Mods are in sig. I've put 1000 miles and two oil changes on it so far. Been using the Rotella T 15W-40 for the break-in. Getting dyno-tuned on friday and wanna switch to synthetic before I go. I'll probably use Mobil 1. Should I go with a thinner oil or stick with the 15W-40?

Also, when changing over to synthetic, do I just do a regular oil change and leave it for a few thousand. Or do you fill it and let it run for a while and then change it again to get all the dino oil out? Thanks

 

Diesel Engine Oil? Why?

Where do you live (climate)? How did your machinest put the motor together? Loose, target, or tight side of the (bearing) specs? I use Mobil1 10W30 on a stock motor... but I live in Arizona. Probably anything colder than my climate I would recommend 5W30... assembled to factory clearance tolerances of course. I would not recommend anything higher than that unless you are trying to improve an existing oil low pressure condition based on loose motor assembly.

Bill

 

I always use Mobil1 or Amsoil 10W-30

 

I was told by a number of people to use the Rotella T for about a 1000 miles just for the break-in. It's supposed to contain stuff that helps the rings sit.

 

I thought strokers required a thicker oil?

 

I like Royal Purple. What were your main/rod bearing clearances?

 

ive heard this before by alot of people

once i get my truck back im going to amsoil 10w/30

 

Whoever told you that was a moron. Bearing clearance, bore clearance, etc don't change just because the engine's a stroker. The only thing I've EVER used 15W-40 or 20W 40 for is a worn out old 305 with really bad rings and anything thinner would burn because of the bad rings.

Tight bearing clearances require the larger range oils, like 5-30, 0w30/etc. With the thicker oil in a NEW or remachined engine is just tearing it up quicker... which I could guess would seat the bearings/rings in faster due to the increased wear. But I'd never do it...

I've always assembled with a straight 30 weight NON-DETERGENT oil (detergent oils attract dirt, it's their job). Run for 20-30 minutes at varying idle speeds, drain, then fill with what ever oil I'm going to run forever... usually Amsoil 5-30. Today's technology rings/etc require very, very little break in compared to the olden days and their brittle little rings.

 

Your stroker will burn more oil than an conventional engine because of the ring placement. Because of the increase stroke the rings must be slid up to the top of the piston. I have not switched to synthetic yet because I want to get an Idea what my oil consumption will be whith dyno oil then see what happens when I switch to synthetic. I would use a 30 weight of some sort if it were me.

 

I just bought some Royal Purple 10W-30. Thanks for the info guys!