Need help with engine oil.
 

The persons mechanic I got the car from recommended Amsoil 20w-50 full synthetic. However, I called the shop who built the motor and they said they only use that weight of oil to dyno with. Then they recommend to drop down to a conventional 10W-30 in the winter and a 10W-40 in the summer.

They also said only to use synthetic during break in then switch to a conventional oil. I have talked to a few friends of mine and a mechanic and they say go with a 10W-30 conventional or synthetic and switching back won’t hurt the engine if I decide to go with conventional.

Can anyone add some clarification to this? The car is leaking a bit of oil and I won’t to get the right stuff in there this time around. I posted a pic of the engine build sheet below.

https://uploads.tapatalk-cdn.com/201...41aaa6cba2.jpg


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The answer to every oil question is: It depends.

What are the bearing clearances, and how are you using the thing? What do your oil pressures look like hot at idle and a WOT?

What is the oil recommendation from the lifter manufacturer? Erson told me never to use anything heavier than a 5w40 with my lifters. The cold weight is important. If there's not enough flow into the lifter at startup to pump the lifters up, you'll get a bunch of loosey goosey pushrod action and it'll make a ton of noise and hammer the cam bearings.

You can switch back and forth between synthetic and conventional. That's not a problem.

Where's it leaking?

Thats normally the other way around.

Conventional wisdom, yes.

I'm not sure it really matters on a roller motor anymore. Breaking in on conventional is definitely more economical. No sense spending $8 a quart on something that's only going to be in the engine for a short time.

I have to be honest most of the questions you just asked are way above my knowledge of engines. I will check the gauges next time I am driving it. I am mainly just driving it around for fun and running the piss out of it from red light to red light and in deserted parking lots to burn a little rubber.

My plan is to lift it up this week sometime and get up under to see where the leak is coming from. All gaskets were just replaced in October. The engine manufacturer said it could be the full synthetic that's causing the leak. I personally don't know how much I believe that though. Engine was purchased and built by Skip White performance.

That's a big negative, Ghost Rider.

Synthetic oil doesn't cause leaks. Failed containment (seals) causes leaks. Period.

My thoughts exactly

A good quality conventional 10w-30 like a Brad Penn is where I'd start unless you road race it and it see's extreme temps. Then I'd go with a synthetic. Your hot oil pressure will dictate the ideal viscosity. If you have over 20 psi at idle hot, you are good to go. If you want to get another 5-10 psi, bump it up a viscosity or two.

As it turns out, it really doesn't matter what brand you use.

https://gallery.mailchimp.com/f64139...Aug_17_ENG.pdf

It's basically all the same crap regardless of what's on the label. Unless you need the high temp capability of a top-line synthetic, anything you get in the proper weight is going to be fine.

Spend the money on a quality filter.

Hi,
My thoughts are I would just make it as simple on yourself as possible and not use conventional if you can afford synthetic. I'd pick 1 viscosity oil and run that year round. Based on what you said I'd pick the 10w40 because you don't get really cold temps for any extended period of time in Texas. Have the UPS man deliver your AMSOIL oil and filters and all your other lubricants to your door to make it even easier on you. :ups:

Here's a link to free shipping on orders of 100 or more directly from AMSOIL