Valve lapping test...

[C.Berry]

Ok so just done all my valves on my sbc400 heads for my 350 and was wondering what ways you fella know to test the seat of the valve without pressure tests... I used water and then oil to check for leaks after putting valves back together and seemed fine but found that some ppl claim that isnt a way to check em yall know any better way or did i test them the best possible way without pressure test? thanks

 

[Blkvoodoo]

 

[Chris_Keziah]

As long as there is a distinct shiny line all the way around both the valve and seat your good to go.

 

[C.Berry]

Yeah didnt have any machining blue and couldnt find a damn marker or anything to use... Yeah i done each valve about 3 times each seemed to work well we will see soon enough thanks!

 

[nctom]

Go to the medicine cabinet and grab some rubbing alkyhaul. It will tell you in 15 seconds if you are sealed up. Much thinner viscocity than water. I have used this trick for years and it works very well.

 

[C.Berry]

Damn good idea man ill test the head i still have off if it leaks ill pull other one back off and get back to lapping which i found to not really like all that much after 16 valves... Thanks i didnt think about alcohol except drinking it while doing valves!