Roush 402 R Oil pump question!

[WardL]

Roush recommends straight 30W oil. Your pressures might be normal with the heavier oil.

[mln385]

Originally Posted by WardL

Roush recommends straight 30W oil. Your pressures might be normal with the heavier oil.

Is this via a conversation? Their literature and my tag says 10W30 427 R Crate Engine

I have a 427 and the link is for same but I do have an original catalog with the 402R and they recommend the same.

[jhv48]

Roush recommends 10w30.

Try 20w50 non synthetic and see where your pressure goes.
My Roush 427sr ran 45-50 lbs at startup and then settled around 42 lbs when cruising warm. Hot idle was around 35lbs at an idle speed of 900 rpm. This was with 10w30 royal purple synthetic oil. And then the engine destroyed itself.

[mln385]

Originally Posted by jhv48

Roush recommends 10w30.

Try 20w50 non synthetic and see where your pressure goes.
My Roush 427sr ran 45-50 lbs at startup and then settled around 42 lbs when cruising warm. Hot idle was around 35lbs at an idle speed of 900 rpm. This was with 10w30 royal purple synthetic oil. And then the engine destroyed itself.

Do you know what the cause of the failure was?

[jhv48]

Originally Posted by mln385

Do you know what the cause of the failure was?

Valve guides worn, cylinders scored, piston cracked, bearings shot. excessive oil consumption. No single cause. At 13,000 miles it looked like it had 100,000 hard miles when we tore it apart. Needed a complete rebuild.

[Gaz64]

Originally Posted by jhv48

Valve guides worn, cylinders scored, piston cracked, bearings shot. excessive oil consumption. No single cause. At 13,000 miles it looked like it had 100,000 hard miles when we tore it apart. Needed a complete rebuild.

What rods in this engine?
Do the rods have a timed spit hole, I doubt it.
Is rocker geometry correct with minimum contact patch width on the valve stems?

[Gaz64]

In these days of multigrade oils, why would one run a single viscosity oil?

Depending on how the engine is clearanced is a high determining factor in oil viscosity selection.

30W cold is thicker than the majority of current multigrades.

And then when hot is thinner than most.

Oil flow with a thin oil is more important than low flow with a thick oil.