I HAVE CANNFIELD ALUMINUM HEADS ON MY 540s. JUST HAD THEM REDONE WITH NEW GUIDES ON BOTH SETS,VALVE JOB ETC. BOAT WENT GREAT AT THE BEGINNING OF THE YEAR AND HAS SLIGHTY FELL OFF ON TOP SPEED. I DID A COMPRESSION TEST AND LEAKDOWN TESTON BOTH MOTORS ONLY TO FIND I HAVE 7 WEAK CYLS BETWEEN THE TWO MOTORS. ALL LEAKING OUT EXHAUST VALVES. QUESTION IS ARE THE EXHAUST GUIDES PUSHED THROUGH WATERPORTS? IT LOOKS ALL WET AROUND THE BOTTOM OF THE GUIDE THAT STICKS INTO THE EXHAUST PORT.

Do yopu have INCONEL valves??? you can tulip valves and start to lose sealing ability...

If you tulip the exhaust valves, and they dont seal well, it can suck water back in from the exhaust when the piston goes down. Thats probably where your water is coming from.

I would start there for sure......been there..!

They r inconnel. I have a cam with 110 centerline. I'm just trying to see if the guides didn't seal properly. That's why I'm wondering if they go through watterports

Yes they do and guides can rot through

Yea...but even with messed up guide....should still seal....look for tuliping

Inconel valves can tulip also.

What did you have timing set at? Considering both engines are showing issues, Im gonna rule out exhaust problems, cracked head, etc. .

I believe your heads have the guides thru the water jacket, but not sure with a canfield head.

Yes they do!!!! I had inconel tulip this summer......got lucky it didn't break....

my guess is timing set to low and egt,s are sky high,i have seen this happen even with inconel valves.