Cracked Block

[Paul Mascuch]

I am looking for advice on how to approach a repair to the XPAG engine block on my 1948 MGTC. Looking at the engine block from the rear, the right lower mounting hole in the block for the bell housing has cracked through the hole and the small ear projection by where the starter mounts has fallen off.

I have removed the engine from the car and stripped down the block. Can this be welded so the repair will hold long term?

Any advice would be greatly appreciated.

Best regards, Paul Mascuch

1948 MGTC
1952 Jaguar XK120
1986 Caterham Super 7
1997 Jaguar XJ6L

[frenchblatter]

Paul,

Do a Google search for "stitching cast iron". These are the specialists who can repair the block.

There are quite a few but not sure if they're near you.

By the way, what model Caterham have you. Mine is a 1989 BDR but heavily modified. Have a look on www.frenchblat.com

[Gene Gillam]

Paul,

I've had two XPAG blocks successfully weld repaired. You need to find someone with experience in welding cast iron but it's not a hard job for someone who knows what they're doing.

Gene

[Warmuthb]

Paul:
I bevel out both sides of the crack and use a nickel rod on my arc welder at about 70 amps or so. Also pre-heat the General of the area with a neutral flame on a acetylene torch. Then if possible after the weld cover the repair and the general area with some heat resistant material, even slag, glass beads or sand...you want the area and weld to cool as slow as possible. I'm sure when you find a qualified welder he/ she will know this...but it's good to go in with some info anyway. The repair then be ground to shape or flat as needed. If the weld goes through a threaded hole, you may have to drill and re-tap also.

Good luck!
Brian W

[Marv]

Paul: Hope you've got the block fixed by now but wanted to say the Brian is spot on. The trick is to preheat as large an area around the weld area as possible. Chamfering or v-grinding the area for fill with the 95% nickel rod makes for strength and longevity. The big item is to insure the area cools down ver-r-r-y slowly. Even to the point of putting the block on a bed of glowing charcoal after welding and letting it sit there until the charcoal dies and the block is cool. Covering the block with a sheet of tin or a non-flammable material would be excellent. I've had a Tractor block running for 10 years that I repaired that way and I did sit it into a glowing pile of charcoal an covered it with a big sheet of galvanized tin sheeting. Do your grinding, drilling and tapping afterwards and you're good to go. Cheers,, Marv P.