2112

Are you running the bearing less version?

I too am chasing bizarre valve train issues and it has come done to harmonics as the only plausible explanation. I run Milodon timing gears and that may be the ultimate culprit. I may have to switch to belts.

Several have suggested going the the new tool steel, thick walled pushrods. I have 7/16ths tapered now and although they are not bent or damaged, the push rod holes show signs of contact. They be flexing in there somehow.

My valves are so stinking heavy (stainless intake, Inconel exhaust), I have been running 280# seat pressure to keep them on the seat, so far that seems to be working up top but tappets are getting beat up. I run an old Ultradyne cam which makes buttloads of power but may also be a contributing factor. It never shows signs of damage though.

mrhorsepower1

I am a WD for everyone and can sell you cheaper than anyone .

2112

So what is your opinion of the issues mentioned above?

nocigarette

I know ya run ford power but, i have the milidon gear drive on my 540 and have no harmonic problems at all........I am not totally sure the harmonics of a well set up gear drive cause any damage at all....It beats the rubber band timing way.....imho...........

2112

I don't think this is a Ford/Chevy issue. My tappets and pushrods don't know which brand engine they run in.

Those who have suggested the timing gears may be the culprit in communicating the harmonics were the Manley and Manton pushrod Reps who had no idea we were talking Ford power. I believe BTW that belts are now considered the best possible method of driving the cam. Most if not all NASCAR (endurance motors) run belts, not gears.

2112

Also, The more blueprinting I did with my heads (shaft rockers, perfect valve train geometry, valve guides etc) the more the mystery stuff started happening. When I had the less accurate set up (Guide plates and stud mounted rockers), it was masked over IMO.

BenPerfected

Mr. G,
I just when thru a process where the valve train failed. It may look like the lifters but may because of other problems. Because someone gave me a lead, I had my cam Rockwell tested. The industry standard spec's for a solid roller cam are are for a Rockwell between 58-62....don't know about a hydraulic roller cam. This is an inexpensive test that can be done at numerous local businesses.
My input is to eliminate the cam as a potential issue before you chase ghost. When two parts fail, you don't know unless you test.

nocigarette

I am not saying that the belt drive isnt good i just get a little nervous with a rubber band controlling my timing......I know a ton of people use them with no issues, it just scares me....I just cant believe how much ya can micromanage a valve train and still have some faliures...

Mr Gadgets

Some very interesting points! Good food for thought. Keep them coming.
I was running a solid roller.
Had 68hrs with Schubeck lifters (roller X type) on this cam. At 57 of those hours I broke a cylinder head and added T&D rocker system. I also added the 7/16" .165" wall push rods at that time.
Then an oil PSI issue, bad gauge, torn down the motor and found a crack in two Schubeck lifters. Total time on cam with Schubeck lifters was 68hrs.

Switched to Isky Red Zone with EZ wheels no needles. 20hrs later I hear some ticking and find damage to 5 lobes. Now one thing, the Schubeck lifters weigh about 1/3 the Isky's.

Now during the life of the cam, I usually turned 5700-5800 rpm. After sorting out EFI issues, I started to turn the motor at 6k and above. It was the result of adding a crank trigger to stablize my tach signal to the EFI computer.

My valve springs are Isky Tool Room springs. 280# seat and 675# over the nose.
The damage that was done to the cam was mostly on the back side of the lobe. Like I was launching the lifter over the nose. Out of five lobes, two were just starting to self destruct. I made my last pass with light gas and very little in the nose of the boat. Removed cushions, porta potty, etc. I dont know how hard the motor was turning, but it had to be over 6k. I went 4mph faster than I ever had before and wasnt fully trimmed out.

I have always run a timing chain, so the idea of the problem being there is a possiblity.
My buddy runs the same springs I have, same push rods, but shorter for the shorter, tall deck block, but he is running a jessel belt drive.
With an erratic tach signal, it may be indicating a cam harmonic problem. I will have the cam Rockwell tested and see what happens.. That would at least take one more thing out of the equation, or put it in..

So my thought is that with the new push rods (read that heavy) and new Isky lifters (heavy) and higher rpm's, that something isnt working. It seems to me that I should have stiffer springs to keep things together. But I have been told that lighter springs are the answer.. sort of.
I know some people have found more spring is better. Others say that isnt good.
Well my next move was to go to a wimpy cam and keep the big springs, add a Procharger to make power on the top. During the process of finding out what my problem is.. The new cam showed up on my door step. It has less duration, but more lift on the intake. So I am not sure if I will be fixing the problem or not??

The Isky lifters have had new wheels installed and rebuilt using a different bearing, that has seen 1000# spring pressures.

Any ideas will be taken with appreciation..

Thanks
Dick

2112

Tons of similarities;

Same RPM range, T&D rockers, and I went up in spring pressure (same) because I thought the lifters were launching too. I have 10.300 deck height BTW. Heavy valve train here too.

So are you getting a new and improved Red Zone wheel? Does it have a name?