question for Jim Weise or anyone else

so my question becomes,

am i hurting anything with the bigger clerances, or is it just that i won't have the great oil pressure.

Also Jim what is your opinion of a 30 or 40 weight oil or perhaps a 20w 50 in the summer, will i hurt anything like this?

thanks for the help

 

No, your not hurting anything, under normal driving conditions..

But I would bring up the R's a little before I matted the pedal.

That's because you want to get a bit more pressure to the rod bearings, before you subject them to the pretty serious loading that happens right at the "hit of the throttle".

In what seems like another lifetime ago now, I used to do alot of ociliscope work during troubleshooting and tune ups on '70's and early 80's vintage cars.

And when you crack the throttle quickly, with the scope hooked up, you can see a 10-15 Kilovolt rise in the amount of voltage it takes to fire the plugs, vs at an idle situation. This is due to dramatic rises in the combustion pressure in the cylinder, when you crack the throttle hard.

And even if it looks like the oil pressure "comes right up", I highly doubt that the rod bearings are seeing any increased pressure that fast.

I won't sit here and say that I have done any scientific research into this, but it seems like common sense to me. So you might want to bring it up against the converter and get the oil pressure up a bit, before you hammer it.

IN other words, don't "mat it" directly from idle..

Yes, you can run a thicker oil, but if you do, unless the kids are bleeding or the wife is pregnant and about to pop, don't rev the motor past 3000 rpm until the oil warms up. The stock relief system in our pump cover design can only by-pass so much, and when that by-pass get's overwhelmed by the pump ouput, is when you start hurting parts, with oil pump strain.

JW

 

so Jim, I have a 2500 Coan converter, when i go to the track, your saying bring it up around there before take off right and the same for the street. get it off idle before u peg it

at 2500RPM its holding about 45 to 48PSI of pressure. Thats enough right?

what oil do you recommend? and what brand? should i stick with Vavoline but go to about a straight 40W oil, and make sure the oil is hot before i flog it.

thanks for sticking with me here i am sure learning alot from you.:Comp: thanks

 

Personally,

In the summer time, I would run straight 40 wt Kendall in that thing, with a bottle of EOS from GM..

Valvoline is commonly known as "cheap oil" uh....ohhh.. I just went against one of my own rules here... never comment on oil, politics, or religion.. oh well, fire away..

Yes, and you don't have to go all the way to 2500.. anything above idle will help, and the converter will heat up if you can pull it up all the way to stall speed with the brakes..

Just say 15-1800 or so should be fine.

 

Ok Jim you lost me Kendrell oil and EOS what is that?

How about AMSOIL 40wt
I need to keep a conventional oil in it for a little bit longer
it has 500 miles on it but maybe next summer i will switch to synthetic.

i had been running a 10w 40 in it and it would hold about 18 at 800RPM just a bit higher than 10w30. or maybe the bearings are wearing a bit or the pump cover is wearing a bit that is what is bringing it down to 15 to 16.

I know crusing down the highway it holds at least 40PSI so I think I'm good there.

this may sound like a stupid question but if you are wearing bearings really bad, besides seing metal in the oil will it sound like a knocking noise. Mines not i was just curious. when the shavings are present, is it really noticable or is it just fine particle matter.

thanks

 

I agree with Jim again. Let straight weight oils warm up before going full tilt with the engine. Since they hold viscosity better than multi-vis crud, longer, they require longer warming periods before flogging the engine.

And, I have seen large, excessive main and rod bearing, rod side clearance issues allow the hot oil to to run off critical areas like those bearings when the engine is shut off, only to experience low lubing conditions on cold restart, taking more running time to recharge the oiling system and get oil pressure established when the leak of all the clearances is larger than normal. This means the rod bearings have to put up with the compression pressures withut adequate oiling film until the oil pressure catches up with and overtakes the clearances and oil runoff of the bearings/clearances.

And, Jim, the KV uprize upon throttle up I have seen and can attest to, is a real thing. As you said, it is compression resistance of the spark plug electrodes that causes the KV's to go skywards. It happens very dramatically, especially when you see it on a scope.

 

EOS is GM Engine Oil Supplement.

I buy it by the case.. and it goes into every engine built here, before initial startup, and I recommend it at every oil change to my engine customers.

I also recommend that my engine customers change the oil, in as little as 500 mile intervals, depending on the particular build, and how it is driven. Other customers can do just fine with the standard 3000 mile oil changes. I do not recommend synthetic, due to the fact that most high performance engines contaminate the oil with fuel, during low speed operation, due to the camshaft overlap causing the engine to run erratically at low speed, thus pushing raw fuel past the rings into the oil. And a lot of these cars are not driven long enough distances to evaporate that fuel out, and in any event, the fuel does affect the oil's additive package.

I have never tested synthetics against conventional oil in a 455, weight to weight (meaning 30 wt conventional vs 30 wt Synthetic)

That would be the test one would have to do, to get an accurate assessment as to the gain with just the oil, in friction reduction. We manage friction reduction with dry film coatings on the engines built here, so I doubt we would see any benefit.

My dyno operator, who has seen this test run time and time again, reports to me that they see very little to no power gains from synthetic vs conventional oil, in a variety of different engines. I have seen tests where folks went from 20w50 conventional, to 30 WT Synthetic, and they have seen 5-10 HP gains, but that's from the difference in oil weight, more than anything else. Thin oil requires less energy to pump it, and cost less in Windage loss.



EOS contains a few of the anti-wear agents that modern oils are missing these days.

If I recall correctly zinc is the big thing that is missing out of the oils now.

This recommendation comes directly from Dennis Manner, the Buick power train engineer that designed the 455, and it's common knowledge in the engine business that you have to have EOS in it for initial break-in.

I do believe that Dennis wrote and article about it that was in the GSXtra a while back, I am sure someone reading this has that copy, and can give more details.

JW

 

where can a person buy EOS i am very intrested!

Also when my motor was built up we used a clevite 77 bearing set in it. So i do't have the grooved cam bearings. Will the thicker weight oil affect this.

I know the cam bearings a very sensitive in a buick and i was just hoping that the thicker weight oil wouldn't affect this problem.

Iknow you said that when a cam bearing fails, it is usually at initial startup. When this happens what is the affect. Is there no oil to the driver side galley? or will it make a bad ticking noise?

I have the same amount of oil on both sides of the motor. I check very often.

If i did hurt the bearing at startup how long would it take to show up. I would think Immediatly!

If the bearing is not hurt, are you not going to have problem from then on until she gets a lot of miles or what?

On the motors you dyno Jim, after you make a few pulls, does the valve train tend to make more noise or not.

When I fire mine up it sounds great, but as soon as the motor gets up to temp the roller rockers seem to get noisy form both sides. I guess this is normal. I know all the chevy motors i dealt with make alot of ticking! I guess the oil is breaking down and is not as thick, making the rockers noisey.

any input?

 

Just about any GM dealer will have EOS in stock.


oil weight will have no affect on the cam bearings, at this point in the motors life. It could on a new motor, and that's why we break in new motors on nothing heavier than 5 or 10w30.

First sign of cam bearing failure is a drop in oil pressure. The bearings are "bleeding" oil. It might dry up the driver side galley, but that is not a given.

I have seen motors go 500-800 miles before the bearings get bad enough to really be a problem. Others don't make it that long. Depends how many of them fail.

Once the bearings "live" thru initial startup, then your just looking at normal wear failure stuff..

The only time a valvetrain should make noise, is when your running solid lifters. Period..

Now, I have seen a few cam grinds that are a little noisy, at say 1500 rpm.

Noise is generally caused by lash (free-play) and with a hydraulic lifter, you should never have that.

Snug the roller rocker adjustments up 1/8 turn.. that's the quick fix.. or go thru the adjustment proceedure again, but this time do it with the motor at normal temp.. you prolly have a cold rocker adjustment deal going, and if you had say .010 or less preload cold, you could be right at zero preload, or have a little lash, when it's hot.

When we build aluminum head motors here, with solid cams, I always subtract .010 from the lash settings during initial setup on the stand... and after the motor comes up to temp, the heads have "grown" enough to open that lash up, to near the hot setting. Iron heads won't grow quite so much, but they do somewhat..

JW

 

Well Jim, i did check the lash and it seemed fine. When i lashed the valves I use one hand and feel the pushrod and start turning the rocker till you can spin the pushrod but has no up and down play.

then i go 3/4 turn and lock it down. Now when i am talking valvetrain noise I mean a tick not a clack. it almost sounds like header noise. I will run them again and maybe give them a bit more than 3/4 turn. I do no, when it is on the base circle there is not up and down play on the pushrod.

If you take the rockers themselves and move them side to side, you hear a tick and i think that is what the noise might be.

As far as cam bearing failure, where do you notice the oil pressure drop, at idle or when you are going down the road.
My idle pressure fluctuates but no mater what at about 2500 down the highway it always holds around 42. when you let off it goes to 35 or so but goes right back up when you touch the throttle.

so where do I look for the pressure drop from cam bearing failure, at idle or when running it.

 

You may be experiencing some lifter noise then.. that's pretty common..

TA rockers don't make any noise.. I have run many sets on hydraulic cam motors over the years.

With 3/4 turn cold preload, unless you missed getting a lifter on the base circle, I doubt your preload is too little.

Re-check for a loose rocker, by spining the motor over until the intake on the cylinder checked is at max lift, then check the exhaust, and vice versa.. this is the most accurate way to be sure the lifter for the rocker your checking, is on the base circle.

And if you have the lifter bleed down issue, you will see this during this test.

40 psi at 2500, even with .003/.0025 main clearances, scares the hell out of me..

If I built it, with those clearances, it would not leave the shop until I knew it was not bleeding oil out of the bearings.

If you want to, pull the intake, and inspect the cam bearings.. attached is a pic of a motor with failed bearings, and what your looking for..

If you don't see bearing material hanging out around the shell of the bearing, then pull the dist, and spin the oil pump with a drill and a primer tool.. then watch around the bearings.. if they have failed, you most likely will see oil squirting out of them..

We just saw that on a 350 here, that was in for some of the new lifters that don't bleed down, after it was built by a local guy here.. and after we changed the lifters, and set up the valvetrain, I wanted to prime it, to be sure the main galley was full so we primed it in the manner I described, with the intake off... holy gusher from the front cam bearing.. I was spinning the drill, and noticed oil squirting back on the cam..

Long story short, we replaced the front 3 cam bearings, with the motor in the car (that's a fun trick), and doubled his oil pressure.

He had 10 psi at idle, and 40 somthing going down the road.

He has 20+ at idle now, with 60+ or so after 2000 rpm. That motor has big clearances in it too..

Now, it was not just he new cam bearings that helped, but I also modified his oil pump, when we had the timing cover off, and rebuilt it properly.

But there can be no doubt, he was bleeding oil, and losing pressure.

To understand what is going on with the pump, and where you will see the pressure loss first (idle vs at higher rpm) we need to consider that he pump is a variable displacement unit.. meaning it delivers more oil the faster it spins, up to the point where the pressure relief valve opens, and reduces oil output from the engine.

In short, the faster you spin the pump, the more ability it has to fill the bearing clearances, and the galleys. The amount of "space" that has to be filled stays more or less constant.. more oil will bleed across the bearings at higher rpm, but the pump should be more than capable of keeping up with that increase in demand.

Considering you have a TA assembly, I would first check to see where your pressure regulator is set at, by a visual inspection of how much of the adjustment stud is sticking out of the lock nut, on your pressure regulator. I typically end up with maybe three threads of the allen stud showing, beyond the locknut.

Now, that brings me to another topic.

For years, all of us have been saying that the pressure regulator does not affect idle oil pressure.. but, my dyno operator and I have a theory going.. that the pressure regulator is affecting the output of the pump, at all times.

why?

Simple.. with the pump in operation, it's impossible to read the localized pressure, right at the pressure regulator valve. We are reading it after the oil makes a couple of 90* turns, goes thru a filter, and thru a bunch of passages.. even if you reading it off the front of the motor.

We feel that the pressure regulator valve may be occilateing at some rate, all the time, slower at pressures below what we could consider the 'set" pressure, but it's always working.

I have see some motors pick up idle oil pressure, after we adjusted the regulator, to set the high rpm pressure. I have seen some not change.. But the ones that did not change, were the motors that idled at 40 psi.. And we have seen that.

So check your regulator setting, and go from there.

Here is that pic.. these are big-time failed cam bearings.

And from what it looks like, I don't think I have to tell you that this motor was not built here.. you guys have seen my stuff. And this new motor is way to dirty looking inside to be anything that came out of this shop. It had maybe 500 miles on it, when we got ahold of it.

Your looking for it to have "peeled" the bearings.. and that little "peeling" sticking out. If it just melted your stock cam bearings, then you might not see this.. then you need to run the pressure test.

If nothing else, it wil give you piece of mind anyway..

JW

 

Jim---Check the label on your "EOS" bottles---I think GM re-labeled it under another name---in case there is any confusion when people go to buy this stuff. I think it may now be called Engine Assembly Oil or something like that. Same part number but different name. Thnx Patton

 

Patton..

GM now calls it E.O.S. Assembly Lubricant

PN 1052367

Black bottle, blue label.. 16oz..

JW

 

Hmm..... that motor looks familiar! Brian uzzled:

 

Ok Jim

Checked the adjuster and there were about 10 threads showing.

cranked that sucker in, and now shows about 4 1/2 or so. results

200deg. motor
idle in drive 800 RPM - 16 to 17 PSI
idle in part 950 - 1000 - 24 PSI
2000RPM down highway - 50PSI
2500RPM Down highway - abut 58 to 60PSI
5500 shift point around 70PSI

This is all acheived with vavoline 10w30 and lower bearing clearances of .003 on mains and .002 - .0025 on rods.

I guess this is better that 40PSI at 2500 RPM huh:Brow:

so i guess i am switching oil now to get it up a bit more. I didn't take the intake off by the way, could there still be a bearing problem. I saw no shavings in filter or oil.

i still just don't like that 16 to 17 PSI at idle but I guess I will live with it.

 

Doesn't look like that anymore...

:Brow:

JW

 

Jim would you still take the intake off and inspect the cam bearings or due you think since i have "chevy" bottom clearances in it that the pressure it good.

if there was a bearing problem would it have shown up by now?

my guess is no because the pressure went up with the help of the adjuster screw. If it was bleeding off i don't suspect it would get up to 60PSI at all. maybe I am wrongo No:

 

not unless oil pressure drops off from what you told me it was now, on the phone tonight..

JW

 

This has been one Very informative and interesting thread,
Thanks Jim for all your input on it.I know it has enlightened me to some very usefull information that I wasn't even aware of.Well,I should say info I thought I knew about until now.
I love this Forum.
Thanx Guys:TU:

 

i agree, i have learned so much from this and i am glad i posted it.

it has been real nice working with you Jim, and thanks for all of your help. :beer

if i have any other questions i know i can count on you!