting a spare just in case. They've gone for as little as $20.00 at auction.
 
I had a custom made header for my be and my sprite. I will have to take a pic of it, I have ran it on the sprite for about 2 years, sounds great. The trick was to find a machine shop that wanted to try it. I took a little calling and stopping around but the two headers cost $65 each and they are built exceptionally well.
 
jaegzie said:
I had a custom made header for my be and my sprite. I will have to take a pic of it, I have ran it on the sprite for about 2 years, sounds great. The trick was to find a machine shop that wanted to try it. I took a little calling and stopping around but the two headers cost $65 each and they are built exceptionally well.
Click to expand...

yes, pics please
 
Thanks to the specific needs of the turbocharger, I had to make a custom intake and exhaust for Bugsy. It worked so well that I got brave and have since welded up two sets of headers. 1/4" mild steel plate for the faceplate, and carefully assembled slices from U-bent pieces from the local hotrod shop. By slicing up the prebent tubing and combining with straight pipe, headers really aren't that hard to make. As long as no one ever asks how much grinding it took to make them look good after my mediocre welding, all is good.
You need an angle grinder, MIG welder, drill press, and time.
It helps to pick uncommon projects that have no aftermarket stuff available. You get to learn lots of fabrication skills! If "Junkyard Wars" or "Monster Garage" ever come back, I'm finally ready.

Glen Byrns
 
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