plumbers crack

Just purchased a new motor with solid lifters,the cam is around 700"lift.The builder says change out lifters and re adjust valve lash at 1st 20 hrs,then again at 50 hrs.Why must this be done and can I change this over to hydraulic roller and not lose power?This seems like alot of work.The motor is a 510 cu inch with single dominator 9.5 around 650 hp.

JohnJan

As the valvtrain heats up, the parts expand. Hydraulic lifters rely on oil pressure within the lifter to variably take up any clearances required to accomodate the expansion due to heating. This same feature also accomodates wear. But, hydraulic lifters have more moving parts and are a bit heavier. Because they're heavier, they won't typically follow as agressive a profile before floating (loosing contact with the cam lobe. In order to minimize the maintenance, you will probably nead to reduce the lift on the cam and so yes, you will lose power. You can NOT substitute hyd lifters for solid and keep a cam designed for use with solid lifters. Like they say, if you want to play... ...you gotta pay.

MIAMIBOYZ

No substitution for solid rollers, if you want to make serious power nothing compares to it, all it takes is valve lashing 1/2 hour job once you have the valve covers off. All our race motors have solids, we check them after every race and they dont loose a bit, you need to keep the spring preasure above 200/250.

MESABALANCING

If it's not a race engine and you use it for pleasure or under 5600 rpm I don't think you need a solid roller here's a pic of a 509 for a twin engine 35 cig that made 623 hp at 5500 rpm with a custom hydraulic roller and 9:6.1 comp with a Dominator and an old Team G intake done by Wilson . It also made 624 ft lbs at 4500 rpm which is nothing to laugh at for a small motor compared to some of todays poker run engines. If you need help with the cam feel free to call me and I'll give you a hand Sincerely yours Laz Mesa

Iggy

There's nothing like the sound of a solid lifter cam.
There's nothing like having to adjust 16 valves, having hot oil dripping onto your hands and fingers, burning your self on a hot exhaust system or on all the hot engine parts, keeping a supply of valve cover gaskets on the wall, and a whole bunch of other "fun" things that go with it.

No, you cannot substitute hydraulic lifters for solid.

You'll need to adjust the valves on a regular basis because they tend to rattle themselves loose over time. The harder you run the engine the sooner it'll need valve adjustments.
Depending on how close the exhaust manifolds are you may need to pull them to gain access to the valve covers. Wouldn't that be a fun job in the August heat? You could spend the bucks and buy a set of two piece covers.....$$$$$$

It used to take me about 2 hours to adjust the valves on my old GT-350 Shelby. And that was a straight forward job. Not much to get in my way. I wouldn't attempt it in the confines of a twin engine compartment.

plumbers crack

Thank you,now how about the procedure for adjusting valve lash?what is the best method?

JohnJan

Crane Cams has always published the best poop on adjusting valve lash. Look here...

http://www.cranecams.com/?show=techa...5b8fc8afb38799

WETTE VETTE

Iggy has some good points on the maintenance of solid lifters. I can have mine done in about 1/2 hr and that includes taking the valve covers off. I do have 2pc KE covers and they easily clear header type exhaust. It isn't necessary to check the lash with the motor running. Hot lash is what you want so I set it cold and check it hot to get a baseline as to how much it changes. Mine loosen up about .004" when hot which means I set the cold lash at .016 to get the specified .020 hot lash. I also use a remote switch to bump the motor around or if the plugs are out I turn the motor over by hand.

Craig

paradigm shift

I follow the same procedure. I have not adjusted valves HOT for some time. You just have to get a good base line for changes when warm. How much change will depend on alluminum or cast heads. Too bad we can not come up with an overhead cam so these valve train issues would go away.

PC you wrote change lifters at 20 hrs. Is this correct or just adjust? Mine will go 50hrs with no adjust. If things are changing you need to look at why. Just my .02

plumbers crack

Good Info,I take it we are using a feeler guage to set lash?and this is done between the rocker tip and pushrod?I still need the cam cards from the builer to get specifics,thanks mesa,and all who replied.Please share any other info.

ps.I have a custom stud girdle so 2 piece valve covers may not work.