Oil Mods 440

[tooslow]

There is lots of info on this , almost to much , confusing .
A fresh look
I drive my Dart w a 440 at Road America and other tracks for fun, track days . I also drive it to work and pretty much all over
I have trouble with the main bearings failing.
446 CI RPM is 3500 to 6000 for 20 minutes at a session
10.5 to 1
Crane Roller rockers 1.6
Source one AL heads
M1 intake
EFI Carb
Milodon Pump HV
8 quart road race pan w swivel pickup and baffles
3 quart engine accumulator
Purplestick 557 lift dur 296 108 centerline
Manual Trans
> Should I use full grooved bearings or 3/4 ?
> too bush mech lifters or not to ?
> I have read about opening up some of the oil passages with a reamer ?

Any suggestions besides use a smallblock or an after market block are appreciated

Thank You,
Bill

 

[vitamindart]

every big block I have built for myself or buddies has had, full groove mains and the oil passages to the mains opened up with a ream. I also debur the block and clean off any major slag. you may want to consider an external pick up in that pan. a single line should be plenty. that's my 2 cents, opinions will vary but its worked for me and anyone I have built one for.

 

[moper]

What is happening to the mains? How long does it take to happen? How do the rod bearings look? What are the clearances on the mains and rods?

 

[yellow rose]

There is lots of info on this , almost to much , confusing .
A fresh look
I drive my Dart w a 440 at Road America and other tracks for fun, track days . I also drive it to work and pretty much all over
I have trouble with the main bearings failing.
446 CI RPM is 3500 to 6000 for 20 minutes at a session
10.5 to 1
Crane Roller rockers 1.6
Source one AL heads
M1 intake
EFI Carb
Milodon Pump HV
8 quart road race pan w swivel pickup and baffles
3 quart engine accumulator
Purplestick 557 lift dur 296 108 centerline
Manual Trans
> Should I use full grooved bearings or 3/4 ?
> too bush mech lifters or not to ?
> I have read about opening up some of the oil passages with a reamer ?

Any suggestions besides use a smallblock or an after market block are appreciated

Thank You,
Bill

Full groove mains only help with Rod bearing issues.

I hate accumulators. If the pan is made correctly there is no need for it. All that plumbing and extra crap reduces flow and pressure. You'd better have a big pump and keep the pressure way up.

You can open the oil feed galleries up to 9/32 (.287) because the factory was pretty sloppy doing that kind of work.

Of you are killing mains that's a pan/volume/pressure issue.

Or you have an internal leak somewhere.

 

[AndyF]

If you're staying below 6000 or 6500 rpm then just make sure the oil feed holes to the main are open and not full of slag. Use 3/4 groove main bearings if they are available. You can experiment with oil pumps and springs to get an oil pressure that you're happy with. It is a balance of pump volume, oil viscosity, oil temp and bearing clearance.

 

[moper]

If you're staying below 6000 or 6500 rpm then just make sure the oil feed holes to the main are open and not full of slag. Use 3/4 groove main bearings if they are available. You can experiment with oil pumps and springs to get an oil pressure that you're happy with. It is a balance of pump volume, oil viscosity, oil temp and bearing clearance.

Pretty much where I was going. Basic machining has to be good, clearances need to be decent (high end of stock or a little bigger), the feed holes clear, I like the 3/4 groove myself but the bearing dujour is full grooves, and it "should" be fine.

 

[roccodart440]

I'm a fan of 3/4 grooves. When I've tried using full grooves I was left running heavier oil with minimum oil pressure requirements.