Intake manifold saga continues

[DavidM]

I started a new thread cause I need more help. Things were going pretty good. Mainly just had to disconnect hoses and wiring connectors to be able to remove the manifold. The only gotcha was when I moved the power steering pump out of the way to reach the bolt on the bottom side of the manifold. Turns out my adjuster pulley has no adjuster on it so I had to disconnect the entire bracket to loosen the belt (Anybody else have no adjuster?).

Things went bad when I tried to remove the manifold. All the bolts were out except the one that I had broken the head off of. I was going to just try and pull the manifold off the bolt so I didn't have to drill it. Even with all the bolts removed the manifold would not separate from the head. I wiggled it while pulling, but nothing. Then I noticed that the upper left corner of the manifold had a crack in it. Turned out it wasn't just a crack, but that a chunck of the left corner of the manifold was broken off (more on that in a sec). I wiggled some more and was eventually able to get the manifold to loosen from the head, but it wouldn't come off the broken bolt. So I had to drill it, which involved removing the throttle body to get the drill in there, and use a bolt remover.

It turns out that there was no gasket between the manifold and the head. Looks like just a layer of gray RTV was used and not much of a layer at that. This is why the manifold wouldn't separate from the head - the RTV was holding it on. I don't know what caused the corner piece to break off the manifold, but I'm suspecting it was a combination of using a bolt instead of the factory stud on the corner hole and the bracket underneath not being bolted on. Here's some pics of the manifold and the piece that broke off.

http://home.comcast.net/~dmontgomery/manifold_web_1.jpg
http://home.comcast.net/~dmontgomery/manifold_web_2.jpg
http://home.comcast.net/~dmontgomery/manifold_piece_web.jpg

Here's where I need some advice. The break is clean and it appears that I could use JB weld to put the piece back on. I'm not sure if that's a good idea though. The piece that broke off has one of the holes in it to hold the manifold on to the head and it also contains the seat for the #4 injector. Theoretically JB weld could work, but will it hold?

I have a spare lower part of the manifold, but it's in need of some work. It needs to be cleaned up and then it needs some ports plugged to match the one I pulled off the car. The one on the car had 3 or 4 ports plugged that used to be water outlets or other things. Here's a pic of the two lower pieces together and you can see the one on top has the hole plugged. I guess this was for the EGR valve or some such.

http://home.comcast.net/~dmontgomery/two_manifolds_web.jpg

So my next question is what machince shops in Atlanta could do the necessary work on the extra lower piece? It doesn't look like difficut work, but I don't want to just take it to Joe's machine shop around the corner.

As an added extra bonus I removed the top piece of the manifold from the lower piece. No gasket there either. I guess Bob (or whoever put Bob's motor together) didn't want to spend the $15 on gaskets or he didn't know where the local Nissan dealer was located. :wacko: The car has lots of go fast parts, but it's the simple things that are killing me.

As usual, thanks for any input.

David

[lateapex911]

Wow....

That intake is now scrap metal.

But, get an allen socket and pull the plug out from the blocked opening, and head to your good auto parts store. Show them the manifold and the plug, and they'll set you up with a tap and new plug. I suspect its' a British Pipe thread plug, which would be a good thing in this application. Then Tap it, and put the plug in and you'll be back in business.

IMHO, of course!

[erlrich]

Here's where I need some advice. The break is clean and it appears that I could use JB weld to put the piece back on. I'm not sure if that's a good idea though. The piece that broke off has one of the holes in it to hold the manifold on to the head and it also contains the seat for the #4 injector. Theoretically JB weld could work, but will it hold?[/b]What Jake said - I wouldn't even consider re-using the old manifold. Racing puts way more stress on parts than normal driving, the last thing you want is a part that may or may not hold together under the hood. I'm a little surprised at the way the thing was put together - maybe Bob just got tired of buying new gaskets every time he had to go through tear down :)



I have a spare lower part of the manifold, but it's in need of some work. It needs to be cleaned up and then it needs some ports plugged to match the one I pulled off the car. The one on the car had 3 or 4 ports plugged that used to be water outlets or other things. Here's a pic of the two lower pieces together and you can see the one on top has the hole plugged. I guess this was for the EGR valve or some such.
[/b] Yes, that's where the EGR valve was. I would think any competent machine shop would be able to tap the hole. At the same time you could have them hot tank (or whatever they do with aluminum) the manifold to clean it up. Or, if you don't want to go to the trouble, it wouldn't take much to make up a blanking plate from some flat aluminum.

Good luck.

[its66]

That isn't the first one I've seen broken there. Scrap it. It isn't worth trying to save. Be sure to use that support bracket when you put it back together. JBweld will work to seal up many of the holes you'll need to seal on the replacement intake. I didn't need a machine shop when I replaced mine. PM me for details if you want.

Jim

[DavidM]

Thought I'd post a follow-up now that I've had the car on track. I took my extra manifold to a local machine shop (Ewing machine shop if you're in the Lilburn/Snellville area) and had them match what had been done to the one I took off the car. Basically, 2 water outlets and 2 air holes had to be plugged. I also had them epoxy the holes where the swirl valve rod went through each runner (thanks for mentioning that Jim). Put everything back together with new hardware and new gaskets. I used some gasket sealant all the way around the water hole on both sides of the gasket. I also bolted back up the support bracket underneath.

Made it through the weekend without any issues or water leaks so I would say the problem is fixed. Car ran nice and cool. Of course, I broke a wheel stud, fried a 75A main fuse, and had a fuel line break (during the race) over the course of the weekend. I did manage to make it through half the race so that I get credit and points though.

Thanks to all who helped.

David

[joeg]

While I am a big fan of JB WEld, I would not use it in such an application.

If the manifol is a rare item, it can be welded back together. It would need to be really cleaned and tig welded.

It may have to go in the mill to true up the surface after welding and the port may need some die grinding, but it is certainly repairable.

If it is not rare, you made the right choice to just scrap it.

Cheers.