high all again, I have got everything on my rebuilt 390 finished. I have got adjusttable valve train, a crane 941 cam and crane lifters. I have got the push rods in. What kind of gap should i have with this set up? and also how do i go about getting this gap?


thanks
-brandon-

 

Brandon with a Hydraulic Cam...you dont have a Valve lash..you have a lifter preload..

Turn the Adjustment on the rocker arm until you feel a slight drag on the pushrod..turn the pushrod as you turn the adjustment scew....and then when you fingers feel that slight drag on the pushrod... Some guys take them another full turn..some only run them down another Half turn on the Adjustment screw...

It should say somewhere How many thousands of preload you should have on the lifter? I dont remember off hand...And if I remember right..I measured it one time with a dail indicator..one turn on the adjustment screw was around .040" I think?

Russ

 

ps. be sure each cylinder is on the compression stroke with the piston at TDC

 

After much reading and discussion I turned mine 1 full turn more. You can get all the valves with just 2 positions on the engine. The details are spelled out in Steve Christ's book. Having done it both ways now, I think I prefer doing each cylinder's valves independently when that cylinder is at TDC. It takes a little more time this way but I feel more comfortable that the cam is in the best position for rocker adjustment.

Tracy

 

This is just a thought


when turn the motor so that each cylider reaches TDC will that cause problems with the cam?

damgeing the the lobes or anything?

 

nope...not a problem at all. BTW...on a past post I had promised you the name of the oil additive for cam run in. Sorry but I had misplaced the stuff...finally ran across it the last couple of days. What I bought is Crane Cams Super Lube break-in lubricant, pt. # 99003-1. You can find information on it on their website.

Tracy

 

Thanks i have been wondering about it. Is it better to use that or not really? does it matter?

 

heck I don't know. I decided it couldn't hurt and maybe it will be better so I went ahead and bought it. I got it from a local speed shop and they swore by it...probably to get me to make the purchase...LOL.

Tracy

 

I have wondered about adjusting preload using the same 2 positions that are used for setting lash on a mechanical lifter cam. I've never seen anyone recommend that method for preload. Why would'nt it work?

 

I think that it would work. Its just a security thing for the other valves (really me) just to make sure that they are all set right

 

I usually go out and get a case Of Vavloline VR1 it contians .15% zinc..which help greatly on break in...

If you allready have breakin lube on your cam and bearings you'll be fine...I run the engine 20 minutes changing the revs from 2000rpm up to 3000rpm down to 2500rpm them back up again...Once breakin is done and all the newly painted stuff has baked on and the cloud clear's...

I drain the old blood and cut open the filter after it off to see if anything came apart on break in..LOL...I use wix filters I forget how many Microns they go down to for cleaning the oil?

Put in the new Blood and filter....and drive it for 500 mile's but never at a steady speed..you dont want to build up a piston ring ridge!!

After the 500 Miles..I change the blood again..And just me personally..I start driving it like I stoled it!!!!

If it gonna Break it'll break then..If not It will run until the driver does something stupid!!

And if your running moly rings..and the cylinders have been prepped for the moly's as they should be....Moly's Will either break in Quick or not at all...

Alot of guys and Machine shops...Will put moly rings in with the cylinder prepped for standard cast rings....And they will smoke like the devil..and be down on power..etc...

If the Cylinder's have been prepped for moly's it will have almost a shine to the cylinder's...

Good Luck!!

Russ

 

It does work. I think it's a bit easier to be sure each cylinder is at TDC as opposed to finding the 2 positions to adjust all the valves. I did use the 2 position method this time myself but I kept doublechecking and doubting as it's just not so obvious that the cam lobes are really completely down so you can adjust all the valves that you can. It's obvious when I turn a cylinder to TDC.

 

Russ I got the VR1. I got the cam lube on it.

I would be the one to do drive for a while and then do something stupid.

Everything that the machine shop is supposed to do has been done. I trust them but i still went back and doubled checked everything. hopefully i will be firing it up really soon.

My ankle is feeling better so i might go put a motor and trans in tonight.