Bench Testing for Air Leaks

[hivoltagesledhead]

Just thought I would post some results for my 800r turbo that I am putting back together. I did some bench tests for air leaks and found numerous locations that are leaking air. Tests are done with carb boots and y-pipe on as per the service manual. I put 10lbs of air in the block and waited 3 mins. Lost about .5 to 1 lb over the 3 mins but noticed that with soapy water I have air leaks at both my y-pipe gaskets and around my carb boots. Also leaks around the egt sensors, but that just needs a better plug for the test. I assume that once I screw the egt sensors on that leak will be gone. Hopefully new exhaust gaskets will cure that leak and the carb boots will have to be addressed. It easy to see now why I was having soooo many issues trying to build boost these past two years. With the internal stinger falling off and all of these leaks, it is very difficult to have an efficient system.
I assume that the block should hold the air indefinately, unless there is an acceptable bleed down rate, but with a turbo, every leak is a bad leak.

I will replace the gaskets and try again. Will post results later today.

 

[badass1000]

Right on. I have never tested the engine by itself. I had my engine all apart to regrease the crank and install all new seals. I actually kind of looked into getting some stuff to presure test just the engine, but gave up on it and didn't do it. I didn't think I would have a problem.
I did presure test my whole turbo system installed on the sled though. put a cap over the turbo inlet and a plug in the exhaust outlet and presureize it with a compresor. I don't think you will ever get it to preasurize to 10psi and hold it, but I got rid of all the biger leaks.

 

[hivoltagesledhead]

Ya I agree.Unless you wanted to get away from gaskets and use gasket maker or a combination of both it is going to be very difficult to get a full proof system. I think that losing .5 to 1 lb over 3 mins is acceptable in my world. Had a xmas party last nite so dont feel much like wrenching today. I did get some new gaskets so when I get them on and pressurized it will post results.

 

[hivoltagesledhead]

So I changed the exhaust gaskets and still have a small leak....I think it is because they are ceramic coated and it is not a perfectly flat surface. Gonna have to use gasket glue or deal with a small leak. I think .5 lb over 3mins is sufficient. Big thing is that the carb boots dont leak anymore. Time to put her back together.