Using Lucas 20/50 break in oil all the time

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Mar 31, 2009
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Delaware
I had a 383 professionally built and dynoed for my 65 Impala. The builder is telling me to use Lucas 20/50 Break in Oil all the time because it has the highest zinc content. Using "break in oil" all the time sounds wrong to me. People are also telling me that is too heavy of an oil to use. He did say if I was going to drive the car in the real cold months to use Lucas Hot Rod/Classic 10/40 high zinc. I just want to use what is right for the engine
 
I had a 383 professionally built and dynoed for my 65 Impala. The builder is telling me to use Lucas 20/50 Break in Oil all the time because it has the highest zinc content. Using "break in oil" all the time sounds wrong to me. People are also telling me that is too heavy of an oil to use. He did say if I was going to drive the car in the real cold months to use Lucas Hot Rod/Classic 10/40 high zinc. I just want to use what is right for the engine
Good God, does he have that little faith in his work or quality of components?

I assume this was kept flat tappet and not converted to roller?

Also, many of us wouldn't touch anything Lucas sells with a 10ft pole. If it really needs higher levels of AW additives than can be found in your typical Euro 5w-40/0w-40, then something like Valvoline VR-1 would be a good choice, AMSOIL also makes a "hot rod" oil, and of course our own @High Performance Lubricants I'm sure makes something for this style of engine.
 
Sounds like his shop is a Lucas Outlet. I'm just not a fan. The break-in on a flat tappet is critical. And having enough zinc is important. But the options @OVERKILL listed should work. Motorcycle oil also is very high zinc. Is the engine broken in yet?

Prelube if you can, 2500-3k rpm right off the bat for 20 minutes, no idling. Cam and lifters need splash lubrication.
 
Good God, does he have that little faith in his work or quality of components?

I assume this was kept flat tappet and not converted to roller?

Also, many of us wouldn't touch anything Lucas sells with a 10ft pole. If it really needs higher levels of AW additives than can be found in your typical Euro 5w-40/0w-40, then something like Valvoline VR-1 would be a good choice, AMSOIL also makes a "hot rod" oil, and of course our own @High Performance Lubricants I'm sure makes something for this style of engine.
Was not cheap and he builds race motors for local racers. It is not a roller. I am alos questioning if I should be using 20/50
 
Was not cheap and he builds race motors for local racers. It is not a roller. I am alos questioning if I should be using 20/50
Since to the quality of cores for FT cams in the last few decades (since no OEM is using them anymore) has become questionable (and the source of most of the failures) it usually makes sense to spend a few more bucks and go roller. It also opens up a huge portfolio of more modern lobe profiles too. I appreciate that this isn't an option now however.

This is actually a thread where the old 10psi per 1,000RPM applies! being an SBC. Sorry for my amusement, but that old SBC hotrodding rule gets tossed around quite universally when it of course isn't. Do you know what he used for an oil pump and what he selected for bearing clearances? If it is built to stock clearances, yeah, that 20w-50 is going to be dumping a huge volume of oil through the relief and you'll be wasting a lot of power pumping oil back into the feed side of the pump while observing extremely high oil pressure.

Our local circle track builder swore by 15w-40 in all his engines. It was cheap, worked, and readily available. My buddy and I used it in the FT SBC we did the cam swap in in his dad's S10 with a Lunatti Voodoo (pretty wild FT cam lobes) and it held up just fine (though that engine had been put together by a monkey). Eventually swapped that engine out for a better roller mill that the aforementioned builder put together.
 
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I have all the dyno stuff but nothing on clearances. Just kicking around switching to 10/40. Not sure why he is telling me 20/50 in summer.
 
Sounds like his shop is a Lucas Outlet. I'm just not a fan. The break-in on a flat tappet is critical. And having enough zinc is important. But the options @OVERKILL listed should work. Motorcycle oil also is very high zinc. Is the engine broken in yet?

Prelube if you can, 2500-3k rpm right off the bat for 20 minutes, no idling. Cam and lifters need splash lubrication.
He told me yes that it was broken in on the dyno. Yet he was insisting that I keep using the 20/50 Break in Oil in the summer because it has the highest zinc. I search the net and see nothing about anyone using break in oil all the time. I keep reading that too much zinc will corrode so I am skeptical about keeping it in there much longer. Just wondering if a high zinc 10/40 is OK
 
I’ve run flat tappets hundreds of thousands of miles on SC 10W40….

Unless this has crazy valve springs, it’ll be fine on just about any oil with a decent AW package.

To make it simple, the AMSOIL Z-Rod comes in several viscosities. I think a 10W30 would be more than enough for this engine.

It‘s a small block Chevy. 350 block with a stroker (400) crank. It doesn’t need a 20W50.
 
Power Glide. Cruises about 2800 @ 60
Well you kind of need the cam specs to select the correct torque convertor, unless the builder picked one for you.

EDIT: rear end gear ratio would be nice to know also, but i'm guessing at a 3.31:1 or 3.55:1.
 
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