small block exhaust manifold bolts and gaskets

Knebel

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I am going to replace the exhaust manifold gaskets on my 360 and oh lucky me I could loosen all bolts without breaking a single one!!! Anyways, I didnt take it apart yet because I want to get new bolts for it.

Does anyone know which ones and where to get them? I would prefer some ARP stainless bolts or something!

Also, I heared something about them going into the coolant and that needs to be drained? Is that correct?

Then...how do you get to the nuts holding the exhaust downpipe to the manifold!? I can't seem to get anything down there to have any kind of leverage!?

Whats the best gasket for head to mainfold sealing?
 
If any of the exhaust manifold-to-head bolts go into the water jacket, then #2 Permatex should be on the threads, for sealing. If there's not a gasket between the manifold and head now, you can put it back that way, although there might be some header gaskets (get the "black" ones rather than the soft white ones that are common) that can be used.

As for the pipe to manifold bolts, can't offer any suggestions there, other than copious amounts of penetrating oil down there. Don't recall if the bolts/nuts down there are "prevailing torque" or not. Might be good to use a flat washer under the nut, for good measure, when you put it back together. Almost any gasket down there will be good . . . nothing really trick about them, other than to put the correct ones down there.

In ANY fastener situation, there will be ONE part of the fastener situation that will be sacrificial in nature. "Softer" bolts that screw into harder metal, for example, so that the threads aren't damaged should the bolt break-off. If use a harder bolt, the threads strip in the main casting, it's quite a bit harder to fix correctly.

I understand the desire for the stainless fasteners, but normal Grade 8 might be a better choice. Might also desire to put all studs in rather than use bolts?

ONE thing to always use with any exhaust manifold fastener is to use a flat washer under the bolt head or nut-on-stud. Reason for the "heat washer"? That allows the manifold to move a bit as it heats and cools so it doesn't try to crack from it being "nailed down" too tightly by the un-washered retainer.

Just some thoughts,
CBODY67
 
Yeah studs seem to be the better idea to me too! It currently has gaskets under it! I dont know about a gasket between the pipe and the manifold, it looks more like a conical fit!? However, I mean... how do I even get to those bolts with a ratchet or wrench??? do i need a super long extension and go from below?
 
With a wrench on the top bolt head, wedged so it won't move as the lower nut might turn it before things break loose, then a short extension on the ratchet or break-over bar can give you a better leverage to get things broken loose to remove. Boxed-end usually works better than an open-end wrench. Fuel line wrench can also work there, too. Key thing is that you can use both hands on the ratchet/break-over bar. "Torque" carefully to get things to move initially. Try to keep the angle of the extension perpendicular to the nut being torqued, for best results.

If the lower manifold/pipe interface is a ball joint connection. Just clean it with a wire brush or similar, pipe and manifold. to reinstall. Walker used to have a "muffler pipe cement" that was thick and viscous. Something like that might work, too, but shouldn't be needed. If the pipe touches the manifold in the exact same place as it did previously, just the cleaning should be fine as there was not a gasket/seal on the ball joint connections.

CBODY67
 
Well WTF how are you supposed to get a wrench on top on that screw to hold it!? lol I just had to walk away from it for a littlebit haha
 
If your manifold to exhaust pipe bolts have been on there longer than 5 years... save yourself time and aggravation and just torch them off.
 
well one bolt doesn't wanna come loose on the passenger side but I'm soaking it now. Got tje drivers side mostly done.

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question, How do you seal the piece with the heatriser/flappy thing thats flat on one side and a cone on the other to the exhaust manifold? its just two flat mating surfaces that are held together with the pressfit of the 2 screws. That leaves lots of room for a leak and what should I do there? Very thin high temp silicone? dont know if that will work!?
 
On the small block the exhaust flanges do not seal, the pipe is flared to match the manifold. They are then bolted together without a gasket.


Alan
 
Did you ever do what I mentioned about cam baseline on the other thread.
yeah sort of, haven messed with it too much lately but changed the cam setting. idk..it doesn't have a huuge effect, just changes the fuel table that adapts anyways a couple %

before i proceed further I want to make sure all my exhaust connections are sealed as perfect as possible!
 
Well yeah!? Im going through everything now. I think that it was a problem with timing and the engine not pulling enough vac for the vac advance to work right. Also looking at the manifold gasket i am sure that didnt seal right anymore and threw iff the o2 a bit! Maybe the engine is just tired, I have no idea how many miles are on the thing but i assume it must be well over 100k.
 
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