Exhaust Manifold Bolts.
Discussion
Good afternoon fellow PHers/S series pilots,
Today I am happy chappy as my nice shiney new stainless manifolds have arrived from Peninsula TVR. This of course means that I will eagerly be watching the weather forecast and anticipating spending the best part of Saturday, spanners in hand, fitting the aforementioned. I have of course one minor problem. I plan to do the whole job in the day, not an impossible task but this won't give me time to go out sourcing new bolts, which I would like to fit. The question is does anyone know what size said bolts are (2.9 engine). I am aware that they have a 1/2" AF head rather than the expected 13mm, this inturn suggests an imperial thread rather than the expected metric. If anybody has the thread size, pitch and length this would be much appreciated.
Thanks (hopefully)
Carl.
Today I am happy chappy as my nice shiney new stainless manifolds have arrived from Peninsula TVR. This of course means that I will eagerly be watching the weather forecast and anticipating spending the best part of Saturday, spanners in hand, fitting the aforementioned. I have of course one minor problem. I plan to do the whole job in the day, not an impossible task but this won't give me time to go out sourcing new bolts, which I would like to fit. The question is does anyone know what size said bolts are (2.9 engine). I am aware that they have a 1/2" AF head rather than the expected 13mm, this inturn suggests an imperial thread rather than the expected metric. If anybody has the thread size, pitch and length this would be much appreciated.
Thanks (hopefully)
Carl.
There are arguments for and against stainless bolts. With stainless the heads stay in better shape, but you run the risk of galvanic rust siezing them in the head. Personally I went for mild steel (that's what the guy at ACT recommended). i am sure that so long as you use plenty of copper slip you should be ok in both cases.
Z
Z
Just had a look, they are definately studs, and are 8mm X 1.25mm if you measure the thickness of the manifold flange you should be able to work out the overall length req'd.
Its worth noting that on both sides of the engine there are 2 or 3 studs snapped in, so if thats typical I would recommend soaking the area with plus gas a couple of times before saturday and letting it really soak in, the last thing you want to do is snap one off,not trying to teach you to suck eggs but good a clean round the threads with a wire brush will help if you do it before applying any easing oil. My son is working on a golf GTI head at present and has bought new studs they are pretty much the same length so if you decide to stick with new studs, and Ford don’t have them which is more than likely you could ask a Volkswagen dealer for part no 044 411 5 chances are they’ll have them in stock @ 57p ea.
if you go for "bolts" to an engineering supplier remember to ask them for setscrews not Bolts they are very defined and will give you Bolts which have a flat on them,the flat may be longer than the thickness of your manifold flange.
ps that doesnt explain the half" head
Its worth noting that on both sides of the engine there are 2 or 3 studs snapped in, so if thats typical I would recommend soaking the area with plus gas a couple of times before saturday and letting it really soak in, the last thing you want to do is snap one off,not trying to teach you to suck eggs but good a clean round the threads with a wire brush will help if you do it before applying any easing oil. My son is working on a golf GTI head at present and has bought new studs they are pretty much the same length so if you decide to stick with new studs, and Ford don’t have them which is more than likely you could ask a Volkswagen dealer for part no 044 411 5 chances are they’ll have them in stock @ 57p ea.
if you go for "bolts" to an engineering supplier remember to ask them for setscrews not Bolts they are very defined and will give you Bolts which have a flat on them,the flat may be longer than the thickness of your manifold flange.
ps that doesnt explain the half" head
Edited by clarenceboddiger on Thursday 21st September 06:56
Edited by clarenceboddiger on Thursday 21st September 06:58
Tim - do you know which bolts you used in the end?
My passenger side manifold (replaced by previous owner) is hle don with bolts (13mm head) but the driver's side (probably original) was still on the now drilled-out studs.
I'd like to use bolts for the new manifold if I can get right ones.
My passenger side manifold (replaced by previous owner) is hle don with bolts (13mm head) but the driver's side (probably original) was still on the now drilled-out studs.
I'd like to use bolts for the new manifold if I can get right ones.
Thanks for all your help, as usual, chaps.. I decided to take 1 bolt out to be on the safe side. Ken, you were correct (never doubted you) they are indeed standard M8x1.25 set screws.. Still find it odd that mine have 1/2"heads rather than 13mm but hey ho..
s3swiss... you will require M8 set screws 25mm thread length if thats the way you wanna go (they will have 13mm head), thats what I am using, mine already had a full complement of set screws rather than studs anyway.
Thanks again guys,
Carl.
s3swiss... you will require M8 set screws 25mm thread length if thats the way you wanna go (they will have 13mm head), thats what I am using, mine already had a full complement of set screws rather than studs anyway.
Thanks again guys,
Carl.
oops - just tried a M8 set screw in my head - as wobbly as a wobbly thing! Guess Imperial thread it is (in my head anyway). Suppose different heads may have been supplied to TVR by Ford? An old 1/2" bolt I had lying around fits the threads nice and snug. All part of the joys of TVR ownership I think!
Gassing Station | S Series | Top of Page | What's New | My Stuff