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Will the big thick washer that clamps down intake and exhaust flanges does rock a bit. When installing mine I did think about the possibility that it may not clamp the intake as hard as it did the exhaust. However I always had and exhaust leak. Even tried 2 gaskets before I gave up and just went to the copper silicon. Worked like a charm and still working. ok take a rope and hang me but it saved hours of time ****ing over a slight mismatch
Bet you 10 bucks it will still leak after you get it back form the machine shop.
Just the nature of the beast. You really think you can get the header clamped hard enough with half a bolt contact way out at the end of the flange?
 
One of the reasons I try NOT to use tube headers.

I located cast LH manifolds for my flatmotor drivers to avoid the issue with my flatmotor hotrod.
Warp, rustouts, weld leaks, sometimes you just gotta do what you gotta do.

Another thing is to re-tork the manifold nuts HOT.

Dave
 
Have I mentioned this is really frustrating? With my work and gig schedule it's been since late June that I last really drove the car. :madder:
 
I know.
BTDT.

Been doing this stuff for a lot of decades, and I know.
I also sometimes know how to make future access and maintenance a bit easier.

You'll get it.

Hang it there.

It's what draws us to these cars.
 
Hate to throw a wrench in the works but IMHO it appears to me that the intake manifold is imprinting on the gasket and there is no sign of the headers doing the same. If Drew wants to save a lot of work it should be possible to get a close enough measurement of the manifold and header flange in the car. If there is a difference in the thickness between the two tack welding a shim to the clamping washers to take up the difference is the easy way out.

I farm, If it can't be fixed with baling wire, it can't be fixed!!

Kurt.
 
The third photo is the only one that looks like exhaust, barely, bottom right corner.
You can see the imprint of the header flange clearly, and what appears to be a cutout for the rear stud marked.
 
nomad said:
Hate to throw a wrench in the works but IMHO it appears to me that the intake manifold is imprinting on the gasket and there is no sign of the headers doing the same.

Kurt.
Click to expand...

I clearly see where the header are making contact with the gasket, look at the picture again and you can see the header flanges clearly defined, and even a section of gasket between the intake and header flange where nothing mounts andsee it looks a different shade.

This however did make me think of another possible cause, on the 1275, you have loacting rings that sit on steps in the intake runner and the head to positively locate the intake, actually a really good idea by MG, thats why I make sure to utilize them in a street ported head. Ok most of te time I source these locating rings new, because the old ones are kind crusty up or long lost, if this locating ring was a tad too long, it could make the intake stand off.

Another question, Drew were your carbs the later smog type, I rebuild alot of carbs so I don't remember, if so, they would have two PCV tubes on them exiting the side of the carb bodies at a 45 degree angle, and if you have these type of carbs you have, you would need to do one or two things, utilize the PCV system or plug the tube, if left open, these would create a huge vacuum leak.
 
I'll check those rings, Hap, and make sure they're not interfering. They do look new.

The carbs are the later smog type, and you did put some little rubber caps over them.

carb_plug.jpg


I'll be back at it tonight. Had to take last night off, before I started hitting things on the car. In a better frame of mind today, so I can get back to it.
 
What about doubling up the gasket? Is that a bad idea?
 
When you find yourself walking toward the car, 8 pound hammer in your hand and a fixed stare on your face...

You might be an lbc owner...

or

It's time to take a break :wink:
 
Doubling gaskets can work....and can also create a whole lot more issues in the near future.
Gaskets crush.
Two gaskets crush more.
I have seen them crush out at the sides, bend and break manifolds on in-lines.

Me?
I wouldn't, based upon experience.
 
Does any one sell a better gasket for that application? Can't say i was impressed by the looks of that one.



m
 
One more thing.
I have looked at the photos until I am cross-eyed, can't see....
Take an inspection mirror and a flashlight, look UNDER the header at the flange, see if you can see any black coming out where the pipes fit into the flange on the outside.

Just humour me.
 
SilentUnicorn said:
Does any one sell a better gasket for that application? Can't say i was impressed by the looks of that one.



m
Click to expand...
I recently had to re-install my header due to the addition of some HS4s to the 1380. I used a gasket matched to the big bore
head and pipes. Worked great but then again it worked great before with the gasket that was on there.

I have had this fitment problem on my Land Cruisers.
For them I use the Remflex gasket. It does "soak" up some flange differences. Some swear by them, some hate them.
They have been good to me. Never used one on an A Series.
They are kind of pricey.
https://catalog.remflex.com/SearchResults.asp?Search=MG&Search.x=21&Search.y=17
 
Took a mirror and light out, and can't see any black on the underside of the flange. Of course, I've had my hands all over those headers so could easily have wiped it off I suppose. Nothing there now, though.

New gaskets are in hand, Payen brand. The one on there came from Hap, so I'm sure it's a quality piece.

Funny, I'm finding exhaust work to be the most frustrating yet. I'd rather pull the engine again... down to having the proper tools and skills, I guess. The work on the pipe may require some professional assistance -- if I do get it off, I'm not quite sure I can get it back on! Should have dealt with the header *before* I had the new pipe installed. Now I know... :wall:
 
RickB said:
When you find yourself walking toward the car, 8 pound hammer in your hand and a fixed stare on your face...
[...]
It's time to take a break :wink:
Click to expand...
A lesson I have learned well during my work on the Tunebug. I'm no longer afraid to take a few days off during a frustrating job.
 
I never had a header that did not have flanges at both ends.
 
I have, hence my demand for my headers that downleg flanges be installed.
Yes, sometimes you can flex the header enough out of the way to get the engine out, sometimes not, and it's hacksaw or sawzall time.

I don't use flexible joints on the exhaust end of the header, either.
I hate those things.
 
If I can't figure out a way to get things separated myself, I may wind up bringing it down and having the shop pull the pipe -- then re-install it later once I've got the header sorted.

There's not much room down there for a flange, really as the exhaust is quite close to the floor and the ground, for that matter. Might be something I need to ask the exhaust guys about.
 
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