Just finished a rebuild on a 400, I had the machining done for me, gathered all the parts and assembled it myself.
I have been hearing about lifter preload, I have an idea of what it is, but dont know how to check it, or adjust it if need be.

Oh, BTW, almost everything is new as far as valve train,, pushrods(stock), cam- lifters(hi-po), springs(hi-po), rocker arms(stock). I had a valve job done on the original valves and seats.
Heads are surfaced slightly, deck has not been touched.

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Do you have a manual on rebuilding your engine? You REALLY need a manual when assembling an engine to avoid mistakes. You can buy a manual on rebuilding Ford engines at the online store here as well as at many parts stores. The pictures and diagrams are worth the price many times over. Add in the other information and it is a real value.

 

lifter preload is a important part of engine building.

 

Note- TQ1st, I am still without help here.

I dont have a manual, or a link to the info I need, thats what I need.

 

Thanks mark, I know its important, HOW DO I DO IT?

 

Buy a manual, the procedure is complicated to explain with words. The diagrams etc are much better. You will need the manual for all of the other little tricks and tips anyway. Someone here may be able to point you to an online resource but the pedestal mount rocker procedure is probably not covered. There are many other points to check in the valvetrain etc at the same time so GET A MANUAL! Not a generic Haynes or Chiltons either. There are several parts stores in McPherson that probably carry the manuals. There are speed shops in Salina, Hutch, or Wichita that carry them. This is the one you need: http://www.motorhaven.com/customer/p...&cat=44&page=1

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If I'm not mistaken, checking your lifter preload is done by checking the valve stem to rocker clearance with the lifter completely collapsed.. My Ford manual states 0.200 is the max allowable gap with 0.175 desired... They show the use of a "special" tool that grabs the nose of the rocker with a handle that is bent back over the pushrod to create a fulcrum effect for pulling the rocker back down on the pushrod and collapsing the tappet... It also shows a sequence of 3 crank rotations starting at 0 TDC and what valves to check at each rotation using the tool again to collapse the lifter... If the gap is out of spec, they state the use of longer or shorter pushrods...

I too have just rebuilt my 400, but went with the Bolt-On Roller Rockers from Ford... The sequence and method was totally different in that you check each cylinder in the both valves closed position (same as 0 TDC for No. 1) and then torque the roller to 15ftlbs.... At each position, after torqueing they said to make sure to pushrod can be turned by hand, but with no up and down play between the tappet and rocker seat... Seemed way to easy to me, but so far no problems and noises... I did double check it, though..

Since you haven't done much in head milling and deck work... and your valve job is the maybe the first one since stock??? I doubt that you would have any issues on the clearance tolerances... But it's always the things you take for granted that come back to bite you...

Sorry for the long post, just trying to give back to what I've learned here

Dave

 

That process won't get the job done when checking for lifter preload. About the only thing that is doing is checking for binding.

 

Lifter preload is how much the the lifter collapses when the rocker arm is tightened down at tdc. It is figured into valve train geometry. I use checking springs on the valves & a adjustable push rod that I made. They do make a tool for this if you want to buy one. With #1 on tdc, put your push rod in and adjust so there is no play. Look at the valve tip / rocker tip from the front of the engine. Start turning the crank and watch the rocker tip sweep the valve tip. It should start in near the top of the valve tip and end near the bottom of the valve tip. If it doesn't adjust the push rod length accordingly. Once it sweeps the valve tip perfectly remove the push rod & measure it with dial calipers, then add your recomended preload to this measurement and thats your length. Any company that makes push rods will make custom lengths for you.

 

Check the Crane cams site. they have a tech article on preload for the 335 series engines. different length push rods and shims are available.

 

Thanks for the correction... I was confusing my installation instructions between the bolt-on rollers and new lifter pre-load checks... crammed alot of info in a short time with my first rebuild...

I used the CompCams instructions for preload check by setting No. 1 cylinder with both valves closed and the rockers properly torqued, scribed a mark on the pushrod with a razor blade edge using a steel straight edge across the valve cover gasket surface of the head... I then loosened the rockers enough to free the lifter plunger and then scribed another mark in the same fashion... the difference between the 2 masrks showed my lifter preload dimension... After measuring about 10 times I determined I was between .020 and .030, which according to the Cam instructions is acceptable...

I'll stop typing now

 

Sounds good to me.

 

It will most likely not make any difference on a push-rod, but keep in mind that a scrible line creates a stress riser on any stressed part. A fine-line Sharpie pen worked well for me.

 

glad to oblige beartracks

 

a magnetic based dial indicator is a safe and accurate approach.
I would lean away from scribing any kinda marks.
a fine line sharpie, and a really good pair of eyes, eh ok.