Exhaust Manifolds that crack

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vlad01
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Re: Exhaust Manifolds that crack

Post by vlad01 »

Holden202T wrote:I don't think I have ever seen a commodore V6 motor that hasn't had at least one side cracked!

had the opposite experience, fist ever cracked ones i came across about a month ago on a VP engine i removed from a car.

i literally have a pile of manifolds in the yard, not one is cracked, i have tossed several pairs before them too with no cracks. I been keeping an eye out for cracks as most people mention the cracking. I thought it was a myth to be honest lol
Last edited by vlad01 on Sun Apr 26, 2015 12:58 pm, edited 1 time in total.
vlt304
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Re: Exhaust Manifolds that crack

Post by vlt304 »

VL400 wrote:There is an old school method of drilling along the crack and then peening bolts in. Trying to find a video but not been sucessful yet...
when I was an apprentice the shop I worked in used taper cast iron plugs for repairing cracks in heads. you would drill and tap the head with a special tap and screw in the plug when it got tight you put a nic in the side with a hack saw and snap the head off then drill and tap the next 1 about 1/4 into the last and keep moving until you run out the crack. the plugs got dipped in irontite before screwing them in.
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vlad01
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Re: Exhaust Manifolds that crack

Post by vlad01 »

seen a video of that on youtube some time ago
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VL400
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Re: Exhaust Manifolds that crack

Post by VL400 »

Thats the one, have then seen the snapped off bolts peened in to the surrounding metal. Could hardly see the repair afterwards as it nearly matched the casting texture.
vlt304
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Re: Exhaust Manifolds that crack

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Re: Exhaust Manifolds that crack

Post by Charlescrown »

Metal stitching is the term and is OK for both cast iron and alloy heads but you need to know that the plugs used are tapered and will put extra load on the crack. I would think the manifold would then crack further. Either buy another one or do what HQ355 suggested. You might find it's not that expensive. If your in Sydney Harris Engines can do it. I see your in Melbourne. Hunt around a few engine reconditioners.