honestly I've never heard about it before. When you think how many 496 Motors are out there it's probably not a common problem. I followed my machine shops advise and replace them. they did not make any money on it as I supplied the valves. I would not lose sleep over it but it wouldn't hurt to yank a valve cover and look. You should not have to pull a rocker arm to be able to see the valve from the side.

Coming along nicely. Startup vid here soon.......

Turned out good for a rattle can job. Little touchup needed once its back home in the boat. Waiting on my adj fuel psi regulator to test fire. Probably next week. Other than that it's ready.

Added a Jegs billet oil catch can. Inside the Raylar intake had a fine oil coating in the plenum and runners. The PCV pulls from the lifter valley into the intake behind the throttle body.

I posted a couple of pics of a piston we took out of a 496 we are doing with 337 hours,a lot of people say the pistons on the 496s are junk,well they may not be the best thats for sure but I think they are better than people give them credit to be,this engine hydro locked and destroyed the connecting rod as you guys can see,but the piston did not break,also had the crank magnaflux and its fine,just thought I would share this info with you guys,now if you add a whipple or supercharge it then I would think anything could go at any time,but that would go for any engine

Just don't detonate them. Hope to test fire tonight or tomorrow.

It's Alive!!! Started up yesterday. Ran for 20 sec and shutoff itself. wtf? Attempts to restart resulted in a backfire thru exhaust. Troubleshot. No codes. Fuel, spark all good. No tach signal to Techmate or analog test gauge. Replaced Crank position sensor today and it fired right up. Ohh well, better for it to die now. Everything looks good. Compression test after running 155psi across all cylinders. Time to drop back in the boat this weekend.

Sounds and looks GREAT!

Padraig

just a few things -- the crank position has 3 only pull out and reinstall. After that it needs to be replaced with a brand new --- regardless.

also make sure your fuel pressure dampner internally is super spotless clean and rail lines to it. Paint and or fuel varnish and or rust really can settle in its base and in the dampner itself plus its small rail lines. Just some added info.

The dampner will have U clip for a hold in place and 2 O rings internally and has to SEAL 100 percent. The 2 o rings can also become dried out and or cracked. The 2 O rings alot of times will need to be changed out with new. Sometimes not but alot of times YES they will need to be changed.