Rebuilt 454 in motorhome, oil weight

[userfriendly]

My last 10 SBCs & BBCs were built loose like that, maybe 2 1/2 on the mains. Lots of side leakage so a high volume oil pump is needed to keep up.
I feel the more oil that gets thrown up towards the cam the better. I use the big long filters, old Frampa # PH373, and leave the filter bypass operational.
SBCs are more forgiving in the oil department, but the BBCs as mentioned, like the thick stuff. Wait until the oil warms up before beating on the engine.
If you lose a rod bearing, maybe the oil wasn't thick enough. More pressure won't help as long as the furthest away bearings from the pump are getting oil.

 

[VSAWMike]

Originally Posted By: Alex_V
Originally Posted By: spasm3
If he does not know the main and rod clearances, could he use the oil pressure gauge as a guide? Try some 10w 30 and watch the pressure as it warms up, stopping to check pressure idle pressure at various stages of heating up. If the pressure drops too low at idle dump and go with the 40wt.
.

That's how I would go about gauging what weight oil an engine likes/will tolerate. If idle pressure is at least 25 at a good hot idle, with a high quality 10w30, and the engine isn't making a racket, no reason to think it needs a thicker oil.


Weight? No weight in motor oil. Only viscocity.

 

[VSAWMike]

Originally Posted By: dlundblad
Originally Posted By: skyactiv
10W30. Your engine oil temp will run cooler than a 15W40 would on a hot Arizona day.


I could see this being the case with an air cooled engine, but liquid cooled not so much.

Look at the wide spectrum of approved oil weights for vehicles in Australia. Zero catastrophic oil related failures with 20w50 or thicker.


What is an approved "weight"? No weight in motor oil.

 

[VSAWMike]

I'm trying to figure out why so many keep mentioning weight. No weight in motor oil.

 

[kschachn]

Originally Posted By: VSAWMike
I'm trying to figure out why so many keep mentioning weight. No weight in motor oil.

Now you've got me trying to figure out why this would be your repeated first post since joining today.

Do we already know you under a previous name?

 

[VSAWMike]

I also asked about changing to synthetic in my F-150. But I kept reading weight and wonder what was up with that. Never been on this site before, why?

 

[kschachn]

Originally Posted By: VSAWMike
I also asked about changing to synthetic in my F-150. But I kept reading weight and wonder what was up with that. Never been on this site before, why?

Just wondering.

The other just seemed like it was vitally important since you asked it four times, three times in one thread.

 

[CT8]

Originally Posted By: VSAWMike
Originally Posted By: dlundblad
Originally Posted By: skyactiv
10W30. Your engine oil temp will run cooler than a 15W40 would on a hot Arizona day.


I could see this being the case with an air cooled engine, but liquid cooled not so much.

Look at the wide spectrum of approved oil weights for vehicles in Australia. Zero catastrophic oil related failures with 20w50 or thicker.


What is an approved "weight"? No weight in motor oil.
pick up a gallon jug there is weight.

 

[Garak]

Yep, I haven't found a weightless motor oil yet.

 

[VSAWMike]

I mean the W in 10W40 means winter not weight.

 

[rrounds]

Originally Posted By: VSAWMike
I mean the W in 10W40 means winter not weight.

Well thats why you don't know what the "W" stands for on this site. About three years ago we took a vote and if I remember right the vote was 4535 to 3671 to change the "W" to weight instead of winter.

See, simple
ROD

 

[roadrunner1]

Originally Posted By: rrounds
Originally Posted By: VSAWMike
I mean the W in 10W40 means winter not weight.

Well thats why you don't know what the "W" stands for on this site. About three years ago we took a vote and if I remember right the vote was 4535 to 3671 to change the "W" to weight instead of winter.

See, simple
ROD


And a vote here means what?

 

[userfriendly]

I never got a ballot, the Russians must of hacked my account.

 

[BrocLuno]

Yeah, I never voted, did I ...

 

[c502cid]

Originally Posted By: leroyd92
Thank you for clearing that up for me I'm not am engine builder.

My friend just told me he typically used 1qt every 4500 miles. So it seems like the motor is happy with. 15w40


Either your friend is fibbing or I want the name of that engine builder! A big block that uses 1 qt every 4500 miles!

 

[BrocLuno]

I've put together some BBC's that only use a quart every 3,500 or so. These were not race motors, but just pick-up engines. Hastings cast iron rings on well prepped cylinder walls will usually do it

 

[c502cid]

I've had a factory 8.1/496 do 2500-3500 depending on the conditions but never a 454 or a 502. Whether factory or built with forged pistons it was usually a quart per 1000-2000 miles and I was just fine with that.

 

[userfriendly]

I doubt we will ever see an LS based big block form GM, but here is a 519 CID 8.55L V12 from AU.

https://www.youtube.com/watch?v=4hn8bsGjCik the builder

https://www.youtube.com/watch?v=4ssA_O4GGhA on the dyno

https://www.youtube.com/watch?v=PsQjS6WIaEY in a Camaro & SEMA show

www.fullBOOST.com.au

www.V12LS.com

 

[FlyNavyP3]

Originally Posted By: userfriendly
I doubt we will ever see an LS based big block form GM, but here is a 519 CID 8.55L V12 from AU.

https://www.youtube.com/watch?v=4hn8bsGjCik the builder

https://www.youtube.com/watch?v=4ssA_O4GGhA on the dyno

https://www.youtube.com/watch?v=PsQjS6WIaEY in a Camaro & SEMA show

www.fullBOOST.com.au

www.V12LS.com



The 8.1L Big Block put in 3/4-1 ton trucks was essentially an LS technology BBC. No distributor, crank trigger ignition, etc. It was/is a fantastic engine.

 

[DoubleWasp]

Originally Posted By: c502cid
Originally Posted By: leroyd92
Thank you for clearing that up for me I'm not am engine builder.

My friend just told me he typically used 1qt every 4500 miles. So it seems like the motor is happy with. 15w40


Either your friend is fibbing or I want the name of that engine builder! A big block that uses 1 qt every 4500 miles!


It's possible. A lot of the marine big blocks we do go 100 hours of a lot of high rpm operations, and we get out as much oil as we put in in the first place.

On-topic:

Those who are saying thick oil for the valvetrain are correct. BBC valvetrains are not exactly happy with constant high rpms, and a motorhome will give you exactly that. Consider 15w-40 your minimum. I'd run a 20-50 if it were me.

Using VR1 and Schaeffer 20-50, we've been regularly beating the wear universal averages while running the oil twice as long as the universal averages.