Tightening Up the Inlet Manifold Bolts

[Guest]

Last summer I replaced the inlet manifold gaskets as it was weeping a little water. The operation had no effect at all as it is still weeping a little - very little in fact but it's annoying. As I have recently bought a a refurbished set of carbs I will take the opportunity to tighten up the bolts again hoping for better results. My question is: in the case that a bolt strips the thread, would it be advisable to purchase a similar bolt but with more 'bite' in its thread to avoid helicoiling?

[wilf]

If one strips, helicoil the lot. only way to fix the problem once and for all. If you drive in an oversized bolt, you may lose the ability to helicoil later.

Plenty of threads here on this subject, complete with the recommended drill/helicoil/bolt sizes. Search is your friend!

[mole42]

And, although tedious, Helicoiling the manifold bolt holes isn't difficult.
And well worth the effort.

[V Mad]

I am sure you know already, but Stag water pumps usually weep a little water occasionally. Could this be the cause of the water leak?

[nib]

Last summer I replaced the inlet manifold gaskets as it was weeping a little water. The operation had no effect at all as it is still weeping a little - very little in fact but it's annoying. As I have recently bought a a refurbished set of carbs I will take the opportunity to tighten up the bolts again hoping for better results. My question is: in the case that a bolt strips the thread, would it be advisable to purchase a similar bolt but with more 'bite' in its thread to avoid helicoiling?

Do remember some of the bolt holes at the bottom are very close to waterways so tread carefully with long bolts, I shouldn't think it would take much to punch through the alloy into the waterway.

[wilf]

I am sure you know already, but Stag water pumps usually weep a little water occasionally. Could this be the cause of the water leak?

Especially if you have fitted a ..................can't bring myself to mention it. But anyhow, mine does exactly that.

[ham204stag]

Especially if you have fitted a ..................can't bring myself to mention it. But anyhow, mine does exactly that.

Yes it has an unmentionable container high up.

Chris, it doesn't have the waterpump any more as it's been replaced with an electric one. I'll have a look with an endoscope to see if there are any leaks before I take off the carbs though.

[V Mad]

I didnt realise you had the EWP Mario. In that case I guess the inlet manifold must be the culprit. I need to check mine soon as I am losing water invisibly. I just hope the PO used the correct method of alignment when fitting the heads.

[v8ken]

Could also be a core plug.

When I have Helicoiled into aluminium,I've never needed to drill first.This was as per my helicoil instructions, as I thought at first I would need an angled drill...you don't.
Ken.

[Bandit1200]

Last summer I replaced the inlet manifold gaskets as it was weeping a little water. The operation had no effect at all as it is still weeping a little - very little in fact but it's annoying. As I have recently bought a a refurbished set of carbs I will take the opportunity to tighten up the bolts again hoping for better results. My question is: in the case that a bolt strips the thread, would it be advisable to purchase a similar bolt but with more 'bite' in its thread to avoid helicoiling?

Try K seal first.
Steve

[ham204stag]

Try K seal first.
Steve

Hi Steve, I did, it stopped for about a week and then started again!

The strange thing is that it appears to leak when it's laid up, rather than when the engine is running

[wilf]

That is exactly what mine does, but I know it is from the waterpump seal, which is fine when it is running.

[new to this]

You said you replaced the inlet manifold gaskets and its still leaking,did you check that the manifold was sitting up against the heads squarely ( i mean no gaps at the top or bottom )some times you may have to have the inlet manifold skimmed

Dave

[mike@thenook]

When I fitted my inlet manifold and heads after the last re-build I did up the bolts on the inlet manifold before torquing down the head studs.
This presumes that you will be undoing the heads or at least one before you try to sort the inlet manifold leaks as doing it with the heads in place is very difficult, not recommended and likely to only last a short while if at all.
Cheers

Mike

[ham204stag]

[QUOTE=mike@thenook;350975]When I fitted my inlet manifold and heads after the last re-build I did up the bolts on the inlet manifold before torquing down the head studs.
This presumes that you will be undoing the heads or at least one before you try to sort the inlet manifold leaks as doing it with the heads in place is very difficult, not recommended and likely to only last a short while if at all.
Cheers

Mike[/QUOTE

I read somewhere that Triumph actually suggested to loosen one head before torquing up the manifold - which is a big No No I think. I would have thought that new gaskets and gasket sealer would take up any differences between the mating surfaces. I am following the Rimmer video which is in the Technical Section for the process