LZ-24 Frankenstein engine question please

[spottedog]

This is a Z24 block with a L20-B (W58) that I built last year, it ran fine until the bronze intake valve seats went south, so I took the head in for a valve job.

 

To refresh my memory about reassembling this engine (hey, I’m a old man :) ) so I downloaded some instructions with pictures.

The instructions I got are for putting a L20-B head on a Z22 block, but I assume Z24 head gaskets are the same except for a bigger “fire ring”.

 

I drilled the eight required holes in the block, head gasket, and 0.020” copper head shim, but now I see I was also supposed to (according to the guide) drill the trapezoidal coolant hole at the rear of the block (please see picture 100_0318, location marked “B”)

 

It would be a real bitch to add this hole to the block (not to mention the head gasket and shim) because the engine is in the truck.

 

Right next to where the trapezoidal hole should be drilled is a

Edited February 26, 2009 by spottedog

[hang_510]

cant recall whats on my Z24 block...

 

i did this to the Z22 block over the weekend. rather than spending time making the new round hole trapezoidal, i just drilled the biggest round hole and matched in on the gasket = increased flow!

 

more flow through the back of the head could be a critical area, esp if you were getting hot before.

 

doing it in the truck may cause issues...it worked before right???

done carefully, the remnants will only be in the cooling system. :mellow:

then upgrade the radiator, once youve broken it in. :D

[datzenmike]

I would not worry about it myself. Coolant flow is up out of the block and then forward across the top of the cylinder to the front. Ask Hang_510 he has one.