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I know it’s a cost vs convince thing, but how many have wiped out a cam. This is assuming proper break in oil, assembly lube,and start up procedures .

Don H
 

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1967 Ford Mustang fastback
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I've done it twice. Both times on a comp cams xe274. After the second time I got the motor freshened up (351w) with new bearings and went with a howards cam roller conversion with the link bar lifters. The added expense of the kit I think is worth the piece of mind.
 

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67 Fastback T5 331 TCI Frt End, Canted 4 link rear susp
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Plus, any time you can reduce internal friction would seem to be desirable.
 

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Spammer Hammer
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I can say many vintage racing rule books are being rewritten to include the use of roller cams specifically for reliability. So there must be something to it.
 

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I know it’s a cost vs convince thing, but how many have wiped out a cam. This is assuming proper break in oil, assembly lube,and start up procedures .

Don H
Me...I'm a convert too.
 

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I have always had flat tappet and have never wiped a cam. Is oil better today than it was when they started reducing zinc and going to rollers in the mid '80s? Yes. With modern oils is zinc "the" factor for determining a good oil for flat tappets? NO! For stock to mild builds is a roller "necessary"? No. Will a roller of the same grind make significantly more power? No.

Is a roller less likely to wipe a cam? Yes. Can rollers accommodate a wider range of cam profiles? Yes

Given my engine is not stock, my next cam would be a roller. I think I could get a custom grind that would better take advantage of my engine components and the extra $650 or so would not be the end of the world. Am I rushing out to replace my flat tappet for the sake of having a roller. Hell no.
 

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I've installed multiple flat tappet cams. I've wiped one. It was a very good quality, solid lifter cam from Bullet Racing Cams. Why it happened is still a mystery, but I suspect there was an issue with the valve train. I used break-in oil and I followed the manufacturer's procedures for break-in. Standing by to be flamed, but here is my take:

- There is really no "reduced friction" with a roller cam compared to a flat tappet cam. I know that sounds counterintuitive, the but the reality is flat tappets ride on a layer of oil which has almost no friction.

- Roller cams can allow for different lobe patterns. This is more a factor of geometry than friction.

- Roller cams have the advantage of no break-in, no need for oil with adequate zinc and you can easily swap them in and out without worrying about matching the lifters and such.

- As for performance advantages, here's where the keyboard warriors start fighting. I have never seen or experienced anything which demonstrated any performance advantage with a roller cam for a street car. There's all kinds of talk about "under the curve". Sorry. Not convinced. For actual performance, I still think a flat tappet cam can do anything a roller cam can do below 7,000 RPM. I admit I'm not a cam expert. But there are cam experts out there who do agree with me.

Ultimately, it's a matter of personal preference. If you don't want to bother with cam break-in, with finding oil that contains adequate zinc or risking a wiped lope, by all means go roller. But if you're expecting a performance advantage from a roller cam in your street car, you're setting yourself up for disappointment. And roller tappets are not indestructible. Many a hot rodder has suffered catastrophe due to a failing roller lifter.
 

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I've only installed a hand full of cams, maybe half a dozen and back when I worked all the time I had around the same number of kits installed in engines for me by shops or builders. They have all been flat tappet hydraulic and solid cams so far. Have not wiped a lobe or dropped a lifter but I did break an old antique stock rocker arm. I probably should have upgraded the rockers from the get go on that build up because I went quite a bit up on the valve spring rate.
 

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I have always had flat tappet and have never wiped a cam. Is oil better today than it was when they started reducing zinc and going to rollers in the mid '80s? Yes. With modern oils is zinc "the" factor for determining a good oil for flat tappets? NO! For stock to mild builds is a roller "necessary"? No. Will a roller of the same grind make significantly more power? No.

Is a roller less likely to wipe a cam? Yes. Can rollers accommodate a wider range of cam profiles? Yes

Given my engine is not stock, my next cam would be a roller. I think I could get a custom grind that would better take advantage of my engine components and the extra $650 or so would not be the end of the world. Am I rushing out to replace my flat tappet for the sake of having a roller. Hell no.
Like you, 35+ years and have never wiped a cam, always used plain STP for breakin. I've often wondered if this problem of wiping out flat tappet cams is partly because of lower quality metals being used in manufacturing the camshafts themselves.
 

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In my current trek for the 408 stroker this thread interests me and has been on my mind all this week actually.

In preparation of sending my engine off I binged on Engine Masters the past couple months. From what I remember the roller only made more than a couple hp difference at very high rpms. I'd have to refer back to my notes to be certain on that.
 
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I've installed multiple flat tappet cams. I've wiped one. It was a very good quality, solid lifter cam from Bullet Racing Cams. Why it happened is still a mystery, but I suspect there was an issue with the valve train. I used break-in oil and I followed the manufacturer's procedures for break-in. Standing by to be flamed, but here is my take:

- There is really no "reduced friction" with a roller cam compared to a flat tappet cam. I know that sounds counterintuitive, the but the reality is flat tappets ride on a layer of oil which has almost no friction.

- Roller cams can allow for different lobe patterns. This is more a factor of geometry than friction.

- Roller cams have the advantage of no break-in, no need for oil with adequate zinc and you can easily swap them in and out without worrying about matching the lifters and such.

- As for performance advantages, here's where the keyboard warriors start fighting. I have never seen or experienced anything which demonstrated any performance advantage with a roller cam for a street car. There's all kinds of talk about "under the curve". Sorry. Not convinced. For actual performance, I still think a flat tappet cam can do anything a roller cam can do below 7,000 RPM. I admit I'm not a cam expert. But people who are cam experts agree with me.

Ultimately, it's a matter of personal preference. If you don't want to bother with cam break-in, with finding oil that contains adequate zinc or risking a wiped lope, by all means go roller. But if you're expecting a performance advantage from a roller cam in your street car, you're setting yourself up for disappointment.
According to Lunati Cams, "Sliding frictional forces are higher than rolling frictional forces. Therefore, a roller cam takes less horsepower to turn and generally does not wear out as quickly."
 

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According to Lunati Cams, "Sliding frictional forces are higher than rolling frictional forces. Therefore, a roller cam takes less horsepower to turn and generally does not wear out as quickly."
While I respect Lunati cams, they are trying to sell us the more expensive roller cam. And, while it might be technically true, I think the difference is so slight so as not to really matter. Wondering how many of us has actually worn out a flat tappet cam.

Another anecdote; when I ordered my cam for Bullet Racing Cams, I asked them about running a roller cam. The on the phone was the guy who machined my cam and he said, "A roller cam won't do anything for you. It will just cost more."
 

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While I respect Lunati cams, they are trying to sell us the more expensive roller cam. And, while might be technically true. I think the difference is so slight so as not to really matter. Wondering how many of us has actually worn out a flat tappet cam.
Well, there had to be some reason the OEM's went with roller cams over flat tappet. They are not going to spend one penny more than they have to, and using a roller cam vs a flat tappet will definitely eat into their profit margin.

Usually on a flat tappet engine, it's the lifters that wear, not the cam.

I actually did wipe a cam in a BB Chevy. Did all the proper break in procedures and it still wiped.
 

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Well, there had to be some reason the OEM's went with roller cams over flat tappet. They are not going to spend one penny more than they have to, and using a roller cam vs a flat tappet will definitely eat into their profit margin.

I actually did wipe a cam in a BB Chevy. Did all the proper break in procedures and it still wiped.
Manufacturers went with roller cams primarily to extend the life of catalytic converters. Zinc/ZDDP can poison cats and replacing cats for warranty is expensive. I've read Ford was hoping for improved MPGs by using a roller cam in their "5.0" engines, but that didn't work out. Here again, one would think the lower friction from roller tappets would result in better fuel economy, but in the real world, it's not the case.

I wish I could find it again, but I read an article years ago about Smokey Yunik doing dyno testing. He tested a typical racing engine with flat tappets and non roller rockers. He then installed a roller cam and roller rockers. The power output gain was zero.
 

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Manufacturers went with roller cams primarily to extend the life of catalytic converters. Zinc/ZDDP can poison cats and replacing cats for warranty is expensive. I've read Ford was hoping for improved MPGs by using a roller cam in their "5.0" engines, but that didn't work out. Here again, one would think the lower friction from roller tappets would result in better fuel economy, but in the real world, it's not the case.

I wish I could find it again, but I read an article years ago about Smokey Yunik doing dyno testing. He tested a typical racing engine with flat tappets and non roller rockers. He then installed a roller cam and roller rockers. The power output gain was zero.
Klutch, you clearly know more about this than i do, but I would suggest that the film of oil is just a coating, and not the same as pressurized oil, such as a rod or main bearing. In fact, it is the friction that causes the surface hardening of the lobe during break-in. I enjoy this discussion, which I would enjoy more over a beer!
 

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Roller cam convert here for a variety of reasons. Yes, technology cost more.
 

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Guys, Klutch is explaining this to you correctly. For the vast majority of us, the roller cams are not going to show a big power gain. A roller COULD, in a street car, show significantly higher power if the a custom profile were ordered to take advantage of the ability of the roller to follow more agressive profiles. BUT, 99 % of the folks who choose a roller cam get an off the shelf grind without agressive lobes. Its available, but it is even MORE money over the roller upgrade. You have to choose where you want to spend your engine dollar. LSG

PS- no wiped cams, personally. Saw just a few at the shop. Usually happened with offshore lifters and crappy oil with it. DID see one customer with a BBC wipe THREE cams in the same block. We wanted to check the angles between the cam & lifter banks, customer said no. BBC is frequently a tough break-in, and we recommend single springs during break-in. Some listen and are fine. Some DON'T listen and are still fine sometimes, but sometimes not.
 

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To be clear, I'm not at all an "angry warrior" about the flat tappet vs. roller tappet issue. I tend to be skeptical about most things. LSG explained my position pretty well above. Basically, although roller cams do offer advantages, I'm simply skeptical that the typical street rodder is going to benefit from those advantages. High RPM racing? Sure, a roller cam can help. Otherwise, not so much.

When we break out of "Pandemicland", I would like to discuss it over beers with anyone willing and available. Even if we disagree, that's cool with me. Talking smack over beers is a big part of American Hot Rodding!
 
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