rebuilt 502 burning oil
#1
Registered
Thread Starter
Join Date: Mar 2007
Location: new jersey
Posts: 257
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
my 502 was redone over the winter. it always burned oil and is still doing it. about a 1/2 quart every 1-2 hours. is this common? no leaks at all. i change it out every 10-15 hours. using napa premium 20-50 with wix racing filter as per my motor builder. also can you check it on the trailer or do you always check it in the water?. thanks mark
#3
Platinum Member
![](https://www.offshoreonly.com/forums/images/icons/platinum_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
Gm 502's originally used j/e pistons with metric low tension rings,it sounds like you re-used your pistons and the rings even though they may be new are not sealing. When my boat was new in 2000 it used oil like crazy,I made those pistons into ash trays and put in j/e srp's with STANDARD rings,it barely burn't 1 quart of oil every 10 hours after that even with a supercharger. The replacement pistons were a few thousandth's bigger so you could hone the block on a tq plate and re-assemble it without boring it out,they weighed so close it did not need re-balancing either. Smitty
#4
Registered
Join Date: May 2007
Posts: 64
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
Just my 2 cents but ...I have seen a lot of engines rebuilt and
use abnormal amounts of engine oil....
On big blocks the finish of the cylinders is extremely important
if they are too rough you will go thru everything in the crankcase in a day!
use abnormal amounts of engine oil....
On big blocks the finish of the cylinders is extremely important
if they are too rough you will go thru everything in the crankcase in a day!
#5
Registered
Join Date: Oct 2004
Location: CHESAPEAKE,VA
Posts: 692
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
my 502 was redone over the winter. it always burned oil and is still doing it. about a 1/2 quart every 1-2 hours. is this common? no leaks at all. i change it out every 10-15 hours. using napa premium 20-50 with wix racing filter as per my motor builder. also can you check it on the trailer or do you always check it in the water?. thanks mark
#6
Registered
Thread Starter
Join Date: Mar 2007
Location: new jersey
Posts: 257
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
isn,t rebuilt stock. pushed it up to 550 hp. cam, heads, stainless marine exhaust. the motor only had 300 hours on it so we did reuse the stock pistons with a hone. new rings, new mains. i had heard that they are built to run a little wet. we also are running a 150 degree thermostat but i really don,t think thats the cause. i understand the 40 wt option but i am trying to keep with the program that the mechanic told me to follow. just trying to learn and get fresh ideas.
#7
Registered
Join Date: Dec 2007
Location: Plymouth Meeting, Pa
Posts: 68
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
How good is NAPA oil? Sounds like the rings never seated. Maybe the hone was not correct for the ring you are running. I would also check you pcv system. Just a suggestion.
#8
Registered
Join Date: Oct 2004
Location: CHESAPEAKE,VA
Posts: 692
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
isn,t rebuilt stock. pushed it up to 550 hp. cam, heads, stainless marine exhaust. the motor only had 300 hours on it so we did reuse the stock pistons with a hone. new rings, new mains. i had heard that they are built to run a little wet. we also are running a 150 degree thermostat but i really don,t think thats the cause. i understand the 40 wt option but i am trying to keep with the program that the mechanic told me to follow. just trying to learn and get fresh ideas.
#9
Registered
Join Date: Jul 2005
Location: Tulsa, OK
Posts: 1,729
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
That seems like a lot of oil consumption to me. Really, on a fresh engine with a new bore/pistons/rings, I don't think you should see any real measurable loss of oil. My re-done 454 has around 20 hours on it and I have seen no oil loss at this point. The oil was changed at 8 hours after the first weekend on it, and I'm getting ready to change it again. I am running Amsoil 20W-50 and the Amsoil filter.
#10
Registered
Thread Starter
Join Date: Mar 2007
Location: new jersey
Posts: 257
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
what brand of 40 wt are you using? are you checking it on the water or trailer? i really don,t want to run a synthetic. to expensive to change at 10-12 hour interviles. would my wix filter be holding alittle? thanks mark