Replacing inlet/exhaust manifold studs with bolts
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    Question Replacing inlet/exhaust manifold studs with bolts

    Is there any reason why I can't (or shouldn't) use bolts instead of studs here?
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    more likely to seize in place and then snap when you try and undo them i should think, but wouldnt be an issue if you use a quality bolt.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Now, where do I source quality bolts from? I have a box of the right size from a motor factors but I don't recall the manufacturer.
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    It is a good mod as you can remove the manifold much quicker with bolts. Get stainless bolts and use an anti-galling compounds to stop the materials seizing together.
    Why is the time of day with the slowest traffic called rush hour?

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Do screwfix sell this sort of bolt? If I'm not mistaken, I want M8s?
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    That reads badly, I do have some friends
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Try yellow pages under bolts and fasteners. There are usually local plaes that sell really good quality bolts at really good prices.
    Why is the time of day with the slowest traffic called rush hour?

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Cheers. I don't suppose anyone knows what length the bolts should be?
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    Re: Replacing inlet/exhaust manifold studs with bolts

    Inlet will be ok with bolts exept that a couple of studs would still be a good idea as they would locate the gasket in place while you fumble down the back to locate the manifold
    As to the exhaust...the main reason I see for using studs is that they do tend to lock in the head and not come loose, that together with the copper coloured flanged locking nuts that are supposed to be use once only mean that the manifold doesnt leak past the gasket due to the nuts/studs working loose. Fitting bolts may just cause you grief with blown gaskets.
    Cars where bolts have been used instead of studs/locknuts have problems with loosening over time. Of course you cant use spring washers or threadlock sucessfully due to the very high temps involved.
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    Re: Replacing inlet/exhaust manifold studs with bolts

    Just out of interest why do you want to downgrade to bolts in the first place?

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Interesting, I've used bolts with a washer on my on XE exhaust for over 3 years without problems but I am often taking it off.

    Why are studs less likely to work loose then bolts?
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    chip> because I've just dismantled the head and it's going to take me ages to put all the studs back in (perhaps I shouldn't have taken them out in the first place).
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    doesnt take long at all mate, just put two nuts on each one locked together (at the top of the thread dont wind them right down), then do up as if they are bolts with a socket set until they bottom the threads out, then undo the nuts one at a time.

    Easy peasy.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    if you do this, then helicoil all the threads before you start. Torqued steel bolts will very happily remove soft aluminum threads, at least that's what I've found every time I've done it. I believe the aerospace industry do this as standard with threads in aluminum/magnesium.

    for bolts, try www.fastfixdirect.co.uk.
    Originally Posted by Brian_S: Woooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo!

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Quote Originally Posted by jonix
    Interesting, I've used bolts with a washer on my on XE exhaust for over 3 years without problems but I am often taking it off.

    Why are studs less likely to work loose then bolts?
    If you are already happy doing it then why ask the question

    Perhaps you have no problems because you dont leave it on long enough for any to work loose

    Studs will be tighter as the thread is tapered towards the stud blank so it bites when done up properly, the nut being vibration proof also assists in the act of keeping it tight.
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    Re: Replacing inlet/exhaust manifold studs with bolts

    Animal, people do the same thing with ally engine blocks on stuff like pugs when they want to have some faith in the head bolts, IMHO you should never be torqueing hard into ally.

    Chip

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    Re: Replacing inlet/exhaust manifold studs with bolts

    MikeT> I suppose I was more concerned about the inlet manifold, but I thought I'd better check whilst I was here about the exhaust manifold

    I think I've been convinced to stick with the studs.
    Don't squat with your spurs on.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Quote Originally Posted by Animal
    if you do this, then helicoil all the threads before you start. Torqued steel bolts will very happily remove soft aluminum threads, at least that's what I've found every time I've done it. I believe the aerospace industry do this as standard with threads in aluminum/magnesium.

    for bolts, try www.fastfixdirect.co.uk.
    Very good point there Animal, we have some machinery at work that has kit that we have to take of and refit weekly, the manufacturers fitted steel bolts (M12) into threaded holes in the alloy parts of the machines and I had to go round replacing the bolts with studs where possible and with helicoils where not due to wear on the alloy parts. It doesnt take long to end up with a worn thread hole.
    Drove: C20xe'd Astra 3 CD, now turned into a c-max diesel!

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    Re: Replacing inlet/exhaust manifold studs with bolts

    a worn sloppy hole is no use to anyone

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    Re: Replacing inlet/exhaust manifold studs with bolts

    enough about your mum chip

    I agree that it shouldn't be necessary, but when you fit the big SBD FWD manifold, there'a a lot of weight and a lot of leverage on the bolts, and I found that each time the manifold came off, I lost at least 1 thread.
    Originally Posted by Brian_S: Woooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo!

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Quote Originally Posted by Animal
    enough about your mum chip
    That reminds me, you still owe me 50p from last time!

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    Re: Replacing inlet/exhaust manifold studs with bolts

    50p! I hope that included the cup of tea.

    Anyway she said that I'd get a discount, due to size issues
    Originally Posted by Brian_S: Woooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo!

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Yes mate, its 25 pence per inch of length, but she gave you a 50% discount to 12.5p per inch.

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    Re: Replacing inlet/exhaust manifold studs with bolts

    cool, that makes it 1" + the tea!
    Originally Posted by Brian_S: Woooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo!

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    Re: Replacing inlet/exhaust manifold studs with bolts

    Well there we are then
    Don't squat with your spurs on.

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