Compression #s, are they OK?
 

Procharged 502s with heads ported and 3 angle valve job. Not sure about compression. 8:?

Reason for testing is because exhaust manifold risers were leaking and surface rust was around exhaust valves. Pictured below is 1 valve that seems "off center", and also has the lowest compression.

Readings

155 155
163 156
145 162
155 157

These might be off by 1 or 2 lbs.

Re: Compression #s, are they OK?
 

ANY TIME THESE ENGINES INGEST WATER AND YOU GET THAT TYPE OF CORROSION AROUND THE VALVES YOU SHOULD CONSIDER REPLACING THE VALVES AND REVALVE JOBING THE HEAD YOU GET PITTED VALVES AND SEATS AND YOUR COMP WILL VARRY BUT THE BIG CONCERN IS LOOSING A VALVE THATS NOTHING BUT TROUBLE. THE VALVE BEING OFFSET CAN BE A WORN VALVE GUIDE FROM CORROSION . LOOK AT THESE POSSIBILITIES CLOSELY YOU CAN MOST LIKELY HAVE A GOOD SHOP IN YOUR AREA HELP YOU GET BACK IN THE WATER QUICKLY. IF YOU CANT FIND ANYONE LOCAL THAT CAN HELP GIVE US A CALL AND ILL HELP ANYWAY I CAN LAZ MESA WWW.MESABALANCING.COM

Re: Compression #s, are they OK?
 

You have a 20psi variance in pressure. I'd say the numbers were ok, if it wasn't for the one cylinder. Knowing the amount of rust you have in there, I'd pull the heads and replace all the valves.

Re: Compression #s, are they OK?
 

Valves get brittle from being very hot then quenched by rogue water. They can shatter due to brittleness at a later date. Replace at least the valves in this hole.

BT

Re: Compression #s, are they OK?
 

That is if they don't form the shape of a pretzel first. this is why they are so quick to cap the exhaust tubes on the top fuel dragsters.

Roby

Re: Compression #s, are they OK?
 

I think this is a case of a guide that is worn to $hit. The valve probably isn't bent but I bet the rocker isn't hitting it square on the head either. need to fix this. If the rocker get off the valve too much it can free the keeps. That's when you start seeing smoke in the shape of dollar signs $$$ coming out of the hatch