Hot Rods Temporary exhaust manifold leak fix

My Buick 263 straight eight seems to have developed several leaks at the exhaust manifold over the winter. The car resides in a heated garage and I have driven it only a few times since the weather has changed and I have noticed that I have some new leaks that I did not have before. My understanding is that these engines are notorious for the exhaust (and intake) manifolds expanding and contracting at a different rate then the block. My heat riser is stuck all the way open and always has been. Engine has about 40K on it. I have plans to put headers and change the intake to compound carbruation (have one) but not until this winter cause I just want to drive it this summer. Currently I have no known intake leaks just exhaust leaks. My question is....can the exhaust leaks be temporarily remedied or reduced without tightening or unbolting it the manifold? I was thinking of some sort of malleable material that could be hammered or inserted in the gap. Would love any thoughts from the crowd.

 

I'm guessing anything you do taking hours of painstaking labor tucking will last about 15 mins.

Last week I saw a truck where the shock bushings gave out. The guy dug out the remains of the rubber bushing stuffed the hole and around the stud with shoelaces and siliconed over the laces. That took him 3x as long as changing the shocks did and lasted 35 miles.

 

If your looking for bubblegum fixes

Coppaseal high heat silicon works

And muffler cement

Be pressured to reapply often as back pressure will blow it out periodically.

It’s messy but the nice thing is it’s not permanent so when you decide to fix it coreectly the old smootz will come off easy

 

Band aids are just that and generally a big Pain in the Ass. I would never do this myself but if I was going to not do that specific job right I would use Wood Stove cement sealer. It's compound is made for High heat and expands and contracts just a little. Now for good information I'll tell you I stopped using Exhaust Manifold gaskets of any kind on every motor I work on some 20 Years ago. This started when we went to Alum. heads and steel header flanges. When you get a leak between them that High Dollar head pays the price. Chrysler has a R.T.V. type sealant that job now. It is amazing stuff and never has failed me. When I get into the shop today I'll get the part number and post it up. I could tell you stories about what I've done with it but you'd just think I'm making it up. Let me just say it works and impressively so.
The Wizzard

 

i have used liquid glass on cracked manifolds . paint it on the crack when it is cold . when it heats up it expands to seal the crack . lasted about 3 mo .

 

There may be other R.T.V. type products out there that will do the same thing but I haven't found it yet. I know this one stands the test of time. It's sold under the Mopar brand and the part number is 82300234 MS-GF44D And they actually call it Gear Sealant but is High temp.
The Wizzard

 

The Wizzard is a true believer. Answered similar question the same way 2 1/2 years ago. Good stuff!
https://www.jalopyjournal.com/forum/threads/hemi-header-gaskets.999997/

 

Thank You gentlemen. Ultimately I will do it right and pull the manifold and go with headers along with the swap on the intake to the dual carb system. I know what I an trying to do is bogus but I want to quiet her up a bit and reduce the exhaust fumes. I figure if I can at least limit it for the summer I can drive it and do the "project" when the weather is bad. Last year I only got to drive it until August and had a master cylinder go bad on me. I did a front disc brake conversion and lets just say it was quite an engineering nightmare and cost me about 2-1/2 months of driving fun so right now temporary bubblegum and bogus will have to do. Again thanks for the suggestions.

 

Was specifically recommended Yale Muffler cement here by somebody, and it works pretty well as far that kind of thing goes. NAPA sells it.

 

Tell us again, why you wouldn't want to just put in a new set of gaskets, shouldn't be more than a few hours work and would probably last more than some cobbled goop

Sent from my Nexus 5X using The H.A.M.B. mobile app

 

This stuff has been holding tough on my tractor ex manifold. I had similar stuff on it before that blew out quickly.

 

Rich the reason for not wanting to just do gaskets is the straight 8 exhaust manifold and intake manifold (as I am sure your are aware) share the same bolts for attachment to the block. The heat riser from the exhaust also attaches to the bottom of the intake manifold. So basically I run the risk of creating a fuel leak, breaking off manifold studs, and if I am going to go thru that than I might as well change the system to headers and dual carburetion. I picture the project becoming a PITA where I am drilling out broken studs especially the rear one closest to the firewall. Please talk me into doing it the right way the 1st x! I am all ears. I'd prefer it. Will you drive down from MN to help me drill out the studs?

 

I'd be spraying those down with BP blaster at least once a week, maybe once a day till then.
Might sound stupid but it seems to work for me.

 

Put a box end wrench on each of the manifold bolts. Work it back & forth - if each moves, then you can slide the manifolds out just far enough to put gaskets in without disturbing anything. I just can't see trying to patch a repair that easy to do right.

 

Has the same problem with my Buick 8. I also figured out that the previous owner did too. I pulled the manifold set, put a straight edge to them and the problem was obvious. Took the set to my local automotive machine shop and had the manifolds surface ground. Problem solved.......fortunately I did not break any studs off, but I did use the opportunity to upgrade the hardware while I was at it. Absolutely no regrets for the labor vs benefits.

Ray

 

this is the right thinking.

 

He is scared that Murphy's Law is going to bite him hard and make a no nothing job and turn it into a nightmare, then lose more time having to work on it and not be driving.

I feel the same way with 20 year old cars and fixing them. Brittle plastic breaks easy and often a simple job ends up replacing half the damn hoses and connectors. I wouldn't fear this one as much, but I see his concern anyway.

 

there are no simple jobs, on old cars, get used to it, adapt, overcome........

 

Fix it right or just live with the exhaust leaks. I worked in the exhaust repair field for quite a few years and those quick fixes usually cause more problems than they cure.

 

What are the chances that not only the manifold needs machining but the head too? Again I am just trying to get thru until November. Then I can pull it apart and do it right. I'll make you guys a deal. I will do it now and do it the right way but if it goes South nobody gets to drive their car until mine is up and running Deal?

 

Not being able to drive it for the entire season is just terrible. It happened to me last summer with the master going out. It was like being that kid who gets sick with the flu in the middle of summer and all you can do is look out the window and watch the other kids play in the nice weather. All the other kids saying come on out it's nice and we're having fun . It sucked.

 

Cars with long exhaust manifolds like straight eights and some straight sixes have a problem with heat expanding the manifold and head at different rates. This wears out the gaskets and causes leaks. DO NOT tighten the bolts more than the factory recommends. If the parts can't move around the manifold may crack.

Best solution is new gaskets. As others have pointed out you can move the manifolds away from the head just far enough to slip new gaskets in. Sometimes it works at least for a while. If the manifold is warped or uneven it helps to machine them flat. If it was mine I would try sliding in a new gasket and see what happens. If it lasts for a couple of years I would just keep putting in new ones.

 

VERY doubtful the head needs machining, VERY likely the manifolds do. Report back when you are finished. I am betting you will find this not nearly as dreadful as you have been thinking it will be....and BONUS.....the problem will be fixed and not blow gaskets in front of your fellow enthusiasts......

Ray

 

Update: Weather here near Chicago has been dismal so I have not been driving....so I soaked the nuts/studs with PB blaster and have managed to get them all to crack loose without breaking them. One stud was already busted at the front of the engine so I may have to do an extraction here. Looking at my replacement gaskets it seems that the intake and exhaust gaskets are 3 parts BUT each has the ports for the intake and exhaust integral. This means that I have to break the seal of the intake manifold too in order to sneak the gaskets in as Rusty Ol Toole suggested OR cut them OR remove both manifolds. I am happy nothing broke but now I am wondering about the intake and exhaust manifold pilot rings as well. Seems like these will get in the way of removing and sliding the new gaskets behind the manifold(s). I do not have the replacement for these either. Before I go too far here does anybody have any in site as to whether these issues will force me to remove both manifolds in their entirety. Seems like this is going to snow ball already. Another thought is that I have a spare engine with both manifolds that I could remove and have machined in advance. Or I could bite the bullet and machine the dual carb manifold but this would force the header situation. The existing gaskets do not even look that bad so it has me thinking maybe I try tightening without removing and see if I can shut it up. New hardware or old?

 

I would NOT separate the the manifolds unless absolutely necessary....which would not include machining the manifolds. When I did mine, I removed the manifolds as an assembly (I think I removed the carb from the intake, though) and took the works to the machine shop. That way, ALL ports are on the same plane. The pilot rings are typically reusable and no need to cut apart the gaskets.

Absolutely no disrespect intended, but I get the notion you have exaggerated the difficulty of this job in your mind and are determined to prove it.

On the other hand, with what you have already done, getting the nuts loose, you are almost halfway home. Don't let this get you down......you CAN handle it!

Ray

 

Just by breaking the bolts loose, you have overcome the largest dragon.
The broken one is in the front, fine. That's easier.
The season is early. Jump and run.
I did a frayed wire repair over the weekend that was a 15 minute splice-n-go, that turned into a 2 hour excursion in takin half the engine bay apart. In my defence, it was behind the r/s valve cover down where it took a contortionist to get.
That's the joy, and pain of keeping the old ones going.

 

Ray you should be a psychiatrist ...you are right I have exaggerated this in my mind. I tried to exaggerate my front disc brake conversion too. Even after doing that I could not believe the contortions I had to go through to complete it. Guess I am gun shy after that. Just want to drive and not have a season ending injury.

 

Double up the gaskets?

 

You are very generous in your comments.....many people, including a fair number on this forum, would rephrase that to read "Ray you should see a psychiatrist".... and they may be correct

Ray

 

It’s Murphy’s law happens to me all the time
A simple no nothing job that I think will take an hour turns into a can of worms and two days of yelling and screaming !!

A job I expect to be a can of worms just falls apart and goes back together before you know what happened!

Just the nature of the beast