| Author |
Message |
    
Jeff D.
| | Posted on Wednesday, May 08, 2002 - 02:15 am: | 
|
I recently found a huge crack on both of my manifolds, I was wondering if anyone has put an aftermarket exhaust manifold such as janspeed. What are my options in doing this? |
gp (Garrett)
| | Posted on Wednesday, May 08, 2002 - 12:02 pm: |
|
depending on size and location of crack you can weld. worked fine for me. |
Doug Wendyker
| | Posted on Wednesday, May 08, 2002 - 12:03 pm: |
|
What is with the manifolds on the Discos cracking? Not to sound like Seinfeld but really, what is with those things!?! I recently purchased a 97 and in my search for my truck I would say almost half of the Disco 1 that I looked at had cracks in the manifold! I looked at two trucks in the same day from private owners that had a replacement in the rear of the truck waiting for an install. Is there a recall that LR is replacing cracked manifolds under a reasonable amount of milage? Is this a design problem or poor casting practices?
By the way the 97 I bought recently developed a crack on the passenger side manifold.
I would imagine this has been discussed before, but this stuff is all new to me.
Thanks -Doug |
gp (Garrett)
| | Posted on Wednesday, May 08, 2002 - 12:11 pm: |
|
i have had 2 discos. a '94 and my '96 i have now. my '94 cracked at about 80K and was under $100 to weld. my '96 with 73K has never had an issue with the manifold. they were loose one time, but never cracked. |
RVR OVR (Tom)
| | Posted on Wednesday, May 08, 2002 - 01:31 pm: |
|
I think it is because of the different heat dissapation characteristics of the engine block (aluminum) and the exhaust manifold. The block heats and cools at different rates than the manifold, therefore causing undo stress. Kind of like if you brew a big pot of coffee, pour it out, and then stick it in a sink full of cold water and it shatters.
Just a theory...
Tom |
Kyle
| | Posted on Wednesday, May 08, 2002 - 01:37 pm: |
|
Lean , lean means hot. Hot means cracks..... The Y pipes crack alot too...
Kyle |
Matt M
| | Posted on Wednesday, May 08, 2002 - 03:18 pm: |
|
On my Audi, the fan used to run after I'd switched the engine off to help alleviate this problem.
I think other manuf's do the same too.
Matt. |
Jeff D.
| | Posted on Wednesday, May 08, 2002 - 08:35 pm: |
|
I was considering welding but I thought that would just be a temporary solution....Has anyone put aftermarket heads? |
Kyle
| | Posted on Wednesday, May 08, 2002 - 08:47 pm: |
|
You can weld them up , just make sure they terminate the crack by drilling a hole at the end of it.... Its not temporary if done right..
Kyle |
doug james (Dgj95lwb)
| | Posted on Wednesday, May 08, 2002 - 08:53 pm: |
|
My 95 4.2L (10% more heat than Disco, theoretically) has 100k, orig eng and manifolds, etc. and ZERO cracks. Properly maintained, not too hot, not too cold....ie no cracks. Too lean = hot, leads to cracks yessir...
The charge used to fuel the power stroke, is also used to cool the exhaust valves-to a lesser degree if mixture is 'off'.
BTW: Has little to do with the "fans of Audis being on"- sheesh. |
rover30076
| | Posted on Wednesday, May 08, 2002 - 09:16 pm: |
|
I have the same issue with my 97, a badly cracked passenger side manifold. Although I plan on replacing it (way to far gone to weld), has anyone used a product such as JB Weld as a temporary fix? I have a club ride next weekend and would rather not show up with it sounding like this. |
doug james (Dgj95lwb)
| | Posted on Wednesday, May 08, 2002 - 09:23 pm: |
|
JB weld is a fine fix for certain things, often is permanent. NOT in this application, but fine for the club jaunt/wheelin' trip this weekend, I believe. |
rover30076
| | Posted on Wednesday, May 08, 2002 - 09:48 pm: |
|
thanks Doug, uh and I agree with your Audi fan comment. Isn't there an audiweb.org |
Brian
| | Posted on Friday, May 10, 2002 - 10:31 am: |
|
Replaced my passenger side on my '97 D1 (it eventually broke, and my Rover sounded like a giant lawnmower for a few days). Cost $189.00 for passenger side and I had mangled knuckles, but it works great. Just make sure you use Loctite on the exhaust pipe studs or they might work themselves out over time. |
rover30076
| | Posted on Friday, May 10, 2002 - 10:34 am: |
|
Brian,
have any issues with breaking studs? Thats the primary reason that I have yet to tackle this project. |
Neil Cawley
| | Posted on Monday, May 13, 2002 - 07:37 am: |
|
What about using the manifold off of a 4.6. I hear they are a stainless tubular header. Anyone know for sure? At what price can they be had? |
Brian
| | Posted on Tuesday, May 14, 2002 - 10:24 pm: |
|
Rover30076,
When I ordered the new manifold I ordered the new studs and nuts to go with it. I put these studs in (with Loctite) before I bolted the new manifold in place on the head. When I say studs, I mean the things that bolt the manifold to the exhaust pipe/catalytic converter underneath. I did not have any problems with them breaking. What do you mean? |
Ron
| | Posted on Tuesday, May 14, 2002 - 11:11 pm: |
|
1. don't use loctite on them, use anti sieze, high temp anti sieze! Personally I like the earlier style of fixing that uses locking plates FWIW
2. NBS RR manifolds will not fit on a disco. The head end is the same but there is not enough room for them to clear.
3. I have never seen a rover run lean so that theory does not hold much water with me. I think the issue is underhood temps are fairly high in a rover and you are not dealing with a high flow system that would keep exhaust temps down
4. I broke a stud doing my heads but use of some vice grips got it out.
Ron |
Rick
| | Posted on Wednesday, May 15, 2002 - 01:25 am: |
|
Check out www.scorpion-racing.co.uk They have a Janspeed exhaust system and manifoldsm should fix yrou problem and give you a little more hp |
Brian
| | Posted on Friday, May 17, 2002 - 12:47 am: |
|
I was talking about using Loctite (red) on the manifold to exhaust pipe studs, not manifold to head. Of course you would not use Loctite on those. |
Bruce
| | Posted on Thursday, May 23, 2002 - 07:10 pm: |
|
I have a slight crack in the passenger side as well. At this point, no air is passing through, but I know it has to be addressed. Called many shops in my area, most said "oh sure, we can weld cast..." But when I asked how they did it, all shops did not mention slowly heating / weld / slowly cooling, except for one shop. So, he gets my business. The major point for me is the disassembly/reassembly, not the cost of a new manifold.
So my question is, IF you could purchase new for the same price as weld, what would you do, weld or new?
Caveat - this is a theoretical question, ok?
Thanks. |
Kyle
| | Posted on Thursday, May 23, 2002 - 08:47 pm: |
|
Bruce , on a manifold that heating and cooling thing is not greatly important... If I was welding a radius arm I would be all over it but not on a manifold....
Kyle |
Bruce
| | Posted on Tuesday, May 28, 2002 - 10:58 pm: |
|
Kyle,
So could you elaborate why you think heating/cooling for a manifold crack is not that important? I don't know, but I did quite a bit of reading before I formed my orginal opinion. I have never welded anything so I am clueless here but with talking to many shops, nobody ever dispelled the approach myths.
Thanks in advance... Bruce |
weespeed
| | Posted on Tuesday, June 04, 2002 - 06:03 am: |
|
When welding cast iron, you don't want it to get too hot, because this will cause the surrounding area to get too hot and become prone to cracking. Usually when welding cast iron you should start by drilling a hole at the start and the end of the crack, and do a little section at a time, then get a small hammer and peon(sp?) it. Lightly tap it a few times while it is cooling down. This will make the weld actually stronger. I used to weld and fix cast turbo manifolds and they would never last. But after this method I haven't had any problems. And tubo manifolds see extreme temperatures, especially when we push 2bars of boost. |
|
Closed: New threads not accepted on this page