The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: dave55 on 28.05. 2020 12:10
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Hello, could anyone please tell me what is the recommended method to seal exhaust front pipes in to the cast iron head.
It is the first time i have had them off and one side is loose with nothing sealing it and the other has some kind of string wrapped around and stuffed into the head then the clamp pushed op to it, i am wondering what you fellas recommend ??
Thanks Dave
adm edit: removed capitals (SCREAMING) in title.
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Not sure if it's recommended but i use silicone from the gun. Not too much and towards the outside, ie just as i push in the last quarter inch. Bear in mind i am a bad person but it works for me. Someone will be along soon with the proper way.
*bright idea* *bash* *good3* *beer*
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Dave.... Standard fitment is a big dose of Faith, Hope and Charringtons.*
Standard nominal size of the ports is 1 1/2". Standard pipe OD is 1 1/2". Result, a perfect seal every time. If the pipe is a sloppy fit, something is wrong with the sizing of the parts you have. The standard size pipe joint eventually seals itself as carbon becomes deposited in any gaps. A dab of grease on cleaned up ports ensures the pipes go right back into the head, to the step at the back of the ports.
Jim's Silicone is fine, and easy to dismantle. Exhaust paste will also do the job but after using this, getting the pipe out again may prove very difficult.
Mounting points may need to be amended and tweaked to ensure the pipes fit fully into the head with no straining. Brackets welded onto the pipes in the wrong place are common.
Swarfy.
*A popular brew from a long time ago when these bikes were new.
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I use exhaust sealer paste.
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Exhaust paste will also do the job but after using this, getting the pipe out again may prove very difficult.
I dont recommend exhaust paste. It was used on the A7 when it was rebuilt. I have tried twice to get the pipes out and failed. The pipes are still near perfect and I only wanted to check inside the primary case but not enough to damage the good pipes.
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I use a smidge of the permatex red heat resistant silicone on header pipes at both ends
components easily removed after
works for me
S
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Standard nominal size of the ports is 1 1/2". Standard pipe OD is 1 1/2". Result, a perfect seal every time. If the pipe is a sloppy fit, something is wrong with the sizing of the parts you have.
And if the pipes won't even go into the head it's your own fault for buying from Armours.
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CB - if you reckon Armours pipes are rubbish, clearly you haven't tried the opposition! Been using them for over 40 years.
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Yup my pipes came from Armours and they too are a poor fit. (why I'm reading this thread!)
Thx
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Thanks for the replies, silicone it will be then. I wondered if there was a copper ring went in like some exhausts was my first thought.
Fit seems ok, been on since i got the bike and exhaust stamped Campbells so maybe pipes are theirs too.
I remember Charringtons from my apprentice drinking days, Bass Charrington i believe ? But today Swarfy it will have to be Faith Hope and Atherwoods Amber Adder when they get put back on. Cheers Dave *beer*
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Any silicone is good. It is all heat resistant enough but I do recommend giving it at least 24 hours to go off before starting so that it doesn't get blown out anywhere.
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And, don't try to complain to Armours about crap fitting pipes, they did not serve in the Diplomatic Co.
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No, I wouldn't complain to Armours about crap fitting pipes because they don't supply them. Had pipes for several different bikes over several decades from them and never been disappointed. Fit is always good, chrome is good and they're very helpful. Had a few one-off pipes from them too. Excellent service so don't understand people slagging them off. Maybe some people don't know how to fit exhausts? Sure, sometimes a pipe will need a tweak, but the same goes for OEM (both bikes and cars). Now, if people were complaining about CWC ....
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Hi RDfella, glad you had good dealings with them as two systems I had were absolutely crap. First one was a Siamese system for my RGS, admittedly several years ago, the short pipe would not fit at all in the correct position, when it did, the long run pipe was so far out, I could put my foot down between the frame and pipe. Tried them again in more recent times for a hi-level pipe for my old B31, in trials trim, very similar situation, I could not get my foot on the footrest and obviously, the short silencer was miles out from the frame. This one got a touch of surgery in a industrial bending machine, the chrome not liking it, but fortunately the heat shield covered it.
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Has anyone ever considered fitting stubs and going push over like some "other brands"
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Other brands.....That's how Ariel did it on the Huntmaster. You often see Huntmaster Cylinder Heads mis-described as A7 or A10 as the basic casting looks the same, but the clincher is the stubs.
Certainly a better idea, but no standard pipes available for BSA, dunno if Huntmaster pipes would fit.
Swarfy
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i have put stepped ally inserts in the head interference fit and pegged with a 3/16ths allen grub screw fixed between two head fins near the exhaust port opening. the pipes fit over them and but up to the step and have been ok for years
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I could only find siamese pipes at Armours. They were very helpful, when I ordered. Interestingly they don’t have a proper bracket, just a stud welded to the pipe, when fitted you can make a correctly sized bracket to fit between the stud and the engine stud. They were a pain to get into the head though. Sorted when I realised they weren’t exactly round. Judicious use of a vice sorted this. Overall I’m happy with Armours for my iron head plunger.
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Hello, after cleaning some very hard crap out of exhaust ports the pipes went in right up to the shoulder and when tightened up seem like they will be fine without any sealant, i am guessing previous owner must have not cleaned port out and old string and some sort of plumbers sealing putty was preventing pipe going up to shoulder on right hand side.
Alls well that ends well ! Thanks Dave