Cracked exhaust manifold flange

[KevinNY]

Cracked exhaust manifold flange: EDITED with photos

Took my Series on its first real offroad trip this weekend and suffered a cracked manifold flange. Looks like I took a shot on the bottom of the downpipe and the flange craked through on one side. Its really not too bad unless you are hard on the throttle, then it gets louder. Any pointers on the replacement of the exhaust manifold? Does the intake have to come off to do it? One spot where it could have happened.

 

[antichrist]

If it's stock, yes, the intake has to come off. They are bolted together and there's a gasket between them. For the gasket between the manifolds and head use the fiber replacement gasket. Series III's had no gasket on the intake, but I never liked that setup. Be very careful to torque the exhaust manifold bolts to the correct torque and in the right order. Snug the bolts between the intake and exhaust, then snug the one's to the head, then tighten the ones bolting the manifolds together, then the head bolts to torque spec.

 

[KevinNY]

I'll have to poke around and check it since it has a SU carb which makes me suspect that it is not stock, especially since I have another exhaust manifold and Zenith carb in my spare parts boxes that came with it.

 

[antichrist]

Well SU and Zenith were both stock carbs. SU up until about 67 or some such, I can't remember the exact year they went to Zenith. If you have either of those carbs you have the stock intake and exhaust manifolds.
I'm assuming you're putting on the other stock manifold as opposed to trying to get your cracked one welded.
They can be welded, but it takes a skilled knowledgeable weldor to do it so they last any length of time. Takes nickel rod, and careful pre and post weld heat treatment.

 

[KevinNY]

I thought Solex was the other stock carb? By SU I meant Skinners Union Carb, the one with the oil chamber float. I guess I need to start pulling it all apart first and see how things match up.

 

[Dan Ratcliffe]

I I broke two of them before I realised that I needed to have ALL the exhaust hangers in place. I also discovered that because I wasn't careful when I bolted the exhaust to the manifold, I had loded it with energy and when I smacked something with the exhaust pipe, it over stressed the manifold.

I haven had a problem with it in several years now, despite some pretty severe off roading.

Hope that prove useful.

 

[KevinNY]

Now is where it gets interesting. 1st pic is of my intake/carb setup, notice how it does NOT bolt to the exhaust manifold. The exhaust manifold is capped with a plate.

Here is a closeup.

Here is the spare manifold I have. It looks like the old bolt was drilled out, hence the nut/bolt combo.

So, it may be that I don't even have to remove my carb and intake manifold. Would you use this spare exhaust manifold or make a 20 minute drive to Atlantic British and buy a new one for 89 bucks?

 

[antichrist]

I thought Solex was the other stock carb? By SU I meant Skinners Union Carb, the one with the oil chamber float. I guess I need to start pulling it all apart first and see how things match up.

Sorry, you're right. I shouldn't post until after that first cup of joe.
SU's were on the 6cyl.

Ok, yeah, that's no where near stock what you have. I've never seen that setup.
I wouldn't drive that far in this weather if you have down header pipe, as it appears. There's a good chance of cracking a valve sucking cold air in.
A new manifold will need a cap bolted on like your old one. I did that on mine. Don't forget to get the gasket that goes on the top if the exhaust manifold.

 

[antichrist]

I think I found a setup like yours, on ebay.
http://cgi.ebay.co.uk/Land-Rover-2-...itemZ4591452756QQcategoryZ31348QQcmdZViewItem

 

[KevinNY]

Just had to drop the front pipe to get it out.

 

[Bogatyr]

stock exhaust, not intake

Kevin,
I believe your exhaust manifold is stock, with the exception of that cover that is bolted into place where the two manifolds normally mate up.

You should just be able to bolt that cover onto the existing stud holes in the new manifold, assuming that it was done with bolts of the right size...

I don't have the equipment to weld cast iron, but I'm assuming that by this point you've already sourced a replacement. I don't believe I have a spare exhaust manifold lying around here.

Matthew

 

[KevinNY]

AB has them in stock for under 100 bucks. While its apart I might as well go new. Should have it running again by this time tommorow. Then I can work on pulling the OD

 

[Rocky]

That one is junk!!!!!

 

[antichrist]

FWIW I meant the intake/carb setup was not stock. The exhaust definitely is.