fleming442

This guy seems to know what's up. I guess I was wrong about the cores being soft (and Ding How). The video shows some Rockwell testing, and how wiped cams usually don't have the right angle on the lobe, which doesn't spin the lifter.

Olds64

Interesting video. I fixed the link.

Andy

Interesting..unfortunately it still doesn’t pinpoint the problem many are having..

CANADIANOLDS

whats there to pinpoint when the parts don’t show a problem?

I’ve posted many times on here I’ve never had a single issue with a flat tappet set up.

that leaves only one thing left..they install and break in procedure gone wrong which is all on the builder

I don’t use low rate break in springs either or specific break in oil unless it’s a max effort valve train

Andy

You’re one of the lucky ones then..many long time builders have had this happen. And all aren’t doing a wrong install and break in procedure. Even the guy in the video shows cams that went bad due to the lobes being ground with zero slope..But I am sure you would have caught that being the legend you think you are..lol

OLDSter Ralph

Interesting video.
1. I can see he used a fairly new model Wilson Rockwell hardness tester.
2. He used "magnetic V-blocks that are usually used on a surface grinder for round parts.
3. He checked the cam load hardness above an unsupported section of the cam.
All in all, the cams and lifters he checked were hard enough using sloppy procedures.

He claimed that the lobe "taper" (Andy calls it slope) should be .002". According to one of my sources, there should be up to .005" for a 3/4" wide lobe. He didn't check the lifters from the failed lobes. He didn't really point to a single cam lobe/lifter failure. There is a lot we still don't know. They have used flat tappets for a 100 years and they worked. In the old days, you poured a can of GM EOS on the cam lobes, installed the intake manifold and fired it up. You expected the engine to run 100,000 miles, and they did.

CANADIANOLDS

it’s not luck when there is no proof the parts are not up to snuff.

if you want to call me a legend for not whipping out every flat tappet I use, that’s fine. thats a really low bar though.

ill continue to use flat tappets successfully because there are benefits to using them over a roller…it’s not just the cost. I won’t get into it with you..that would be like talking to a wall

Andy

Oh no you’re definitely a legend, your post all prove that..none the less just from reading your post I have zero doubt you know what you’re doing when it comes to building engines..You’re a knowledgeable guy, to bad you have to be such a Richard head about it all the time..I love flat tappet cams, just had my w30 rebuilt after having bullet grind me a cam, no problem on start up or anything..Same guy who has built 100 engines helped me with it..He just put a flat tappet solid l78 cam in his 396 Nova, same procedure as he always uses..and it ate a lifter pretty bad immediately, didn’t grind down the lobe as we shut it down once we heard the ticking after 9 minutes of run time. Thats after verifying all lifters spinning, primed the pump, all the correct cam lube, using Brad pen break in oil, engine fired on second rotation.. this was using Howard’s solid lifters, with the weep hole in the lifter face..**** happens..

CANADIANOLDS

he isn’t a legend. I’ll bet he’ll blame the parts

Andy

Richard Head strikes again, just can’t help yourself..must be a Canadian thing..enjoy Thanksgiving..oh whoops, that’s an American thing..

CANADIANOLDS

so I was right…he blamed the parts for failing. That one lobe, that one lifter, jeeesh, what bad luck

we actually had our thanksgiving on the second Monday in October every year, so you’re a few weeks late to the party

Andy

Well Mr Legend..if you treated every lifter, lobe and assembly the same with one failing..please enlighten me with your supreme wisdom..parts fail, maybe in in the USA, not Canada..hmm. Interesting.. glad your early thanksgiving went well.
Its not who has the first Thanksgiving but the best celebration..enjoy yourself while we celebrate this great nation

CANADIANOLDS

here’s how it works skippy…if one single lobe on the cam goes bad..it’s not the cam.

if the lifter was not up to the task, the lifter would have got eaten up , not the lobe. when one lobe, and one lifter out of a set fail together, it’s the break in. Especially on a mechanical cam where the slightest increase in lash will kill it.

it’s always best to set lash tight on a flat mechanical cam break in…tighter than what the normal lash is.

Andy

As stated, the lifter failed, barely made a mark on cam lobe..lash was set at .021.. this is a silly debate..you never had a fail. Good for you

CANADIANOLDS

if we were having a private conversation, yes it would be silly because I would be wasting my time.

but it’s not private…others are probably getting something out of this.

it’s not always about you…no matter how much you wish it was.

66SportCoupe

Jesus why does everything here seem to go to ****?

CANADIANOLDS

relax…just read through the tech stuff. it’ll keep you from having a heart attack and a flat lobe

that “****” stuff is mostly your overactive imagination..it’s words on a screen.

CANADIANOLDS

never run .021” lash on a new mechanical flat tappet during break in ..ever. No matter what the hot or cold lash recommendations are..always tighten it way up during break in.

as long as you have clearance and the valve will close, run that lash as it will open up when hot. Run .008” or even less.

after break in and a total cool down, check each one for any increase from initial lash setting. If all are similar, open up lash to half way between your initial break in lash and recommended cold lash..run it again for 20min . Check again when cold..if they are all similar..set to final recommended min cold lash.

Fun71

Gonna say thank you for sharing your experience. What are your thoughts for a flat tappet hydraulic break-in since that is the most common application.

Bernhard

Thanks Dale for sharing.
You sad that you felt their are benefits to a fat tappet cam. Is it to do with the mass of the lifter and that you can run a lighter spring?

CANADIANOLDS

there are a few benefits. Mass of the lifter is one but not critical….you can’t run a bunch of rpm with a hydro roller in the first place.

the biggest benefit is getting the valve off the seat at an incredible rate with a flat. The only roller that can come close, which they can’t, are super aggressive solid low rpm solid rollers.

all that helps with idle vacuum, more low end TQ, a broader power band and more top end power.

there is no downside to a bigger diameter lifter and taking advantage of it by using a lobe designed to max it out. It doesn’t matter if it’s a super low rpm grocery getter or a max effort deal…it’s better

then there is the overall cost.

CANADIANOLDS

I’ll post how I go through a flat tappet break-in in a separate thread.