Intake Manifold (Two Questions)

[thinksound_mike]

dear FAQ,

 

I've been trying in vain to get my intake manifold off my car for several hours and have basically hit a stopping point. I don't want to round the bolts to the point where they're stuck. But, I can't seem to get three of them off. The two closest to the firewall and the one closest to the front of the engine. Is there a trick to this? I put the car up on jack stands and was looking at taking my starter out for better access, but that didn't seem like I was gaining much in the way of room. It's really difficult to get a socket on the bolts because of the odd angle; even with a wobble extension. I've mostly resorted to wrenches but not having much luck getting any leverage.

 

The reason I'm doing this is to swap out my 32/36 for a 38/38. I think I basically have two choices:

 

A. Keeping busting my knuckles and figure out a way to get those bolts off so I can either swap the manifold for a Canon manifold or hog the existing one out. Leaning towards using the stock manifold.

 

or

 

B. Stuff the manifold full of oily rags into the passage ways and hog it out while it's still installed. Remove rags and proceed to vacuum like crazy to make sure I get all of the metal shavings off.

 

Any advice is much appreciated. 

 

And I thought doing my heater box was a pain...

 

Thank you.

 

Mike

 

 

[xr4tic]

IIRC, the nuts are an odd size, 12mm wrench?  Make sure you're using the right size socket.  Bloody knuckles are just part of the experience.

 

Removing the manifold is definitely the best.  While it's off, you need to check the coolant ports for corrosion.  When I cleaned mine up, I found several holes in the hose nipple and had to get another manifold.

 

Plus, you need to remove a lot of material:

 

More pics/details in my blog:

https://www.bmw2002faq.com/blogs/entry/1186-sowhere-was-i-2016-catch-up-part-1/

 

[tech71]

If you haven't already, hose them down with a good penetrant spray and walk away for a few hours.

[TVeye]

Open end wrenches only. Never been able to get a socket on any of them.

[thinksound_mike]

2 hours ago, TVeye said:

Open end wrenches only. Never been able to get a socket on any of them.

This is what I've been trying but it's hard getting your arm in the space while maintaining any sort of leverage. I'll hit them with penetrating spray tonight and give it another go tomorrow. I was thinking of picking up a set of ratchet wrenches, but I don't think I'd be able to get the end on the nut since it's so tight. The socket certainly doesn't want to fit right.

Thanks for the tips! 

[TVeye]

If they're that tight, overnight with some PB buster or the like should do the trick.

The Ratchet wrenches I've seen are usually larger than a socket and wouldn't improve leverage either.

[Dudeland]

I.E sells manifold nuts that are smaller O.D.  You may want to think about future upgrades and replace them once you get the manifold out. 

 

[Simeon]

The meta comment here is that you don’t need to hog the manifold out (but not trying to swing this thread in this direction). If you want to do it then you can hog it in place with the precautions that you have discussed. 

 

Overall, I would really try and get your manifold off because you will need to overcome this hurdle when you go to side drafts ?

[thinksound_mike]

8 minutes ago, Simeon said:

The meta comment here is that you don’t need to hog the manifold out (but not trying to swing this thread in this direction). If you want to do it then you can hog it in place with the precautions that you have discussed. 

 

Overall, I would really try and get your manifold off because you will need to overcome this hurdle when you go to side drafts ?

 

Hey Simeon,

 

Why would I not have to enlarge the opening? I thought you had to enlarge it for the 38/38 or swap to the Canon. I have the nuts soaking in PB blaster now and I'll leave them overnight. But is there any performance difference with the 38/38 on the standard 2bbl stock manifold vs modified? If not, then I'll save this exercise for side drafts

 

Mike

[Chris_B]

The consensus seems to be that the 38/38 is a significant performance improvement over the Solex 2 barrel. 

 

You might want to see if you can find a thin-walled socket andf/or grind down a socket so you can use it with your wobble adapter. What I have used with great success on these same nuts is what is called a "crows foot" wrench. This works because it will fit around the bottom of the nut without interference with the manifold. Once you loosen the nut slightly you can use some other tool (open end?) to remove it. 

[Scott Sislane]

Take the head off, problem solved. ;)

 

[Dudeland]

In addition, when you take the manifold off you can port match it to your head.  Mine had a lot of meat to take out.  Also I used a ball hone to smooth things out a bit as well.   You can see on the top left side of the port how much material was removed to port match it in the first picture.    The picture of the ball hone from amazon fully used up and the finished port at the bottom. 

 

 

 

 

[Simeon]

Without doubt there will be an absolute difference in terms of maximum air flow between the stock manifold and a literal 38mm x 38mm inlet throat. The problem is that this is marginal and is only possibly relevant at 100% wide open throttle. There are three positions: stock (undersized), machined out to 38/38 and hogged out ‘peanut style’ with a large single opening underneath the carb. With each increase in flow you will see a massive decrease in air velocity. This has a big effect on drive ability pushing peak power away from normal set-ups. I doubt you would be able to determine the difference between a stock manifold and a manifold cut or hogged in any way. 

[TobyB]

Flex- head sockets.  Long extensions.

 

For the sidedrafts, I have a 10mm that I cut and ground down

so it could get at the locking tab nuts.

 

t

what works for me.

[thinksound_mike]

19 hours ago, Dudeland said:

I.E sells manifold nuts that are smaller O.D.  You may want to think about future upgrades and replace them once you get the manifold out. 

 

I have those on my exhaust manifold and their studs. The allen wrench opening on the end is great. Made inserting the studs supers easy.