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Discussion Starter · #1 ·
I have a brand new 402 crate engine and just got my all my gauges on the dash working. My question is What should be my oil pressure be and does it change when the rpms increase? Also I have a 100 amp alt. any thoughts on what my volt meter should read. Water temp?

Any thoughts you have to share are appreciated,

-Travis
 

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It depends on several things. Do you have a high pressure oil pump? Are the clearances tight or loose? What weight oil?
 

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During normal operation, the voltmeter should read 13 or 14 volts. It will dip a bit when you turn big amp items on, like lights and the radiator fans.

Water temp depends on a lot of factors too. What thermostat is installed? At idle? While cruising?

Cheers
Bill
 

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Travis:
The only way to get a real answer is to ask the builder- Roush.
They will know the oil pump , bearing clearances and whatever other factors that will give you an oil pressure reading that will make sense based on how they built the engine.
Paul M.
 

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Here are some vague numbers to go by:

You're probably looking for 55-70psi oil pressure cold at idle and 25-40psi warm at idle.

A simple rule of thumb is that you need 10 psi per 1000 rpm of oil pressure.

When your engine is warm and you are on the throttle hard (WOT) you should see 65+ lbs of oil pressure. You DON'T want it to go too high. I think a stock oil filter is rated at about 90psi. They do sell beefer oil filters such as a Fram HP1.

-Dan
 

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Discussion Starter · #7 ·
Thanks all, lots of good info. I did not know to check. I will get in touch with Roush and see what they recommned. And Cory, congrads on the new cobra acquisition. I will get some pics out to you on my beast soon. Body is back from paint, car is wired thanks to the fine folks at I-Squared, and I'm now starting to install the carpet. Should have her done by the end of next month

-Travis
 

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Travis I would expect fresh engine at idle to be 40psi min. once warm. Anything over 75-80 at idle warm I would suspect a high volume oil pump is installed. Most feel these are not the best for street engine as they put too mch strain on the oil pump shaft and distributor. The main reason for contacting the builder is to get thier recomendation on what whieght oil to use. That too will have an effect on the oil psi.
Voltmeter will hang around 13.5-14.5 depending on electrical load. Good running water temp will be 195-200*.
 
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