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322 ci Flathead Intake Manifold Rebuild

Started by 39LaSalleDriver, May 22, 2020, 01:48:57 AM

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39LaSalleDriver

The time has come where I think the intake manifold needs to be pulled and repaired. I've suspected for some time that I had a leak developing somewhere in there (throaty sound under hood which has gotten louder, smells when driving down the road; but after a six hour run the other day, it has become pretty obvious. I shot some Marvel Mystery Oil down the carb and watched white smoke roll out from the valley under the carb by the firewall.

I think I'm going to buy some Pyro Putty to have on hand to even out any pitting on the block.

Should I get copper, composite, or try the Remflex gaskets? I'm pretty much leaning towards the ones from Olsen with the block offs.

If there is thinning along the wall of the intake manifold, how do I remedy that, or does it even matter if I use the blocked off gaskets?

Permatex or no?

Should I replace the bolts and studs, and if so, where should I get them? I've searched thirty pages of hits on this forum and most of the information is several years old and things may have changed.


Any other issues I should be aware of?
Jon Isaacson

1939 LaSalle 5019

LaSalle5019

Since the intake and exhaust manifolds interface to the block parallel from side to side (vs at an angle on newer V8s), they can easily be milled flat without messing up the geometry where they attach to the block.  This will solve any erosion issues on those parts.  If the block has major erosion then you either remove, disassemble and mill the block (lots and lots of work) or try the Pyro Putty solution just to the block side. Since I had my engine out I had that deck milled flat.

I used the Olson gaskets with the cross over blocked off - these only come in the composite design and they recommend no sealant. 

That is a pretty heavy wall on the intake manifold cross over.  I doubt it is eroded through.

I was able to reuse my old studs. I just sandblasted, chased threads and repainted.  Reinstall the studs with a sealant as they terminate into the water jacket.  I used Permatex #2 so if I got any movement when re-torquing the seal would not break (same as head bolts).  I replaced the 4 intake manifold bolts where the cross over goes with new stainless steel ones (parts book says they were originally SS). Since you are taking off the exhaust manifold, plan on heli-coiling the four threaded bolt holes for the cross pipe attachment and install new bolts and anti-seize. When reassembling the exhaust, install the cross pipe loosely and tighten it last (once the manifolds are located and snugged to the block).
Scott



39LaSalleDriver

Thanks again for the advice Scott. I've already to the Pyro Putty on the way, and placed an order with Olsens for the block off gasket kit. I know that at least the exhaust manifold has been off at some point because there is some Permatex drippings around the port edges. My bet is that this isn't the first time that this (or a similar) problem has cropped up before with this engine. As a result, I'm hoping those will at least come off without too much hassle. I plan on soaking them down with PBlaster for a couple days beforehand. Ditto for the other bolts, but who knows what I'll get into with them.

Of course, now you all have me worrying about the idler gear and making me wonder if I ought to look into that while I'm under there.  :-\

All things considered though, maybe I'd better leave well enough alone with that for a while. I don't really need to drop another $1000 on it at this time if it isn't an absolute necessity. At least in theory it should be easier to take down the manifolds in the future should I need to. Which, if I were able to find a better set of exhaust manifolds than mine I would do in a heartbeat.
Jon Isaacson

1939 LaSalle 5019

LaSalle5019

Don't let that bronze idler bother you.  I would suggest you check your distributor support shaft for excessive play and if it's bad, re-bush it and move on. If you want to take a peak at the idler, then you are mostly there with the manifolds off but it would have to look really bad for me to decide actually replace it.  It's going to wear over time - so what.  I really doubt many cars or the WWII tanks were breaking down due to a bronze gear failures.  I will say that it's a bit different when you just spent several thousand dollars rebuilding an engine, everything is new and you have all those parts in your hand already. At that point you want everything 100% like new.

Regarding the exhaust manifolds....you could do an eBay search and see if any listed there are better than what you have.  I would still heli-coil those 4 threads though.
Scott

Rich Iannelli

I bought a nice set of exhaust manifolds off of eBay with nice ceramic coating. I used the Olsen manifold with the block off. Bill Hirsch engine paint for the intake and block. I PB blast the bolts for a week. Lucky to find no large rusty burnt areas, just a cracked gasket. Uneventful instal and no more exhaust smell and it is super quiet. Take your time and enjoy working on your LaSalle.

Rich Iannelli
Aim at nothing and you will hit nothing

jackworstell

#5
....Hope I didn't cause undue concern about the idler gear.....

( but I was given some good advice ....pull the distributor tower
and check it visually.)


About the manifold exhaust leak ....we went
thru this about 2  years ago on our 1937 series 60

The leak was where people predicted....the surface of the left
entrance to the exhaust cross over ( part of the intake manifold) that goes under the carb.
And,,,the corresponding surface of the block itself was  also damaged.
Both surfaces had to be repaired.

In our case....we had no trouble getting the manifolds off and on.
Perhaps because our engine had been rebuilt maybe 6 years ago and so
everything was "clean".

We repaired both surfaces using something similar to Pyro Putty.
And then to this we applied a thin coat of a sort of high temperature
silicone based permatex
Both of these came from the nearby auto store.

This seemed to have worked well so far.....  Of course it's only
been about  two years.........

Jack Worstell

PS...the exhaust manifold....we took it off as one unit...
in our case we didn't have to separate the three pieces.

39LaSalleDriver

After consideration, I think per the advice here, I'm just going to leave well enough alone for now in regards to the idler gear. So far as I know it isn't giving me a problem and there's no sense in poking the bear.

I had already been shopping for new manifolds on Ebay and even found a pretty nice looking set. Unfortunately, they are the wrong ones as mine has the choke stove arrangement on the drivers side.

I have now determined in my own mind that this is the problem I'm having. Not only is the sound and smell pretty rough, but the engine is acting up by sputtering and missing especially under load. It certainly wasn't doing that last week and I have a hard time imagining it's a coincidence.

I might be overly optimistic, but it looks like most of the bolts except for on the crossover are in pretty decent shape. I've shot them with penetrating oil and will continue to do so over the next few days. I've also got some Pyro Putty on order as well as a set of gaskets with the block outs from Olsen's on the way.

In going through all the threads on this forum, I've come up with the following information. Should they need replacing, the studs for holding down the exhaust manifold are 4 7/8” long; Grade 5; threaded 7/8” with 3/8 X 16 (NC) threads on bottom, threaded 3/4” with 3/8  X 24 (NF) threads on top; qty. 8; torqued to 25-30 foot pounds. The bolts for holding down the intake manifold are stainless steel 3/8” X 16 (NC) X unknown length; torqued to 25-30 foot pounds. The bolts for the exhaust crossover are Grade 5, 3/8” X 16 (NC) X unknown length; 4 qty.; torqued to 25-30 foot pounds. Does that sound about right?

Finally, if they need it, am I better served finding someone to mill the bottom side of the intake manifold to even it up, or is it safe enough to be done on a belt sander as I have seen recommended?
Jon Isaacson

1939 LaSalle 5019

harry s

You can do it on a belt sander. Just be sure the bed is large enough to accommodate the entire length of the manifold. Make certain to keep it even while sanding and very little pressure, just enough to clean all ports evenly. Like wise on the exhaust manifolds. They should be checked with a straight edge for warping.     Harry
Harry Scott 4195
1941 6733
1948 6267X
2011 DTS Platinum

39LaSalleDriver

So I decided to go out today and start dismantling the manifolds. Everything was coming off so easily, no muss, no fuss...except for one of the intake bolts...I monkeyed around and snapped it off  >:( >:( >:( >:( >:( >:( >:( >:(

Guess I'm going to have to try and drill it out and hope I can salvage the threads. Failing that, guess I'll learn how to do my first helicoil.

Anyway, everything else went great. The gaskets, if you want to call them that were a mess. Coming apart, Permatex mixed in, who knows what all was going on in there. The valley is a mess of oil, grime, and exhaust residue. Believe it or not, it was cleaned and repainted by myself two years ago, and looked pretty good considering I didn't really take anything off but the generator. Just a testimony to what all was going wrong in there. Here are some before and after pictures of what found. Clearly, there has been a bunch of blow-by at the center port on the drivers side. Because it was such a mess pulling it all off I can't say if it was a gasket failure or erosion though.

To me, it looks like there is a bit of a beveled edge along the center ports on both the driver and passenger sides, and on the block and intake manifold side too. I have included pictures of everything showing how it looked when I pulled the intake, as well as after very lightly hitting it with a wire toothbrush to knock away loose residue, oil, and soot.

Certainly, it doesn't have a perfect, freshly milled surface like Scott's does, but in some ways, it looks like it was cast that way. Does anyone have any observations they could offer?
Jon Isaacson

1939 LaSalle 5019

carlhungness

       There's a fella on YouTube whose mission it is to test all manner of tools and product. He did a test on rust remover and of course included PB blaster. His results showed a mixture of 50% acetone and 50% transmission fluid was superior to any other rust remover on the market. I've used the mixture very successfully over the past year.

39LaSalleDriver

Starting cleanup of the block. Ignore the mess, I was interrupted by a squall line and had to quit and wasn't able to finish  or clean up.

Anyone have any suggestions as to if or where I should apply Pyro Putty or milling? I have labeled the photos so you know what you're looking at.
Jon Isaacson

1939 LaSalle 5019

39LaSalleDriver

Part 2
Jon Isaacson

1939 LaSalle 5019

35-709

Right, Carl, I first touted the 50% acetone/50% trans fluid to break loose rusted parts here some years ago --- not that I was the first to ever come up with it --- but only that it has been out there for a long time and I too heard it from someone else.  Trouble is, those of us who are here all the time (and read all of the posts) see these things, but those who only come here for a specific reason miss a lot of the good info that gets passed along.  Another good post that gets lost over the years and should be in an archive file.
PB Blaster, used by many, is only so-so compared to 50/50 acetone and trans. fluid.   
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

39LaSalleDriver

Part 3
Jon Isaacson

1939 LaSalle 5019

Cadman-iac

#14
Quote from: carlhungness on May 24, 2020, 04:14:19 PM
       There's a fella on YouTube whose mission it is to test all manner of tools and product. He did a test on rust remover and of course included PB blaster. His results showed a mixture of 50% acetone and 50% transmission fluid was superior to any other rust remover on the market. I've used the mixture very successfully over the past year.

That is interesting. How would you apply it? Or is it necessary to dip the part into it?

I have been using salt of all things. Of course it is mixed with vinegar. One gallon of vinegar to one cup of salt and you can immerse your part in it. Once you remove it from the solution, you must dunk it into a solution of water and baking soda to neutralize the vinegar and salt solution.
However it's not a good idea to put aluminum in it. It will destroy aluminum.
I discovered it when I was looking for something to clean up the evaporator core on my 56 A/C system. It works great for copper,  but again, you have to neutralize it afterwards.
I only discovered that it worked on steel out of curiosity. I really didn't expect it to work because of the salt, but it did.
For what it's worth.

Rick

And I thought PB Blaster was the best thing I've ever used so far.  I must try this acetone mix out soon.
Thank you for the tip.
CLC# 32373
1956 Coupe Deville A/C car "Norma Jean"

35-709

#15
"That is interesting. How would you apply it? Or is it necessary to dip the part into it?"

I mix it 50/50 in a small pump type squirt can, suppose you could mix it and brush it on with a brush also.  Don't bother mixing a lot of it because the acetone evaporates off pretty quick, but that is probably why it works so well, the acetone acts as the carrier and brings the thin mixture to the site and then evaporates and leaves the tranny fluid to lubricate.
There are other things that work better than PB Blaster, Mouse Milk is another, but acetone and trans. fluid is usually best.
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

39LaSalleDriver

Just to clarify, I misspoke about using PBlaster, I actually used Liquid Wrench. If you look into a guy on Youtube who has a channel called Project Farm https://www.youtube.com/watch?v=xUEob2oAKVs , his testing shows that Liquid Wrench is a better penetrating oil than the ATF/Acetone combo. I suppose others mileage may vary, but I would doubt that the numbers would be different enough to make much of a difference. For me, I'd just as soon buy an aerosol can and be done with it rather than mixing home brew.

Regardless, I'd rather keep this on point with my manifold issues. What's done is done, I sheared the bolt off and will have to deal with it as I go along. If we want to discuss which penetrating solution is better than another that is best served in it's own thread.
Jon Isaacson

1939 LaSalle 5019

Cadman-iac

#17
Mouse milk? That's another one that I have never heard of until just the other day.  Somebody mentioned it on one of these threads, but I can't recall which one it was.
So is this something you can actually buy off the shelf?

Point taken.
CLC# 32373
1956 Coupe Deville A/C car "Norma Jean"

35-709

Mouse Milk is used a lot in aviation circles, you can get it at Aircraft Spruce & Supply, Chief Aircraft, Sky Geek and many others --- including eBay --- and probably Amazon.

Another good penetrant is Deep Creep by Seafoam.
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

Cadman-iac

CLC# 32373
1956 Coupe Deville A/C car "Norma Jean"