Choosing oil for a bracket racer drag car

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I work on three different strip/street V8/RWD bracket cars. What are the qualities or specifications I should be looking for in choosing an engine oil? All three are single carburetor, hydraulic flat tappet camshaft engines. Ideally the engines get torn down and inspected every other season. An average season is around 150 1/8th mile passes during the heat of summer.

So the engines are a 406 small block Chevrolet, a 427 small block Ford, and a 440 big block Dodge. Changing oil often is not a concern; keeping expensive crankshafts, pistons, and valve trains in good shape is the goal. Maximum engine rpm is 6500 for all three combinations.

Currently using, depending on each engine owner's favorites, 10/30 VR1 and 20/50 Brad Penn. None of these engines have ever had major failures but I feel I'm always guessing on what to put in the crankcases.

Thanks ahead of time for your thoughts.
 
Spend the money on a used oil analysis and see where your current oil brew is letting you down, then compensate!
 
It depends on a number of factors. Long list:

Rod and Main clearances for the bottom end, Cross-drilled or grooved Crank,

Are you gauging oil pressure at both ends of the crank or lifter gallies,

The valve spring geometry (Rev Pack, or just spring on valve?),

Valve spring pressures over the nose,

Who's lifters, made during what decade, what style (Direct Lube, or plain OEM style),

Distributor gear and oil pump (volume and pressure, as in HV or HP, or special race pump),

Are all the in-block oil pressure reliefs blocked off,

What kind of windage tray,

Any extra oiling holes or channels created when assembled,

Piston to wall clearances, and to a minor degree, what rings end gaps,

Debris screens epoxied into lifter valley to catch debris,

What filter (remote or direct mount),

Any signs of trouble so far? Any UOA's ... What do the cut-open filters look like,

Magnetic drain plug show "hair",

The oil has to fit the spaces and not foam from getting whipped up at anything above about 4,000 ...

Do you let these engines idle much? Are they warm at 180* coolant temp when you come to the line? What temps is the sump when you go out the big end?

Tranny's being cooled by the radiators?

How rich are you it idle and staging?

Any black smoke out the headers when the driver backs off,

Any trouble keeping the carbs full, w/o overflowing ...

That'll give us a good starting point
smile.gif
 
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I'm no expert, But here is my 2 cents. I have 2 friends that race every week. Sometimes twice a week. They both have BB Chevys. Don't remember off hand the cubic inches I do know they both are above 800HP and lift the fronts every time. One of them use M1 10w30 the other uses VR1 10w40. Neither one of them have had catastrophic engine failures. They get rebuilt every 2 years.
 
Why do you not teardown every season if not sooner?
Years ago when Dad raced we ran a straight 40 wt.
We had to replace a crank every 40 runs.This was when 1/4 mile was the norm.
I would just check with other racers and get an idea on oil.
 
Look at AMSoil dominator 20W-50 , Gibbs Driven 15W-50.

Something more common found in stores Mobil1 15W-50 has 1300ppm zinc

Be careful with diesel oil, don't use bottles that say API CK4/SN rated. Should just say only CK4.
 
Originally Posted By: BrocLuno
It depends on a number of factors. Long list:

Since the most recent overhaul was on the 406 sbc, let's work on this one.

Rod and Main clearances for the bottom end, Cross-drilled or grooved Crank,

Mains 1-4 and .002-.003,#5 at .0035 with .006 endplay.

Are you gauging oil pressure at both ends of the crank or lifter gallies,

Oil pressure at the lifter galley only, 55 psi@5800 rpm @ 190 degree coolant temp.

The valve spring geometry (Rev Pack, or just spring on valve?),

No rev kit, yes spring on valve.

Valve spring pressures over the nose,

No information on over the nose pressure. No spring checker in the garage.

Who's lifters, made during what decade, what style (Direct Lube, or plain OEM style),

Comp Cams lifters from about 15 years ago. OEM style and always re-installed in their original locations on the cam.

Distributor gear and oil pump (volume and pressure, as in HV or HP, or special race pump),

Iron distributor gear and standard oil pump, no HV or HP.

Are all the in-block oil pressure reliefs blocked off,

Stock oil pressure relief at the filter mount is functional

What kind of windage tray,

Tray is welded into a deep sump pan with a short OEM tray bolted to the rear main bearing caps.

Any extra oiling holes or channels created when assembled,

No extra oiling holes

Piston to wall clearances, and to a minor degree, what rings end gaps,

Wall clearances were .003 to .005 on older TRW forged flat top pistons. I don't recall the ring end gaps and that note book is not nearby at the moment. I'm surprised at what I am remembering.

Debris screens epoxied into lifter valley to catch debris,

No debris screens

What filter (remote or direct mount),

Wix, direct mount

Any signs of trouble so far? Any UOA's ... What do the cut-open filters look like,

No troubles, no UOAs. The cut filters never show any major debris. This engine has never hurt bearings or camshafts.

Magnetic drain plug show "hair",

No magnetic plug

The oil has to fit the spaces and not foam from getting whipped up at anything above about 4,000 ...

Do you let these engines idle much? Are they warm at 180* coolant temp when you come to the line? What temps is the sump when you go out the big end?

They only idle moving the staging lanes. Always at least 180 coolant temp after the burnout. No oil sump temp sensor.

Tranny's being cooled by the radiators?

Yes and an additional external cooler.

How rich are you it idle and staging?

LM-2 shows 14 to at idle and staging, 12.5 through the traps.

Any black smoke out the headers when the driver backs off,

No one has ever made that observation.

Any trouble keeping the carbs full, w/o overflowing ...

Nope, 1/2" fuel lines and a return style fuel system and electric pump

That'll give us a good starting point
smile.gif
 
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