I need to switch out my W manifold due to heat riser being rusted shut. The inside of the flange is rusted bad and won't seal. I have a Thorton manifold to replace it.

Do I need to remove the steering shaft at the rag joint and firewall to access the manifold bolts?
Does the started need to be dropped?

I know it would be easier if the motor was out to install but not wanting to pull the motor right now.

Thanks!

 

Should not be a problem to do, Only with headers is it a BITB, on a Olds.

 

You may not have to drop the starter but I'd definitely recommend it. It'll make the job much easier/quicker in the end. The manifold might be able to be maneuvered out of the hole once off but it's tight. I was stubborn when doing mine and ended up dropping the starter in the end. No problem with the steering shaft. Leave it be.

 

So If I drop the starter I don't have to remove the steering shaft? It looked like it was in the way of getting a socket on the bolts.
Thanks!

 

Steering shaft should not need to be touched but yet to the starter as already said. Only use a 6 point socket and don't be surprised if the bolts fight you or worse.... If the bolt heads are rusted a 9/16 socket may be too large. If so a 14 MM may work.

 

Copious amounts of PB Blaster, over a few days, with a few light taps with a hammer to set up a vibration, in between applications of PB.. Eventually this will cause capillary action to draw the PB Blaster into the threads. After a few days of this process my manifold bolts came off as if they had never been torqued. I can't say they were "finger tight," but they came right off without any real effort. Then I used a propane torch to burn the remaining PB Blaster out of the bolt holes before installing my headers.
YMMV.

 

Spray PB blaster or some other rust penetrant on the bolts after a long drive when everything is hot. Sure, it’s going to smoke and stink but the heat will help the oil wick into the threads.

Use 6 point tools on the bolts, chances are 50 plus years of corrosion has made the hardware slightly undersized. As someone mentioned, 14mm is slightly smaller than a 9/16, so have “brand X” tools on hand. And definitely don’t reused the old hardware unless it’s in excellent condition.

No need to remove the steering shaft, once the hardware is removed the manifold will lift out from the top. It looks tight, but it will come out. Removing the starter might not be necessary either, but definitely disconnect the battery before starting the project.

 

Do not use a gasket correct? I guess the factory did not use one, I have heard using some high temp RTV around the ports is an good idea?
There is a gasket on the manifold now so they have been off when the motor was painted incorrect 70 blue.

 

My experience was different from matt69olds. The manifold definitely looked like it could have been lifted out through the engine bay but no amount of mental gymnastics made that happen. Out from the bottom was the ticket for me.
I would highly recommend you check flatness of both the manifold faces and the mating surfaces on the heads. Those original manifolds have been heat cycled thousands of times and the mating faces can easily be warped. The good news is that a competent machine shop can skim the surface to get it flat again. I reinstalled mine (after facing) without gaskets and did not experience a leak. However, I switched them out for headers after a few months so it's possible they would have started leaking over time. I'd see what some of the others have to say before making a decision on gaskets.

 

These manifolds are new from Thorton. I do not see how its possible to get a 1/2 drive wratchet in there with the steering arm in. I bought a low profile 3/8 and so far the bolt below the pcv is turning going back and forth each way. Did you uses studs to join the pipe/manifold? I have heard olds did not use studs but all Fusick sells are studs. I got lucky the bolt towards the rear was loose so just 4 to get out!
Thanks for the advice guys!

 

Some bolts may require a box wrench.

 

can you get a box wrench in 6 point?

 

Yes, you may need to do some searching. I have several 6 point wrenches in my collection.

 

The factory did t use gaskets, the head and manifold were machined smooth. Unfortunately, after 50 years of use the manifold and head no longer have that precisely machined smooth surfaces, a gasket will almost certainly be needed.

 

Its the bolt under cylinder 5 plug that needs a box end. PB Blaster did its job they are all loose!
Yes I don't see how to get the mainfold out without dropping the starter and feeding the new one in from the bottom.

 

Remove the left motor mount cross bolt. Put a block of wood between your floor jack and the oil pan. Jack up the motor it it will come out through the top with room to spare. I would go back with gaskets but its your choice. I would also put a bead of high temp silicone or Joe recommends walker acoustiseal (I think thats what it is called) on the flange joint.
good luck.

 

Jacking the motor up sounds like the best option, don't need to drop the starter?
Thanks,
Mike

 

I cut the open end off off a 6 point 14 mm wrench so i could slide a pipe over it to get at the bolts that a socket wouldn't get to. I had excellent leverage to loosen the bolts just be aware that there is a chance those bolts will snap off which is what happened to me on two of them.I was swapping the heads so i didnt need to be careful. I wouldn't dare not using a gasket i have the worst luck with leaks .Good luck with your project.

 

Ready to go on, painted with Eastwood factory gray manifold paint. CSM says torque for mainfold bolts is 25 foot pounds, do you use anti sease on the studs?
Thanks!

 

Yes I would