Valve Adjustment, finally

[BuffaloBillPatri]

I assembled my 355 14 years ago, but never started it.

 

It sat with cam, hydraulic roller lifters, heads & valve spring pressure.

 

When I started working on it again, I found that 5 of the lifter plungers were stuck in the bottom. There was no 1/8" give when pushing on the pushrods.

 

I adjusted the rockers before starting as best I could, but they weren't right.

 

For break-in, I used good oil (Shell Rotella) + EOS + a quart of Rislone with hopes of the lifter plungers loosening up, after a couple of hours run time, they did.

 

Today I adjusted them hot with the motor running method. My Scorpion roller rockers make quite a bit of noise & I couldn't hear very well.

 

At 900 RPM almost no oil escaped onto the headers.

 

So I used a 3/8" x 24" wood dowel rod pressed against the rocker nut & along side my ear & It worked GREAT.

 

I could hear exactly the point when tightening the nut would stop the rocker clatter. I gave them another 1/4 turn.

 

Happy, BBP

[kc8oye]

BBP: I took an old junk chrome valve cover and cut a window in the top of it just wide enough to get my 5/8 socket onto my stock rocker nuts & arms.. works great for controlling oil

[Heckeng]

Nice. I'm surprised the plungers sprung back like that. 14 years is a long time to be compressed! Congrats on the resurrection!

[BuffaloBillPatri]

They made noise on cold start (35*) today.

 

Aluminum heads expansion?

 

So readjusted them again (HOT) with 1/2 turn after clatter stopped. Much quicker with practice.

 

BBP

 

[Heckeng]

Lots of people think it is ridiculous to adjust lifters with the engine running, but it sure does make it easy, and it doesn't take long at all, and you can't mess it up by turning the crank too far or not far enough.

 

I've read that aluminum heads will expand about 5 or 6 thousandths, which on a big block would be almost 1/8 turn.

[BuffaloBillPatri]

First posted on Crane's website on January 3, 2005:

Hydraulic Roller Lifter Adjustment Recommendation

 

With the increased popularity of hydraulic roller cams, our phone techs are getting more questions on proper adjustment of hydraulic roller valve trains. First, a hydraulic roller tappet weighs more than a hydraulic flat tappet due to the extra mass of the wheel, axle and support struts. This extra mass, as well as the quicker opening rates available to the roller cam design, requires the use of higher valve spring on-the-seat pressures and higher valve spring open pressures to control the increased inertia of the lifter.

 

Higher seat and open pressures can cause pushrods to bend; therefore, use the stiffest pushrods available to assure proper valve action. (This is a “speed secret” that we’ve seen proven in countless dyno tests. We prefer heavy-wall pushrods for just this reason!)

 

Finally, hydraulic roller tappets will perform best with at least one turn of preload on the lifter. This is different from flat-faced lifters which perform best at zero 0 to ½ turn of preload. Tests at Crane R&D have consistently shown best performance (for hydraulic roller cam valve trains) occurs with the preload set at 1 ¼ - 1 ½ turns down from zero lash. This adjustment will maximize power throughout the RPM range and increase the useable top end by 200 - 300 RPM. This preload setting has been confirmed on every engine family we have tested! Check the tutorial in the front of the new Crane Cams Valve Spring Catalog for spring pressure recommendations for various applications.

 

I found this today & set mine again to 1.5 turns. My rockers seem to make less noise & I verified oiling.

 

I have Lunati hyd roller cam, lifters, & beehive valve springs 170/360#

 

BBP

[Andy's Auto]

BBP, very good info. We all know a non roller hydraulic lifter much past 1/4 turn has the potential to hold the valves open when the lifter pumps up with oil pressure. But the cure would be a solid roller, which if you ever run one you know what a PITA it is to constantly adjust the valves. And most cam grinders only give you a hot lash setting giving you more aggravation with hot parts.

 

Andy

[BuffaloBillPatri]

I loosened up my exhaust rockers by 1/6 turn. So now they are 1-1/3 turn C/W past where clatter goes away, adjusting them with motor idling hot.

 

Reason being: that the exhaust rockers all felt too tight by hand twisting on cold motor.

 

The exhaust valves are more susceptible to burning if they don't contact the seat, so I was a little nervous.

 

The intakes all felt as if they had a little looseness, so I left them at 1-1/2 turns C/W past where clatter goes away.

 

BBP