15w50 in new chevy v8?????

[TXsilverado]

i had a custom engine built. it is a iron block 408 LS style engine. the builder told me to run 15w50 in summer time and 10w30 during the winter months. i was curious why he would say this. the motor was built with a little extra clearance for nitrous use. i live in houston texas so it gets hot as [censored] during summer and winters are pretty mild.

i just did my first oil change from joe gibbs br30 as my break in oil, and put in some mobil 1 15w50. fifty cents more and i could have got some royal purple lol. anyways i was curious to the theory of running 15w50 on a gas engine since ive never heard of running that weight of oil in a gasoline engine.

 

[IndyIan]

Do you have a pressure gauge? Get one and an oil temp gauge and you can see if you need the 15W50 or not.

 

[justinf89]

I wouldn't run it unless your working it very hard or its burning 40wt. I don't know what the clearances are but It wouldn't warrant 50wt. If it can run 30 in the winter id say it'd be fine with 40wt

 

[TXsilverado]

oil pressure sits at about 34 at idle and probably pegs 80 at wot.

 

[ARCOgraphite]

NO. Oil pressure alone does not define weight required, you have those pistons to keep from slapping and Dynamic rod loads that require more viscous oil. The pump just gets the oil into the bearings, the viscosity determnes load capability. I would think with a real Syn in a race formula you could get away with a 10w-40 off the bottle. How big a Nitrous shot you talking?

 

[TXsilverado]

Originally Posted By: justinf89
I wouldn't run it unless your working it very hard or its burning 40wt. I don't know what the clearances are but It wouldn't warrant 50wt. If it can run 30 in the winter id say it'd be fine with 40wt


ill be spinning it past 7,000 rpm and hitting it with a 250 shot of nitrous.

 

[TXsilverado]

I just read a thread that told some info that you guys like to see so here it goes.

this engine is in my weekend warrior 4500 lb truck. when it is driven on the street, it is driven hard. it will also be put to the track. i live in houston where it is HOT. i will spin it to 7000+rpm peak. 250 shot of nitrous will eventually be used.

 

[addyguy]

If the builder told you to use 15W-50, use it.

He built the motor, he knows what it needs.

That's 'usually' the advice here, no?

 

[40Deluxe]

If you respect the builder enough to take the engine to him,then his oil recommendation should be followed,he must believe in 15w50.

 

[TXsilverado]

sounds good. i just wanted to make sure im not the ONLY one doing this lol. is it normal to run 15/50 in an engine like this, or would most normally run 10/30 or 10/40?

 

[440Magnum]

If you're pushing 80 PSI on a Chevy, I'd *guess* that you don't really need 15w50 to make up for the clearances. SBCs usually run lower than that. But then I'm GUESSING, and the builder should (theoretically) KNOW what he's doing. Problem is lots of engine builders do things because "that's the way we've always done it" and not based on good engineering. But the bottom line, you bought it from him, you probably should do what he says. Its not like its your average grocery-getter anyway.

 

[TXsilverado]

definately a well know engine builder with an awesome reputation. HKE racing engines out of houston tx built it. people from all over the US know of them though.

my stock LS1 with 10/30 royal purple ran 40psi idle and pegged 80psi at WOT too. these newer sbc engines do push alot of oil. this motor also has a melling high volume/high flow oil pump.

 

[Steve S]

I would follow the builders recommendations. It would be the best choice. And you posted the reasons the 15w-50 is recommended.

 

[Steve S]

Originally Posted By: TXsilverado
I just read a thread that told some info that you guys like to see so here it goes.

this engine is in my weekend warrior 4500 lb truck. when it is driven on the street, it is driven hard. it will also be put to the track. i live in houston where it is HOT. i will spin it to 7000+rpm peak. 250 shot of nitrous will eventually be used.
The 15w-50 will protect due to the pressure from the nitrous.

 

[901Memphis]

Also that M1 15w50 is a top notch oil either way. It would probably be wise to listen to the engine builder.