I am running 20w50 in mine I was just wondering what most people are running in their LT1 race engines

 

20-50 redline syn. (5 qts.) with a dash of Lucas oil stabilizer (1 Qt.). Large bearing clerances. (97ss 383 - D1 - M6/ Moser 373) B.

 

I run 20W-50 semi synthetic in my race car. Frankly, I am thinking of switching to a thinner oil. However, the race car is alcohol and it is traditional to use a thicker oil in alcohol cars to combat the effects of oil contamination. This likely stems from blower cars, which blow large amounts of fuel past the rings and may well not be needed in an NA setup. For the LT1 I have always used 10W-30, as I would in any gas small block. Maybe even something thinner in that situation.

Edit: unless like above I had a motor that I deliberatly set up with wide clearances.

Rich

 

10W-30 on motor, Pennzoil 25W-50 Racing Oil with the 300-shot, per the engine builder's recommendations.

 

10w-30
I'm running .003 on mains and rods

 

5-30 synthetic but I am also only revving to 5800 RPM.

 

I think mine is .003 as well and I am running 20w50 and turning about 7600rpm does this sound right? Maybe I should try 10/40 for one race.I do change it every time I goto the track.Is it better to use a higher weight on a newer race engine to protect against steel fragments a bit or not?

thanks
Dave Jones

 

The people I have been helping do engines run 10-30 in most everything gas powered. Say there is no need for the thick oil. But they are all race engines and most all of them are .003

I have 10-30 in mine now regular oil but plan on going to the Brad Penn after a few passes

 

I'm running Valvoline synthetic racing 10W-30. And my car seemed to pick up a few numbers when I changed to the synthetic. I broke it in using 20W-50 conventional Valvoline.

WD

http://www.valvoline.com/pages/produ...asp?product=95

 

Keep in mind oil temperature plays a very important part in oil viscosity.

If this is a drag race application, even thou the water temp is 180+ the oil could be 120 or lower. Depending on sump size etc.. it generally takes 3X's the time for oil to get to operating temp vs water.

Running a thick oil like 20-50 at lower temps is like using gear oil. In this instance a 10w30 would be much better suited.

I would match oil viscosity to bearing clearances, operating temp range, and also additional considerations such as fuel dilution as mentioned earlier.

For the vast majority of applications - A thick weight 30 (generally the high mileage blends) or A 5w40 or 15w40 Diesel oil is an excellent and cost effective solution.

 

I use Shell Rotella 15-40, my clearances are .0025/.0028 on the mains.


David

 

I'm running 10/30 Lucas full synthetic race oil. Per my builders rec. I'm going to switch to the Valvoline race oil as soon as I can find it locally. 8qts per oil change gets to expensive but racing specific oil provides much better protection over conventional and standard synthetic oils.

Never been a big believer in using cheap oil for break in, during the most critical period of operation you want the best not the worst. I will never under stand what thats about. I used synthetic race oil for everything. $100 an oil change but I have $15k into the motor, so its cheap if you think of it like that.

 

I also have .003 to .005 on mains and rods, and I use 5w30 mobile 1 synthetic. I broke her in on GM mobil 1 non-synthetic 5w 30. After the initial 5 minutes of running, and heat cycling her once, and putting on 50 miles, changing the oil to non synthetic again, and then letting her have my foot up her ***, its been running absolutely flawlessly for 4000 miles! After 3 motors, I learned to break it in like you are gonna drive it, and dont be affraid to show her the R's. hehe. But yea, 5w 30 mobil synthetic now. works great.

 

wow hows that work? My rear main was about .0045 but the rest I had to set-up, some had taper out of the box and it took me about 10 hours to get it right.

Where exactly do you have .005? I'm curious b/c I lke to free em up.

You don't even want to know what my piston to wall clearance is.......

 

I thought that you would want a thinner oil, for less resistance = more power which in turn = faster, no?