Bingo, i think

Sorry to be pestering about this same issue for about a month now i think, but it's almost gotten the better of me. the issue is this glowing exhaust
manifold on a 6 cylinder 2.6 litre series 3 rover. just a quick recap, i have rebuilt the carby and distributor, and put a new exhaust on it this morning.
i took the exhaust manifold off this morning to replace the manifold-to-engine block gasket. while giving the manifold a bit of a clean, i found a small crack in it. i sprayed some oil into the manifold which seeped through and was visibile on the outside, so it is definitely letting air into the exhaust. first question:
is this likely to cause the excessive manifold temperature and the backfiring during decelleration?? (i am fairly certain the answer to both is yes, but just want to be sure)
secondly, how do i fix this? i had a crack at arc-welding it with a standard rod, but this just ate away at the manifold and didn't fuse with the electrode metal at all. i stopped before i did to much damage. will i need it professionally welded (mig or tig or something or other), or can i fill it with exhaust glue or some such.
I think i have just about cracked the problem that has been buggin me for over a month, and i can't thank you guys enough. hopefully this will be the last question you'll hear from me for a while.
Thanks in Advance.
Samuel.
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Samuel wrote:

Certainly the backfiring and possibly the heat.

Get some proper arc rods for use with cast iron (they will be a nickel rod of some sort). You'll either want a DC welder or a high OCV AC welder to do it successfully. It's well worth veeing out the crack carefully and prehating the manifold before welding, then letting it cool slowly.
--
EMB

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both is

standard
need
fill
Thanks EMB. you have confirmed most of my suspicions. upon doing a little google-research on cast-iron welding, i am leaning towards getting it done professionally. i dont have access to a furnace to heat the manifold up, and i only have a standard AC handyman arc welder, doesnt sound like it's up to the task.
Cheers.
Sam.
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Check out Ebay. Alex may alsop have one knocking around as he used to have a 2.6 which I think he broke.
Sis got 2 2.6 Engines from ebay for 10.51,,, jammey sod she is too.
Lee D
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a
i live in australia, and those 2.6 motors are getting very thin on the ground here. all ex-army series 3's used the motor but i'd guess 90% of them have been replaced with holdens and used as boat anchors etc. i can prolly get a second-handy for under $50 (they want $275 for a newy), but if i can repair it i will. i like doing that sort of stuff.
Cheers.
Sam.
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Samuel wrote:

A SH one for $50 sounds pretty good. $50 wouldn't get me to even start welding a manifold commercially - the time involved in doing even a small crack properly is worth more than that, not to mention decent NiFe welding rods at about $10 each.
--
EMB

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