Hi all,

I'm at the point in my engine rebuild where I need to select pushrods and possibly new rockers. I had the heads done at a local shop and one valve looks like it sticks out .020-.030 farther than the rest. Pictured below. What would be the best and cheapest way to account for this? Could I shim the rocker stud to fix the geometry or am I going to have to switch to an adjustable set up?

Thanks,

-Mike

 

they look fine can u adjust lifters?

 

Here is a picture of the lifters. I'm not sure how to adjust them. Most of the parts came in a kit with my camera, a Complete Cams 42-221-4 kit. Side question, do I take the clips out of the top of the lifters?

 

Please forgive the autocorrect. Cam not camera.

 

Do not take the retainer clips out of the lifters. I see pushrod guide plates installed, which is not a stock set up, what type of rocker arms do you currently have? Stock rocker arms do not need the guide plates.

 

The rockers have a roller tip on them. They came with the car and didn't seem too badly worn. I can take a close up picture if this one isn't clear enough.

 

Mike, your rocker arm kit will probably account for the that stem being a little tall. The weak link is the poly lock nuts. Some people like to replace those, sooner or later you might need too.

Do not take your lifters apart.

Ideally you want those valve heights consistant, for now I'll think you'll be fine.

Its not necessary to soak your lifters. It might cause a false reading leading when setting them .

You really need to measure for proper push rod length, using a checking push rod. The ones supplied in the kit might be ok, or they might a little long.

 

I may have taken one lifter apart to check it out, but put it back the same way. Hopefully that won't be an issue. I bought a checking pushrod from Comp Cams, the kit didn't come with pushrods. I figured I would measure first then buy them since I had the heads cut down a bit and didn't know own what the previous owner did if anything.

 

You're on the right track Mike.

 

Can you put a straight edge across the top of all the valves and actually see how far off, if any, it is?
My other thought is since you are using an adjustable set up there probably won't be any problem.

 

It seems like the third from the front on the driver side is the only one that is off. It is taller than the rest so it's tougher to measure than a short one.

 

So should I order some poly lock nuts? The ones I have are just regular nuts. If I get those will I have to replace my valve covers? Thanks for all the info!

 

I used Mr Gasket poly locks due to all the stories of the stamped nuts coming loose. I used the thicker Fel Pro rubber gaskets and they fit under the factory valve covers with no issues.

 

Look for 1" poly locks. There are a bunch of companies that make them.

 

So I put the length checking pushrod and one that came with the car in. A picture of the valve stems with marker on them is below. Are these slightly too short? The measurements were taken after zero lash plus a half turn with no oil pressure. The adjustable push rod was set to 8.40".

 

Too long.

 

Toward the valley side or intake side means too short. Toward exhaust side is too long.

 

So those are slightly too short. How much will the line move once the lifters are pressurized?

 

Not at all or your valves will be stuck open.

As the valve seats are ground, the valve sits higher in the head, more protruding stem. Thus you need more pushrod protruding as well. You're not that far off, just losing a little bit of cam lift which may already be more than the head can utilize anyway, unless the head is ported and flowbench tested to determine which cam you should use.

 

Since you used the stock springs while testing for push rod length you probably compressed the lifter to it's seat in which case your push rods are most likely not too short.

 

You have an adjustable pushrod, so why don't you use it and figure all this out???
You can see if your lifter compressed or not by watching the plunger. New lifters don't want to compress easily. The last set I installed needed the engine to fire up before they would compress. I'm not sure what they were filled with but it was significantly stiffer than oil (Comp).

 

I did use it... it was the left cylinder in the picture above. I was asking if the wear mark was in the right place for lifters that weren't pressurized with oil. The springs and cam are not stock, they are from kit 42-221-4 from Comp Cams. Should the wear marks be anywhere inside or outside of the center of the valve for this set up? Its zero lash plus a half turn too tight for checking pushrod length?

 

The head was not ported or flowbench tested, i just went with a driveable cam profile from Comp Cams that operates in the 1000-5600 rpm range. Would you say to stick with the 8.400" pushrods then or bump up to an 8.450" or 8.500"? The machinist did a 3 angle valve job and decked the heads about .020"

 

You're fine. Typically you want to check pushrod length at zero clearance, skip the 1/2 turn extra. You're still approximately in the middle of the valve tip. Getting that geometry corrected may be worth 10hp, but you're splitting hairs if the rest of the build isn't done to that same meticulous level.

 

Thats good to know. I was worried that not getting the pushrods exactly right would result in cam damage, valves hitting pistons or some other catastrophic damage. I didn't refresh the bottom end and I'm not putting on headers so I'd say I'm not being too meticulous. Also, this is my first attempt at restoration of any kind so I may be over thinking it.

 

Yes you are overthinking it. The rockers are adjustable. Once lash is properly set, nothing much else can go wrong, unless you're off to the edge of the valve, which you're not even close.

 

Nice, thanks! I will still check the other head and the one valve that is sitting proud to make sure everything is good. I'm not trying to build a race engine or anything, just want a little more hp than stock since i have it open anyway.