351 C oil pump

[barnett468]

I seem to have come across more distributor gear probs with comp cams also. I wonder if they're doing something different with their cam gear?

i have some anecdotal info on that for what its worth and will post it later. but imo, the jury is still out . . its easy for someone to say this part or that part caused the failure like many are saying about comp cams, but they dont post enough info to definitively draw that conclusion, and in fact, it may very well not be the cam but the distributor gear or the placement of it on the shaft etc, or it may be that both the cam and the gear or its placement is the problem, so imo, in light of a definitive answer in this case, i do the checks and mods i mentioned and add the oil hole to the galley plug and use high quality oil and hope for the best, lol.

in your case, it may very well be the cam alone, and if you gather enough info, you should be able to figure it out . . you could put a hole in the galley plug and see if the additional oil helps, or you could try a different brand of gear etc, but obviously you would rather just fix the prob for once and for all and not just keep testing until you determine the actual cause.

 

[Carolina_Mountain_Mustangs]

I wish there were digital cameras back in the 60's. I read in one post that oil pressure could not damage a bearing. We all have opinions and I respect those. Most here are dealing with a 1/4 or 1/8 mile engine and not running hundreds or even thousands of miles at 7,000 to 8,000 with the only break stopping for tires. The oil will erode the bearings and not taking about scoring but it actually washes the bearing material out down to the metal shell. Back then most ran on a shoe string budget not multi million dollar budgets like today where the engine runs a few hundred miles. They would run an engine 2,000 miles on the track and bring in for a refresh. That was new valve springs, touch up the valves and seats, check push rods, rockers pistons and change out the bearings & rings. The crank might get a polish. You could buy a complete Holman Moody built 427 Ford side oiler engine for just over $2,000 and that was a bunch back then. We were doing engines for the little guys in NASCAR but all had to use the same parts. Buck Baker was the best know driver that used an engine from Roger Ingram's shop for his Pontiac Firebird Trans Am car. Back then it had to come from the dealer to run on the track. GM had to make oversize lifters for the Pontiac engines they were all way oversize coming from the factory and would starve the bearings.

The bearings on an engine that had ran on the track for 2,000 miles would erode from the hole out and looked like a small scale washed out ditch. It was the normal and you saw it in every engine, Ford & GM unless it had dropped a valve early in the run. They would not run that long if something was not right when you put them together.

David

 

[barnett468]

well, this is a complicated issue and no one doubts what you saw and we all want to learn new things . . you were also in a situation that the rest of us were not, however to definitively say it was caused by high oil pressure from the oil pump is inaccurate unless you did testing to prove this . . i did engine and chassis and suspension testing for a living when i was a project engineer at a major motorcycle mfg and we were building 165 mph championship winning bikes back n 1986 and we did a lot of oil testing.

one would need to simply use less oil pressure and run the same miles and rpm with the exact same parts as you did then try lower oil pressure to have any comparison . . then they would also have to run a different brand or type of bearing with both oil pressure settings . . they would also have to run all these tests at least twice and achieve similar results both times before any definitive conclusion could be drawn, and the obvious problem is that no one is willing to do this test AND it may be that even if the oil did cause this, the parts that are available today may be different than the ones you used and may not have this problem.

if in fact the oil pressure did cause this in your case, better bearings may not have suffered the same fate, but irregardless, there are simply no examples of bearing wear that are even remotely like what you describe these days, so even if it would still be a problem under the exact same conditions as you describe, no one on any of these forums runs their car for car for 2000 miles at wide open throttle so it is not a problem.

as the crank spins, a wedge of oil is formed, and it is my understanding, although it may not be 110% correct, is that the faster the crank spins, the greater resistance to pressure this wedge has, and this wedge is in the thousands of pounds range, which is far greater than any pressure any oil pump can put out, so if the wedge theory is correct, which every bearing mfg and other expert in the field says, the pressure from the pump is not what was wearing your bearings, it was the extremely high pressure created by the pressure from the oil wedge and this theory sounds a zillion times for plausible than suggesting they wore out from maybe 100 psi of oil pressure.

heres some info on oil wedges/hydrodynamic barrier lubrication but it is not what i was looking for which is in one of my computer files somewhere.

http://kingbearings.com/wp-content/uploads/2014/10/optimization-of-clearance-engine-professional.pdf

Anyway, if you think of it in simple terms. the pressure created by the combustion process is in the thousand lb area . . if you put a flat plate on a press then drill a hole in the center and install a fitting in the hole which will supply 100 psi of oil to it then place a round bar on top of the hole and put 1000 lbs of pressure on the bar, it will squeeze virtually all the oil out and be metal to metal, thus proving within a reasonable degree that the hydrodynamic wedge has a much higher pressure than 100 psi.

something else to consider is bearing wear caused by metals in the oil that came from engine wear, and there definitely was wear on your engine as there is on all engines, and unless you had a bypass type oil system that filtered out 99.9% of ultra fine particles, it seems reasonable to say that at least part of the wear came from contaminated oil but even still, i would think this would be a very small contributor.

.

 

[Carolina_Mountain_Mustangs]

well, this is a complicated issue and no one doubts what you saw and we all want to learn new things . . you were also in a situation that the rest of us were not, however to definitively say it was caused by high oil pressure from the oil pump is inaccurate unless you did testing to prove this . . i did engine and chassis and suspension testing for a living when i was a project engineer at a major motorcycle mfg and we were building 165 mph championship winning bikes back n 1986 and we did a lot of oil testing.

one would need to simply use less oil pressure and run the same miles and rpm with the exact same parts as you did then try lower oil pressure to have any comparison . . then they would also have to run a different brand or type of bearing with both oil pressure settings . . they would also have to run all these tests at least twice and achieve similar results both times before any definitive conclusion could be drawn, and the obvious problem is that no one is willing to do this test AND it may be that even if the oil did cause this, the parts that are available today may be different than the ones you used and may not have this problem.

if in fact the oil pressure did cause this in your case, better bearings may not have suffered the same fate, but irregardless, there are simply no examples of bearing wear that are even remotely like what you describe these days, so even if it would still be a problem under the exact same conditions as you describe, no one on any of these forums runs their car for car for 2000 miles at wide open throttle so it is not a problem.

as the crank spins, a wedge of oil is formed, and it is my understanding, although it may not be 110% correct, is that the faster the crank spins, the greater resistance to pressure this wedge has, and this wedge is in the thousands of pounds range, which is far greater than any pressure any oil pump can put out, so if the wedge theory is correct, which every bearing mfg and other expert in the field says, the pressure from the pump is not what was wearing your bearings, it was the extremely high pressure created by the pressure from the oil wedge and this theory sounds a zillion times for plausible than suggesting they wore out from maybe 100 psi of oil pressure.

heres some info on oil wedges/hydrodynamic barrier lubrication but it is not what i was looking for which is in one of my computer files somewhere.

http://kingbearings.com/wp-content/uploads/2014/10/optimization-of-clearance-engine-professional.pdf

Anyway, if you think of it in simple terms. the pressure created by the combustion process is in the thousand lb area . . if you put a flat plate on a press then drill a hole in the center and install a fitting in the hole which will supply 100 psi of oil to it then place a round bar on top of the hole and put 1000 lbs of pressure on the bar, it will squeeze virtually all the oil out and be metal to metal, thus proving within a reasonable degree that the hydrodynamic wedge has a much higher pressure than 100 psi.

something else to consider is bearing wear caused by metals in the oil that came from engine wear, and there definitely was wear on your engine as there is on all engines, and unless you had a bypass type oil system that filtered out 99.9% of ultra fine particles, it seems reasonable to say that at least part of the wear came from contaminated oil but even still, i would think this would be a very small contributor.

.

I have read the technical papers on the hydrodynamic oil wedge and seen all their charts and graphs showing where the greatest pressure is reached.

I am simply stating what we saw and yes they did testing reducing the pressure and seeing bearing failure due to not enough pressure. The bearings I am talking about did not fail or spin just had a washed out area in them. It was a good thing to see not the copper or steel shell showing.

I was engineering manager at Husqvarna and while there me and my son race go carts. So I played with the cart engines on the dyno in the lab. It was of little use since the computer was programmed to prevent run away engines so we could not go over 5,000 rpm on the dyno but on track when geared incorrect the memory tach read over 7,000. When we were marginal on getting in the front of the field we would drain all the oil and run the qualifying lap with no oil in the case. This would allow the engine to turn easier but not very long. We never blew an engine. This was and is still common practice in cart racing 2 laps no oil is possible. It takes the resistance of the crank throw and rod hitting the oil out of the resistance pool.

It testing in the lab it was proved that running excess oil in the crankcase caused more damage than say running it half full. In testing the engine would run longer running 1/2 the recommended volume in the crankcase. This was due to the beating the rod takes getting through the oil. That is another reason why most race cars run a dry sump system. Along with not covering the track with oil when a hole goes through the pan when blown.

Oils and lubes have resistance to movement that is why the car companies have put millions into development of a ceramic engine that requires no lube or coolant. It probably will not make it to market but some are using ceramic liners in the engine and can get way more HP that on iron or aluminum.

Again in cart racing you take the bearings on the rear axle and pull the grease seals out and wash the grease out and only spray some light lube in when in the pits and you will turn a faster lap with no grease due to resistance. Small engines are the ideal place to see what happens when something is changed you will see the difference much easier than with an 8 cylinder.

I am not recommending that anyone on the forum reduce their oil pressure I am only telling my experience. Most people worry about things that mean little or nothing and miss the big problem. I am sure we have members that think if they put the best forged pistons, hottest race cam in and strongest valve springs that they will never have an issue but an engine built like that will not last as long as stock. That is what keeps aftermarket in business short life and the market thinking it is better.

I know people that never changed their oil only the filter and added oil and got over 160,000 miles without any problems. I would never do that but he did and saved a bunch on oil changes.

David

 

[barnett468]

yes, i didn't think your bearings had spun and believed the bearing damage you saw . . my point was that it doesn't stand to reason that it was caused by the 100 psi the pump puts out when the pressure from the hydrodynamic wedge was so much greater bu these things weren't known back then which is why many people including ford built engines with fully grooved bearings etc.

as far as the cart guys go you had to be using 4 stroke engines then . . i have seen some cart races and some of those guys are incredibly serious about it.

the road race engines we had were 4 stroke and the MX ones were 2 stroke . . this was in the mid 80's.

the 4 stroke mx bikes have so much power these days they put traction control on them.

.

 

[Paul of MO]

David - you must be as old as I am. Very nicely written.

When Clevelands first showed up and were being used in the faster classes in NHRA and IHRA we did everything like we had in the past. Found out real quick most of the traditional stuff really did not work as expected.

Running 100 psi oil (wet and dry sump) caused bearing erosion exactly as David observed - from the oil hole back. This was on engines running 7500 rpm and up. Dropped the pressure and the bearing issue vanished.

After more than one failure and the gruesome postmortem we could tell it was oil system / starvation issue. We monitored the pressure and flow throughout the galley system and discovered the need to put a external line to route oil pressure to the back side of the engine and into the valley to feed psi directly to the mains aka the Hank the Crank modification. That, along with some well placed restrictions to make sure everything that needed to be floating on a film of oil was floating on a film of oil solved the problem.

I have never drilled a hole in a galley plug - I have on occasion installed "wigglers" - these are galley plugs with a very tiny hole with flared pin inserted in the hole. Very little oil gets past the pin and it is more like a seep - certainly not a spewing stream of oil.

If the front cam bearing is installed correctly the chain on a 351C will get plenty of lubrication. If you want to put a wiggler in to get a bit more oil on the top sprocket and fuel pump eccentric it will do no harm.

All of these oil modification like other discussed on this site were needed on high rpm, solid lifter, full race engines. Launch at 8500, shift at 8,000, shift at 8,500, shift at 9,000, go through the lights at just under 10,000 rpm. Get your trophy - kiss the pretty girl. If you are not going to drive like this then you do not need to modify your oiling system.

If still want to then you can buy new style lifters that are restricted internally, and or you can buy special push rods that have a smaller passage in them, and or you can buy cam bearings made with smaller holes in them just for this purpose.

Lastly - run a standard pump. On a non mechanical cam street engine along with the ass backwards oiling system in a Cleveland a high volume pump will push all the oil up into the heads and starve the mains. This is not a pressure issue but a quantity concern.

Example: If you run a 7.5 quart pan with baffles and a high volume pump the backed up oil above the head can push the breather right out of the valve cover.

Oil simply can not drain back to the pan as fast as it is coming up the pushrods but the extra 2.5 quarts oil will still keep the main fed. 5 qts is simply not enough oil by volume to keep up.

The symptoms are - constantly having valve cover gaskets leaking or pushing out. Oil consumption and engine smoke due to oil being pushed down the valve guides and being burned. Oil pressure readings will "bounce" as the oil pumps sucks air if the pan is pumped dry especially during hard cornering. Main bearing failure.

The best way to know if you have the "balance" between quantity and pressure is to let the engine idle with the drivers valve cover off. If the oil fills up just to the lip of the head and drains nicely down the rear oil return you are good to go. A small amount may spill over or shake out.

If however you have a significant flow of oil over the back outside edge at idle then you are at risk of starving the mains with a stock 5 qt pan at higher RPMs.

Do not do this on hot engine - you will make a lot of smoke and or start a fire. It only takes 20 seconds or so to see if the oil is draining back at the same rate it is coming in at idle.

Clevelands are old and obsolete technology but still a lot of fun to build and drive.

Do not over think building one of these or get wrapped up in all the possible what ifs.

Just ask yourself how many 71 through 73 mustangs were "hopped up" driven hard and still lasted for 150,000 miles with none of these changes?

- Paul of MO

 

[barnett468]

.

some stock engines had premature bearing failure even though they were properly maintained . . we had a stock 70 montego with a cleveland and it ate the bearings at around 85,000 miles and the oil was changed every 3000 miles . . other stock clevelands failed much sooner but it was not a lot.

 

[basstrix]

This has been an interesting thread... I especially enjoy hearing from the "old timers" that were involved in the very beginning.

 

[barnett468]

thanks i for one feel like a geriatric now lol

 

[basstrix]

Lol

 

[boilermaster]

thanks i for one feel like a geriatric now lol

I will say one thing (being a relatively new member)

YOU GUYS ARE WELL BEHAVED !

I also belong to a Harley Davidson Shovelhead forum and things get very heated very fast.

I remember I posted my dyno report for my lil 93'' motor 108hp 101tq.

People were doubting it right from the start , the usual bogus correction factors, weather conditions etc.etc.

Never had the heart to post my 111hp. or 114hp. numbers.

Was just on there today and it was brought up again, it is going to get posted to back up a manufacturers flow numbers.

I am liking it here more every day.

Boilermaster

 

[barnett468]

.

Unfortunately civility is a very rare commodity on many forums, and for the most part, this forum is an exception.

I know exactly what you are talking about regarding a hole comments about your dyno report, and it is true that not all dynos and dyno operators produce exactly the same results, but irregardless, there's no reason to beat someone up over their results.

it really comes down to the fact that some people have a need to appear superior to others to satisfy their needy ego.

 

[Paul of MO]

I will say one thing (being a relatively new member)

YOU GUYS ARE WELL BEHAVED !

lollerz

Did you see our last thread about porting a 351C 4v stock head? Classic...

(I'm still right and Barnett is still wrong)

Glad you like the group and welcome!

- Paul of MO

 

[boilermaster]

.

Unfortunately civility is a very rare commodity on many forums, and for the most part, this forum is an exception.

I know exactly what you are talking about regarding a hole comments about your dyno report, and it is true that not all dynos and dyno operators produce exactly the same results, but irregardless, there's no reason to beat someone up over their results.

it really comes down to the fact that some people have a need to appear superior to others to satisfy their needy ego.

Barnett468,

Just so happens it was my first shovelhead build, wanted to prove a point that I could follow a recipe and make good power.

Been the highest on the spread sheet there for nearly 4 years.

Naturally they want to tear you down .

Guess I cannot be accused of being a thread pirate, forgot this is my thread.

Boilermaster

 

[barnett468]

Did you see our last thread about porting a 351C 4v stock head? Classic... (I'm still right and Barnett is still wrong)

At 93 years old I keep things for nostalgia..

Unfortunately he forgot to keep his brain!

.

Barnett468, Just so happens it was my first shovelhead build, wanted to prove a point that I could follow a recipe and make good power. Been the highest on the spread sheet there for nearly 4 years. Naturally they want to tear you down. Guess I cannot be accused of being a thread pirate, forgot this is my thread. Boilermaster

congrats on your success but i guess your not a "real" harley guy otherwise you would probably like that forum, lol.

.

 

[basstrix]

Did you see our last thread about porting a 351C 4v stock head? Classic...

(I'm still right and Barnett is still wrong)

I must have missed this one....gotta go look it up

 

[boilermaster]

Did you see our last thread about porting a 351C 4v stock head? Classic... (I'm still right and Barnett is still wrong)

At 93 years old I keep things for nostalgia..

Unfortunately he forgot to keep his brain!

.

Barnett468, Just so happens it was my first shovelhead build, wanted to prove a point that I could follow a recipe and make good power. Been the highest on the spread sheet there for nearly 4 years. Naturally they want to tear you down. Guess I cannot be accused of being a thread pirate, forgot this is my thread. Boilermaster

congrats on your success but i guess your not a "real" harley guy otherwise you would probably like that forum, lol.

.

Barnett 468,

I know not what a " real" Harley guy is,

no tattoos or a long grey beard, the only Harley clothing I own is a rain gear, seldom frequent the dealership and I am also kind of font of Triumph triples cycles as well and I do enjoy the shovelhead forum.

The best way to sum myself up is Gearhead.

Boilermaster

 

[barnett468]

Barnett 468, I know not what a " real" Harley guy is,

no tattoos or a long grey beard, the only Harley clothing I own is a rain gear, seldom frequent the dealership...

LOL, yeah, actually the guys that consider themselves to be "real" harley guys are like your first part of your description, plus most wouldn't be on a harley forum or own a mustang unless they were gettin "old" . . The "real" harley guys consider people like me and you as "posers" as in a wanna be real harley guy . . I know this because I actually know a few, but that's not really relevant . . As long as you like your bikes and cars etc, it doesn't matter what anyone else thinks.

...I am also kind of font of Triumph triples cycles as well and I do enjoy the shovelhead forum.The best way to sum myself up is Gearhead.

Boilermaster

Ahhh, the mighty Trident . . I have ridden one of those . . I like old vintage bikes like that too.

 

[Ron Tanzi]

There are many good and helpful people on this forum. No fighting or name calling. Disagreements sometimes....sure. All in the name of a healthy debate. Unlike the World we live in today.

Ron

 

[secluff]

Got to remember regardless of what "Rings your Bell", people are usually passionate about it. I have seen situations get totally out of control to the point of "Burning Down to the Ground"! No matter if discussing cam selections, head building, or dog grooming. There are some spirited discussions that arise here occasionally, and that's to be expected. Your dealing with people from all demographics. What may of worked great for me when I was drag racing my Mach 1, may of been something someone else was doing and lost an engine.

All I can say is I'm so glad I found this site by accident. I was on a couple a Mustang sites (I'll mention no names) and really got tired of 71-73 bashing! Couldn't sleep one night so got on my laptop and Googled 71 Mustang and the rest is history.

Also would like to give a shout out to our Moderators and Administrators who keep us in line. Not always a popular job, but one that has to be done.