Oil Temperatures

[David Jackson]

Hello Mike;

I saw and read the thread on cylinder head temperatures as measured with some sort of temperature reading gun. I don't have one of those but I do have concerns about oil temperature.

My bike has HD Syn 3 oil in all cavities. After the ride I checked the oil level and it was somewhat low.

I have had an oil temperature guage (Harley's) installed on my bike between the two handlebar clamps with a Harley mounting bracket. This is an electric unit I think; that is it uses some sort of electric readings for temp.

On a hot day (yesterday) I went on a 200 mile ride through the hills near where I live in northern California. My oil temperature on this guage registered just above 230 degrees at the lowest to about 260 degrees at the highest. The actual numbers are a little hard to give and the dial is small and the graduations therefore pretty close together as well as at some odd intervals. I was pushing the motor just a bit I suppose.

My motor is 113" from HD Bigger Bore Cyls and SE 4 3/3" stroker flywheels with SE CNC HTCC ported heads a Wood 505 modified CV carb and Wood 408G cams. I have the Latus case breather set up in the cases and Northwest balanced the flywheels. I have the Feuling racing oil pump, racing lifters, the Latus spring in the Feuling cam plate, the Feuling fasteners, the SE rockers and supports, and I guess that about covers the motor. I am using a HD set of stock header pipes with SE II slip on mufflers (partly because they aren't all that noisy and my bags fit, and partly because my D&D Boarzilla won't fit for some reason. I do have a V&H ProPipe with both baffles to choose from, though I don't like the sound the Pro Pipe makes very much. I only mention the exhaust systems in case one of them is better for oil temp than another.)

Trans is stock 5 speed.

I have two oil coolers mounted on the bike; both JAG ones. I have the HD model which goes between the frame tubes and a JAG 10 row made for Electra Glides mounted on the left frame tube. I looked through the instructions which came with the HD oil cooler and have not found any specifics about which is intake for oil and which is exit. My intuition tells me it does not matter but maybe I am wrong. I have the coolers mounted in series, so to speak. Would you think there might be a specific way to set the hoses for the two coolers for maximum efficiency? I just thought that oil goes in one end and comes out the other.

Is this oil temperature too high? Should I get another oil cooler (then I will have three!!)? Should I get another guage, the dipstick mounted one and compare it with the handlebar one? Are the handlebar guages inaccurate to the tune of 20 to 30 degrees?

What is the most effective oil cooler on the market in your experience?

Many thanks in advance;

David Jackson

[Mike]

Those oil temps under those conditions are absolutely normal!!! Temps as high as 350 can be acheived with aggressive riding or in parade situations. Typ., if the bike is overheating, detonation will set in an be heard as "pinging", in addition, the lifters will not maintain zero pump-up and start to clatter. These audible indicators normally cause the rider enough concern to stop the bike and rest. The h-bar mounted gauges are notoriously inaccurate but the in-tank dipstick LED gauges are very good. The SE mufflers can contribute to higher oil temps vs. more open exhaust as a function of heat retention in the exh reflecting back into the head exh ports. Higher compression ratio's and naorrow cam timing (i.e., higher cylinder pressures) also contribute. The reason for the higher HP that goes with hi-cyl press. is that more energy is released in the form of heat.
Big displacement motors can have higher oil consumption because of greater ring/cylinder diameter and more difficulty in maintaining good ring seal for the same reason. Another contributor to higher consumption is breathing capacity as the area under the piston increases with motor size (as the piston goes down, more air is compressed into the same area as a stock 88ci motor). This addtitional pressure can make it more difficult for the oil to be effeciantly seperated and scavanged. Our reed valves transfer some of this additional pressure to the cam chest and rocker boxes. Overfilling of the oil tank will cause excessive consumption as the oil seeks it's normal level by purging the excess out the head vents.
So long as the Oil coolers do not have built-in thermostates, running in series is Ok. Just remember that when the oil is cool this can create substantial resistance to oil flow back to the tank which may then cause exess blowby through the vents and wet sumping in the crankcase. If mounted in parallel, the oil will simply take the path of least resistance (i.e., may not flow through both coolers, this is actually how the thermostats work). As the temp. increases, it will more easily flow through more of the cooler. We can cool these motors too much. They are designed to be run with temps. typ. at 220-280.
Thanks, Mike

[David Jackson]

Thanks Mike;

You have given me some things to think about; as you always do.

One of these days I may look for some sort of "T" fitting and try running the coolers in parallel; but it seems as though I might be wasting one cooler if I do that.

I have the Latus case mods, I have the Feuling race pump and other Feuling goodies and also the Latus spring in the Feuling cam plate. If my motor wet sumps with cold oil will those components in my motor empty the sump when the oil gets warm?

I rode down to the local dealer's today and the service manager stuck his digital dipstick from his brand new FLHTCUI into my oil tank. It read appreciably higher than my hbar guage. I suppose it would be a good idea for me to get the appropriate dipstick guage for my bike and compare readings (while stopped, of course!) so I can know when my guage says "X" the temp is really "Y". I like the hbar guage because it can be monitored while riding.

Regards;

David Jackson

[Mike]

The other case mods we do along with the reed valve allows the oil pump to scavenge the oil from the crankcase sump, even in a slightly wet sumped situation, vs. the stock setup.
Thanks, Mike

[Sundance]

Mike,

What kind of case mods are you referring too? Thanks

[Mike]

We have proprietory mods we do to increase scavenging, breathing and scrapping for large cubic inch motors. They are done in-house and if you call I'll be happy to explain exactly what these are. The cases must be disassembled and what mods are done depends on motor size.
Thanks, Mike