What Is Your Main Bearing Clearance???

[BeachMonkey100]

The GT500 oil pump is also a "high-volume" pump with a different pressured spring (80#) to the GT's (60#) spring. I would assume that has something to do with it.

 

[dysan]

I am running 5w-30 with .0028 clearance but I also run the high volume low pressure melling 10227 oil pump. With that setup my cold startup oil pressure is 90-95psi at idle and then full warm I am down at 18-20psi of oil pressure. Cruising at 1800-2000rpms on the highway it is pretty steady at 60psi of pressure. Againstallodds1 is the same as me for oil pressure cold/hot and when I have had to teardown my engines due to other stupid issues all of my bearings have looked great.

 

[AutoXRacer]

I don't understand something. The GT-500 uses oem GT narrow clearances... yet they spec motocraft 5W-50 oil ( which shears fast..down to a 40). Why are they using 5W-50 with way smaller clearances than autoXracer?? The oil pressure would be higher vs a 4.6L oem eng using 5W-20. I think the flow would be the same though.

What am I missing here ?

Is it possible to use 5W-20 or 5W-30 with the much bigger clearances ? It would flow easy enough.

I think the GT500 and BOSS302 spec 5W-50 because they are intended to be high performance cars that will see track/heavy duty use.

A GT Mustang is just a regular passenger car so its speced to use 5W-20 for economy.

At least that my take on it. But lets not concentrate too much on oil unless its regarding bearing clearances.


Update:

Just spoke to the engine builder...he set it up for 0.0025" clearance. He mixed the STD and X bearings to achieve this clearance.

And I just found out my crank and balancer are at a balancing facility...he ask for me to drop off my flywheel and clutch assembly. I didn't know this was required on modern engines...???

 

[sportinawoody]

if you want it balanced right then yes. don't forget to send the crank bolt and 4 flywheel bolts if your 8 bolt, 3 if your 6 bolt and all your pressure plate bolts. clutch disc isn't necessary, only pressure plate.

 

[BruceH]

I don't understand something. The GT-500 uses oem GT narrow clearances... yet they spec motocraft 5W-50 oil ( which shears fast..down to a 40). Why are they using 5W-50 with way smaller clearances than autoXracer?? The oil pressure would be higher vs a 4.6L oem eng using 5W-20. I think the flow would be the same though.

What am I missing here ?

Is it possible to use 5W-20 or 5W-30 with the much bigger clearances ? It would flow easy enough.

A good guess is that the clearances open up with the increased heat a tracked car produces. A regular GT isn't going to see that heat and therefore will keep tighter clearances. It's just a guess though. I do know that Ford will only accept oil that is made to their specs. Has any oil company been able to meet the Ford spec except for whoever makes the Motorcraft oil?

I think the GT500 and BOSS302 spec 5W-50 because they are intended to be high performance cars that will see track/heavy duty use.

A GT Mustang is just a regular passenger car so its speced to use 5W-20 for economy.

At least that my take on it. But lets not concentrate too much on oil unless its regarding bearing clearances.


Update:

Just spoke to the engine builder...he set it up for 0.0025" clearance. He mixed the STD and X bearings to achieve this clearance.

And I just found out my crank and balancer are at a balancing facility...he ask for me to drop off my flywheel and clutch assembly. I didn't know this was required on modern engines...???

Most balance shops will want the flywheel, clutch, and balancer. If they do it right first they balance the rotating assembly, then add each part and rebalance.

It isn't required but it is preferred.

 

[AutoXRacer]

Most balance shops will want the flywheel, clutch, and balancer. If they do it right first they balance the rotating assembly, then add each part and rebalance.

It isn't required but it is preferred.

OK, so what happens when you need to resurface the flywheel or decide to go with an aluminum flywheel vs a light-weight steel...or even change out the clutch for a different setup (single vs twin)...?

What if you change out the balancer for another brand, go over-driven or under-driven.

Whats the point in balancing the rotating assembly...its probably going to be untouched until the clutch discs wear out...then what?

 

[Dubstep Shep]

OK, so what happens when you need to resurface the flywheel or decide to go with an aluminum flywheel vs a light-weight steel...or even change out the clutch for a different setup (single vs twin)...?

What if you change out the balancer for another brand, go over-driven or under-driven.

Whats the point in balancing the rotating assembly...its probably going to be untouched until the clutch discs wear out...then what?

If you balance each and every rotating component independently there is really no need to have the system balanced in the end. That's the difference between internal and external balancing.

 

[BruceH]

That's why I said if done correctly then first the rotating assembly is balanced. If something else needed balancing material would be removed or added to that part only.

OK, so what happens when you need to resurface the flywheel or decide to go with an aluminum flywheel vs a light-weight steel...or even change out the clutch for a different setup (single vs twin)...?

What if you change out the balancer for another brand, go over-driven or under-driven.

Whats the point in balancing the rotating assembly...its probably going to be untouched until the clutch discs wear out...then what?