That covers a lot of the points recently mentioned with responses. However I appreciate peoples interest and efforts posting information. But it is fairly well covered in the linked thread.
Thanks,
AdrianSeries one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
23rd Oct 2021 12:11 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347
Finally done a bit more work but held back by some health issues.
Main bearings:
Started by grinding the slot for the bearing cap on the bottom shells. I put the slot on the left-hand side of the block looking from the front. The idea being that if the crank tried to rotate the bearings then the bearing shell tab would just hit the block split line. If you put the slot on the right-hand side, then if the bearings rotated, the tab would act like a ski ramp and push the bottom shell out into the crank. If the bearing/crank seized in reality the tab will not stop it rotating, but the thought is there.
Then I ground the slot for the tab with a Dremel by hand. I was concerned about leaving burrs on the cap split line, so I blued up the cap on a surface plate before and after to check I did not leave anything proud. I also used the Dremel so the disk rotated up from the bearing bore up to the split line. The idea being to prevent getting a burr on the bore that would push the shell out towards the crank.
Bluing the split line:
Masking tape and pencil lines to grind to:
End result:
I have seen a tidier job - Defector posted some similar pictures - he must have amazingly steady hands. But the grove is functional.
Bearing Crush
Next job was checking the bearing nip or crush. I ended up doing this with a 6" s/s rule and feeler gauges as follows:
1/. Push the shell into the bore with one end sat proud of the split line (left hand side on this picture)
2/. Use your 6” rule at and angle so it only rests on the split line on the side with the bearing shell sat proud of the split line. Push down so that you get the shell in line with the split line
3/. Place the 6” rule across both sides of the split line & use a feeler gauge to check the size of the gap you have on the proud side (the other side to the one you started with, right hand in the above picture - couldn't hold the rule, camera and feeler gauges)
The result with the old shells was a consistent 0.008" to 0.010" (0.20 to 0.254 mm) proud on the cap/lower shell and < 0.002" (0.05mm) on the top shell. The Ford F-150 bearings gave the same readings, i.e. the Ford bearings have the same bearing crush as the original 2.7 bearings.
Bearing Clearances:
I then moved on to checking the bearing clearances. I initially got higher clearances than I hoped. But finally worked out that you need to do the full main cap torquing sequence to get the cap to sit down properly, i.e. 60Nm + 145 Nm does not fully seat the cap. You need to do the 90 degrees as well (another tip that I got from reading Defectors posts - thanks!)
So I went back and rechecked the bearing clearances with the original shells. I had originally got 0.040mm - top of tolerance range. Adding the 90 degrees to the cap main bolts got this to 0.030mm. To be honest as the tolerance is 0.023 to 0.040mm the old bearings were not as bad as I first thought......... maybe I didn't need to do this job???
So the new Ford F-150 bearings. These are coded in various ways, but are sold based on the colour - this is a dab of paint on the the side of the shell, like this big end shell. I could not find any remaining colours on my old main bearing shells.
So I ordered one main bearing shell set of each colour. Some measuring later told me
'Blue' - Numbered '3' on the shell - Thickest shell, i.e. gives the lowest bearing clearance
'Yellow' - Numbered '2' on the shell - middle sized shell
'Red' - Numbered '1' on the shell - i.e. gives the biggest clearance.
There is 0.005mm (0.0001" or 5 microns!) step differences in shell thickness between the grades. However there is some variation, so if you want to tune the clearances across all 4 bearings a bit of measuring and putting the right shells in the right location would work (if you have OCD).
So on No. 1 main bearing I fitted each size of bearing, measured the resulting clearances with plastigauge (strangely Plastigauge 'black' is actually red??):
I got:
Blue/Blue (Blue lower shell, Blue upper shell): 0.033mm
Yellow/Yellow - 0.040mm
Red/Red - 0.045mm - I expected 0.050mm. But one read shell was 0.002mm thinner than the other and the plastigauge accuracy is not to the nearest 0.001mm.
I then repeated on main brg 2 & 3 and found that with Blue/blue shell combination I got 0.035mm clearance on both bearings.
The LR spec for the main bearings on a 2.7 TDV6 is 0.22mm to 0.040mm. For a Ford F-150 3.0 TDV6 it is 0.27mm to 0.063mm. I believe that Ford have opened up the clearances slightly to get a higher oil flow through the bearing, all though this would need a higher capacity oil pump to keep the same or greater oil supply pressure. I believe they did this to increase the cooling at the bearing, hence keeping oil viscosity up and hence reducing the potential for bearing wear.
So I decided to go for a clearance of 0.040mm. Top end of the old 2.7 TDV6 clearance, middle of the 3.0 TDV6 clearance. So after a bit more testing I need:
Brg 1 - Yellow/yellow
Brg 2, 3 & 4 - Yellow/Blue
This 'should' give me 0.040mm clearance on all 4 bearings.
Main brg 4 - I planned to use my sample bearings from mains 1 through 3 to size main brg 4. But I chickened out on estimating the slot/tab location based on non thrust main bearings. But based on the journal sizes across the crank, old bearing clearances and old bearing thicknesses I estimated the shell combination.
Conclusion - Ford F-150 3.0 TDV6 main bearings do fit a 2.7 TDV6
After all this Ford USA now have a bloody stock out of bearings due to pandemic delivery issues.... FFS!
Next mission - a higher capacity oil pump & sizing the big ends.Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
9th Nov 2021 2:11 am
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26700
Great detail there. You have the patience of a saint!
9th Nov 2021 8:44 am
jenseneverest
Member Since: 12 Jun 2017
Location: somewhere
Posts: 760
Great to see your able to get back to this
Very nice that the ford bearing do actually fit.
Im not sure i understand your thinking on the larger clearance tolerance as an attempt to cool shells by Ford. IMO the only cooling done by oil is onto the piston /bores with the oil sprayers.
Oil is essentially used to stop friction, this is best done with tight tolerances, the hotter and thinner the oil gets, the less effective it becomes...... i would be aiming for the smallest allowed tolerance.
I would not mix and match the blue/yellow shells either, by mixing them your effectively making the housing oval, all be it by a ball hair.
Just my 2 cents.... another great, well detailed write up as always
9th Nov 2021 11:54 am
Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20727
The oil also takes away heat from the lower engine components. More flow = more cooling effect (in theory)My D3 Build Thread
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347
Mistake....Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
9th Nov 2021 6:06 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4628
Thorough work Adrian well done, great to see you're back at it again too.
I agree with your view regarding the oil flow/cooling, is there any difference in the oil channel between the original bearings and the F-150's or are they the same?yµ (idµ - eAµ) ψ=mψ
9th Nov 2021 6:33 pm
sailormike
Member Since: 04 Apr 2007
Location: Norfolk
Posts: 165
jenseneverest wrote:
Great to see your able to get back to this
Very nice that the ford bearing do actually fit.
Im not sure i understand your thinking on the larger clearance tolerance as an attempt to cool shells by Ford. IMO the only cooling done by oil is onto the piston /bores with the oil sprayers.
Oil is essentially used to stop friction, this is best done with tight tolerances, the hotter and thinner the oil gets, the less effective it becomes...... i would be aiming for the smallest allowed tolerance.
I would not mix and match the blue/yellow shells either, by mixing them your effectively making the housing oval, all be it by a ball hair.
Just my 2 cents.... another great, well detailed write up as always
It is not the case with multi grade oils that the hotter they get the thinner it becomes.
An SAE 15w-40 will have a viscosity of 15 when cold thickening to 40 when hot. Obviously the thinner oil when cold helps starting and economy etc.
A ship I sailed on was retrofitted with seven Volvo generators of about 400kw. The oil change interval was 500 hours but if the machines had done much over 200 hour from an oil change then run at higher than 2/3rds load the oil filter Differential Pressure alarm would go off. The oil pressure was fine.
After much changing of oil and oil brands for Volvo and sending oil for testing, eventually Volvo accepted the ships view that the oil was getting thicker and the alarm settings on the filter were set too close. The change in oil temperature was only about 5 degrees for this to happen.
The ship even got emails from the Oem incorrectly stating that the oil would get thinner as it got hotter.
Eventually Volvo had to send a rep to reprogram the controls to increase differential pressure range on the filters as it was locked into software we had no access to. The also had to do the same mod to all of this type of generator set that had been sold.Disco 4
Burstner motorhome
BMW 225e (only 1/2 way to electric)
9th Nov 2021 9:16 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347
PROFSR G wrote:
Thorough work Adrian well done, great to see you're back at it again too.
I agree with your view regarding the oil flow/cooling, is there any difference in the oil channel between the original bearings and the F-150's or are they the same?
Profsr G,
I profess that I have not measured that (must try harder.....). But have a look at this side by side comparison:
There is visually no difference.
However Christian ('LR Time' on U tube) has noticed that King bearings have a bigger oil inlet hole diameter, see picture below shamelessly cropped from his Utube video:
Click image to enlarge
AdrianSeries one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
9th Nov 2021 9:51 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347
sailormike wrote:
jenseneverest wrote:
Great to see your able to get back to this
Very nice that the ford bearing do actually fit.
Im not sure i understand your thinking on the larger clearance tolerance as an attempt to cool shells by Ford. IMO the only cooling done by oil is onto the piston /bores with the oil sprayers.
Oil is essentially used to stop friction, this is best done with tight tolerances, the hotter and thinner the oil gets, the less effective it becomes...... i would be aiming for the smallest allowed tolerance.
I would not mix and match the blue/yellow shells either, by mixing them your effectively making the housing oval, all be it by a ball hair.
Just my 2 cents.... another great, well detailed write up as always
It is not the case with multi grade oils that the hotter they get the thinner it becomes.
An SAE 15w-40 will have a viscosity of 15 when cold thickening to 40 when hot. Obviously the thinner oil when cold helps starting and economy etc.
A ship I sailed on was retrofitted with seven Volvo generators of about 400kw. The oil change interval was 500 hours but if the machines had done much over 200 hour from an oil change then run at higher than 2/3rds load the oil filter Differential Pressure alarm would go off. The oil pressure was fine.
After much changing of oil and oil brands for Volvo and sending oil for testing, eventually Volvo accepted the ships view that the oil was getting thicker and the alarm settings on the filter were set too close. The change in oil temperature was only about 5 degrees for this to happen.
The ship even got emails from the Oem incorrectly stating that the oil would get thinner as it got hotter.
Eventually Volvo had to send a rep to reprogram the controls to increase differential pressure range on the filters as it was locked into software we had no access to. The also had to do the same mod to all of this type of generator set that had been sold.
Sailor Mike,
You made me stop and question myself. Eventually found this oil temperature against viscosity curve on the internet:
Clearly shows reducing viscosity as temperature increases. If I get chance I will double check with a friend who works at a lubrication oil company as an oil expert.
AdrianSeries one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
Last edited by Breg90 on 9th Nov 2021 10:01 pm. Edited 1 time in total
9th Nov 2021 9:55 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347
sailormike wrote:
jenseneverest wrote:
Great to see your able to get back to this
Very nice that the ford bearing do actually fit.
Im not sure i understand your thinking on the larger clearance tolerance as an attempt to cool shells by Ford. IMO the only cooling done by oil is onto the piston /bores with the oil sprayers.
Oil is essentially used to stop friction, this is best done with tight tolerances, the hotter and thinner the oil gets, the less effective it becomes...... i would be aiming for the smallest allowed tolerance.
I would not mix and match the blue/yellow shells either, by mixing them your effectively making the housing oval, all be it by a ball hair.
Just my 2 cents.... another great, well detailed write up as always
It is not the case with multi grade oils that the hotter they get the thinner it becomes.
An SAE 15w-40 will have a viscosity of 15 when cold thickening to 40 when hot. Obviously the thinner oil when cold helps starting and economy etc.
A ship I sailed on was retrofitted with seven Volvo generators of about 400kw. The oil change interval was 500 hours but if the machines had done much over 200 hour from an oil change then run at higher than 2/3rds load the oil filter Differential Pressure alarm would go off. The oil pressure was fine.
After much changing of oil and oil brands for Volvo and sending oil for testing, eventually Volvo accepted the ships view that the oil was getting thicker and the alarm settings on the filter were set too close. The change in oil temperature was only about 5 degrees for this to happen.
The ship even got emails from the Oem incorrectly stating that the oil would get thinner as it got hotter.
Eventually Volvo had to send a rep to reprogram the controls to increase differential pressure range on the filters as it was locked into software we had no access to. The also had to do the same mod to all of this type of generator set that had been sold.
Sailor Mike,
Were the generators running on heavy fuel oil? If so, any fuel migration past the piston oil rings would tend to increase the lubrication oil viscosity over time (Fuel oil more viscous than the lubrication oil - heavy fuel oil needs to be heated to inject/burn I think).
However, on a diesel engine, diesel migration past the piston rings reduces the lubrication oil viscosity as the diesel is comparatively much less viscous than the lubrications oil.
AdrianSeries one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
9th Nov 2021 10:01 pm
sailormike
Member Since: 04 Apr 2007
Location: Norfolk
Posts: 165
The engines were 10 or 12 litre, basically lorry engines running on marine gas oil. Basically diesel.
They were fitted in about 2008 but the ships are now razor blades somewhere.Disco 4
Burstner motorhome
BMW 225e (only 1/2 way to electric)
9th Nov 2021 10:19 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4628
Breg90 wrote:
Profsr G,
I profess that I have not measured that (must try harder.....). But have a look at this side by side comparison:
There is visually no difference.
Adrian
Agreed, they do look identical, I suppose there's little advantage in enlargement, if indeed any. yµ (idµ - eAµ) ψ=mψ
9th Nov 2021 10:20 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347
jenseneverest wrote:
Great to see your able to get back to this
Very nice that the ford bearing do actually fit.
Im not sure i understand your thinking on the larger clearance tolerance as an attempt to cool shells by Ford. IMO the only cooling done by oil is onto the piston /bores with the oil sprayers.
Oil is essentially used to stop friction, this is best done with tight tolerances, the hotter and thinner the oil gets, the less effective it becomes...... i would be aiming for the smallest allowed tolerance.
I would not mix and match the blue/yellow shells either, by mixing them your effectively making the housing oval, all be it by a ball hair.
Just my 2 cents.... another great, well detailed write up as always
Jensen,
Bearings do generate heat from the viscous shear of the oil in the bearing. We don't have the measurement equipment on the oil system/bearings in an engine to measure this. But on an industrial compressor, gas turbine or gearbox there is typically (usually all data available to trend via a data historian):
1/. Oil supply pressure (after pressure regulator valve)
2/. Lube oil supply temperature (after the oil cooler)
3/. Bearing metal temperature - RTD device embedded in the bearing shell ~ 2mm below the shell surface. Note these machines have thick-walled bearing shells that allow this
4/. Bearing housing oil drain temperature
You will always see a clear uplift in temperature between the oil supply temperature and the bearing housing drain temperature. For example, a 40 MW Gas turbine I support at work – bearing housing drain oil temperature ~ 30 C above inlet temperature, bearing metal temperature about 40 C above oil inlet temp. Even if the supply temp varied by 10 C the increase in oil bulk temperature over the bearing is still 30C.
So, the same will occur in an engine. Yes there will be more heat input to the oil in the sump from the oil sprayed at the bottom of the pistons, but assuming the oil cooler was sized correctly by the engine designer, oil will come out of the oil cooler at ~ 85C whatever (I assume there is a little thermostat on the oil cooler). Some will be sprayed on the pistons; some will enter the bearings at ~ 85C.
Effect of bearing clearances:
Very low:
Clearance too tight to allow the oil wedge to form between the crank journal and bearing - metal to metal contact and immediate bearing failure
Shaft is heavily constrained in the bearing, i.e. shaft can’t move far, very difficult to get it to vibrate in the bearing
Low:
Oil wedge can form, but not enough oil flow through the bearing to carry away heat generated in the oil wedge. Viscosity of oil in bearing drops due to increased temperature, load carrying capability of bearing declines (oil can squeeze out the side easier). After while metal to metal contact occurs and bearing fails
OK Clearance – This is a wider clearance range then you think
Oil wedge forms. Oil flow through bearing sufficient to stop heat in bearing dropping oil viscosity excessively
Bearing clearances not excessive:
shaft is adequately controlled
Massive clearance (needs to be bigger than you think)
Shaft moves excessively
Oil leaks out of clearance with out being pushed around to the oil wedge at the load point
I think that the ‘low oil pressure’ light makes us think that the key parameter is pressure. It is flow we are after to top up leakage oil. If the bearing is heavily loaded we might need an element of pressure, but to drive the flow of oil through a bearing. The oil pressure to support the load in the bearing is generated by the rotation between the shaft and bearing, not the oil supply pressure. As an example, the simplest journal bearing set up is:
As the shaft rotates the brass rings are spun by the shaft. Oil on the rings (they dip into the oil in the little sump at the bottom) is brought up to the top the bearing and flows just by gravity into the bearing. The bearing still generates a high oil pressure under the shaft (the oil wedge) due to its rolling action, hence supporting the shaft on a film of oil.
Ideally we would have a low oil flow light on an engine – but flow is difficult to measure. Pressure is however easier to measure. Given that no oil will flow from the pump, though the filter & cooler to the bearing without pressure to force it there, then it’s good proxy for flow.
So a slight increase in my bearing clearance will result in a cooler running bearing provided there is an increase in oil flow – hence I need a higher capacity oil pump.Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
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