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WheelhorseBob

Engine oil preferences.

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ebinmaine
4 hours ago, Greentored said:

....and once again- this is why I love this place!  This is THE ONLY site I have EVER been a member of, where an oil debate thread doesn't turn into a war, period.

You guys rock!!!

Keeping in mind the fair amount of experience you have with high-powered high pressure race engines, I'm curious to know if you've ever seen any evidence that the valve springs in these small engines actually produce enough pressure on the tappets or followers to warrant getting a huge concern over zinc phosphate? I've seen arguments in both directions. Just wondering what your thoughts are.

 

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oilwell1415

My personal opinion is that the value of ZDDP is overrated.  There are a lot of misconceptions out there about how moving parts in engines and drivetrains interact and the cam and lifter interaction is one of them.  The common belief is that the cam and lifters slide across each other and that is not the case.  The face of a lifter is actually convex and the cam lobe face is actually slightly slanted.  This causes the lifter to spin in its bore and the lifter face to roll across the cam lobe.  Because of that, there isn't nearly as much friction between the two as is commonly believed.  The problem occurs when valvespring pressures get high and the cam and lifter faces start to deflect and no longer roll across each other as they were designed to do.  When that happens is when you start to get lobe and lifter failure.  The point that this happens is way beyond what you will see with stock valvesprings.  The only time I would expect it to be a problem is during cam break in before the mating surfaces of the cam and lifter have adjusted to each other.  Once that happens you should be good to go.  Obviously different engines are designed with different geometry in the cam and lifters and some will be more sensitive than others, but collectively I don't see it as a real issue.  That's not to say that a ZDDP additive isn't cheap insurance, because it is.  I just don't believe it is absolutely necessary most of the time.

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Greentored
1 hour ago, ebinmaine said:

Keeping in mind the fair amount of experience you have with high-powered high pressure race engines, I'm curious to know if you've ever seen any evidence that the valve springs in these small engines actually produce enough pressure on the tappets or followers to warrant getting a huge concern over zinc phosphate? I've seen arguments in both directions. Just wondering what your thoughts are.

 

Man, i'd have to agree with @oilwell1415 , he hit the nail on the head, at least from what I've seen on a personal level.

In the automotive world, I have most definitely seen an increase in cam failures in the last 15 or so years when customers change their own oil and throw any off the shelf oil in there. Some are bone stock and in good condition, some were worn out to start with, and some were hotrods with big spring pressures. Yes i've seen them fail using high zddp oils too, but believe it or not it is MUCH more uncommon. We have lost two cams in the shop during break in out of maybe a couple hundred builds. Using a higher zddp oil, only ONE that im aware of failed after being broken in, and that was my own experimental build in a daily driver with a beefy spring- it suddenly ate a lobe at close to 100k street miles. 

Not even sure if we could get enough spring on our little one lungers to hurt anything. Heck, a typical stock V8 might have 200psi open spring pressure, multiplied by 1.5 rocker, thats 300# on the lobe! Never checked a garden tractor, but bet its closer to 40-50 pounds, if that.

Most automotive cams also get their lube from splash below/return oil from top draining down, and they typically idle about half of what our tractors idle at.

FWIW, I actually set the idle higher than spec on all the flat tappet stuff, and instruct the customers 'avoid extended idling/click it in neutral in when stopped in heavy traffic'.

Like Oilwell said- cheap insurance, probably not absolutely necessary.

 

 

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lynnmor

Couple of things:

Lifters rotate very little and do not roll with the cam, this is a sliding action with minimal surface area in contact to take the load.

ZDDP is an anti-wear additive that is beneficial throughout the engine, not just cam lobes.  While lobe failure is rather catastrophic, the long term degradation of the engine is also something to consider.

Racing oils are made to run from 1/4 mile to several hundred and may not have the additives to deal with condensation, sludge and other long term issues.

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ebinmaine
5 hours ago, Greentored said:

Man, i'd have to agree with @oilwell1415 , he hit the nail on the head, at least from what I've seen on a personal level.

In the automotive world, I have most definitely seen an increase in cam failures in the last 15 or so years when customers change their own oil and throw any off the shelf oil in there. Some are bone stock and in good condition, some were worn out to start with, and some were hotrods with big spring pressures. Yes i've seen them fail using high zddp oils too, but believe it or not it is MUCH more uncommon. We have lost two cams in the shop during break in out of maybe a couple hundred builds. Using a higher zddp oil, only ONE that im aware of failed after being broken in, and that was my own experimental build in a daily driver with a beefy spring- it suddenly ate a lobe at close to 100k street miles. 

Not even sure if we could get enough spring on our little one lungers to hurt anything. Heck, a typical stock V8 might have 200psi open spring pressure, multiplied by 1.5 rocker, thats 300# on the lobe! Never checked a garden tractor, but bet its closer to 40-50 pounds, if that.

Most automotive cams also get their lube from splash below/return oil from top draining down, and they typically idle about half of what our tractors idle at.

FWIW, I actually set the idle higher than spec on all the flat tappet stuff, and instruct the customers 'avoid extended idling/click it in neutral in when stopped in heavy traffic'.

Like Oilwell said- cheap insurance, probably not absolutely necessary.

 

 

 

6 hours ago, oilwell1415 said:

My personal opinion is that the value of ZDDP is overrated.  There are a lot of misconceptions out there about how moving parts in engines and drivetrains interact and the cam and lifter interaction is one of them.  The common belief is that the cam and lifters slide across each other and that is not the case.  The face of a lifter is actually convex and the cam lobe face is actually slightly slanted.  This causes the lifter to spin in its bore and the lifter face to roll across the cam lobe.  Because of that, there isn't nearly as much friction between the two as is commonly believed.  The problem occurs when valvespring pressures get high and the cam and lifter faces start to deflect and no longer roll across each other as they were designed to do.  When that happens is when you start to get lobe and lifter failure.  The point that this happens is way beyond what you will see with stock valvesprings.  The only time I would expect it to be a problem is during cam break in before the mating surfaces of the cam and lifter have adjusted to each other.  Once that happens you should be good to go.  Obviously different engines are designed with different geometry in the cam and lifters and some will be more sensitive than others, but collectively I don't see it as a real issue.  That's not to say that a ZDDP additive isn't cheap insurance, because it is.  I just don't believe it is absolutely necessary most of the time.

 

 

I agree with the cheap insurance.  

 

It's a good benefit to me that I can get Kinetix oil for around the same price as newer rated oil. 

 

 

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peter lena

obviously we all have our preferences for oil , I  think  the major issue is a  VARNISH BUILD UP , that is seldom mentioned . having brought back a few older engines from the brink , RISLONE  engine treatment , will get after that , you will quickly notice the blacker oil , where do you think that is coming from? the oil/solvent mix is cutting and cleaning oil debris, older engine smoking ? filthy oil rings stuck with varnish will start to flush out , (  as they were designed to do ) . usually a couple of HOT oil changes ,with RISLONE  added will do it . I also put hours on the oil , to increase its cleaning ability . engines that I have gotten , that were a noisy , Smokey neglected wreck , slowly came back to life . recovering neglect and using the wrong oil , takes time. all my oil changes are HOT OIL CHANGES , fresh oil and a varnish cutter will make your engine live on . sorry if I said anything to upset anyone , just my own experience, pete   

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WheelhorseBob

Well now that was a polite oil discussion! Keep the zddp in your older flat tappet engines, keep it clean and full. BTW there is a site by a guy named BOB for all your oil concerns.

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Greentored
On 11/21/2020 at 9:24 PM, WheelhorseBob said:

Well now that was a polite oil discussion! Keep the zddp in your older flat tappet engines, keep it clean and full. BTW there is a site by a guy named BOB for all your oil concerns.

...and he IS the oil guy! :handgestures-thumbupright:

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tom2p
1 hour ago, Greentored said:

...and he IS the oil guy! :handgestures-thumbupright:


Bob Is The Oil Guy ... BITOG

1FBC5453-F494-4C8B-B6E8-2FA8B2AB63ED.jpeg
 

and Bob Jr is the builder :

 

B34D0C8B-5004-4519-9100-E84FACA1EE9B.jpeg

Edited by tom2p
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tom2p
On 11/21/2020 at 9:24 PM, WheelhorseBob said:

Well now that was a polite oil discussion! Keep the zddp in your older flat tappet engines, keep it clean and full. BTW there is a site by a guy named BOB for all your oil concerns.


zinc / ZDDP is great stuff - great anti wear and detergent properties 

 

only one issue - the stuff can foul cat converters so don't use in the family grocery getter 

 

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WheelhorseBob
On November 14, 2020 at 8:40 PM, lynnmor said:

Can you direct me to a full synthetic 10W-30 that is not rated SN?

Amsoil small Engine and possibly the VP small engine sold at TSC.

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Greentored
3 hours ago, tom2p said:

"Can we fix it?"

"No its ****ed" LOL

 

B34D0C8B-5004-4519-9100-E84FACA1EE9B.jpeg

 

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peter lena

tom2p, very aware of the effect ZDDP has  on converters , I only use it in older style small engines , but my own experience with it has been really good. first thing you notice and feel is the total engine ease at doing anything , oil tends to go longer between changes , but when it gets grey , its black inside and time for a hot oil change . and a refill , a lot of the lubrication experiences  I have had makes me take a look on how I  can take advantage of the change . my response is different from others , but is a  gain on a used to be problem or issue .  pete 

 

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