5...4 Quarts???..
 

We recently purchased a rebuilt 302 bored .40 over to a 306. Heres the thing guys...the dip stick shows almost a quart over. But were using 5k quarts of oil last time we changed and with a new filter. Im wondering why its saying this so? Any help? :D

First of all, .040" over is a 308. I just built one.

Second, did you run the engine first, before checking the oil level?

Good points PKRWUD.

LayanRubr, you need 5 quarts. :)

Yes I did :) as well Chris I dont mean to try to hack on your knowledge there cause you know a damn lot more than I ever will :D but most .40 I've seen claim 306 :confused:

Then you need to ignore those people. If they can't do simple math, I wouldn't take any recommendations from them, either. :)

To figure an engine's displacement, the formula is:

pi / 4 x bore squared x stroke x # of cylinders

Now, pi (3.1415927) divided by 4 equals .7853982, so the first part of the formula will always be .7853982:

.7853982 x bore squared x stroke x # of cylinders

Now, a 302 has a 4" bore, a 3" stroke, and 8 cylinders, so, by substituting those numbers, you get:

.7853982 x 4 squared (16) x 3 x 8 or:

.7853982 x 16 x 3 x 8 = 301.5929 cubic inches

With me so far?

Okay, now let's say you bore the engine .030" over, which means increasing the bore diameter of each cylinder to 4.030". Then the formula would look like this:

.7853982 x 16.2409 x 3 x 8 = 306.13375 cubic inches.

If you were to bore it .040" over, the formula would become:

.7853982 x 16.3216 x 3 x 8 = 307.65492 cubic inches

Get it?

As far as your oil problem goes, if the engine has been ran, then clean the dipstick and check it again. When you see where the oil mark is, get a punch and a hammer, and punch a dimple at the top of the oil line. This is now your new, accurate dipstick.

Take care,
-Chris

Oh God, he's breaking out the math formula's..........just take his word for it, hehe

Holy shee :D well I cant argue with a formula now giving me +2 cubic inches ;) thx Chris!

Good point pkrwud.

Somtimes people put a different length tube(Universal) which could be a little longer and make the level show low b/c the stick isnt going in far enough.....another way is to take the measurement difference off the stick and mark the difference on the top of the tube,,,,,, get a tubing cutter and cut off the difference off the top of the tube...this will allow the stick to go in further and read accurately on the stick.

dip stick
 

PKRWUD-
So are you saying to fill the motor with 5 quarts...let the motor run to get oil into the filter, shut off & then re-check dip stick and put a punch where the oil is? You got me thinking here...because I was under the impression that most 302s took a little less than 5 quarts. So is it more like 4 & 3/4s of a quart...or 5 quarts even?

It depends. Different filters hold more oil than others. Just go with 5 quarts, and forget about it.