lifter and oil pressure questions

[rritchey]

leadertape,

I don't think you are missing any plugs because if you were you would never see 50 pounds of pressure. You really do not need more than 40-50 psi at cruising, and if you have 20 or so at hot idle your fine. You probably have big clearances, which is not a bad thing - to a point. I actually set all my FE's up with a little more clearance than factory, and the oil pressure usually is in the 20 psi range at hot idle, and around 50 or so at speed. Look at it like this - if you have your engine set up and your oil pressure is 70 psi hot, this means your oil pump is pushing like crazy to try to move the oil but the oil is not moving very fast. If the oil was moving fast, the pump would not build up so much pressure. The critical issue is not really pressure, it is making sure your bearings are constantly supplied with fresh oil. You want the oil to get into the bearing and get right out. You do not want it staying in the bearing too long - it will get too hot. The bottom line is I think people put too much emphasis on oil pressure when the real issue is oil flow, and high pressure does not necessarily mean high flow. One more thing - do you have your idle set at about 800 RPM? I've seen some guys complain about their oil pressure being too low at idle and come to find out that the only problem was they had their idle set at about 400 RPMs. That's too slow for the pump to work.

[RICK LAKE]

rritchey Couple of things. First you don't say how tight or loose you set your motor up at for specs. I know guys running .003 on the rods and .0025 on the crank. Are you using a G&L coating on your bearings?? Unless you have a stock low compression motor, 20 psi is not enough in my 20+ years of wrenching motors. Maybe a chevy with a wider rod and crank bearing but not an FE motor. I don't have 20 years with FE motors yet but I want that .0015 film of oil to flow well and keep the bearings and crank from rubbing each other. If you are going to rebuild a motor every year, I would agree with you. I have G&L coating on the bearings and swan coating on the pistons skirts and tops. Ron Miller from CALI. runs loose motors, .003 on the mains and .0035 on the rods but this is for racing motors, not street engines. In a blueprinted book I have the spec are .0009-.0029 clearance on the rods, crank is .0020-.0035. My motor is, crank .0028 and rods are .0025. I have 1 other question, Just because you see 20 psi at the gauge do you think you have this in the whole engine with it running? Which block are you using? Side oiler,center oiler, top oiler?? These motors have different oiling systems as you know. Each motor builder has his own ideas on build a motor. Me I want that volume and pressure. I have never heard of oil wearing out a set of bearings (thats CLEAN oil). Have a good one Rick Lake

[Mr.Fixit]

"Me I want that volume and pressure. I have never heard of oil wearing out a set of bearings (thats CLEAN oil). "



Too much oil pressure will pit bearings. Pictures of what that looks like are right on the wall chart from the bearing manufacturers.

EDIT:

I mistakenly called it "pitting" when it is referred to as "cavitation erosion" where the oil blasts away the surface of the bearing

[Cracker]

and my engine builder said it should be 28 psi minimum (ideally). My oil pressure is 38 at idle & 93 at 6K. The engine by the way with standard stroke & Bore pulled 543 Hp / 496.3 TQ (yes the .3 is important ) Keep the pressure up!

Tony Hull
Cracker on CC

[rritchey]

Rick,

As you said, there are as many "correct" ways to set up a motor as there are motor builders. I usually set my clearances at .003" for both rod and main bearings. This is my standard clearance for a "Street" motor. If I know it is going to be run really hard, I'll go .0032" or .0033". Aside from reasons I mentioned in my earlier post about oil flow and such, how can I be sure that motor is never going to be run hard? I've yet to meet anybody who can completely resist the urge to flog it now and then, and if the guy goes over the deep end he won't have to worry. My .003" clearance is right in the middle of the acceptable range that you posted for cranks, and only .0001" more than the upper value for rods so I still feel very comfortable. I've built lots of FE's over the years and they all seem to be fine as I have never had any return to me for oiling problems. I did have a 427 recently that ate a cam lobe, I posted about it last week - but that is the only one.

The coatings are good to use, but I leave things like that up to the customer, after explaining what the benefits are. Again, the way I see it, these motors were built with plain old cast pistons (most of them anyway) and plain old cast rings and it was not uncommon for them to go well past 100,000+ miles and still be running strong (with the un-modified factory oil holes...GASP!!!). I'm not saying I'm against using modern technology or improving where we can, just that for most engines it is easy to go overboard. If you buy good pistons to start with, they are usually coated or empregnated with something to reduce wear anyway.

I agree the motor does not have uniform pressure throughout, the guage is just what the name implies, a guage. It is just an indicator of what is going on.

Cracker, those are nice dyno numbers - why don't you share with us what you used?

[Cracker]

It's NOS Side-Oiler 427:
11:1 Compression
JE Pistons @ .005 over standard
Eagle H-Beam rods (Forged & etc.)
LeMans Steel Crank (10/10)
Edelebrock 427 Heads (70 cc chambers & Big Valves/2.19 etc.)
Crower .591 lift ex / 5.79 Int. Solid Cam 260 Ex/255 In @.50
Jesel Roller Rockers & Chevy oiling system through
lifters & pushrods - this part was cha-ching$, cha-ching$ for me)
Port matched Edelebrock Single plane Victor FE Intake
Mighty Demon reworked extensively 825 cfm
MSD Billet Distributor
Shelby water pump
double belt (safety) March billet pulleys
Aluminum flywheel
12" McLeod Clutch & Pressure plate
1.7/8 headers
Completely balanced/blue printed off crank center line and every flat surface
decked for trueness (BHJ Blue printing standards? or something like that)
Oh, I almost forgot - one big BILL!

Max HP: 543 @ both 6000 & 6700
Max TQ: 496.3 @ 5100
TQ Range: 461.5 @ 3300 to 474 @ 6000

Hope this is what you were looking for!

Tony Hull
Cracker on CC

[RICK LAKE]

rritchey You run a loose motor. Your numbers are on the edge of the blueprint spec. There was a few things that I didn't ask. Oil. Somepeople use a multigrade oil, some a Mobil1, and some a straight oil sae30. For your .0001 on rods the oil will have no problem taking up the differents. Bearings. As you know there are different hardness of bearings. I believe that the tri metals are what most of us run, but you can order softer or harder. I have not heard of any cobra with the orginial motor with out rebuild or freshing up go 100k. I know a friend with a countrey squire 390 with a 162,000 miles and only replaced the timing chain set and water pump, valve cover gaskets too. This car is not beat on and his wife is a good driver. The car does 70% highway driving. He put a preluber in the car 10 years ago. He runs 10-30 in the winter and 10-40 in the summer Quakerstate.If the body doesn't rot out first it will go 500,000 miles. This motor does not see more than 3500 rpm. The harder you beat on a motor the short the life span. Cast piston 30 years old where better in metal than the stuff we buy today. The machining with cnc is better but that old machist 40 years ago had more pride in his job and better materials to work with. I will keep my pan loose to check for this pressure damage, next year I am going with a 484 kit with chevy rods. Wider bearings, more choises to pick from. The power game is changing from long stroke or square motors to short stroke large bore and 9000 rpm. With my blower I am happy where I am. Have a good one Rick Lake

[ed cougar]

I see you've got a lot of experts thinking but nobody mentions your pump to block gasket leaking, maybe I'm out of my league but could this cause your oil pressure to be low? I would think so.