cracked exhaust manifold on '53

[jmxkf1]

Hi, is there a way to fix a crack without removing everything to take off the exhaust manifold?  I assume carb and intake needs to come off before it can be removed.   That means finding a gasket kit for everything too.   thanks,  Jim

[boatingbill]

Not that I know of. NAPA stores have the exhaust gasket for the 226 ci engine. Exhaust manifold
cracks are a common problem.

[dpledger]

There are epoxy products that sometimes work- I think JB weld makes one. As the aperture of a crack is very small, the actual pressure exerted on the patch is also. Sometimes this works, and it costs little and requires no tearing things apart. If it doesn't hold you aren't out much. Sometimes it will hold for a year or so, in which case you just repeat. Little to lose, potentially a big gain. Has worked for me and others.

[51Deluxe]

Is there a particular place on the manifold that usually cracks? I suspect mine may be cracked due to the new noise level, but it looks perfect from the top view.

[boatingbill]

On my '51 Kaiser the first and the second manifold cracked on the underside. I could hear it, but had to climb under the car
to see it with a bright light. Look for a black soot mark if you drive it enough miles.

[51Deluxe]

What causes cracking? Vibration, overheating, or both? My noise started after she ran a bit hot.

[kaiserfrazerlibrary]

Cracking reflects structural issues within the casting and can be a mix of  poor fill during the casting process, marginal raw materials, operating out of the temperature parameters and outdated equipment.  !947-1953 manifolds were cast at the Dowagiac Foundry and there were problem castings from 1947 on; during the Korean War period as castings demand increased for military work, they got the first-line foundry equipment and cars got the older less reliable units.  This helps explain how the unit got an "E For Excellence" type award from the Navy for the Wright R-1300 engine castings made there.

[DTort96646]

Just my input on the cracked manifolds, are you carefully tightening the manifolds in sequence from the center out and limiting the torque to 30 foot pounds? The manifolds expand as they get hot and actually "float" on that gasket. If the manifold can't expand and contract evenly, it will eventually crack at the weakest point. Sometimes a stud will shear off and then the gasket burns and leaks. Also don't over torque the manifold bolts that hold the manifolds to each other. A cooler intake manifold and hot exhaust manifold will expand and contract at different rates. Check the service manual for the torque spec and sequence. Over tightening is easy to do.  Not second guessing anyone just suggesting.

[joefrazer]

And age doesn't help as well. 60 plus years on, the heat/cool cycles have taken their toll on manifolds. I know a few Hudson guys and they have the same problems with their cars. One doesn't even have to go back to the 50s to know of vehicles with manifold issues. Just look at any late 90s Ford pickup with the 5.4 engine and most will exhibit manifold problems. I know...I had one.

[DTort96646]

My point is that judging by most of the posts I read on this Forum are from folks that have no real mechanical expertise and want to enjoy the hobby by doing their own fixes. Great in theory, but unless some of the basics are followed, the end result is some of the horror stories and disappointments that have been posted. The old car hobby can be daunting to a novice with the best intentions, but limited budget. I'm a master technician and have been working on cars for over 50 years. I know, the old cars now were the new cars when I started. How many "backyard" mechanics have $250.00 torque wrenches and actually use them. I don't mean that in an insulting way, just describing where they work. I personally would not put a used part on any of my vehicles unless I had glass beaded it and rebuilt it, then installed it per the service information. And to the point of 60 year old equipment, I think folks take for granted that the old stuff is going to be like the new cars of today. In 1950 oil and grease was done at 1,000 miles, not 5,000 or more miles like today. Cooling systems had 4 psi cooling systems not 18 to 21 psi cooling systems. Put that much pressure in a Kaiser or Frazer and the radiator and heater core will burst at the core plates. This is just my personal opinion and I'm only trying to emphasize how important that service info was in the 1950's and the same today.