Josephine rebuild

[PJGD]

Keith,
What is the story on the camshaft? Obviously it is new. I assume it is steel and not machined from a cast iron slug. Any idea who manufactured it?

[Forumadmin]

I bought three from Bill Lock. Two of them have oversize journals as one of my blocks has worn ones. He made two sorts, this I think is the early one , the later had black lobes.

Scott also has a few and we used one on the Alaska trip, so not a bad test.

[Keith Clements]

The test equipment needed some restoration work of its own since it would not hold vacuum.
After pipe and Terry clip renewal, the Pintel gauge feed was sealed with a blanking plug and the system evacuated to 15 inches of mercury. There was a slight leak so some sealer was put around all the joints in the test system. Now holds within 2 inches for 15 minutes.




All bearings were assembled with Molybdenum Disuphide compound.

I spent an afternoon trying to find my piston ring compressor and failed so made one with a Terry clip and some shim stock. Loctited and torqued con rod bolts to 35 lb.ft


Note the clamps on the liners to prevent the seal being broken.

The heads, water inlets, crank pulley and sump were prepare and painted with enamel. The sump required its jointing face and its base flattened.
You see the parts curing on the wood burner as it was freezing outside.


Jack came around to pick up a Bradford steering column that he will get copied by a firm in Birmingham in probably a vain hope of improving the steering on his Braddie. It did 30 miles yesterday but Jack was complaining about the noise from its straight through exhaust!

[Keith Clements]

With the valves ground in, the combustion chambers were balanced to around 41 cc. I was unable to find the two pieces of glass with holes drilled in them that give a slightly more accurate way of measuring by sealing the chamber. Instead a plate of glass was used and filled through the shallow end.
The delicate burette was retrieved. Grease was used to seal the valves and face of the head.



This first reading was an overshoot. Each chamber was measured at least twice. No 4 was 41.6, No 2 = 41.6, No 3= 40.8, No 1= 41.2
I was happy that a variance of 0.8 cc was good enough with air bubbles and grease creating a possibility of .2cc error without my holy glass.

I reckon the surface area of the combustion chamber is about 25 square cm. so .5 cc is a depth of .2mm which is what would be needed to shave off the 4/2 head to get it down to 41 cc. See tuning notes which reckons it would be .15mm.

See tuning notes

Any corrections to the capacity can be made by machining the Cylinder Head Gasket Facing 0.011” (0.2794 mm) removed here reduces the capacity by 1 c.c.

I have a selection of head gaskets and will see what compression ratio I can get with these pistons.

[Keith Clements]

Today I sorted out the valve springs and retainers. The springs were checked for length (ideally you should check under a known load). I had a new boxed set of Terry's Aero Valve Springs and a new set of Tranco. Plus a set of Tranco that were used on the Morocco Rally in 1998 as well as 20 sets of unknown usage. I will post dimensions tomorrow as they are down the garage. I chose the Terry ones. They do seem of larger diameter , so hope they stay in the retainers.

The top retainers were all checked for wear. Anything less than 1.4 mm was rejected as I have had a couple let go whilst racing.

A couple of sets of collets were inspected and the best chosen. They were assembled with Moly

After assembly the valves were tapped with a copper mallet before removing the compressor to make sure they were bedded in. The gap was checked on the collet.

All faces were cleaned with panel wipe and the gaskets and faces coated with Hylomar. Solder around top 4 head nuts that have chamfered washers to retain solder. Heads torqued to 35 lb.ft.

[Keith Clements]

So now to test the oil pump.
This is the rig I built consisting of an old sump filled with 10/40 oil . A bar with three captive nuts to support the pump.
A cover for the timing chain spray. An old oil cooler bypass cut off that feeds a pipe with a union to feed the T piece for oil pressure take off to the gauge and tap to simulate oil load.
An offset drive that goes where the distributor drive normally goes that is put in the chuck of a variable speed reversing drill.


The tap is opened and the drill run up to speed carefully as there is a large increase in torque as the pump is primed. Once primed the tap is shut off and the pressure increased slowly to make sure the relief valve opens. The pressure was noted and initially was 50 psi. The lock nut was released and quite a few turns were needed to take it up to 70 psi. The tap was then opened slightly and the pump run at speed to make sure the relief valve opened smoothly and maintained a constant pressure at different speeds.

You may see that the oil was aerated which I was not happy about. After checking two other pumps and setting them up , I then returned to check out the original pump. I thought I saw a crack in the brazing of the pipe so this was crack tested , But no crack was found. Then the gasket was inspected and found to have a break around one of the holes. The gasket was put back with silicone, and tested again. Still aerated. So as I could not find another gasket I tried without but the pump locked solid so I found a gasket in another pump and fitted it. Tested again and good. The oil came out without any air bubbles.


This was a picture I took before I cleaned it up and you can see the break in the gasket.

Without this test bed a faulty pump (which had been reconditioned) would have been fitted. Oil pressure would have been OK and only after a few hundred miles would the bearings have failed.

Some picture follow showing the diffrences of the intermediate and deep body pump. The early pumps had a smaller bore (see tuning notes).




So now I have two of each pump reconditioned with new gears and tested and set to 70 psi.

[PJGD]

Keith, re the oil pump, a dynamic pressure test is a good move, but gear pumps are miserably efficient, typically around 50% due to leakages around the gears. Running a thick oil at ambient temperatures in your test will obscure much of the leakage and may make the pump look better than it is. As a result, I would recommend using a thinner fluid that has approximately the same viscosity at ambient temperature as engine oil does at ~90°C, i.e. something around 8 centistokes.

[Keith Clements]

I do not think the temperature or viscosity makes a lot of difference to setting the blow off valve. High viscosity may possibly prevent or slow down the valve from opening and closing but this was a 10 sae oil so thin at low temps. It is the test I wanted to do cold as the back pressure from the bearings is higher when cold. The flow rate made no difference to the blow off pressure but if I opened the valve the pressure did drop as the small bore pipe did not deliver enough oil. I could rerun the test by putting the rig on the wood burner.

Note I confirmed my theory really as I also tested the pump that came out of Josephine that blew off at 75 which is what it ran at when in the engine at all temps. I have a long run of pipe to the oil cooler above the gearbox so a greater pressure drop than normal which is why I have a slightly higher pressure as recommended in the tuning notes.

I will retest the pressure once the pump is installed in the engine and connected to the galleries and oil filter. I will run without the brass drive gear in place on the crankshaft. This will also test the flow to the rocker shafts.

These pumps have new gears that hopefully have been properly machined. The capacity of the pump could be measured I guess in litres/minute to see what it could deliver at say 50 psi. Then viscosity would play a big part. My test rig has small bore so would need to be re-designed to do that.

You really need a pressure gauge take off at the rear main bearing to see how much oil is being delivered there and the condition of that bearing which is usually the one to go first. One block I have had a worn centre cam journal and so drained the oil before it got to the rear main. This I discovered by running the oil pump with the sump off. A messy task! Perhaps a job in future for my new endoscope. You can actually see where the most drips are coming from and thus discover which bearing is worn.

[Keith Clements]

I attached the engine supports and also fixed the centre support to the stand so that the engine can easily be rotated.


Fabrication instructions are in the gallery for both on page 18.

The rocker shafts were inspected but not lightened as per the performance engine that was in the SA. Note the brass collars in place of springs.



The crow's foot used to torque the centre stud. Copper washers above and below oil banjo.


Then the oil filter housing was checked with engineers blue and feeler gauges to make sure the faces were aligned. A little flattening was done with a file to remove high spots.


The bolt holes were then drilled out and helicoils fitted as often too short a bolt is used which strips threads. Always check bolt is correct length and goes to nearly bottom of thread. Bolts are torqued to 25 lb.ft., if helicoiled, otherwise 18 lb.ft.


An aluminium plate was made to hold the O rings 1,53mm diameter to get correct crush.
It is quite tricky getting the holes to align on both faces. Very bad Jowett engineering! Engineers blue was used first to check alignment on block and then on the housing. Judicious filing to make sure O ring seated where it would seal.
A trial fit was done with the timing cover without gasket so as to align horizontally. The vertical bolts are finger tightened then the 4 or five horizontal bolts are tightened to 9 lb ft. Then the vertical bolts are tightened to 25 lb ft.
There was a check then with more blue.








After cleaning off the blue, the felt was fitted in the apex, the faces were coated with hylomar and vertical bolts with flat washers finger tightened. Then the timing cover was fitted without gasket to align housing as before. Note the modern filter adapter which was also assembled today.

[Keith Clements]

Friday was spent finding, cleaning and sorting a couple of thousand nuts, bolts and washers to replenish stocks used on Peter and Jack's cars and get stock for the forthcoming engine rebuilds.


Today the oil pump was attached making sure the locating collars were in place and torquing to 9 lb.ft.

I use this as a torque guide. Grade R (or medium tensile for automotive) is generally a good guide with Grade T ( High tensile) for anything mechanical such as flywheel and con rod ( or the oil housing after helicoiling).

Most bolts I fit with threadlock , studs have the permanent.

The delivery pipe needed all its faces cleaned up.

and all threads were cleaned as most have some sealant on them, very important on aluminium to clean up steel screws!


Paper gasket made and hex screws replaced with allen bolts for easier assembly.

A locating collar was missing for the clutch housing

The paper clutch gasket was fitted with a smear of hylomar.

The human torque wrench was used on the 7/16 and 3/8 BSF. Internal fan lock washers.

but not on the flywheel where I use flat washers and loctite rather than spring washers. Also found that an R grade bolt stretches so replaced with T grade ( the original bolts). Bolts are tightened diagonally and progressively.

Flywheel runout was checked and recleaned three times but could not get below 4 thou (.11 mm). Limit is 3 thou! I suspect the refinished clutch face may be out of true. More investigation tomorrow.

[Keith Clements]

Replenished stock arrived today.
Hylomar for paper/cork gasket and Loctite 518 for metal to metal.
I probably should have used the 518 on the Oil Filter housing . We will see how Hylomar holds up.

[Keith Clements]

This post is at the end of the topic as you may be reading this with newer posts showing first. By clicking on the links you will get posts in chronological order.

This story is in 3 parts currently.
The chassis rebuild and aluminium repair .
The sub-frame repair and body prep.
The body paint.
Addendum to bodywork

Engine posts start here
Further episodes will follow as the shell is refitted and the engine rebuilt after splitting coming back from Oulton Park.

[Keith Clements]

I changed the flywheel to a standard weight one and runout was less than 2 thou (.06mm). So I am in process of making a mandrel to hold the wheel in the lathe.
The lightened flywheel was bought from Wes and the clutch re-facing was done on a mill not a lathe. So I suspect it was not properly set up.
Hopefully I will be able to correct the issue. If it works the mandrel can be used for lightening other flywheels. The main challenge is accuracy so it is testing my lathe skills.

I thought of using part of an old crankshaft but I do not have a broken one!

[Keith Clements]

Found whilst trying to find a piece of steel to make the mandrel.

[Keith Clements]

The first job was to turn the steel billet down to fit into the flywheel crank recess and to face its two sides.

Then the 7/16 BSF tap set was brought out of hibernation. The clearance drill (red) was used to locate the hole for drilling through with the tapping drill (white).
Then the first (tapered) tap was run through followed by the second and final taps. Collets are used for accurately centring the drills.



With all four holes tapped the mandrel was put back in the lathe and refaced before assembling the flywheel onto it.



The clutch face was found not only to be out of running true (4 thou) but also not to be even (3 thou) as it had been milled poorly. Now within 1 thou.


The crankshaft face was also cleaned up on the mill after a test back in the engine still showed runout.

I would have preffered to do this on the lathe but could not easily find a way of holding the flywheel by clamping onto a faceplate. One possible way of achieving this would be to have the mandrel accommodate two socket bolts in the tapped removal holes of the flywheel. However this would require either another pair of holes in the mandrel or some turned down bolts that fitted into the existing tapped holes in the mandrel. Ideally all this requires swapping around the flywheel without removing the mandrel from the lathe ( as this would loose registration). This in turn would require a long key to fit down the shaft inside the lathe . Back to the drawing board!

Normally I would have faced the crankshaft side first (if thought necessary) as the clutch face would be true, but with this bodged job there was no true face to reference except the clutch side surface in the centre that is chewed up by the bolts heads/spring washers.


I decided it was expedient to get rid of the last thou of runout by placing a shim between crank and flywheel. It is not clear from the manual whether the runout is on the clutch face centre or the outer edge of the face where it would be about double that in the centre. I assumed worst case.
The two clutch holding dowels that had been removed for turning were replaced.