Type 1 40W Oil Temp on 100 + Degree Days

I'v been testing Four types of 40W Oil in my 1776cc Type 1 Engine. I've got a Dog House Cooler and Large Remote Auxillary Oil Cooler W/Fan, Dual Dell's and the Engine isn't running lean.

I'm testing Valvoline, Castrol, Tork-O and Kendel.

I live in Central California and I put 300 Miles on the Valvoline and 300 Miles on the Castrol. Both Oils are 40W and so far the Castrol appears to be marginally better. The tests were conducted on two recent trips in weather between 94 - 102 degrees. The Castrol ran at roughly 10 Degrees cooler then the Valvoline.

I'll try the Tork-O next and then the Kendel. I've had excellant results in a Water Cooled Late Model Engine with Tork-O.

On the trip that I conducted the tests, the Oil Temp was 210 Degrees on the Castrol and 220+ with the Valvoline. The average speed was 65-75MPH crusing. The Fuel Milage wasn't much effected with either oil 33 mpg with the Valvoline and 31 mpg with the Castrol.

What oil temperature's have you experienced in Summer Hot Weather Driving?

Jack Blake - 57 CMC Speedster

Jack,
I have a 1776 mexi-crate and am running Castrol 20W50. Last summer in 95+ OAT I was getting a reading in the range of 210 - 215 degrees F via dipstick thermometer. When it is hotter than this outside, I usually find another way to amuse myself.
John H.

Jack, sounds like a good test. I used Castrol HD30 for a year then switched to Kendall 10-40. I like the Kendall GT1 better. I live near Redding, where are you? Eddie.

Jack: Is the hotter oil doing a better job or worse? If it has a higher heat capacity, it is possible that more energy is transferred from the heads to the oil then out to the cooler. The cooler oil may not be able to collect the energy as quickly. What would be telling is to monitor head temps. The cooler the heads run the better the oil for our needs.

Gordon,

I've got test equipment that would only require the attaching of "Thermocouples" to regester the individual cylinder head temperature.

As for effect of the oil, the valvoline had greater loss of Oil Pressure than the Castrol. The Valvoline heated up to a higher temperature and then the Oil Pressure reduced caused by "Thinning". After each test, with both Oils, there was no sign of "Foalming" or "Blackening".

As for the Cylinder heads generating heat faster then "Heat Exchangers" (Oil Coolers) could reject the Heat Load, this may be corrected with a larger Heat Exchanger (Oil Cooler). My Type 1 has a larger Capacity Oil Pump and the plumbing to the Large Auxillary Oil Cooler W/Fan has no restrictions except the pressure drop generated from the Cooler itself.

The engine rejects heat very quickly if the load is reduced however;
my initial results seem to side with Castrol due to lower operating temperatures and less oil pressure loss (Thinning) during high ambient conditions.

Jack Blake

The reason Porsche replaced the temperature gradient numbers with a green bar operating range on oil temp gauges was that their customers were freaking out when temps went over about 220 F. Try to keep oil temp around 185 to 195 but with modern oils (especially synthetics) 220 to 240 isn't too bad if you change your oil fairly frequently and cylinder head temps stay pretty much below 325 F (preferably below 300 F).

I would try Kendall 20/50 GT - if the 40 weight doesn't flow fast enough between bearings and journals it picks up more heat, and if your rod big-end side clearance is tight that further impedes oil flow.

One VW performance engine builder I know will cut relief notches in the sides of the rod big-ends to increase oil flow if his customer insists on tight big end clearances.

My new performance engine is running bearing clearances of .003" rod journal, .0035" main journal, and .018" rod big-end side clearance. Hot oil pressure is 25 psi at idle and 65 psi at 6,000 RPM with Kendall 20/50 GT.

(Message Edited 6/16/2003 4:32:25 PM)

MY 911 pick up is going in for an oil change next week. What oil should I use? It's a 1973 911T that has been breathed on to the tune of about 200 hp. Should I go with synthetic (Amsoil), or I've heard good things about Kendal, as mentioned by George in the above post.
I'm also going to have the tranny oil changed too. Amsoil in the tranny too?
Ron

George & Ron,

George - I was recently at a Race and spoke to several Petrolum Engineers and discuss Oil Viscosities with them. Each indicated the lower Viscosities were primarly designed for upper end fast lubrication for Late Model Engines with OHC's and the Oil Pumps were engineered with closer tolerance's so the Wet Sump Engine could quickly lubricate the Upper End during Cold Starts. The Oil Pumps in the VW were engineered long ago and this is why I've always utilized the Mono-Weight Oils. I've utilized Synthetic's in my Transmissions & Differentials in different Race Cars and the HP out put was over 450HP without any problems (Amsoil). If you know information regarding the Oil Pump Impeller Tollerance Design I'd like to try Red Line Synthetic. Several drivers I know use it in their Late Models however I know of no one using the oil without just "Trying It" and I like to research such areas prior to "Trying It" especially in my air cooled Type 1.

Ron - I owned a 69' 911T and utilized Castrol 20-50w with very good success in the Central San Joaquin Valley where the Ambient reaches easly over 105 Degrees.

Jack, I was in Visalia last week - would have looked you up if I knew you lived in the valley.