Club Cobra - Bob the oil guy website guidlines

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Hi Excaliber. I am agree with you man! Nice idea about the SYNTHETICS. Nice! :D

Quote:

Originally Posted by Excaliber (Post 1081233)

"........................ TO much oil pressure COULD be a problem how ever. Extra stress on the oil pump drive shaft has been known to twist and break them! Over a certain amount and the oil by-passes the oil filter. If you are running "high pressure" it's certainly important to keep the rpm low to reasonable until it warms up......................... Another reason I don't care for synthetic oil is the long oil change intervals usually recommended. My position has remained unchanged for decades on this subject, in spite of "new studies". People ask what oil I prefer, I tell 'em, use a good quality brand name and STICK WITH IT and change it often.

if you are going to run a high volume oil pump, then a chrome moly steel oil pump shaft is suggested. I've never seen a quality chrome moly shaft break or twist. Cheap insurance

I don't have a problem using a synthetic oil & changing it often. Especially with a supercharger, as blow by/contamination is increased. Mobil 1 15w-50, a high volume oil pump, & a chrome-moly oil pump shaft, have been a very stable combination for me. 34,000 miles later no leaks, no measurable wear,

@ 75- 105 degrees F. air temp. with a 180 degree thermostat

cold engine:

pressure @ idle: 82 psi

hot engine:

idle (800 rpm) ...... 35 psi
1500 rpm ..............70 psi
2000 rpm ..............72 psi
2500 rpm ..............75 psi
3000 rpm ............. 80 psi
3500 rpm ............. 82 psi
4000 rpm ............ 85 psi
5000 rpm ............ 85 psi
6000 rpm ............ 85 psi
6500 rpm ............ 85 psi

I've used Mobil 1 15w-50 in several FE engines over the years without any leaking issues that others seems to have. just lucky I guess.

Z.

Been running 0w30 synthetics for years now,1 yr change intervals.

Just remember the golden rule of fluid dynamics;
Pressure and flow (volume) are inversely proportional.
High pressure = low volume.
Low pressure = high volume.

Eric

Quote:

Originally Posted by vector1 (Post 1081349)

changing my oil out and think i am going to use mobil 1 delvac 1300, 15w40. diesel engine oil.

Oil intended for diesels generally have lower rates of "anti foam" additive due to the generally lower RPM ranges of the engines. I would be wary of twisting 7000 RPM with oil designed for a max of 2500. The windage at double the RPMs, despite a windage tray must be substantial. Just saying.......

Eric:
Where did you get that? Who decided that high pressure = low volume? Should we now get into a discussion of "Reynold's Number" as it pertains to oil flow in an internal combustion engine?

How about "Lower Viscosity = Higher Flow", "Higher Viscosity = Reduced Flow".

Bob

Quote:

Originally Posted by TXBLU (Post 1081800)

Just remember the golden rule of fluid dynamics;
Pressure and flow (volume) are inversely proportional.
High pressure = low volume.
Low pressure = high volume.

Eric

don't take that to any extreme. In a Ford engine low pressure is more a result of excessive clearances than any other cause.

Z.

I found some interesting information on oil pressure, if you oil pressure drops across the entire range of operation from new it is worn main bearings, if it is good at lower rpms and drops off at higher rpms it indicates worn connecting rod bearings. The reason being centrifugal force. At 6000 rpms it is equivalent to the rod bearing spinning 165mph around a 1.5"? circle. WOW!!!!

Oh, the most valuable information I found is ALWAYS VERFIY GAUGE READINGS with a second gauge!!!!!!!!!

Hey MM:
Assuming a 4 inch stroke the bearing are traveling 12.57 inches per revolution (pi X d). This is 6,283 feet per minute at 6,000 RPM. That works out to about 71 MPH (not 165). The amazing part to me is that at 6,000 RPM the pistons are going up and down 100 times per second.

Bob

I got the value off the article, I thought 71mph was like 5000 rpm. Needless to say there are forces working that may not be obvious at first.

Quote:

Originally Posted by Bob In Ct (Post 1081882)

Quote:

Originally Posted by Mark IV (Post 1081853)

Delo 400 is designed for gasoline performance engines as well as diesel.
I will be switching on to Schaeffer 705 when I have done some miles in this car, I know of several people who race with Delo 400 in smaller engines, and have read good right ups from people in the US with speedway engines that swear by it.