checking solid lifter adjustment

[FredG]

The solid lifters on my old C1 vette 283 had to be adjusted with the car running using a feeler gauge. I had a set of valve covers with the top cut out to keep the oil under control. I loved the sound of those solids.

Fred

[Gaz64]

Originally Posted by FredG

The solid lifters on my old C1 vette 283 had to be adjusted with the car running using a feeler gauge. I had a set of valve covers with the top cut out to keep the oil under control. I loved the sound of those solids.

Fred

Now Fred, please explain how a feeler gauge can be used on a solid cam valve train while the engine is running. In my 40+ years, I have yet to hear of that. Hydraulic cams can certainly be adjusted with the engine running. I have used a feeler gauge many times on a running hydraulic engine to identify a faulty lifter.
Gary

[FredG]

Gary

We are talking almost 60 years ago. The engine in my vette was a 1961 283 with 270 HP that had 2- 4 barrels. It came with the famous Duntov cam. It wasn't difficult to do. We did a cold setting to get it close then slid the feeler gauge between the rocker/valve tip and socket to adjust with the engine warmed and running . Having the cut valve cover was the key to keep the oil under control. It was the way I was taught to do it by the old time mechanic I worked for and learned from back in the mid 60's. I learned so may things from that guy with regards to cars before computers took over. I loved the sound of that engine. It sounded like a tight sewing machine. By the way, I saw the commenting on changing the magnetic pickup on the Holley forum. Wish I knew that earlier or MSD provided that info with the new pickup. It would have saved a lot of time. Apparently, new ones are much more accessible.


Fred

Originally Posted by Gaz64

Now Fred, please explain how a feeler gauge can be used on a solid cam valve train while the engine is running. In my 40+ years, I have yet to hear of that. Hydraulic cams can certainly be adjusted with the engine running. I have used a feeler gauge many times on a running hydraulic engine to identify a faulty lifter.
Gary

[Gaz64]

I hope others will chime in here.

I still fail to understand how you set a mechanical camshaft valve lash with the engine RUNNING.

It is physically impossible.

The only way you could do this is by sound only, and certainly a feeler gauge could not be in the valvestem/rocker with the engine RUNNING.

https://www.crankshaftcoalition.com/...cam_adjust.pdf

[patrickt]

I have always loved solid lifter engines, and I've been setting valves for almost 50 years. I have never set them hot with the engine running. When I was working at service stations in high school and college, there was always some old flea bag mechanic, who was probably out on parole, who would say "in my day, we always set 'em hot with the engine runnin'." But I never saw anyone set them with the engine running, just say they used to do it that way.

Now, here is one lesson that I have learned with my FE engine regarding solid lifters. I have listened to and studied my iron block/aluminum headed mill for almost 15 years now and the fact that it has a solid, flat tappet cam and the clatter that it makes, or doesn't make, depending on the time and temperature after start up. I gap my valves at .018" COLD and I have aluminum roller rockers. The cam maker calls for a lash of .025" HOT. The classic answer to the difference between cold and hot lash on an iron block/aluminum headed engine is .007", give or take. When I first start my engine up COLD, there is virtually no valve clatter at all. When I then take her out and she begins to warm up, as measured by the coolant temperature, the valve clatter will be at its loudest and sharpest when the coolant becomes hot but the oil is not. That is when the aluminum heads and rockers have now had a chance to heat up, and expand, but the iron block has not. As the oil temperature reaches the same temperature as the coolant, the valve clatter reduces down to a "normal" level of clatter. This is because the temperature of the iron, and the expansion of the block, has now had a chance to catch up with the temperature, and the expansion, of the heads. A few years ago we had a thread over on the FE forum about the difference between cold and hot lash on iron block/aluminum headed FEs with SFT cams. A couple of guys took it on themselves to go out to the garage, check their lash while cold, then they drove the car until the coolant showed it had warmed up, pulled back in the garage, checked their lash again, and proclaimed the difference to be .011" to .013" difference! That was quite a change from the standard answer. Of course they did not run their engines until the block was at the same temperature as the heads, just until the coolant got hot. When I run my engine, the lash starts out as .018" and the valve train is quiet as a mouse, the lash then grows to .030" or more for a short while (when the heads have expanded but the block has not), and the valve train has a really nice, pronounced clatter to it. Then the lash shrinks down to .024" or so and has a "normal" clatter to it. It actually took me quite a while to figure this out.

[eschaider]

Originally Posted by FredG

The solid lifters on my old C1 vette 283 had to be adjusted with the car running using a feeler gauge. I had a set of valve covers with the top cut out to keep the oil under control. I loved the sound of those solids.

Fred

Fred is right about this technique. It was originally used on SBC's with the solid lifter Duntov cams. The technique was useful on ball stud engines like the SBC if the adjuster was either an OEM self locking adjuster or one of the early Polylock adjusters.

This is a pic of the Polylock style adjuster;


The Polylock came about because the OEM adjuster used a distorted thread style of locking mechanism that would loosen over time requiring regular maintenance. The set screw in the top of the Polylock acted as a jam nut to secure the adjuster and extend the time between lash adjustments.

The actual adjustment technique involved, starting the engine and ever so slightly loosening the lash to insert the target thickness feeler gauge for the lash you wanted to set and then progressively tightening the adjuster until the clatter from the lash disappeared and/or you could just barely move the feeler gauge around while the engine was running.

If you over tightened the adjuster, the feeler gauge would not be possible to move and certainly there would be no sound from the lifters as the clearance ramps on the cam gently brought the lifter up onto the opening ramp of the cam.

The technique, other than being messy because of how the SBC oiled the top end, was amazingly accurate. Some argued, credibly so, that it was the most accurate method of valve adjustment. With the arrival of the Polylock this type of adjustment was still possible as long as the body of the poly lock had a slight interference fit with the stud. After the lash was set for each valve the set screw (if you used a Polylock) in the top of the adjuster would be used to lock the adjuster in place.

Without ball stud rockers most other makes would not use this technique. The exception would be if your rockers had self locking adjusters. If they did then you could use the same adjustment style the SBC guys did — with the same oil control/management issues.

Engines with adjusters that used jam nuts required one more hand than available to do this style of valve lash adjustment. As such the EOIC or other approach was used to lash the valves in an engine while not running.

If you are less than 70 you likely never heard about this stuff and definitely never saw it happen — but it did and it was / is real.


Ed

[patrickt]

Originally Posted by eschaider

Fred is right about this technique. It was originally used on SBC's with the solid lifter Duntov cams.

See Fred? I told you I believed you, it was that Gary that needed convincing.