Messages

Many moons ago I worked for a company that built some of the first space junk (communication satelites).
After many failures in testing wiring for everything we could think of to test for like G force of take off, G force of impact from natural space particles, radiation, heat, cold, we found that vibration was the worst enemy. The vibrational G forces encountered on take off in early day space flight vehicles was very high. It could be multiplied many times if the part in question was mounted in such a way as to be suspended between two points and was resonant at the vibration frequency.
Many of the early developments of space junk wiring are still used  today in commercial and industrial applications. One of the most notable being the use of wire with PTFE (Teflon) insulation. With this type of wire in a bundle, if one wire overheats, it won't take out adjacent wires as with commonly used  plastic insulated wire. PTFE insulation is good to 500F degrees. It is highly resistant to the various chemicals in automotive use and highly resistant to abrasion.

As usual in tech articles. Some good info, some bad info, some left out.

They barely touched on the MAIN reason lifters rotate, lobe offset to centerline of lifter.
They mentioned shimming the cam fore and aft..That can get 1 or 2 rotating but screw up others in the process. Sometimes a new block is called for.

A LARGE percentage of cam lobe failures are due to poor production process. Most production cores are induction hardened. If the process is not done absolutely perfect the hardness will NOT be consistent throughout the length of the core. Some areas will be as they should be, some will be rock hard and others will be dead soft. A good example of this is the flathead Ford cams up to 1948. They were excellent. 1949 to 1953, not so much.

They talk like chilled iron lifters are a recent breakthrough.. Isky had them in the 50's.

Pressure oiling the lifter face is nothing new either.

Think about the millions of engines over the years that ran their total expected life with no problems. The small percentage of early failures due to cam and lifter problems are the ones you hear about though. Makes ya wonder if they were end of shift type or maybe cutting corners type or just done at home with used parts type.

In any event it is good tech articles like this that keep up my interest in gardening.

Someone commented that lifter/camshaft dimension, clearance and compatibility is a lost black art.
Not so yet. There are many shops across the country that still know how to do it right with the right parts.
You just have to seek them out. You also have to educate your self on what works for the application you seek.
Pick people that have ACTUALLY DONE THE WORK and have raced and won, to research. If they have an engineering background, that helps.

I didn't look at the video because I have seen it all over the 71 years I have been in the cam business.

When collecting parts for a build, stay with USA made parts that have a known reputation of success.
If nothing is available, find out what others are using and if it is working 100%. Sometimes you have to do it yourself.

When it comes to hydraulic lifters I can say I have never had  one fail. That is because I have never built an engine with them in it.
Hydraulic lifters CAN be reconditioned. Candidates for reconditioning should be selected carefully. The face should be smooth, shiny and with no lines, marks or noticeable wear pattern. The body should be checked for diameter within spec. When assembling the engine, the lifter to bore clearance should be checked carefully.
The internals should be CAREFULLY checked for wear.
The face should be checked for hardness and should be at least 55 Rockwell C.
The face should be reground with .0002 taper. This is a TAPER, NOT A RADIUS as some people think. If you think about this, if it was a radius you would have a pinpoint contact area and the unit pressure would be extremely high resulting in almost immediate failure.
The taper on lifters and cams will vary slightly between OEM manufacturer's but .0002 will work ok.
An easy way to check this is put 2 lifters together face to face and rock them. If you can see light at the edge it will be ok.

After market offshore cast iron cam cores are noted for very poor heat treat. Hard spots and some spots dead soft.
If a soft spot is on a lobe nose, failure will be soon. Likewise for the gear area.
Some 49 to 53 flathead Ford cam cores had this problem.
Very few cam grinders ever checked this.

USA manufacturer's haven't all been lily white over the years
but for the most part when they had a problem it was fixed quickly.
In late 1956 Ford put out a factory bulletin to all dealers that they expected in excess of 3% of all cams in 1957 312 engines to fail within 500 miles due to lobe wear. (bad heat treat)
Their estimate was pretty close. There was never any info release on why this happened.

To the person that suggested a hard face material on lifters, it has already been tried but found not necessary and WAY too expensive for production use. John Deere tried facing lifters with carbide for awhile. While they would last forever, it was just too expensive to do.

Tig with no preheat and only a half inch at a time with long wait between welds.

It WILL warp but in a non race thing, you can probably get away with no straightening.

We had cart with a 250 Yamaha twin on it in 1958. Won the local championship easily even in one gear. It could light the tires in any gear. It had front suspension like an early Ford with cross spring and wishbone..All scaled down to fit a legal size cart...Big Phun!!

The taper on the lifter is .0002 to .0003.
It is a TAPER, NOT a radius. If it was a radius, you would have POINT contact and the cam and lifter would decease in very short time.
The lobe taper can vary from zero to .002
The main thing that helps the lifter turn is the lifter bore offset.

What you want to do can be answered by saying, sometimes it works and sometimes it does not.
All blocks are not the same even if same model and machined on the same machinery.
The best situation would be have the cam reground and lifters refaced.
There is no quick cheap solution.
Pete

"Been in the cam business 70 years"

Got these in a box of items. Any guess what they are?

Chisels for an air tool. I gave a bunch of them away awhile back.

There was a show on Engine Masters awhile back about all of that and what they played with definitely helped.

I have only ever done flathead Fords for vintage circle track racing and over the years found a combination by trial that works very well.

I have ground cams for that size engine. Good thing we had a bridge crane over the  grinder....lol

A friend bought a blast cabinet and put it out in his barn because of lack of space in his shop. The barn only had 2 wire electricity from the old days. He had big time static build up till he reversed the plug in the socket.
It worked but is not a very safe way to operate. Not really legal any more either.

C'mon Frank you know how it has to be done. You are just trying to wheedle out of it.
Mill off the present surface with a carbide cutter. Weld with Airmang rod, mill flat, then cross mill with carbide "V" cutter so you end up with a diamond pattern like original.

Speed secret stuff.

I bet no one remembers Jack Armstrong.

I wonder if that secret radio will get on the Jack Armstrong secret wavelength.