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Manifold Advice Sought


hddennis

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Tore my Maxwell engine apart again chasing a pesky oil leak. Decided this might be the best time to use what I believe is a New Old Stock exhaust I picked up and have been saving. I checked the one I had just removed with a steel rule and it was dead flat. The New old stock one measures a clearance of .005 in the middle port. Would this likely flatten out if I put it on as is or should I have it planed flat IF I can find a machine shop willing to do it in this post Covid world?

 

Howard Dennis2142659460_Page17-Copy.thumb.jpg.78a3a89c9e588d816bcdc46dbbb7c02f.jpg

Edited by hddennis (see edit history)
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1 hour ago, ArticiferTom said:

What you gasketing ?  Center can be thicker . Also are ends ferrules ?

All three ports have ferrules. Originally ferrules and copper rings but period aftermarket companies produced one piece copper and asbestos gasket which I believe is a lot better and what I have been using.  

 

Bhigdog, I love your idea about a shim, Thanks a million.

 

Howard Dennis

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There's a couple of  ways to skin this cat. Both have a few pro's and cons.

 

Head machine.

Pro........Machined flat surface.

Con......Likely a bitch to get it jigged up and indicated. Time is $$$$.

             Accuracy depends on skill or "close enough" mind set of machinest.

             Invasive procedure. Whats removed is gone......gone.........gone.

            Possibility of poor jigging up and damaging manifold.

           No owner control of process or chain of custody.

Shim.

Pro..........Inexpensive.

               Owner has complete control of process.

               Non invasive and reversible.

               No chance of manifold being "lost" by machine shop.

Con........SS is tough and hard to cut although brass would likely serve just as well.

 

So.........Pays your money and takes your chances..................Bob

 

 

 

 

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The new head machine has ZERO set up time........zero...........it's a precision belt sander that is FLAT and large. Puts a non directional finish on it. We use this machine to do ALL our manifolds, an it is a common unit at any decent automotive machine shop. Just make sure the part is clean. Should cost less than 50 bucks.......and then it's not a half assed repair. Also no stress on the part.

 

 

 

 

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I'm familiar. Those machines are just big belt sanders. No set up required because the operator lays the part on the belt. The metal removal rate and where it's removed from largely`depends on the skill and experience of the operator and how long since his last "smoke" break. They are good for quickly making gasketed surfaces pretty. For removing a finite amount of material from defined places, not so much.

As for using shims to effect a close fit between mating parts they have long been used for everything from precision bearing fitment  to bridge supports. The fact that McMaster-Carr lists 1275 items of shim stock, of every kind and type, for industrial use gives lie to the description of it's use as "half assed".

As I said there are a number of ways to skin this cat and, not to mix metaphors, I don't have a dog in this fight.

So........Pays your money and takes your chances................Bob

 

Edited by Bhigdog (see edit history)
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I have done more than 100 heads and fifty to seventy manifolds on the machine above. It’s not just a belt sander..........but it does a great job in the hands of a skilled operator. The heads were all modern aluminum four and six cylinder engines. The manifolds were mostly two piece straight eight combination units that were very long. Never had a failure or problem with them ever..........
 

PS- I always did my own work on the machine, as I never trust modern machine shops with rare and difficult parts.......they always treat them as routine..........and NO pre war work today is ever routine.

 

 

Any restoration or repair shop who shimmed a manifold because it wasn’t flat IS doing half assed work. No customer that I am aware of wants cars fixed by taking short cuts........and what shop world warrantee such a job?  Would you like to pay to have sub standard work done to your modern or antique car? Shim stock has lots of appropriate uses........shimming a manifold IS NOT ONE OF THEM.

Edited by edinmass (see edit history)
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2 hours ago, edinmass said:

Shim stock has lots of appropriate uses........shimming a manifold IS NOT ONE OF THEM.

 

Good to know.

Please explain exactly why, as in this case, using a .005 SS shim to level the contact area is inadvisable as opposed to trusting

"any decent automotive machine shop" with a "rare and difficult" part.

Also wondering what's the worst case scenario of a failed shim as opposed to a failed belt sanding job on said "rare and difficult part"............Just askin............Bob

Edited by Bhigdog (see edit history)
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Trusting a modern shop is a major problem, that’s why when I was in business, I made a deal with the shop owner to use the equipment and do it myself. My point is, no shop would use a shim, it’s not a correct or professional repair that you can charge for......it’s a short cut. In your own garage, if one chooses do that type of work, it’s up to the individual. A professional would never make a repair with a shim. Craftsmanship and standards of service just wont allow it. Today, poor workmanship is the curse of all car owners. Very few shops do good work. As a craftsman I would never use a shim on any car manifold.........it’s hack work.........as an example......my White that we are making a new water pump shaft and timing gear as they are all one piece. I won’t use a spray weld, hard chrome, or other good enough repair......we are making the gear and shaft because it is the only correct repair. I drive exotic pre war cars thousands of miles every year......and we do it reliably without issues..........1800 miles on a Model J over the course of a few weeks. I never have a thought of breaking down, or having a problem, because the car is serviced and repaired properly. I would be embarrassed to open a hood and have a shim on a manifold. I have machined countless manifolds.......matching intake to exhaust manifolds and getting them square is very difficult and time consuming......and then, and only then, can you address the face that bolts up to the block. We recently installed new exhaust manifolds on an early V-16, all six manifolds and flange pipes were new castings. Want to talk about a sxxt load of work? Getting them in line and not leaking was a incredible challenge............it was done without shims. Just careful machine work and craftsmanship. Any job worth doing is worth doing right.

 

One last question? Do you want your surgeon to shim a knee or hip replacement, or use the wrong size stint in you chest? Or would you prefer you medical professional keep his work and service up to medical standards. How about the jet airplane technician working on an Airbus....do you want him to take short cuts on a plane your in at 36,000 feet? No thanks, I prefer to have things done correctly. Yes, I know....it’s just an old car. Hope the chef at the restaurant doesn’t serve you undercooked chicken...........at what point do you draw the line.........everything you pay for as a service must be perfect......except old cars?

Edited by edinmass (see edit history)
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What it comes down to, Ed, is that a .005 SS shim will in all likely hood  effect a satisfactory and long lasting repair, at minimal cost, with zero chance of a ruined and perhaps irreplaceable part. While I respect your devotion to detail and authenticity I think in this particular case grinding is the least suitable solution to the problem. Using a shim is also least invasive with the advantage that in the unlikely event of failure the owner is able to pursue further remedies with no harm done.

I might add that thousands of manifolds are, at this moment, happily bolted to engines with gaskets that also serve as shims to correct minor imperfections.

So......peace brother..........and happy motoring...........Bob

 

Edited by Bhigdog (see edit history)
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I think the take away from this discussion is the OP, Dennis, either needs to use a head machine himself or use a shim. As Ed specifically says to use the equipment personally, do not trust the machinist.....😉

 

Or buy the machine for $5300. 😲

Or did I miss something in the tete-a-tete?  

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Bhigdog is correct, as gasket is in effect a shim........I was wondering if anyone as going to make that comment.

 

All is good in a spirited discussion........and interestingly it seems like I may be making a manifold and water pump for a project from scratch in the next few months......if the project is a go, I will post extensively on it.

Edited by edinmass (see edit history)
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  • 2 weeks later...
39 minutes ago, Restorer32 said:

Yea, using a shim is a quick fix but restoration it ain't.  Using a shim you are assuming the bad flange is perfectly parallel to the others. It might not be, in which case a shim might not work.  Do it once, do it right. 

 

 

That's from a man with fifty years of dealing with these car...........and obviously I agree........

 

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Easy to say when you are spending O. P. M.

I would be willing to bet the farm that a careful examination of any one of the most exacting restorations done by the highest octane ($$$$) shop would uncover more than one "dirty little secret" done in the name of expediency or cost control..........Just sayin.

BTW, the farm is 100 acres of verdant PA countryside...........Bob

Edited by Bhigdog (see edit history)
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Although I 100% agree with a shim not being a correct repair vs getting a manifold flat, I don’t think the manifold in question is out of acceptable tolerance. .005 is nothing with new crush gaskets being used. 

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