Got another Foxbody Mustang. PO has been using VR1 20w50

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Nov 24, 2013
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Rocklin, CA USA
Just picked up a 1988 Notchback full of Maximim Motorsports road race goodies and a built motor :) Combo is a Ford Performance Boss block stroked to 327ci, Vortech V3 supercharger, GT40 tubular Intake, Trickflow aluminum heads, and a mild hydraulic roller cam that passed California smog some years ago. 12k miles on the build. PO has been running VR1 20w50. I’d like to go full synthetic and hopefully be able to purchase at my local Walmart. What do y’all think of switching to M1 15w50, M1 0w40 Euro, or maybe Rotella 5w40??
 
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Jan 25, 2003
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Decatur AL USA
Just picked up a 1988 Notchback full of Maximim Motorsports road race goodies and a built motor :) Combo is a Ford Performance Boss block stroked to 327ci, Vortech V3 supercharger, GT40 tubular Intake, Trickflow aluminum heads, and a mild hydraulic roller cam that passed California smog some years ago. 12k miles on the build. PO has been running VR1 20w50. I’d like to go full synthetic and hopefully be able to purchase at my local Walmart. What do y’all think of switching to M1 15w50, M1 0w40 Euro, or maybe Rotella 5w40??

Do you have a build sheet with all the clearances? If not about all you can go by is oil pressure.

For street and strip cars with similar Ford SB with street clearances with HR Cams we mostly run a 30 Grade Synthetic of some kind.

VR1 20W-50 is usually reserved for engines set up with looser bearing clearances.
 
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Just picked up a 1988 Notchback full of Maximim Motorsports road race goodies and a built motor :) Combo is a Ford Performance Boss block stroked to 327ci, Vortech V3 supercharger, GT40 tubular Intake, Trickflow aluminum heads, and a mild hydraulic roller cam that passed California smog some years ago. 12k miles on the build. PO has been running VR1 20w50. I’d like to go full synthetic and hopefully be able to purchase at my local Walmart. What do y’all think of switching to M1 15w50, M1 0w40 Euro, or maybe Rotella 5w40??

Which Trick Flow Heads did you use and what is the camshaft spec at 0.500 lift?

Mobil 1 15W-50 sounds like its a good oil, and you could order it from Walmart and have it delivered.
 

OVERKILL

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VR1 20W-50 is a fine oil but a little unneccessarily thick for a street 302 with presumably normal clearances?
Roller cam eliminates the need for high ZDDP, a good 5W-40 would be fine.
Yup, unless it's built really loose the 20w-50 will have the pump on the relief and wasting power. It's also hard on the distributor gear and oil pump driveshaft.
 
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Post some pics please! This was one of my dream cars when I was a kid. I always wanted a Fox body Mustang in the trunk design, not the hatchback...

I'd run your pick of 5w40 HDEO. This way you are covered for the street or strip if needed IMO.

Just my $0.02
 

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Vortech V3 supercharger there are potentially higher loading on the crank and rod bearings.
Yep, there's snout load on the crank from the pulley and more pressure on the rods from the higher output and boost, which is why an xW-40 would be a good choice if the engine has stock clearances. Many factory boosted cars (SRT, AMG, Porsche, BMW, Audi) have called for an HTHS ~3.5cP for this reason. Interestingly, Ford did not do that with the termi or lightning, but at stock boost levels, those engines weren't super high HP/L and the Modular has a ridiculously rigid bottom end.
 
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