Chevy style lifters?

[BADASYJ]

Just wondering if anyone has played with bushing the lifter bores in the 4.0 to fit chevy lifters to run on the narrow chevy style cam lobes that every cam now has?
Yo Russ, what do you think?

[jsawduste]

Russ already answered that question, recently.

Lobe width don't mean squat.

[Cheromaniac]

Just wondering if anyone has played with bushing the lifter bores in the 4.0 to fit chevy lifters to run on the narrow chevy style cam lobes that every cam now has?

Same answer as the one I gave about knife-edging the crank; Why bother?
There are better things you can do to make the engine more reliable.

[Russ Pottenger]

Just wondering if anyone has played with bushing the lifter bores in the 4.0 to fit chevy lifters to run on the narrow chevy style cam lobes that every cam now has?
Yo Russ, what do you think?

I'm in agreement with John and Dino's statements but will add with proper can break-in procedure with the proper oils or additives and proper valve spring pressures I haven't seen or experienced any problems.

That said, nitriding the camshaft is certainly a good idea, and if your using a stock connecting rod notching the rod bearing will uncover the oil squirter notch.

[BADASYJ]

Russ already answered that question, recently.

Lobe width don't mean squat.

In a way he is kinda right being a wide lobe performance cam is no longer available. But I just can't refuse to teach you something and expand your knowledge there Dustyfart. So here it goes.

1) The greater surface area when combined with our large lifters increases the elastohydrodynamic film thickness (Lube)

2) The greater surface area provides more load carrying ability.

3) The greater surface area provides for an easier spin of our larger diameter/ heavier lifters.

4) The greater surface area increases the stiffness of the cam helping to cut down on cam harmonics.

It is simple physics my friend.

[jsawduste]

Here we go again. Give you credit for trying at least.

The lifter base is convex. It's contact point to the lobe can be compared to a ball on a surface. The lobe is tapered. The interaction between these two planes causes the lifter to rotate.

Like, Dino, Russ and myself have said. The narrow lobe means nothing when in fact the lifter is only touching the lobe at the tip of the lifter bottoms radius. Which can be measured as .xxx

Sorry buddy, no tacos for you.

BTW how long did your search take to figure out EHL ?
I know you didn't just write that down from experience and knowledge.

[BADASYJ]

Nice try, but i aint budging.Your right about the tapered lobe and convex tappet but it dosent really make contact like a ball, it's more like a roller surface. The lobe would have to be perfectly flat with a convex tappet for it to be like a ball. Very easy to google pictures and see that.
You mention nothing about the increase in elastohydrodynamic film thickness the larger surface area provides which is crucial to providing cushion and lubricity to the LARGER diameter mopar lifter. Plus the overall strength advantage it has. It is simple physics man.
The skinny lobe was designed for the small chevy lifters that are .820 diameter. The large lobes were designed for big .904 diameter mopar lifters. Please do the math Dustyfart, compare tappet Dia to lobe width on both chevy style n mopar style n tell me what % of tappet is covered by the cam lobe on both. I'm not good at math.

I'm assuming not long cause I have no idea what EHL is. Sister company to DHL?

[Cheromaniac]

The skinny lobe was designed for the small chevy lifters that are .820 diameter. The large lobes were designed for big .904 diameter mopar lifters.

The narrower cam lobes of most aftermarket cams were 1/2" wide whereas the wider cam lobes of the OEM & Mopar cams were 2/3" wide.
Though some of us (including myself admittedly) used to believe that wider cam lobes improved reliability, that's subsequently been proven not to be the case. As jsawduste correctly mentioned, the base of the lifters is slightly convex and the cam lobes have a taper to enable the lifters to rotate in their bores. Losing that lifter rotation results in a flattened cam lobe and a cupped lifter base.

[jsawduste]

Never mind BA. Your not going to learn anything because you know it all.

elastohydrodynamic The fancy word you found while trying to defuste my comment. It's common industry shortcut lingo is EHL.
If you knew what elastohydrodynamic was to begin with you would know what EHL was.

Also you have misunderstood what the elastohydrodynamic film is and how it works.

Delivery company, LOL.

[BADASYJ]

Oh no, I don't know it all its just that you haven't put anything forward to support your claim that wide lobes don't matter. All you've done is try to shoot me down. I have put forth my theory. Now how about trying to come up with something other then " because Russ said so" Prove me wrong. Did you do the math and compare surface coverage between the Chevy n Mopar?
Dont worry man I know how it is when someone outside of your trade has a differing opinin. Plus I'm younger then you so that's a double whammy for me. Lol

By the way I knew what EHL was, lmao I was just being a smart ass cause I knew you'd get a kick out of it. Lol

[jsawduste]

BA, your not worth my time arguing with.

Here again in this topic. All the information needed to understand the science behind the issue has been given. You however, refuse to look into it any deeper.

Let me make one more comment. Perhaps if I keep it simple you will grasp the concept.

If the narrow lobe cams were such an issue why do they still exist ? Cam companies would be having failure after failure. Yet the narrow lobe has taken over the market and has done so for a number of years. Sure, there are a couple of companies you can buy a wide lobe from but I`d wager the narrows outsell the wides 100 to 1 as a conservative guess.

So let me understand this, in no particular order, Comp, Crane, Lunati, Clay Smith, Crower, Sealed Power, Melling are wrong and your wide lobe logic is spot on ? If so, why the hell are you wasting your time on JeepStrokers ?



Nice try on the sarcasm of EHL/DHL. You don't have a clue.

[BADASYJ]

Here you go again. You have put up nothing to counter my take on it. Come on , I'm starting to think you have nothing other then insults and condensending remarks. Still haven't done your math, have you?

I'll answer your question Dustyfart. Up until recently it's been fine for the most part. The lower zinc was the breaking point and exasperated the downside to running a smaller lobe on a bigger tappet. Your right the skinny lobe cams did outsell the wide lobe cams because both ford and chevy had small diameter tappets. Only Chrysler had the large tappets at .904 and since they've always been treated like the redheaded stepchild of the bunch theier design was not chosen. Not to mention the extra material that was needed.That is why the standardization of the skinny lobe took place.
I haven't heard nor read of any dd chevy or ford flat tappet motors mysteriously wiping cams like we do. I'm sure it has happened but nowhere near on the scale like it has done us.
I think I've done a very good job at explaining my point. You have yet to even try other then a weak comparison about a ball contact surface or something of the sort.

[jsawduste]

[Cheromaniac]

Your right the skinny lobe cams did outsell the wide lobe cams because both ford and chevy had small diameter tappets. Only Chrysler had the large tappets at .904

John was referring to aftermarket performance cams with 1/2" wide lobes for a Jeep I6 engine that has 0.904" tappets. It's not the width of the cam lobes that leads to cam failures but other factors such as improper break-in, low ZDDP oils, incorrect valvetrain geometry, excessive lifter preload, and excessive valve spring pressure.
Scroll halfway down this article and you'll understand what I'm talking about.

http://www.aa1car.com/library/api_motor ... ations.htm

[jsawduste]

Up until recently it's been fine for the most part. The lower zinc was the breaking point and exasperated the downside to running a smaller lobe on a bigger tappet. Your right the skinny lobe cams did outsell the wide lobe cams because both ford and chevy had small diameter tappets. Only Chrysler had the large tappets at .904 and since they've always been treated like the redheaded stepchild of the bunch theier design was not chosen. Not to mention the extra material that was needed.That is why the standardization of the skinny lobe took place.
I haven't heard nor read of any dd chevy or ford flat tappet motors mysteriously wiping cams like we do. I'm sure it has happened but nowhere near on the scale like it has done us.
I think I've done a very good job at explaining my point. You have yet to even try other then a weak comparison about a ball contact surface or something of the sort.

Son, you better read, research and understand what your writing. Dino is on track and so is Russ. They understand the situation. Unfortunately your missing the boat again.

Chevy and Ford not losing lobes left and right ? You haven't gotten out much.

Your logic on the standardization of lobe width is flawed also. There is a lot more to it then you are understanding.

Since you need to be spoon fed.
Try searching on the failure analysis given out by the common venues such as what you will find on a simple Google search. Use words in your search like "SBC cam failures" or "lobe width and it`s effects on cam failures" Perhaps "lubrication and its effects on cam wear". To bad your not involved with organizations like the SAE (Society of Automotive Engineers) where you could obtain detailed engineering reports. Reports that use big, hard to pronounce words and lofty testing parameters.

Hint, in most cases it`s not the cam that fails. That`s a secondary result of something else. Dig deeper and see if you can find the root cause of wiped lobes.

Another hint, you cannot always blame the oil, spring pressure, lobe width or break in procedure etc........Once you figure out the facts you'll find lobe width in meaningless.

I already know the answer(s). You will have to work for it as I did. That`s where you keep missing the points in my comments on subjects we discuss. I give you enough information to find the answers on your own. You choose to ignore/understand the communication.

I don`t spoon feed..........Till you figure this out all my communications with you will seem half done when in actuality they are the base to work from.