Cracked Block

[KendallF]

I'm putting a mid plate into my car right now; I made the brackets for the plate tonight. I'll take some pictures as it goes along. It looks like I'll have to lose the column interlock rod, the front brake lines will need some relocation, and exhaust will probably mean notching the bottom of the thing or running underneath it.

I decided I wanted the extra chassis stiffness, and the TCI one I bought doubles as a SFI certified flexplate shield. I also have welded on my block close to the motor mount area, and didn't want to pull too hard on it there.

 

[n20junkie]

well i wil have to toss in some welding experiance on top or some airframe and racing knowlage, if I had to fix the crack in my block, first i would have to determine the depth of the crack, its is fully penetrated the thickness of the metal or jsut a surface crack, but knowing cast iron i would have to say that its cracked threw, even if you tried to take a die grinder and remove the visual crack, chances are if you were to magna flux or dye penetrant inspect it the crack is still there, you jsut can't see it. so plan of attack would call for repairing the crack and removing the stresses that caused it, if they can ( eng mounts ) like what was mentioned the only way to weld it right is to heat the whole block in a furnace so as not to impose more stress on the area by heating it to red hot for the brazing, the maching work needs to be redone, and i would put a short fill of block filler in it jsut to make it that much stronger, and alot of sbc guys fill to the bottom of the water pump ports and still run it on the street, and the price of the possible re-machining is way cheaper than another block, and there is only a chance it will need to be redone, or you can spot braze it carefully and then short fill the block, no machining will need to be done, and it should last a while, definatly longer than stop drilling and pinning. which does work, but i would only do it if i was stuck in a money race and needed a fix fast, but thats my opinion .
grant

 

[turbodave231]

Kendall,

You bought a Mid Plate? for a Buick? I thought I'd have to fabricate a plate if I wanted one......just like everything else "Buick".

What did it cost? I'd like to see pictures. My stock block is coming out soon (retiring it to a 1968 GS convertible) and the new Stage 2 is going in. Let the fun begin!!

Dave

 

[KendallF]

Originally posted by turbodave231
Kendall,

You bought a Mid Plate? for a Buick? I thought I'd have to fabricate a plate if I wanted one......just like everything else "Buick".

What did it cost? I'd like to see pictures. My stock block is coming out soon (retiring it to a 1968 GS convertible) and the new Stage 2 is going in. Let the fun begin!!

Dave

Here's a link to Jeg's for the mid plate. It cost $150. I have Dave Wicks to thank for the suggestion of using it.

You do have to redrill the top two holes for the BOP trans case, but other that it's as much of a bolt in as any mid plate...which is to say, not much. I also have to do some grinding on the inside of the bellhousing because the ring for the flexplate shield interferes with the casting of my T400 case.

I narrowed mine about an inch on each side to fit between the frame rails, and made angled plates that will weld onto the frame rails and bolt through the midplate. I'll try and take some pictures this weekend.

 

[turbodave231]

Thanks for the great info Kendall.

I really didn't want to run a flexplate shield. This piece solves that problem. I'm pulling my stocker soon and also taking off all the stock front end sheet metal. I'll have good access to mock up a mid plate.

What motor mounts do you plan to use with the mid-plate? I already have the HR poly mounts (for the stage block). Those should be OK with a mid-plate...right? I saw Pete Bernard was using stock mounts welded solid....but I don't remember if he was using a mid plate or not.

What are you gonna use for a dip stick tube for the trans? Will a stock t400 tube fit around the mid-plate?

Bear with me, I have lots of questions!! Thanks for the help!!

Dave