496 Big Block Chevy street/strip

[Jake_Wade]

Putting together a 4.310 bore 4.25 stroke BBC for the street and an occasional 1/4 mile run at the track. I am running a retro fit hydraulic roller instead of a flat tappet camshaft so a high zinc content should not be needed. Max RPM will be 5800-6000.

Any thoughts on weight? straight 30wt? 10w40? 20w50?

 

[HM12460]

my vote, mobil 1 15/50

 

[Scienceman]

+1

 

[gtoracer]

+2

 

[Drew99GT]

Rotella T5 synthetic blend 10w-30 would be ideal; not too thick, not too thin.

 

[bmwtechguy]

Even without the flat tappets, I would still run at least an HDEO of some sort such as one of the 15W-40's or 5W-40 Rotella or other readily available choice. The M1 15W-50 is a good choice, especially if your oil temps will run high. I would personally not use a 30 grade oil unless your engine builder recommends one, or you use one that is blended for street use/racing and very shear stable such as an oil with a HTHS of 3.5 or greater.

 

[Steve S]

Originally Posted By: Drew99GT
Rotella T5 synthetic blend 10w-30 would be ideal; not too thick, not too thin.
30w drops the oil pressure too much when at operating temps in my engines. I would have the bearing and thrust clearances to the stock specs. Though it is worth a try ,depends upon the oil temps.I really like big block Chevs [not because they are better or worse] as they are easy to get parts and the parts are usually lower priced than Ford and Chrysler plus every body knows how to make them run good . I have had great luck running 15w-40 Chevron Delo 400 and Mobil Delvac 1300 in my BBC engines in my flat bottom drag boats they are econo builds that turn 7,500 rpm and the engines last and look good upon tear downs . BBC like to eat the valve trains with high pressure springs though, so they are considered. consumables.

 

[SteveSRT8]

We run BBC's and have found them to run 100k miles in a really radical street car... our oil was Amsoil 0W-30. Still have a SC stroker in a boat. Same oil.

These engines don't run big oil pressures, volume is much more important.

Break 'em in HARD and run 'em hard, we love them!

 

[Jake_Wade]

Thanks for the feedback! I dont want to break it in on synthetic for ring seating purposes.

I think I will break it in on Delo 15w40 and Mobil 15-50 thereafter.

Thank you

 

[shpankey]

Another vote for Mobil 1 15w50 Racing.

 

[mechtech2]

There are not many oils thicker than a 50 that are readily available.
Are you sure you want to jump up to this right off the bat?
An HDEO like 15-40 or the synthetic 5-40 version had better be all that you need. In other words, if it was machined and put together right, you should not need a 50 except in extreme situations.
How are you going to cool it? Is this a 30 year old radiator? Flex fan, clutch fan, or electric? Always use a fan shroud - the efficiency jumps up greatly.

 

[Jake_Wade]

It has a new aluminum radiator,clutch fan and shroud.

Mobil one 15w50 seemed to be the popular vote here. I have not assembled the short block yet. I have the rotating assembly here and block at the machine shop. Scat crank and rods with SRP 18cc domes. I will most definatly check clearances upon assembly. I expect somewhere between .002-.003 rod/main clearances.

 

[BBDartCA]

Originally Posted By: SteveSRT8
We run BBC's and have found them to run 100k miles in a really radical street car...


I would like to see pictures and get more info on a radical big block rat racking up 100,000 miles in this day and age.

 

[aquariuscsm]

Valvoline VR1 20W50.

 

[Hemi426]

Brad Penn Penn Grade 1 10w-40, Straight 40, or 20w-50

 

[UncleS2]

Chevron Delo, Shell Rotella, or Mobil Delvac in 15w40.

 

[mechtech2]

Up to .003" bearing clearances when new?
OK. You are right to consider heavier oils then.

 

[SteveSRT8]

Originally Posted By: BBDartCA
Originally Posted By: SteveSRT8
We run BBC's and have found them to run 100k miles in a really radical street car...

I would like to see pictures and get more info on a radical big block rat racking up 100,000 miles in this day and age.


If you want I can give you the name of my Machinist. He's my brother-in-law, 3rd generation. One [censored] of a man to know!

He could build one for you.

The motor was in a 66 Nova for four years, then was transplanted into a 89 Chevy truck after sitting for two years. All we did was go through the heads, never touched the bottom end at all. Ran around 660 rwhp depending on the carb used. I ran a 750 most of the time for good response, but it made more hp with an 1150 we had built for it.

It's in someone elses hands now, and they drive it every weekend they can. Still running great.

Heck, my boat motor (SC 502) is over 8 years old and runs perfectly. And it really revs, sometimes in excess of 7500 rpm!

 

[aquariuscsm]

Someone mentioned an oil thicker than a 50 wt. Only ones I can think of that aren`t boutique exotics are Pennzoil GT SAE60 and Valvoline VR1 SAE60.

 

[TC33]

I broke my 496 in on 40 weight Valvoline and have been running Mobil 1 15/50 for 120 hours. The engine in its original form was a 454 magnum Mercruiser with 600 hours on the clock. The original engine had always had a diet of Mobil 1 15/50 and when we tore it down it looked beautiful on the inside. The engine was in such good condition that I was a bit sorry that I had chosen it for my build.

Best of luck on your build!! Mine turned out great and it is an absolute torque monster for a 500 ci engine. Im certain that there are lots of oils that would work beautifully in your application and Mobil 1 has so far worked beautifully for me.