Removing Manifolds

[Chris Cahill]

All true. I was looking at some remanufactured assemblies online earlier today at cruiserparts.net ($599.00, fully machined and ready to install with new heat riser gaskets, rings and springs) and noticed that in one of the photos, they had bolted all the way through the aluminum instead of threading into it. I suppose that would be one way to deal with stripping the aluminum threads.

 

[Slow Left]

I suppose that would be one way to deal with stripping the aluminum threads.

Nice. I like the way you're thinking!

To every step in the procedure a logic...and to every problem a solution...!

 

[Chris Cahill]

Thanks, I will keep you posted. I am probably going to go for it and see whether I can get the bolts out. I don't like the idea of putting them back in with that ancient gasket in place.

I am loving the nice clean engine bay and I have quite the pile of smog parts going. Jim C has had the carb for a while so it should be done soon.

 

[Slow Left]

Alright. One more thing to bring up in a conversation with the machinist. In addition to having the manifolds planed together as an assembly, confirm that they can spot the face of the holes on the side where the bolts/nuts/washers mount to...so that they are even, too, when the bolts are tightened down...if they are uneven, might lead to a cracked intake..

 

[Chris Cahill]

Glad you mentioned that, I would probably have forgotten. Jim C recommended the same to me. Thanks.

 

[Output Shaft]

Just a thought...

A machine shop that knows this manifold and has the experience and tools to machine it... also knows how to work on it.

If I had your manifold dangling in my sweaty paws right now, I would take it (or ship it) to a reputable machine shop and say, "deal with it". Why risk messing up an irreplaceable manifold to save a couple hundred bucks?

They have all the tools (which we don't) and all the experience (which we don't) and they have seen lots of manifolds like yours but in way worse condition (which we haven't). They won't be practicing on your manifold, but you will. They live and breathe broken bolts, helicoils, taps and seized parts. That is what they do for a living.

Unless you are trying to save a few hundy that will mean absolutely nothing to you next year, my vote is to just take the bastard in to the shop and get an estimate.

wow did I just say that?

fred

 

[Chris Cahill]

I couldn't agree more! In fact I just spoke to the machinist who was recommended to me and I am taking the whole thing to him this evening, with the new gaskets and SOR insulator. Hopefully he can just give it back to me ready to install.

 

[Chris Cahill]

One other quick question - do you normally change the rings and springs even if they don't show signs of leaking?

 

[Output Shaft]

I did.
Clean up the grooves nice and pretty so the rings won't bind and can spin easily.
Burnish & de-rust it a bit with 1000 emery and some PB Blaster.. so everything fits nice.

 

[Chris Cahill]

Looks nice, now I'm gonna have to do that too.

 

[Chris Cahill]

Met with the machinist and he is going to split the manifolds, clean everything up, install the gaskets and SOR heat riser insulator, then resurface them. He seemed to know what he was talking about - he is probably 70 years old and said he had done many similar ones from the old chevy straight sixes. i think he is going to use a Do-All sander for the resurface.

I have to put a plug in for PB Blaster. After sitting all day yesterday, 4 of the 5 bolts that felt like they were going to break came loose and I could have easily gotten them out. The fifth was starting to move but still iffy.

 

[Slow Left]

Cool. Sounds like you've got yourself an ally in that machinist.

 

[Output Shaft]

Chris, after you get it all back together with the car running, please post back here with your experience using your new manifold block off plate vs. the stock manifold set up.

Specifically take note of the following:

1. Engine performance when cold compared to stock
   
2. Engine warm up time comparison
3. General engine performance differences noted if any when engine has warmed up
   
4. Fuel Economy

I know that other things will change with your engine besides the manifold, so it will be hard to be certain what is doing what. But I bet there are a lot of us would like to know more about the block off plate's performance.

Thanks

fred

 

[Chris Cahill]

I will do that. Not sure when the carb will be back from Jim C but I will do everything else in the meantime. I have a spare carb
I can slap on if I really get impatient to see it running.

I have 2 other 60's that are stock so I can also compare it to those. Curious to see as well. I just don't want to have to worry about a stuck heat riser down the road blasting hot exhaust onto my intake.

It is so hot here in South TX most of the time, engine warm-up isn't much of an issue.

 

[Chris Cahill]

Ok I got the manifolds back and they look great. Machinist said the cast iron was warped a little, not much. He machined them together. I put them up to the head and wow what a difference.

Here is my new issue. I took the heat riser flap out to trim it so it would clear the SOR insulator. It was a pain to get out, the bolts were spot welded. Anyway I am thinking about leaving it out and welding the shaft hole. Would like some opinions on that. If I need to trim and put it back in I need new bolts and gotta figure out how to tension the spring, which moved quite a bit when I removed the flap.

 

[Output Shaft]

With the SOR insualtor installed, there's no need any longer for the rotating heat riser flap. It won't be doing anything useful. Remove it entirely then plug the shaft hole some way. The machine shop did it this way for me.

 

[Chris Cahill]

I was hoping for that answer. I think I can just tap it here at the house and plug it. It should help the exhaust flow a little more freely. I was just worried that the insulator might need a little protection from the flap at full engine temp but It should be OK. Thanks

 

[Chris Cahill]

A few of pics of the white cruiser desmog/manifold project underway. I sure appreciate everyone's input. I got to thinking, instead of tapping the heat riser shaft hole is there any reason not to just through bolt using some red loctite and maybe some high temp rtv? That way the shaft could be re-installed at a later date if anyone wanted to, for some reason.

 

[Slow Left]

I got to thinking, instead of tapping the heat riser shaft hole is there any reason not to just through bolt using some red loctite and maybe some high temp rtv? That way the shaft could be re-installed at a later date if anyone wanted to, for some reason.

Clean looking rig...

Just to make sure I didn't miss something, is the new heat riser shield that you have installed between the manifolds the OEM or the SOR (basically a block-off plate) one?
If it is the OEM one, it is designed to allow hot exhaust gases to hit the bottom of the intake manifold when the heat riser is deflecting exhaust up to the bottom of the intake (when engine is cold). Then, when the engine warms up, the heat riser moves (there is a temperature sensitive coil that rotates the shaft, and since the heat riser is fastened to the shaft, it rotates) and diverts the hot exhaust down the down pipe preventing the hot exhaust from continuously hitting the bottom of the intake manifold.

The SOR block-off plate prevents hot exhaust from hitting the bottom of the intake manifold at all times (hot or cold) because it doesn't allow any exhaust to pass regardless of what the heat riser is doing...and it also shouldn't allow the heat riser to rotate at all, which is why guys either remove it entirely (as you are intending to do) or cut off part of the blade that interferes with the block-off plate so that it can continue to rotate.

If you have the SOR block-off plate installed, then either make sure the heat riser is positioned to divert exhaust down the down pipe or remove it (as you are thinking).
Plugging the holes where the bushings/shaft went through the exhaust manifold is to prevent an exhaust leak.
Any way you design to plug that exhaust leak must hold up to high temps and corrosive exhaust gases. So, in the case of using a removable bolt, I would imagine it would have to be a grade bolt that can withstand a corrosive environment...stainless steele? Or is there a better material?
Same with the high temp RTV sealant...

I know you've probably already considered this...just talking it outloud in case someone else has recommendations to improve on the plan...

 

[Chris Cahill]

I am installing the SOR stainless steel shield that completely isolates the intake from the exhaust gases. I was thinking of using a stainless bolt in the heat riser shaft hole that faces the rear of the engine. The side facing the front of the engine already has a sealed plug from the factory that looks pretty stout and has held up for 30 years. Was also going to use red loctite, flat washer, lock washer and two nuts with a little orange high temp rtv. Maybe some JB weld on the last nut for good measure.

The shaft wasn't that tight to begin but I never heard any leaks. The bolt should do fine as long as it stays tight. Thanks!