Philm

Good Luck Don.

I floated a valve yesterday on the 598 at approximately 5500rpm, passing 90mph and at 58.5 hours. Pushrod popped out of the rocker arm and rested on the side of the cup, held the intake valve open and bogged the engine down. Something impacted the spark plug and destroyed it. I have not yet pulled the head but the pushrod is definitely bent a small amount. Luckily I shut it down as soon as it happened, so maybe the piston isnt destroyed or the block all goobered up. We will have to see I guess.

I will definitely need to have the head rebuilt, and might as well get both done while I am at it.

lightspeed

And Ill Bet Money Nobody Adjusted The Valves Since It Left My House

DonRoc

You need to adjust them every 20 hours depending on the lift and spring pressure. Some of the less radical maybe 40 hours. I would say 40-50 hours on having the lifters rebuilt also.
That sucks. i hope for you it is minor head work. But being the spark plug was impacted. The piston hit the valve and valve or a piece of the piston hit the plug. Are you going to get it back together this summer? Who will be doing your engine work?
I ran the boat more tonight all the minor bugs are fixed, but had the family aboard and today was swamped at the marina so no prop testing. Tomorrow for sure the lake will have a fraction of the traffic. I will post...

DonRoc

Got my run in With the Bravo 1 30P It ran 90.31MPH @ 5700RPM. Was nice and stabil. I even over trimmed it, it would pad walk with a fair amount of over trim with no increase in speed. So im very happy just a touch of positive trim past neutral gets me the best speed, a flat ride, and no pad walk. Lake was flat, 3/8 tank of fuel and me. I picked up a few MPH and flattened the ride by changing my X. My Propshaft is now 1" above the bottom. I look forward to some waves and a new speed record, lol

lightspeed

Thats Great News,,,Wasnt To Hard To Do ,,,

Philm

I actually adjusted the valves about 18 hours ago to the specs on the cam card, So i dont think that was the problem. Springs were probably just at the limit of time and needed to be changed, sucks because springs are relatively cheap. We will see what it looks like when i get the head off tonight.

I am pretty bummed about it, as it was running great prior to this, but I guess that is just the chance we take. Glad to hear yours is running so much better now Don.

DonRoc

Valve adjustments are important for wear, and power loss, but will not cause valve float. And if the intake was so tight to hold the valve open it would be poping thru the intake on the power stroke.
With the low hours the springs should not be weak I would expect to see a broken spring, a sticky valve stem, or some debris that would have help the valve open. After the valve got hit the pushrod bends and will lodge somewhere besides the pushrod cup. So it is hard to tell if the valve floated or got stuck open for a few other reasons. What you have is the aftermath. Did it float and get hit or stick open and get hit, or something held it open same results. I cant immagine unless the spring broke that they would be week enough to float after only 58.5 hours. When you pull the springs if they are not broke test the pressures. That will tell you if they were out of spec and floated. Really sorry to hear the bad news. Let me know how it goes.
Take Care,
Don

Philm

well, I am not sure what the issue was with the stbd cylinder, but I found another bad cylinder last night. This one broke a valve retainer and broke the iontake valve off, not looking forward to seeing inside that cylinder. This spring is not broken. It did not do this on the other side, on that side the pushrod appeared to be holding the valve open by being out of the cup. Both heads are coming off today to be looked at.

DonRoc

Once the valve stay open by float or other reasons the pushrod/lifter will loose contact with the cam lobe then the pushrod wil get tossed. Kind of the chicken egg, which came first. I would be interested in spring pressure your cam card should give details on what springs are in it. Have you had it over 5500 before? What RPM does the cam card say or doesnt it.
Keep us posted, I am headed out this AM to try a 32p, and some more prop testing.

lightspeed

I Had The Covers Off Every other Time I Used It ,Just To Look At The Valve Train,,And We Set The Valves At 18 Across The Board Not What The Cam Card Said,,,Sorry This Had To Happen To You,, That Motor Cost Me A Good Buck,,But If You Have That Much Damage I Would Be Pulling The Motor And Let Jeff Have It For A Go Thru,,,,,,,,,I Used To Spin That At 6300