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How to Remove the Exhaust Manifold?? [late BJ8]

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crispy

crispy

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Hi All - I'm a new owner of a late BJ8, and new to the forum. Can someone please post the order of operations for removal of the exhaust manifold. Gaining access to the fasteners, especially the ones on the bottom, has me baffled. I'd appreciate your help.

Thanks Again,
Crispy, 67 BJ8, Portland, OR
 
As a new owner, you will need a factory shop manual. It will give you step-by-step information on just about everything.
Get one - you won't be sorry.
Bob
 
I have a BJ8, and I haven't removed the exhaust manifold in situ, but I think it's doable (I assume the engine's still in the car?). You'll need to get the car on a lift or at least jackstands; most of the work will be from underneath (be safe). You have to undo the nuts on the studs on the bottom flange to disconnect the down pipes; if your pipes' flexible sections are in good order you shouldn't have to pull the pipes out of the muffler. The nuts are likely brass and should come off fairly easily, but if you have to really torque on them you could snap a stud, which means you're committed to removing the manifold*; I use a ratchet with a couple long extensions and a deep socket. The top nuts on the studs on the head should be accessible, but I don't know about the bottom ones (you should be able to tell when you get under the car). Some of the nuts clamp both the exhaust and intake manifolds; I don't know if it's absolutely necessary to remove the intake manifold, but it would certainly make things easier. The hard part of getting the intake manifold off is getting the carburettors off, esp. the rear as the bottom nuts on studs are hard to get to; some of us have modified wrenches--1/2"--to make the chore a little easier (I use a 'stubby' wrench I got from Harbor Freight).

I don't have my shop manual handy, but I don't recall any instructions for R&Ring the manifolds; it's pretty self-evident what needs to be done.

EDIT: When reinstalling, check the manifold->downpipes and downpipes flanges. The manifold flanges can erode or even warp a little, sometimes making it difficult to get a good seal, and repop downpipes' flanges are sometimes installed erratically (flat-filing may be in order). The repop gaskets are failure-prone--since they can't use asbestos anymore--and I haven't had good luck with the brass nuts; double-nutting with steel nuts and a good anti-seize works for me. Use a high-temp sealant on the gasket for good measure.

* I broke one once with the engine in the car, but was able to get the stud out by MIG-welding a nut onto the remnants of the stud.
 
From below use a 1/2"deep well swivel socket on an 18" extension to remove flange nuts. The heat shield will make it almost impossible to remove them without removing the intake. I did drill holes in mine to allow me to loosen and tighten the nut if ever necessary. The Carbs have to come off using a 1/2" stubby open end to remove the heat shield. Use 9/16 socket on the lower exhaust manifolds, you can reach under and feel them to install the socket with a 6" extension. The upper ones are easier to see and remove. I have bought extra open end wrenches at garage sales in the past and used a sawzall to cut them down to 1-2" long-much shorter than stubby wrenches available commercially.
 
screenshot.1680.jpg


Or direct from Bentley:
screenshot.1681.jpg
 
Thanks guys, very helpful :smile:. I do have the manual published by Bentley, pictured above. I have a half height lift so hopefully that will make things a bit easier.

So I'm assuming the carbs and the intake manifold have to come off 1st? Can anyone confirm that is true?

If so, then how to i get a wrench on the lower right nut on the rear carb? I don't see an obvious way in. Do I get there from the top, or the bottom?

Really appreciate you help...thankyou.

Crispy, 67 BJ8, Portland, OR
 
The carbs come off first. That bottom rear nut needs to be reached with a short open end wrench from the top. It's easier if you have the throttle linkage out of the way.

The manifold nuts can also be reached from the top with an open end wrench. You will be working blind, though.
 
Crispy

Having a 100 I can't give you specific advice on your BJ8 but I can suggest that you get a set of 1/4" drive sockets with a few extensions and a universal and also some stubby wrenches. Though it may seem impossible to reach and undo some fasteners this is simply a part of the diabolical scheme to test your mettle. Stick with it and keep us posted.
 
Big secret in working the British cars, contortionism and patience.
 
Once you get the air cleaners and carbs off, the rest is easily accessible. Be sure to keep track of which manifold nuts are the tall ones.

Don't worry about taking off both manifolds - you'll need new gaskets anyway. I modified these cheap HF wrenches for carb nuts.

screenshot.1647.jpg


Notching the choke cable brackets makes them easier to remove and reinstall:
ChokeBracketNotched.jpg
 
steveg said:
Once you get the air cleaners and carbs off, the rest is easily accessible. Be sure to keep track of which manifold nuts are the tall ones.



Notching the choke cable brackets makes them easier to remove and reinstall:
View attachment 58669
Click to expand...

I tack welded nuts to my choke brackets. that not only makes the brackets easier to R&R, but the nuts too.
 
Just to close out this thread...After grinding down a couple of wrenches, and a busting a knuckle or 2, I'm pleased to report that the exhaust manifolds have successfully been removed. They're off to ceramic coating 1st thing in the AM. My next project is installation of a new SS exhaust system. Any advice you all have is certainly welcome. Thanks to all for your help...and the inadvertent custom tool thread :smile:

Crispy, '67 BJ8, Portland, OR
 
crispy said:
Just to close out this thread...After grinding down a couple of wrenches, and a busting a knuckle or 2, I'm pleased to report that the exhaust manifolds have successfully been removed. They're off to ceramic coating 1st thing in the AM. My next project is installation of a new SS exhaust system. Any advice you all have is certainly welcome. Thanks to all for your help...and the inadvertent custom tool thread :smile:

Crispy, '67 BJ8, Portland, OR
Click to expand...

Hey Crispy -

I didn't see you were in Portland (Go Blazers) I could have set you up with everything you needed and a lift .......I'm in SW near Lewis & Clark College. My lift is still the available to you if you want PM me.

'57 Rebuild on Lift.jpg


'57 on lift -lr.jpg
 
Crispy, befor you install the SS exhaust system, spend a few moments enjoying how beautiful it looks. If you've bought the Moss Version, it will go together without issue. I don't have experience with other brands, but I will assume they are also great. I don't want to start a kurfuffell but "Go Warriors".
 
I did indeed buy the MOSS SS offering...having no experience w/it, i was a bit dubious. So, i'm relieved and pleased to hear that it is working well for you.

Dougie, great to hear from someone in the hood!! I'm in Raleigh Hills. Let's get together and commiserate sometime soon. I'll reach out once I get her rolling again, and after my vacation...so stay tuned :smile:

Crispy, '67 BJ8, Portland, OR
 
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