I don't understand the 10W30 thing, to thin for me.

 

Found this on Hughes web site.

#5---Break-in oil for roller cam engines?

#8---Bearing Clearance and Oil Viscosity

 

Brian at IMM Engines told me to run 10w30 in the engine he built for me. So that's what I run no questions asked. lol

 

There's usually no need to run a thick(er) oil with a fresh rebuilt engine.
Unless of course you went on the 'far-side' on the bearingclearances for some reason.
There's also no reason to run with 80psi of oilpressure all the time.
Let the oil-pressure gauge tell you want the engine needs.

 

a mechanical roller lifter is not nearly as fussy on oil as say a VVT motor
but the 10 in 10-30 is way obsolete
run 0-30 modern oil or 0-w40 if you are a corvette going to "track day" or have older larger bearing clearances
royal purple or whatever

the link in Hughes #5 (above) is broken
Hughes #8 looks good give it a careful read

 

Didn't notice the date in the corner of #5 is 2014 so that is probably why the link is broken.
Be careful of tight clearances on old mopar blocks, I have seen spun main bearings from tight clearances and that is a block killer. When making a lot of torque and power the block will get some twist and the mains will get out of line. If you have a tight clearance the crank will rub the bearing pushing the oil out and will get hot and grab the bearing and it's all over. I would rather run the mains and rods a little loose and run a heavier oil and good pressure 60 psi at 6000 rpm. I have never lost a bearing in any small block even at 7500 rpm.

 

The mid/late-80s stock rollercammed 318 I had in my Dart ran perfectly on 0w20 oil.

 

I`ve got hughs lifters on my 505 , and use 20w 50 synthetic -----------

 

think about that 20w Bob if you start cold
I used to do 20w-50 in the summer but no longer do
However it really worked good in a mid 80's VW Waterboxer Vanagon
everything else would burn oil- go figure
I rebuilt that motor- got the parts from "Boston Bob" great resource now gone
NEVER AGAIN on that motor

 

cast cranks are stiff
forged flex more so I give them more clearance than cast
point about block flex is well taken
(think late olds and cads had to have lots of extra clearance)
and then there is bearing diameter (bearing speeds) and widths
but that #8 is a great start

 

20w50 , supposed to act like 20 w when cold , and protect like 50 w when hot , that's what I think -----------

 

I suspect the lighter weights are to make sure the oil gets readily into the axles in the roller lifters and the axles in the rockers. Since the OP is looking to use a straight synthetic, I think he will be in very good shape. The synthetic aspect of the oil will work better and it will actually be thinner in the temp ranges when the engine is cold and when still warming up, and so will get to those points better than a dino oil.

Keep an ear open for lifter noise.

 

I'm running the Eddy heads... Hughes Roller lifters.. roller rockers.. on a Hughes cam in my LA 360 and use Driven 10w30 oil. Have no issues. I will stick with the dino oil.

 

sticking with the dino oil works especially with a carb engine where you get choke and cold wash down just change it regularly
However the $20 a jug synthetic at wal mart in 0-30 will show less wear over time as it protects better at start up even in a warm state oil is still "cold"
BTW in tests we did for the local fire department starting and ideling the trucks to "warm them up" cost $$$ big time compared to start- drive easy- backit down (creating a vacuum) and back up a few times and go- changed the oil too
oil analysis etc. The oil never got warm ideling- just the water
and this is So Cal not in the mountains

 

I was using the Brad Penn 20w50 on my 408 with Hughes rockers and roller lifters. Car is in for paint and motor is on the stand, but I may switch to Bran Penn 10w40 when it's time for an oil change.

 

0w- 40 spec for the New Corvette is best available
This is DEXOS 2 which is not Dexos1 version 2
in Mobil 1 it's ESP