Heat exchanger leak. Or is it

[GARRICK.CLARK]

Hi guys.
I've rebuilt a 2 ltr for a mate. It runs well, well balanced in terms of no engine shake like a miss fire, No oil leaks, no popping out of the exhaust on over run etc.
What is happening is that on 1 and 2 side it sounds like the new heat exchanger is leaking. I have removed the heat exchanger and used a file across the 2 flanges . they were level to be fair. 1 of the copper gaskets was sooty on the head side of the gasket. So I refitted the heat exchanger and it was blowing for sure. a lot more noise than before. so back off with the heat exchanger. I have now used 2 extra gaskets just to see what the results were. Now it is fairly quiet now apart from a slight noise that sounds like an exhaust leak.
The back box is an empi single quiet pack. the tail pipe is on 1 and 2 side.
If it was a leak at the copper gaskets it would pop wouldn't it.
I also removed the rockers to check the head torque. Its good.
A head leak would make it run rough wouldn't it and the bottom of the head fins would get oil on the edge and leak.
Could it just be the sound of the empi back box and the lumpy ness of the cam.

[Clatter]

Pull the exhaust and the rockers.

Put your mouth on the flange and BLOW...

Any leaks -should- be apparent at this point.

(Best to do this while parts are clean and on the bench during assembly if at all possible )

Was thinking of rigging up a plate, air pressure valve fitting, etc. to do this with compressed air.
Using a spray-bottle of soap bubbles to check properly..

This is a common issue for sure, and death for a set of heads if run for too long.

[aircooledtechguy]

Pull the exhaust and the rockers.

Put your mouth on the flange and BLOW...

Any leaks -should- be apparent at this point.

(Best to do this while parts are clean and on the bench during assembly if at all possible )

Was thinking of rigging up a plate, air pressure valve fitting, etc. to do this with compressed air.
Using a spray-bottle of soap bubbles to check properly..

This is a common issue for sure, and death for a set of heads if run for too long.

Eeeww!! I would go the hardware store and pick-up a rubber plug and drill a hole in it. Then place a blow gun tip in and keep my lips off the exhaust. . . You really get intimate with your cars huh??

[Clatter]

Have been working on a type 1...

I now love love my type 4s more than ever,
And will do whatever they could possibly want..!