Tom@SpeedInc

iTrader: (5)

So i'm runnig in my 408 i'm changing the oil regularly, its under 1,000 miles, for the first few hundered miles I ran the motor on Kendall GT1 10W40, it seamed like a decent value as I knew I needed couple gallons of oil to wear this motor in. The valvetrain was very quiet with the GT1 mineral oil. As I assume Kendall GT1 is otherwise Motorcraft 10W40 both made by conoco phillips.

So I decided it ran well with 10W40 didn't consume any oil, 500 miles dump in some Castrol GTX 10W30, sounds like a sowing machine used half a quart in 250 miles I'm going back to some heavier 40 weight oil again run an oil analysis, before this motor is switched to expensive synthetic oil.

What kinda oil does everyone else use in larger bore LS motors etc?

11 Bravo

iTrader: (3)

Well, I am using Castrol 10w30. The motor has barely over 1000 miles, but it's using alot of oil. Sounds like I need to try 10w40.

Z'mnypit

iTrader: (58)

Same here got around 1500miles on it, and use castrol 10w30. I dont use any oil, but it makes the sewing machine sound once it gets warmed up. Im going to try the 10w40 this weekend and see if that helps.

xaon

iTrader: (12)

I also run std Castrol 10w40. Has worked well enough for 7k miles in 2 months

ninobrn99

iTrader: (8)

i wonder if my 370 is gonna react this way...

Tom@SpeedInc

iTrader: (5)

That Castrol GTX 10W30 ended up using a 1 quart of oil in 250 miles, switched over to Valvoline VR1 20W50, no oil consumption as of now just passing 1,000 miles on this motor. Normally i'm hesitant to use thick oil but read this months GMHTP, a rep from Lunati was talking about how they use greater bearing clearance in aftermarket crankshafts. Their reasoning tighter main bearing clearance creates more heat. So with a stroker set up I don't see a problem with 20W50.

Valvoline VR1 20W50 was only $2.80 or so quart at autozone.
http://www.valvoline.com/pages/produ...asp?product=50

i'm finding 38-40psi at idle and 60+ WOT