Main bearing clearences.

[Creager]

Whats up guys,

I got my engine back from my machinest the other day, and im in the middle of getting things togeather. (i got some awesome pics ill be posting in my thread later).

I've been measuring these bearings with plastigauge, and things are comming out a little on the tight side. The clearence around main caps/journals/bearings 3 & 4 are comming out right around .002", which is good. Main caps/journals/bearings 1 & 2 are comming out a little tight, approximatly .0015"

My machinest balanced, and polished the crank. Stock bearing sizes.

What could be keeping this thing on the tight side?

I have swapped the bearings halves around between 1, 2, & 4. 4 has been pretty consistant around .002" throughout all the different bearing combinations. I cant swap 3, the bearings at #3 are thrust bearings, although #3 is within spec.

Anyone have any suggestions? New bearings? Have crank grinded .0005"?

 

[Runnin'OnEmpty]

Creager, those clearances do seem to be tight. You shouldn't move caps to different main journals, however. They should stay at the factory positions.

Are you sure the bearings are standard size? The only way to have tighter clearances like that on an unturned crank is to be using an undersized bearing......?

 

[Creager]

Oh sorry, im not moving the caps, im just moving the bearing halves between caps.

Yeah they are stock sized bearings with an unturned crank. But you got me thinking, ill have to check on those sizes when i get home. Arrent undersized bearings usually measured in increments of .010"? The difference im having is really small, .0005"

 

[rookieshooter]

In my Chilton book for an example, for a 4.0 SOHC it calls for oil clearance .0005 to
.0019. If you not getting whatever your specs call for. I'd talk to your machinest. Another thing when you start putting that crank and pistons in, keep checking to make sure the crank is spinning freely. If one of the journals is tighter then the others your machinest might want to align bore it. Another thing did you take the whole block down, or did you take it apart. The reason I'm asking is sometimes people like to clean it all up. I know people that have taken one of those high speed 3m discs and clean the bolting surface of those main caps. And then wonder why the crank is tight on some of those jounals. This is best done by your machinest.

 

[Creager]

man if my specs were for the 4.0 single overhead cam, i'd be good =) According to Vanir's 60 Degree Ford v6 book, i sbould be between .002" and .0025"

I really need to find the ford manual specs for these bearings, i might get lucky if ford says .0016 is good or something.

I took the block apart, i didnt do anything other then clean it with soap, water, laqure, and oil (in that order). No i didnt take a 3m disk to it, although that is something i could see myself doing hehe.

My machinest didnt do anything to the block other then overbore it, and clean it. The crank was balanced and polished.

Alighn bore, hrmm. Im guessing that would require oversized bearings or something?

 

[EMG7895]

Journal to bearing clearance is 0.001-0.0026 service limit 0.006
Mian bearing to crankshaft is desired:0.0008-0.0015 allowed 0.0005-0.0019

 

[Creager]

Journal to bearing clearance is 0.001-0.0026 service limit 0.006
Mian bearing to crankshaft is desired:0.0008-0.0015 allowed 0.0005-0.0019

So your numbers are saying im within spec, are these from the ford service manual? The main bearing to crankshaft is the clearence im looking at.

thanks man. ima do some more research

 

[EMG7895]

These are from the service manual, If you want I can get you the whole page of specs.

 

[ExplorerDMB]

make sure your tightening everything down evenly and to spec

 

[Creager]

These are from the service manual, If you want I can get you the whole page of specs.

is the same thing as downloadable service manual CD avalible on this site? Im working on getting that working, but hey if you got a whole page you can scan me that would rock haha. thanks man

make sure your tightening everything down evenly and to spec

Actually, let me get your take on this. Nor the Vanir book or the Ford service manual snpit give me much detail on this. They both say to tighten all the caps down except for 3 (save for last), starting with 10ftlbs... then 20... 30.. all the way up to 70. Would it be best to stick to one cap at a time? or do 10ftlbs (on both bolts) on cap 1, then do 10 (on both bolts) on cap 2, to cap 4... all the way to 70?

 

[ExplorerDMB]

most of the time you start fromt he inner-caps to the outter caps (meaning - start from the middle of the crank and work your way out - evenly)

The steps on torque is fine...if you don't tighten it down right - you will get what you have - tight spots (if that is what you have)

-Drew

 

[EMG7895]

SPECIFICATIONS
TORQUE SPECIFICATIONS, 4.0L
Description N-m Lb-Ft
Oil Filter Adapter Through Bolt 35-40 26-30
Water Pump to Front Cover Bolts 8.5-12 6-9
Cylinder Front Cover Bolts 17-21 13-15
Timing Chain Guide Bolts 10-12 7-9
Timing Chain Tensioner Bolts 9-11 7-8
Camshaft Sprocket Bolt 60-68 44-50
Rocker Arm Stand Bolts 62-70 46-52
Rocker Arm Cover Bolts 6-8 4.5-5.9
EI Coil Bracket to Engine Bolts 26-32 19-24
Upper Intake Manifold Nuts 20-25 15-18
Camshaft Thrust Plate Screws 9-13 7-10
Oil Pump Drive Assembly Hold Down 17-21 13-15
Bolt
Thermostat Housing Bolts 9-13 7-10
Oil Pressure Switch 18-22 13-16
Coolant Temperature Sensor 12-18 9-13
Coolant Temperature Sender 4.5-7 3-5
Oil Pan Ä Bolts and Nuts 7-10 5-7
Oil Pump Pick-Up To Pump Screws 9-13 7-10
Oil Pump to Engine Block Screws 17-21 13-15
Connecting Rod Bearing Cap Nuts 25-32 18-24
Crankshaft Main Bearing Cap Bolts 90-104 66-77
Crankshaft Oil Baffle Nuts 17-21 13-15
Cylinder Head Bolts (2) (2)
Lower Intake Manifold Nuts and Bolts (2) (2)
Flywheel Bolts (2) (2)
(2) Tightened in stages and in sequence. Refer to text for procedure.
this is half, i'm working on the rest

 

[EMG7895]

 

[EMG7895]

 

[Creager]

Hell yeah, thanks dude. So that puts me well within spec

I actually wasnt using lube, i wasnt trying to turn the crank. I was just installed the bearing caps with a little plastigauge and was measuring the clearence.

I just put bearing guard on all the bearings and tried spinning the crank with everything torqued properly... smoooth as butter. You can hear the lube a lil bit when you spin the crank.

.0015 on caps 1 and 2, .0019 on 3 and 4. Vanir recommended these be a little looser, but aslong as Ford says im good, im good.

My crank End-play was .006," Vanir says .005" is the tighest you want.

This thing is good, crank is in =)

 

[EMG7895]

If theres anything else you need let me know and I'll try to get it.