Roller or flat tappet cams? shop won't guarantee flat tappet...

Thanks. So I guess I wouldn't need to remove any inner springs for break in....

 

Yup.

If your springs were stiffer than ~300 pounds fully-open, you'd have some concern. Not with crappy stock springs.

 

I agree, that's a damper, like Schurkey says. Vet

 

I hear that all to often, and it happened to me, the company either wants cheaper labor and they let the experienced guys go, or they start treating the long timers like poop, hoping they quit.

 

Mark, that's a sign of a business man who doesn't have a clue what he's doing. Getting rid of your most experienced employees is like shooting yourself in the foot.
I guarantee you, he will eventually be out of business. Vet

 

You could ask him to find you a roller cam and lifters, then when he can't you can have a talk about he would do when your forced and have no option but to run tappet. He might not understand that getting a roller cam for a bbb was never easy and now impossible.

I dont know anyone who grinds lifters, there was a few places doing great work but they just totally stopped for some reason......
.

 

Thanks all. No one has commented on the Johnson 1405J lifters that TA sells. Has anyone used them recently or a TA 212 cam with success or any other lifters over the last few years with success?

 

Not a whole lot of experience here, but being a machinist like others here, I think about this stuff.
Is this something that should be considered a blueprint operation.
We all pretty much know you finish hone after you receive pistons.
We finish grind cranks after line hone and bearings are measured. Etc. Etc.
I would suspect if a cam grinder had a roller blank to grind and put a +/- .002 tolerance on straightness of lobe, as soon as they had anything outside of that they should correct it.
That said if they are doing a HFT/SFT blank, if they had a say .010 taper with a +/- .002 and they had anything outside of that, they should correct that as well.
Are we at a point where that info should be included on the order forms for cams and if that tolerance is not met it should be corrected.
As in a custom cam would include "How much taper on each lobe?"
"How much crown on lifters?"
Also in blueprinting you receive certain parts and you match dimensions to as measured said parts.
Would it be safe to say one should have cam in hand,
taper measured and then check/grind lifters to proper crown?
Another thought. Depending on breed of engine, there may be left and right taper on lobes.
Dressing a grinding wheel for opposite tapers is easy enough.
But has anyone ever found a cam with the wrong left or right taper on a specific lobe?
A lot of us have grown complacent on some parts and ASSUME the should be right when received.
In the end, they are made by humans and humans make mistakes. Just some more than others.
And it may be our place to catch that and get it corrected.
That would also help explain why some machinists are that good. And have the reputation they do.

 

I'm asking about the spin test... Can this be done dry with no load on the lifters, or should it be done with a fully assembled valvetrain? I'd guess it's not necessary to use full spring pressure.... maybe just old outers or even checking springs.

And can/should a contact pattern check be done using dykem or magic marker on lobe or lifter base? Or maybe even yellow gear marking compound.

My solid lifter cam/lifters from Comp came in last week. Rollers aren't yet an easy option for Nailheads.

 

Having a motor put together now with the TA lifters.

 

It’s sad really, all you hear anymore is MONEY MONEY MONEY, gotta make MONEY, while that’s true, what happened to pride in workmanship?
Right now I have a Mustang deck lid that’s giving me the red ass, little dingers, can’t feel ‘em, but I can see ‘em, prime block, prime block, repeat. My boss says it’s fine, me not so much.

I “think” there’s a standard degree of taper to promote spin.

I know on the Buick V6 one bank is ground with a reverse taper to keep the cam in the block, machine shops not knowing this destroyed a lot of V6 cams, hence the run to the roller cam years ago for the V6, they even produced a “budget roller” made from cast iron, THAT was a failure, now it’s just billet steel, as it should be.

Best you can do that I know of is make sure the lifters rotate FREELY in their bores, then HOPE the cam has proper taper, and the lifters have a crown.
Check for lifter crown with a straight edge, if the straight edge “rocks” your probably good.

 

If we ignore the rest of the makes out there, and focus on BBB engines, then I can assure you.. it's not soft cams/lifters. That's the go-to excuse for anyone that has ever failed a cam, and wants to point the finger at someone or something else.

Daniel Powell agrees with me on this, based on actual Rockwell testing.. and he even has a failed BBB cam in this video.

https://www.google.com/search?clien...ate=ive&vld=cid:f1493393,vid:DMFikj-TAqo,st:0

Here's some Buick specific advice base on my experience. I have broken in well over 200 flat tappet cams in the last 40ish years in BBB engines, and I have never lost a lobe. These cams have ranged from stock replacement ones with tiny lobes, to huge hairy race cams..

As a young guy building his own stuff, I was taught the correct way to prepare and install a camshaft, and as the years went on, we started to pay attention to the physical cam lobes for taper, and more recently checking the physical location of both the cam and lifters in the block. .

And then we focus on startup procedures. At what point do you have to use a light break in spring set... I was fortunate to have a dyno operator who had dynoed over 10,000 performance engines in his career, who was a very good teacher.

Incorrect preparation/installation/start up procedures are still the biggest reasons for new cam failures.

On the cam.

Taper is the first thing.. anyone with a mic can check cam taper.. lobes will be tapered so as to push the cam toward the rear of the block. Usual taper across the lobe is .001 to .002. Simple check that everyone doing a cam should be checking. While it is rare, I have rejected a few cams over the years, for not enough lobe taper. Surface finish issues are rare, and often hard to detect on a new parkerized camshaft. But that can be an issue. Again, both these are fairly rare.

Lifters

Check the crown on the lifters.. easiest way to do this is simply hold a straight edge on the bottom of the lifter, and then hold it up to a shop light.. the lifters are crowned in the middle, .0005 or so.. You can see this easily with a strong light behind it, can be tricky to measure.

Cam location in the block

Over the years, We would run into a block every now and then that had a groove worn into it by the back of the cam.. several theories were floated as to why this is, from too much lobe taper combined with high valve spring pressures, to issues related to the oil pump.. too tight, binding ect.. We came across one block a while back that had a severe groove behind the cam.. no signs of issues with the oil pump, a mild hyd cam with light valve spring pressure, so it was a bit of a mystery. During the machining phase on all our engines, one check is the camshaft tunnel, checking it's location in relation to the crank centerline.

Over the years we have checked dozens of BBB engine blocks for this, and the vast majority are between .000 and .0015 tilted down in the block, front to rear. It's a function of how the cam tunnel was bored on the production line. That amount of variation is no real problem, but every once in a while, we see one with .003 or more, and those engine blocks have to have the cam tunnel bored and corrected. That is done by using oversize cam bearings.

Lifter bore location and bank angle are also checked. We have a rare piece of equipment in the shop, that being the BHJ lifter tru tooling for a BBB. This tooling allows us to check and correct the lifter bore location in the block. Conventional wisdom is that that you can't oversize Buick lifter bores, but we have done several now to .875 with complete success.. couple of those engines are run hard on a regular basis.

The combination of cam tunnel issues, as well as lifter bore angle and location, is the culprit in those relatively few cases where the parts or the procedures are not the problem. The guy with the cam that Powell is holding in the above video... who failed 3 cams in his BBB engine, and no doubt blamed the cam hardness for it, actually more than likely has issues with his block. Unfortunately for him, his machinist didn't catch this, and prevent a lot of pain and expense.

If the interface of the lifter/cam lobe is such that it causes edge contact, you will put cams in that deal until your eyes bleed, and not get one to live. Assuming the failure is due to the cam, is just a waste of time and money, the actual problem has to be identified. This is not rocket science or some mystical voodoo.

This is the Brand specific, engine specific, knowledge I talked about before.. and I can tell you for sure, at least in the BBB world, cam/lifter failures are rarely the parts, they are more than likely the block or the installation/start up procedures.

And while I could sit here and recount half a dozen or more instances of seeing this and fixing it, the clock on the wall tells me I should be out in the shop building BBB engines..

Bottom line.. on our engines, physical cam failures are rarely due to the cam or lifters hardness. I certainly have never seen a documented case. While I am sure they are out there, the vast majority of cam failures blamed on cam hardness are simply not tested, and not true. Not in our little corner of the world..
----------------------
Now noisy lifters and cam grinds.. that's a completely different kettle of fish, and is, like I said before, in talking with shop owners, those problems are one of the main reasons that many shops simply don't want to deal with flat tappet hydraulic cams. Nothing worse than a beautiful brand new engine, with ticky lifters, or cam/lifter noise at a specific rpm. Very frustrating.

JW

 

P.S. The taper is also ground into the base circle of the lobe. Therefor lobe taper would be half of the difference between fore and aft diameters.

Powell says lifter taper should roughly match the lobe taper. Typically 0.001 to 0.0015" of taper. Over 0.002" is getting to be too much. Do you agree?

I watched this vid which used a dial indicator to measure taper, from a flat work surface.


Another vid from Powell Machine showing taper and lifter edge bevel:

 

Yup, Daniel is pretty sharp when it comes to cams..

JW

 

Hence the wondering if it should be considered a blueprint operation.
.001 to .0015 taper is obviously not much.
Would mean if the lifters were a little +/- of the tolerance of crown you run the risk of contact towards center of lifter(little to no rotation) to contact at the edge of lifter(more rotation),but at the extreme risk of running edge of lifter on lobe or running on edge of lobe.
Again as Jim said, would be breed specifc and based on actual relationship of lifter centerline and lobe location in block.

 

Jim, thank you very much. That is the best description of the internal combustion engine as related to its tolerances. Especially cam bores are NOT in alignment and out of tolerance right out of the factory. That it may be only a very few.

As a machinist, my entire professional life has been focused on maintaining tolerances as specified by engineering blueprints and the check for that is Quality Controle inspections. With out QC checks there is NO way to determine if any mechanical part is reliable or built to specifications.
I have no idea how GM conducts their QC inspections. I'm used to QC'ing 1 in every 10 parts. But that may not be the norm for GM.

Seeing that engines can depart the Buick factory, with OUT of tolerance specifications and camshafts that can be out of their intended location is something that we as Buick engine owners cannot control and I bet most of us don't even know this exists.

I have to agree, you make a sound argument that the most cam/Lifter failures are not due to either heat treatment failures or lack of
the correct materials being used to manufacture both the lifters and camshafts.

To me, what I don't understand is WHY NOW in the era of 2000 is all this happening now.
Again, thank you for taking time out of your busy day to help us all out, I know everybody on this forum appreciates your extra efforts to help us all. Vet

 

.
[/QUOTE]

What happened to our manufacturing expertise? China.

 

I don't blame the shop one bit for their stance. It's their sand box, their rules. Like all good shops, they are likely overloaded with low-hanging fruit. Why get involved with something that can come back to bite them hard, especially on customer-supplied parts that they probably aren't too familiar with. So offering "no warranty" may be a workable solution - it takes the parts quality (sorry, this isn't 40, 30 or even 20 years ago, so that's pretty much irrelevant) out of the warranty equation, and the potential break-in issues off the liability table for them.

In a perfect world, everyone has deep pockets, they drop off their vehicle at the shop, and that shop handles everything from the R&R, machine and assemble work, install, break-in and tuning. You get your vehicle back turn-key with a written, contingent warranty and hand over your 401k. For the real world, it's a real balance of budget, parts and shop(s).

A friend of mine from high school days here in town had a side-hustle in marine racing BBC engines, 6-figure builds, poker run boats. It was a formal job, LLC and all, but his main career was a machinist. He would sea-trial the boat prior with the owner if the crank wasn't in the bilge, formulate a game plan, pull the engine, commence with the plan - overhaul/upgrade or repower. He would take any necessary machine shop work to his day job to do or oversee (he was their crank grinder and did most of the other work too on his own engines), assemble the engine, bring it to his dyno shop, dyno test and tune, install, sea trial with the owner for the final tune, and exchange the keys for a check. An unfortunate and debilitating cruel disease put an end to all of that, and the guy is a shell of his formal self and is on permanent disability for the remaining time he has left. Very sad, but I liked the way he did business. He didn't cater to everyone and didn't worry about how many builds he had under his belt, just the quality of his work, and to do the best job humanly possible.

 

They crank out manuf. engineers like we crank out HS dropouts. IMHO we don't even properly train the engineers we do produce.

 

I put VERY little ATF on the lobes 'n' lifters, so not "dry". Using grease would likely screw-up the results. And, of course, no ATF on the top of the lifter and lifter bore, or you'll never get the Sharpie to make a mark.

But since I do this before ANYTHING ELSE is installed in the block aside from bearings, you won't need the valvetrain, or pushrods, valve springs, etc.

Some lifters spin faster than others, but they ALL have to spin.