Stevec

I need to do a compression test on a 68 400 engine,can someone tell me the specs? Whats acceptable and what isnt.Its a stock engine. Thanks

442Harv

150 to 170 would be great. The main thing, if it is lower, is that they are all in the same area. Like if it is running great, but they read lower, but are all close, that would be OK. If they all get to low, just means it may be time to rebuild.

Stevec

Hey Harv thanks for getting back to me,I did a compression test and they were all between 150 and 170 so good news there. The prob is Im getting some smoke from the pass side tail pipe and Im thinking valve seals or valve guides.Is there anyway to check for bad valve guides? Again thanks for getting back to me.Steve

Rickman48

I replaced the seals and springs on mine, and athough some of the guides were loose, it stopped the smoking.
Also replaced all the rockers and stands, as I broke a stand on the tollway, messing with a BB El Camino at about 90!!

Stevec

I just got a set of valve seals so I will start there,thanks for the info. Steve