When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm in Southern California, so temps are always on the higher side. Right now we're all freezing at 55 F outside.
Even so, wouldn't a 50W oil be too viscous for a daily driven car?
No,,the 50 viscosity is the hot viscosity rating. 50 viscosity at warm temperature is still thinner than the 5 viscosity oil at the cold index temperature. 50 viscosity index oil when hot isn't thicker than 5w viscosity oil when cold, it's thicker than 5, 10, 20, 30, and 40 viscosity oil when hot - the rating scales should be looked at separately at the two different temperature scales.
From driven’s catalog. Xp6 is a 50W, xp9 a 40w. I apologize for over posting this but most people don’t understand how quickly viscosity decreases with temperature.
In addition to external oil coolers, I've considered a pre-start oiling setup where you turn the ignition key and wait 30 seconds for oil to be circulated before starting. It's been discussed here and other places for a long time, but don't really see actual use other than on some racecars and older Ferrari's.
Here’s the setup we use to flush an engine and build oil pressure prior to the first start after rebuild. We pull the oil pressure relief spring and plunger to allow it to fully circulate.
Turn it into a kit! Just need a t-stat, oil cooler (and a place to mount them). I would consider an opening like on the Turbo S on the rear bumper a great spot for one.
Maybe something like this, it includes a fan mounted to the top of the oc (below is a trans cooler):
Turn it into a kit! Just need a t-stat, oil cooler (and a place to mount them). I would consider an opening like on the Turbo S on the rear bumper a great spot for one.
Maybe something like this, it includes a fan mounted to the top of the oc (below is a trans cooler):
What model of cooler / radiator is that? I need one.
Still the same question though, is a 5W50 too viscous at normal temps / daily driving?
I would also like this question answered or at least discussed. If the takeaway from Baz's post is that hot thin oil contributes strongly to bore scoring, then why not use a thicker oil all the time? 5w50? 10w60? More?
No, it's not too viscous. The reason manufacturer's specify the lightest weight oil they can get away with is because the lower friction improves fuel economy and helps with EPA requirements (M1 0W40 is barely a 40W and becomes a 30W after a few hours of use). At some point, an oil could be too thick to form a film on the bearings based upon clearances. But a 50W seems to be the sweet spot for protecting these engines for most applications. If a car is seeing oil temps 245-250F+, then a 60W is required to maintain adequate film strength and oil pressure until additional cooling can be added.
I would also like this question answered or at least discussed. If the takeaway from Baz's post is that hot thin oil contributes strongly to bore scoring, then why not use a thicker oil all the time? 5w50? 10w60? More?
Still, with what Slaker is saying, it's really a 50W after a few hours. Air cooled rear cylinder does get hot in traffic. Engine holds 3 quarts, transmission holds 1 qt, clutch pack holds 1 qt. Master rod/slave rod like a radial. Roller bearing crank and rod bearings. Wet sump (not the VROD 1100cc -Porsche inspired).
Always wondered about the cylinder-piston interaction and sidewall loading. Twin cam pistons have almost no skirt. This is how they can fit 4 inches of stroke (103 cu in) under a bike with a low fuel tank and low down seating position. No skirt, as the crank counterweight comes right up under the piston on BDC. Just enough for the wrist pin.
Steel liner in an aluminum jug with fins. They can easily reach 100K miles unless you flog it at every chance and overheat it constantly. Oil temps are expected to reach 240-250 deg in normal hard (80 mph+) long distance riding. Oil change intervals at 4K miles.
So 1.687 liter engine for 95 hp. About 1/2 the specific output (56 hp per liter) versus my 2006 C4 Base MT (93 hp per liter).
02-15-2024, 05:45 PM
I would consider an opening like on the Turbo S on the rear bumper a great spot for one.
