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Question - Exhaust manifold

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jlaird

jlaird

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I have a very nice 1297 exhaust manifold, have been unable to come up with a 948. Any reason I can't use it? I know the flange to the exhaust pipe is different but can I use a 1297 exhaust pipe on a Bugeye? The 1297 manifold looks a lot more efficient to me?
 
Jack, the 1275 manifold bolts right up to the 948. It's not only more efficient, but the connection to the exhaust pipe is the flange and doughnut type, rather than the horrible split clamp of the 948-1098. A 1275 exhaust works on the Bugeye, but make sure you have the flange that goes on the front pipe. Most systems I've seen require you to reuse the old flange. However, the last Falcon stainless steel system I bought, (from VB) came with a flange. Shouldn't be too hard to find one, should the need arise. You'll also have to switch to the 1275 hangers, as the pipe is slightly larger in diameter. No big deal. Make sure you get the complete hanger that goes from the bell housing to the front pipe. That one is very important, as is the one that attaches to the tab on the muffler.
Jeff
 
Ok, thanks, that's just what I wanted to know. Appreciate again.
 
Now here is an intresting problem. It seems that the sliding flange is not available from exhisting sources, in fact VB even comments that the exhisting one must be used. Sigh, always some darn thing or another. So I got this nice 1297 manifold that is unusable without a sliding flange.
 
Go to your local exhaust specialty (muffler) shop. When I had this problem on my 1500, they had it. They said they could get any flange.
 
Good deal, that flange would be the same size and shape as the gasket would it not?
 
Should be. And if they don't have one, any competent machine shop can make one for you, using the gasket as a template. Heck, with a drill, jigsaw, and some patience, you could probably make it yourself! /ubbthreads/images/graemlins/hammer.gif
 
yep, could. Not a prob. since I think will even have a pattern. Can anyone remember how thick the metal is?
 
Jack... wait a minute. The sliding flange on a Spridget 1275 pipe is NOT the same as on a 1500. The 1500 is a fixed flange taking a triangular gasket. The sliding flange takes a donut gasket. The sliding flange is expected to be reused, but since you don't have one, you "might" be stuck. The good news is it is the same slidinge flange and gasket as any pre-cat MGB. On an MGB the flange is incorporated onto the pipe assembly, AND you get 2 on an MGB. Ask anyone with an old B pipe laying around. I have one a wreck I could cut off for you. Peter
 
Yes, this 1275 manifold takes a donut gasket. The exhaust pipe in the pic looks like it has a fitting welded on it that seats against the donut, behind that is a sliding flange, three bolt holes, the sliding flange then bolts to the manifold and holds the donut gasket and the pipe with the fitting in place.

Are we talking about the same thing?
 
Peter you have a PM.
 
A related question: I recently bought a LCB performance header, along with the VB Falcon stainless exhaust set. I noticed they do not fit together as they currently are...the Falcon is made to fit the stock manifold, not the LCB which comes way down (unlike the stock set-up).

Perhaps a stupid question (but the above thread of doughnut flanges and the like got me to re-thinking my initial evaluation): do I just cut down the Falcon to work with the LCB and just stick a stainless u-bolt to join them together? Will that work?

Thanks as always to the community.
 
Mustafa, I think there is going to be a bit of difference in sizes between the collector on the header, and the stock sized Falcon pipe. You may get away with trimming the Falcon pipe back to the length needed, but if you are committed to using the stock sized pipe, I'd reduce it down from the collector size with an adapter. I don't know the size of your collector, but if it were me, I'd be tempted to stay with that size all the way back, and run it all through a Flowmaster muffler. It seems to be kind of a waste to put a LCB header on, and then strangle it through a small pipe.
Jeff
 
[ QUOTE ]
Jack... wait a minute. The sliding flange on a Spridget 1275 pipe is NOT the same as on a 1500. The 1500 is a fixed flange taking a triangular gasket. The sliding flange takes a donut gasket. The sliding flange is expected to be reused, but since you don't have one, you "might" be stuck. The good news is it is the same slidinge flange and gasket as any pre-cat MGB. On an MGB the flange is incorporated onto the pipe assembly, AND you get 2 on an MGB. Ask anyone with an old B pipe laying around. I have one a wreck I could cut off for you. Peter

[/ QUOTE ]

I did not say the 1500 and the 1275 were the same. I said, when I had this problem on my 1500 (No pipe, no flange, no nothing, the local muffler specialty shop had the flange and made a downpipe). I said the muffler shop said they could get any flanges. How true the muffler shop statement is or not I don't know.
 
yep, understood at this end, the situation is well in hand at this point with the assistance of the fourm folks. Several of them in fact, as usual.
 
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