Budman II

It depends on how much more lift you are talking about. Stay under .550 or so, and you are probably OK with the studs you are installing. The grey area starts when you start increasing lift, and subsequently spring pressures have to go up to control that extra lift. If I was you, I would try to correct this current problem and then enjoy the setup for what it is. You have a turn-key, EFI 502 mag powered boat that runs 70 and has a ton of room on it. I would leave it at that, but that's just me. When you go tinkering around with cam profiles you open the can of worms that is remapping the EFI curve, bigger injectors and throttle bodies, etc. It's a very slippery slope!

Griff

I ran a Crane 731 cam with the ARP conversion studs 3/8 bottom and 7/16 top. The cam lift was.587/.610 and it was fine.
I think the conversion studs were rated up to 475psi of spring pressure and my springs were around 450psi.
I locktited and torqued them to spec at 45#.

BUP

WOT should be really only done after the motor is 100 % fully warmed up - water side and a guestimate of the motor oil side as a lot of boats do not have a motor oil temp gauge. Just saying.

man-of-war

I'm not looking for that much lift at all just a mild upgrade to work with what I have.
The engine has lost 3 mph from this knocking rocker,sticking lifter,worn pushrod,worn cam.broken valve spring problem. It calls for rain this weekend but when I get my parts I'll have to try that throttle body cleaner down the noisy rocker pushrod to flush the lifter.

RPM 4800 MPH 67

Budman II

If I had valvetrain noise (or possibly something else) and I was not sure what is causing it, I would have serious reservations about running it at all, much less blasting WFO across the lake. Glad it went without incident. A loss of 3 mph could be significant and related to your issue, and then again, it might be total coincidence. Is this the same gas that was sitting in there all winter? If so, the octane may have degraded and your engine's computer may have been backing off the timing to avoid detonation. I always go easy on mine the first time out until I know I have burned off any old gas left over in the tank. Maybe you already did this - if so, never mind.

Before you install a bunch of new parts, have you considered pulling off the oil filter and having someone cut it open and examine the media for any metal fragments? If you have a lobe going away you should see some metal in there. However, if you have a lifter sticking or collapsing, that would probably not show up here. Just food for thought - that is something quick and easy to check. You will want to cut it open with the correct tool (similar to a can opener) - a hack saw or cutoff wheel will contaminate the filter media with shavings and give you a false positive.

Edit - just reread my post, and I don't want you to think I am preaching to you, man-of-war. It's your boat, and I'm sure you know what you should be comfortable doing with it. Just trying to offer up some suggestions to try to save you some grief. I'm hoping this turns out to be something simple and easy to fix for you. The water is calling - boating season is upon us. Good luck with it.

man-of-war

It's all good Budman II

My 3 mph loss is not from the fuel. I stored the boat away light with less than a 1/4 tank to keep the stress/weight off the hull. I added 2 bottles of GUMOUT FUEL SYSTEM CLEANER and filled the tank 3/4 full with mid-grade 89 octane gas. I have a spare fuel water seperature in the boat, I'll replace it when this tank of gas is almost done. I know about moisture buildup, ethanol and air volume in a tank.

When I bring the boat home I will cut the filter open with a metal stud shears and take a look. I have 2 Super Strong magnets that hug the filter. I'll leave them on and wash the inner shell of the filter with gas. That should keep any metal particules in place for viewing. Only if it's aluminum, then I'll have to pan for particules.

Either way, I will upgrade to a mild .550 cam and rockers. The kids are in college and are each done the braces for their teeth. I can once again play with My Toy.

I have to get the port side riser pressure tested. I suspect a leak because when I switch the engine off after a run I can hear slow sizzling drips inside the riser. Yep, the same side the knocking is coming from.

Not to mention the gallon of water in the bilge from a leak in the front of the engine. I still can't find where it's leaking from. It only sprays at around 3000 rpm. I'll have to remove the engine hatch and back bench to catch the leak in the act.

Budman II

Those look like Gil risers - do you have the turbulators installed under them? In case you don't know what those are, the turbulators were often installed on the stock Gil exhaust / riser setups. It is a thin metal shim with a "cone" that prevents condensation or reversion from walking back up the pipe and dripping down into the manifold. It is primarily a hedge against condensation when the engine is shut down and water has a tendency to condense on the inside of the riser. The idea is that the water droplets will fall onto the hot turbulator and get boiled off as steam. if these are installed, that may be what you are hearing, but I would expect to hear it on the other side as well. Either way, probably a good idea to at least pull the riser and have a look. You may also consider pulling the manifold on that side and looking up the exhaust port for signs of water reverting back into the engine. With the stock cam I would not expect reversion, but if there is a leak, you need to fix it. Cold water dropping onto a red hot exhaust valve is a recipe for disaster.

Know what you mean about having some disposable income left after paying for kids. Just started the braces things with mine, and the real expenses are still to come - cars, college, etc. I don't know how a guy is expected to afford a boat with college costing what it does down here in the states!

wingnit

Our little guy came along 17 years after we were married. Talk about culture shock.

We were fortunately in a position to prepay his college in full and are now on the tail end of his braces (which is cheap compared to college costs especially if you haven't prepaid them). For those of you still having to pay for your kids college, have a look at the prepaid plans. It will be a lot less stressful in the later years.

So now I get to have my toys and he can still have his toys and education and straight teeth.....and we still have enough extra to buy lots of fuel and party.

We now return you to the previous thread before it was hijacked.

man-of-war

The risers are Harding Marine 5'' Big Guns'. The turbulators were never installed because it reduces to 3 1/4'' I did not want to restrict the flow. I should install one on the port side and see if the sizzling stops,good call Budman II .
I should ask the engine builder if he could press the opening of the turblator to 3 1/2''




I got the rockers today




The engine builder thought he had the correct size studs

SB

Your worried about a 3 1/4" restriction from turbolators and you are going to be running these rocker arms ?

#1411-16 pictured here: