Author Topic: 38 Exhaust Bolts and nuts  (Read 2168 times)

Offline Bill Gauch #23121

  • Posts: 125
  • Name: William Gauch
38 Exhaust Bolts and nuts
« on: March 04, 2009, 10:17:04 AM »
I removed the front section of exhaust pipe yesterday so I could remove the last couple head bolts.  I had some trouble when I first tried to remove the nuts. One of the nuts started to round over. so I sprayed them with penetrating oil and let them sit. I managed to get them off last night and have a couple questions/issues. I don't know what the correct configuration is for these. Two went in with the bolt head in the rear. Two went in with the bolt head in the front. One had a washer on the side with the bolt head. One had a washer on the nut side. All of them had two nuts to "lock" them in place. Lastly, the nuts and bolts looked pretty rusty, but when I removed the nuts, they very clearly looked like they were either brass or bronze, which surprised me.

So, the questions:

1. Any idea what the correct configuration is for these? How many nuts and washers, and in what configuration should they be? Right now, I assume it should be bolt, washer, nut, nut, but the flange is pretty heavy duty so I don't really know what the purpose of the washer is.
2. What material and sizes should the bolts and nuts be. Should the nuts be brass, bronze, or something else? If they are brass or bronze, why would such dissimilar metals be used? I would think that electrolysis would destroy them, considering the bolts are steel.

These may seem like minutia details, but I want to get replacements and bag them up with the correct re-installation configuration for the very distant future when I put the exhaust back on the car.
WANTED: Nothing right now.

- 1938 Series 65 - 4-door sedan - Restoration (slowly) ongoing

 http://38caddy.blogspot.com/

Re: 38 Exhaust Bolts and nuts
« Reply #1 on: March 04, 2009, 09:09:04 PM »
Bill,

usually washers are added when one cannot find the correct length. The shop manual gives the correct lentgh for the head bolts. If not it is in the Sericemen Bulletings ( I can  look it up if you can't find it).

The real critical bolts are for the radiator hold downs that hold the radiator hoses that go to the radiator. If these bolts are tooooooooo long they will do great damage to the engine by breaking things one does not one broken.

John W.
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Offline homeonprunehill

  • JIM CLC #15000 THOMAS 1938 La Salle 5027
  • Posts: 655
Re: 38 Exhaust Bolts and nuts
« Reply #2 on: March 04, 2009, 10:54:37 PM »
03-04-09
Bill, I have a '38 La Salle with a '47 Cadillac engine and  I have one brass bolt and one or more brass nuts. I wish they were all Bress. The reason for the brass is  so the bolts don't freeze and rust. I'am not concern with the configeration of the bolts buit I think they all go in the exhaust connection from the top.  Good Luck,jim
USED,ABUSED AND MISUSED CADILLACS AND LA SALLES

Re: 38 Exhaust Bolts and nuts
« Reply #3 on: March 04, 2009, 11:16:18 PM »
I guess I am getting to old,

If you are wondering about the bolts for the exhaust headers to the flange they are bronze.

I have a set and can send you a picuture of what I believe are the correct ones. These are long nuts and not one normally seen.

John W.

I thought we were discussing head bolts, what a dolt.
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Offline Bill Gauch #23121

  • Posts: 125
  • Name: William Gauch
Re: 38 Exhaust Bolts and nuts
« Reply #4 on: March 05, 2009, 06:46:02 PM »
OK, I just wire brushed the bolts and they are definitely not bronze. The nuts turned brownish-black, but are shinny and yellow inside. So, anyone know where to source some bronze bolts? McMaster Carr has silicone bronze hex-head cap screws fully threaded. Looks like they should be about 3 inches, if mine are correct in length.

John, I would appreciate it if you could send or post a pic.
WANTED: Nothing right now.

- 1938 Series 65 - 4-door sedan - Restoration (slowly) ongoing

 http://38caddy.blogspot.com/

Re: 38 Exhaust Bolts and nuts
« Reply #5 on: March 05, 2009, 09:08:04 PM »
Brad,

The nuts, I believe, to be original.

John W.
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Offline 35-709

  • Posts: 5364
  • The most valuable antique is an old friend.
  • CLC Number: 4719
  • Name: G. Newcombe
Re: 38 Exhaust Bolts and nuts
« Reply #6 on: March 05, 2009, 10:45:48 PM »
Here's one source ----  http://www.aircraftspruce.com/search/search.php   You will have to check with them on the diameter and the thread pitch.
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
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

Offline Bill Gauch #23121

  • Posts: 125
  • Name: William Gauch
Re: 38 Exhaust Bolts and nuts
« Reply #7 on: March 06, 2009, 06:42:32 AM »
I found these:

http://www.jamestowndistributors.com/userportal/show_product.do?pid=160&familyName=5%2F16-18+Bronze+Hex+Caps

My current ones were 3". They stuck out a bit past the nuts and two of them had washers. Since the 3" ones are $13.48 each, but the 2.5" ones are $1.20 each, I think I might go for the 2.5" ones. :)
WANTED: Nothing right now.

- 1938 Series 65 - 4-door sedan - Restoration (slowly) ongoing

 http://38caddy.blogspot.com/

Offline Bill Gauch #23121

  • Posts: 125
  • Name: William Gauch
Re: 38 Exhaust Bolts and nuts
« Reply #8 on: March 06, 2009, 02:32:00 PM »
One more thing... John, could you measure the bolt and the nut for length and width? I found some coupling nuts on McMaster which could be cut down. They're 7/8" long.
WANTED: Nothing right now.

- 1938 Series 65 - 4-door sedan - Restoration (slowly) ongoing

 http://38caddy.blogspot.com/

Re: 38 Exhaust Bolts and nuts
« Reply #9 on: March 06, 2009, 03:31:52 PM »
Bill,

They are 17/32" in length, 9/16" wide (6 sided).

Bolt is standard 5/16" by 1 1/4" long, fine thread.

John W.
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

 

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