Pressure testing block

[Mc Tool]

I have a 3.9 block that Im trying to test . I have made flat steel plates with 2mm thick rubber stuck to them to blank off holes , fitted a pressure gauge and put 30psi in .
The gauge doesnt move at all for an hour but had dropped to 20psi after another 4 hours .
I have done the soapy water thing round all my fittings and the tops of the liners and cannot see any evidence of a leak .
So far I have only done one side of the block .
Is this much of a leak to much ?
Thanks

[stevieturbo]

Can you submerge the block in a tank of water ?

Or pressurise it with a smoke machine to highlight any possible leak areas ?

[ChrisJC]

I used a big bath of water. It was hot water as well.



Chris.

[Mc Tool]

I go it sorted . One of the bolt holes in the front of the block goes thru to the water jacket ( the one with the stud ) and I was loosing pressure thru that . Once I got it air tight it hold 30 psi ......been over 24 hrs now , on both sides , so I have a good block .

[Blown v8]

I do love a bit of ingenuity,
Well done