Oil Back feeding your stage I????

[norbs]

I thought i would bring this up again. SInce the stage 1 does not have a groove in the front cam bearing journal and if plan to use TA performance grooved bearings it could leave the drivers side lifter gallery almost oiless. Even though the cam is grooved the only oil going to the drivers side would be from the two tiny grooves on the back of the #1 cam bearing. I have decided to feed the drivers gallery from the rear with a 1/4" tube nut set up. My question, is this enough volume or not? 1/4" is only about 3/16" I.D?

[Boost231]

i would like to know as well. i have seen this done on one another motor i was like WTF> i dont see that much.

[cabech984]

that sounds like a good idea. Also looks kinda hard to do???

[TurboT231]

Norbs, that was a great idea you came up with . I think your going to be fine with that set up, should be plenty of oil to feed the driver side. I actually went with the TA double groove bearing and those 2 little grooves are feeding just fine so your idea should not be a problem.

[norbs]

Yes its very hard to get the fittings in, there is not much room for error. I wanted to use compression fittings, but was worried it might leak. The power source book says restrict the feed to .080 and turn the cam bearing before the grooved bearings came out. I am going to prime the engine on the stand and see what kinda of oil is squrting out of the top end. I can't see it hurting anything?

[CTX-SLPR]

Since its on the back I don't think its going to starve your front cam bearing but that would be my only worry. Fluids take the path of least resistance and thats probably through the bridge. I doubt its a problem but my concern would be for supplying the front cam bearing with sufficient pressure.

[Lee Thompson]

IF the cam bearing (#1) has 2 holes and # 1 cam journal has a groove--I don't see why you need to do anything. What am I missing? How could you possibly starve the front cam bearing as it gets oil first? BTW, I don't care who says different, once the system comes up to pressure there will be the same pressure throughout the eng. Front or rear--makes no difference--pressure is the same.

[ijames]

Originally Posted by Lee Thompson

IF the cam bearing (#1) has 2 holes and # 1 cam journal has a groove--I don't see why you need to do anything. What am I missing? How could you possibly starve the front cam bearing as it gets oil first? BTW, I don't care who says different, once the system comes up to pressure there will be the same pressure throughout the eng. Front or rear--makes no difference--pressure is the same.

Pressure is the same everywhere as long as there is zero flow. Once there is flow, there will be a pressure drop along the flow channel. How much pressure drop depends on the flow resistance of the channel and the volume of flow. In the extreme think of a garden hose wide open with no nozzle on the end. The pressure in the water main basically doesn't drop from it's 50-80 psi but the hose outlet is at atmospheric pressure, zero psig. The pressure falls along the length of the hose from 80 to zero. Cap the end of the hose and now the pressure is the same everywhere because there is no flow. Notice how you get a burst of water when you first squeeze the handle on a pistol-grip water hose nozzle? The pressure was at max along the length of the hose while it was closed, so you have max pressure right at the nozzle when you first open it so you get a short burst of really high flow. Once the flow starts throughout the hose the pressure will drop and the flow coming out will fall to it's equilibrium value. If the hose is "stretchy" it will also act as a pressure accumulator and you get an extra long initial burst as the hose shrinks back down to normal size (yeah, I spend way too much time staring at the hose while I'm supposed to be washing my car :-)).

As for the back tube starving the front bearing, if you think about it you are now back feeding that bearing up the driver's side gallery in addition to the main feed through the passenger side bearing hole so you will have more oil available at the front bearing, not less.

[Lee Thompson]

Once the system is pressurized--the pressure will be the same throughout the system up to the bearings. Once it passes across the bearing it drop to 0. As an example take the water system in a city (say 50 psi )--you willl have the same pressure @ the pumping station as you will have @ the farthest faucet. Once it goes through the faucet it drops to 0. I have put gages on the front and rear of a running eng. Even switched the gages too eliminate error. Pressure is the same.

[JDEstill]

bad example with the city water system Lee, it does not work that way. You may have 50 psi at the pumping station and at the farthest faucet *if* (and only if) no one between those two points is using any water. If you have a bunch of people along the line flushing toilets, doing dishes, water lawns, etc... the farthest faucet will definitely be less than 50 psi.

norbs, I'm no pro (and therefore not really qualified to comment - but I will anyway), but I would think that if the old standby setup (groove in the cam plus the recommended 0.080" hole in the cam bearing) was enough to supply the drivers side gallery with oil, then the TA bearings with the grooved backside would be at least the equivalent of that. So any tubing at all connecting the galleries at the back of the block is overkill.

John

[Lee Thompson]

But this is getting off topic from Norbs post.

[CTX-SLPR]

I don't think so, its right on what he's asking.

Anyway, what I was saying is there is a lot less flow resistance across the back of the block now and down the lifter oiling galleries. I'm thinking there might not be as much presure in the front cam bearing. I think its probably throughly sufficient but I like you John am not an expert.

[Lee Thompson]

You will have the same pressure @ # 1 cam journal as you have @ # 6 rod bearing assuming your eng. is half way RIGHT.

[norbs]

Well i didn't wan't to get involved with city water pressure, but its an interesting topic also. I think Lee is correct the pressure should be pretty well constant thoughout the engine. I never measured how big those grooves are in the back of the TA cam bearings but they looked pretty small to the eye. Lee on the stage 1 block there is NO groove in the front of the block, only the groove in the cam, which now has the holes located so that the oil galleries are covered. You have to feed all 6 lifters and rocker arms, etc from those two little grooves! Where the passenger side of the motor is fed with a 1/2" hole right from the oil pump. John you could be right, but i can't see this hurting anything correct?

[JDEstill]

norbs, I can understand about the grooves looking small to the eye, but then that 0.080" hole they recommend also looks small to the eye

Seemed to me that they were trying to restrict the amount of oil to the drivers side lifters (I think those are the only things fed by that gallery, or are the #2, 3, 4 cam bearings fed from there too? I always forget), to force more oil to the rods and mains. I guess the lifters don't need that much oil.

Seems like if you had the gallerys joined at the back and deleted the grooves and such up front you'd accomplish the same thing; the rods and mains would always get priority over the drivers side lifters. Is that what you've got? You said the holes in the #1 cam bearing are clocked so that the passages are covered up, so there is no transfer from pass side to drivers side via the groove in the cam? Only by the grooves on the backside of the cam bearing? (you know, you could ask the guys at TA their thoughts, since they are the cam bearing providers. They should know if the grooves alone are sufficient). If you aren't using the holes in and out of the #1 cam bearing to transfer oil to the drivers side gallery, if I was you I'd try to find a cam without the groove in it, to reduce wear on that bearing.

Whatever the case, I don't see that line in the back hurting anything. While Ruggles, et al said that drilling the smaller holes in the cam bearings helped oil pressure, I'm not sure why, the lifters are going to take what they want to take. Unless those tiny holes dropped the pressure a lot in that gallery... I can see that helping pressure, if the small holes in the cam bearing made the drivers side gallery run at 15 psi when the passenger side gallery was at 25 psi... that would explain a lot. Essentially the same as putting a restriction orifice in the gallery feed passage. Your line is counteracting that, of course, but again I don't see it hurting anything. If that's how the small holes were supposed to work then maybe you lose a few psi at idle, but if the rest of your system is up to snuff, I doubt it.

Now, on the topic of pressures being the same everywhere in the system... I hate to bring it up again, but it just isn't so. Fluid doesn't move without a reason. The reason is that the pressure is higher at one end. If the pressures are the same, there is no flow. Whether it is inside an engine or in a city water system. Now the pressure difference can be small, no doubt about that. In the grand scheme of things the distance between front and back of the block is only what, 15"? Across that short a distance even a very high velocity might show only 1/2 psi drop. But that pressure drop is there, it HAS to be. I don't know about your eyeballs, but mine are not calibrated to see a half pound difference on a 0-50 psi or 0-100 psi gauge. If you put a differential pressure gauge on there I bet you'd see it though. City water system, same thing. You can have as big a pump as you want, but there *is* a difference between pump discharge and the last tap. You might have a 24" main that only gives you a couple of pounds drop over a half mile, but the pressure difference is there. As a guy that has had to survey water systems (not city water, but cooling water systems, essentially the same concept), trust me on this. If you had a 10" main instead of a 24", do you still think you'd have the exact same pressure at the last faucet as at the pump? What if you had a 6" main? Or a 2"? If not, why not? It's the exact same principle. Its just a lot harder to see the pressure difference in the big pipes.

John

[gnxtc2]

What type of lifters are you using and what kind of rockers?

On my 109 block, I was using solid rollers with .040" restrictors in the Smith Bros. pushrods. Roller rockers don't need that much oil. Wanted to keep everything down below.

Took the motor apart after about 100 runs and the bearing looked perfect.

Billy T.
gnxtc2@aol.com

[norbs]

I am using the TA shaft rockers, stock stlye, not jesel style. The lifters are the crower solid roller that TA performance sells. The pushrods are comp cams 3/8 .080 thick. I am going to fire this on a stand with a gen 6 dfi for now, since i am tripping over them here. I guess that will tell me the pressures if they are low or not. I'm running a dutweiller pump with a booster plate, and feeding the block from he side passge enlarged to 3/8" NPT.

[Mac in SD]

Originally Posted by norbs

Yes its very hard to get the fittings in, there is not much room for error. I wanted to use compression fittings, but was worried it might leak. The power source book says restrict the feed to .080 and turn the cam bearing before the grooved bearings came out. I am going to prime the engine on the stand and see what kinda of oil is squrting out of the top end. I can't see it hurting anything?

Don't do that Power Source front cam bearing oil restriction on a car that will be street driven or do any significant idling. That's for high-RPM race cars. I've seen engine's where that was done, and they both had destroyed #1 cam bearings. JMHO.

[GARY HARVEY]

Consider how much pressure is feeding the last rod journal and how much oil is actually needed to do the job.
Ends up being a rather small pressure.
Assuming the people gathered for the discussion were correct (form your own opinion... please).
Remember: we are refering to a engine @ speed.
Most everyone agreed you needed at min. 10 LBS. per 1000 RPM (V8) or you were in trouble and would not get the necessay 6/7 lbs. at the last rod to avoid trouble. Seems more was wanted but the best pressure was a measley 6/7 lbs., and a few were suprised that much pressure was given with all of the sprinklers (pressure drops) within a engine. Add them up!
All agreed running without oil was a problem (no fooling).
Have you ever seen how far a 5 lb. stream of fluid/oil will go BTW at whatever size port?
Consider engines with scupper oiling.
Hornet's ran like scalded dogs down the beach, crank splashing into the (oil) reserve, bathing everything. Oil filter, you have to be kidding.