One of the (many) unique features of a marine Chris Craft 427 is the fact that this is a solid lifter motor, and the valves must therefore be adjusted by hand from time to time. On a motor with hydraulic actuated valves you don't have to do this. The requirement to adjust valves on the marine 427 has been the source of complaints from many people who just cant be bothered by this sort of thing, but its really no hassle at all. The engines run beautifully, theyll run almost forever, and they sure appreciate it if their owner uses good oil and adjusts those valves every now and then. Ive seen some recommendations to adjust at 50-hour intervals, and some as much as 250-hour intervals, but I would default to the 50-hour because this is such an easy thing to do.
The Chris Craft 427 owners manual requires the valves to be adjusted cold at 025 and 021 hot.
The valve adjustment can be done two ways, in a static mode by manually turning the engine by hand, or by working on a hot motor that is running. I much prefer to check on a hot running motor, and the most difficult thing is taking off the valve cover, so you can see this really is a piece of cake. If you use the static mode, you must be sure and heat the motor up first, to be sure you are getting an accurate .021 reading. I will post the actual sequence upon referencing the manual one more time (this evening).
Some people suggest running the 427 at .025 hot, out of fear that if they get the setting too tight, they will burn the valves. Street driven stock 427 engines require a setting of .025 hot, but their cams are of a higher lift than our boats, and they have a factory imposed redline set at 6,000 rpm, so I would default to the Chris Craft and Ford recommended settings on the MARINE APPLICATION. I prefer to have the settings right on the money, as the motors tend to idle well, not stall, and reach maximum power if theyre set to marine recommended adjustment points.
I check and make adjustments on a static motor, but I also check my valves with the motor running. Warm the engines, remove a valve cover, put towels down to catch any dripping or spatter, and take the .021 feeler gauge and insert it into all the valve lash openings while the motor is running. Youll be able to tell EXACTLY which ones have a perfect fit, and which ones are a little tight, and which ones are loose. You can mark these for adjustment when the motor is shut off, or you can adjust the valve lash on a running motor if you are able to deal with all of the movement etc.
Heres how to make adjustments with the motor running:
Obtain a 7/16 offsetbox end wrench (which will stay put while the valves are jumping around). Wrap a thick rag around the wrench to dampen some of the vibration, and while the engine is running turn the adjusting nut until you feel just a little drag on the feeler gauge.
Ill post additional specs and some photos at a later date, so this post can become a reference worth keeping on board your boat.
1966 38 Commander Express
Original 427 Power
Here is the valve adjustment section from my Eaton Marine Interceptor owners manual, with regqrds to the solid lifter Ford "FE" series motor, of which the 427 Chris Craft is a member.
Here are some great photo documentary related threads:
All about 427 Valve Seals
All about 427 Cylinder Heads