Let’s talk oil viscosity

Since there are so many different weights of oil curious to see what all you run and why. Not worried about the brand just the weight.

I use the rule of thumb:
.002 or less bearing clearance 0-30w/5w-30
.002-.0025 clearance 10-40
.0025 or higher 15w-50

There are guys who run 0w oil in their engines. A lot of NASCAR teams run it in qualifying and a lot of pro stockers run it also.

What’s your weight?




<font size=-1>[ This Message was edited by: Scotsman on 1/6/07 9:58pm ]</font>

I weight about 205... But my car's they weight about 10W30... Wassamatta? Youse thinkin' I'm a Fatso? [img]/forums/images/smiles/icon_smile.gif[/img]
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did you see the car craft dyno test that got about 17hp by only switching to synthetic?

17hp from switching from conventional to synthetics. Amazing, the most I've ever heard of was about a 3-5hp difference. Car Craft may be over exaggerating as alot of magazines do.
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don't want to turn this into a AMSOIL discussion, I know it great stuff. We was having a bench racing session in the shop the other night and it went to oil viscosity. We got in to issues.....you have to run a dry sump pump with oil cooler to run 0w oils. If you run a conventional pump you need at least 10w. The it went to oil weight compaired to bearing clearances.
How do you all determine what visocity......

<font size=-1>[ This Message was edited by: Scotsman on 1/7/07 12:09am ]</font>

I simply use 10W30 in all my rebuilds. I don't try to determine anything.... But I don't build race motors.... Just good strong ones. [img]/forums/images/smiles/icon_smile.gif[/img]
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I learned a lot at the Engine Masters contest. Going from heavy ( 20-50 racing) down to 0-20 Royal Purple racing was worth 24 HP on a 550 Hp engine. Now I always use 10-30 for most engine buildups, That alone was 10-12 HP for free. On one engine I was running on the dyno, A 350 Chevy, tunnel ram,big roller cam, with his 25-50 racing oil, it made 626 HP, going to # 11 Royal purple(5-30) it made 652 HP with no other changes. JOE SHERMAN RACING

I personally run 5w50 Synergyn synethic oil from Dyson Oils . As far as I am concerned its the best thing out there.

for you all running 0w-?? oils, how many runs before your changing it?

That's a pretty amazing jump in power BigJoe. Dang. I wonder how a 0-30W synthetic oil would respond??
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