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Installing a Phoenix crank in a coil-engined Chummy

Author: Dave Wortley

Pre-installation

I assume conrods have been white metalled to suit the new crankshaft. The conrods should have new big end bolts and new Nyloc nuts or whatever self locking nut you use. Don't use castle nuts and split pins because they are a pain to fit. Make sure the threads in the little ends are not stripped. If you have stripped threads I have got around it by using higher grade than normal locking nuts and HT bolts with loctite and making the tapped hole in the conrod a slight clearance.(I think they were 6 grade instead of 4 grade nuts.) Anyway this setup has worked OK for the last 12 years on my engine.

Fit the bare conrods onto crank, making sure that the heads of the little end screws face the offside of the engine when they are eventually fitted (but not now) and then tighten the big end bolts completely, preferably using old nuts so you don't have to use your brand new Nylocs. Don't put oil on at this stage. The conrods should JUST fall with a little push from the vertical top position round to the little end dangling underneath (bottom position). They shouldn't fall too rapidly as this means they will be too loose. If they don't fall at all then they are too tight. Try letting them fall again after you have given the cap a sharp tap with a smallish hammer/brass drift on the centre of the cap. If no joy and they are still tight you may have to do a little scraping, very carefully and keep trying, blueing and scraping a little at a time until you achieve the ideal fall on the rod. Sometimes the corner radius on the white metal can be the culprit for tightness.

I like to have an end float of at least 0.010" between crank journal and conrod white metal.

Conrods should have been crack detected and are not bent of course. I use Tony Betts' (7 Counties Austins)magnetic particle 2 -part aerosol kit and a strong magnet to look for the propagation of the slit in the little end clamping bolt zone. I don't like the purely dye penetrant stuff as it isn't as good at identifying the cracks. Gudgeon pins should be a push fit in the little end hole of the conrod without clamping screws being present and the hole should be round. I use new HT hex head screws with loctite AND spring washers. These tiny screws are notorious for coming loose, allowing the gudgeon pin to rotate in the little end and wearing a half moon in the screw and also worst of all the gudgeon pin floats sideways and puts deep scores in the cylinder bore. Pistons can be fitted if all is well, with the split in the piston skirt facing the nearside of the engine. They usually have "front"stamped on them so you can't get them the wrong way round. Don't forget to thread the tin oil baffles onto the conrods before you stick the pistons on, otherwise you will need to snip them to get them on, unless you take the pistons off again. Some people don't bother with them though. They get in the way when you are dropping the block with dangling conrods onto the crankcase.

The crank itself

With Phoenix crank on the bench these are things to do first:

Check starter dog screws fully into front end and flywheel nut screws onto other end.

Lap flywheel onto crank using fine grinding paste. Don't overdo this, just get a matt finish on all of crankshaft taper and check with engineer's blue to get 75% or so marking on crankshaft taper.

Fit flywheel Woodruff key separately in flywheel and crankshaft to get light interference fit in flywheel and crankshaft. You should be able to lift the key out of the crankshaft keyway with a small screwdriver prising under key in keyway without bending the screwdriver and to remove key from flywheel keyway it should need only a gentle tap with a very small hammer and brass drift.

Assemble flywheel onto crank with key in crank. Check that flywheel is on crank taper and not riding on top of key. You can check the gap here by cutting a piece of shim (say 0.004" shim) narrow enough to fit the flywheel keyway.

Try the timing gear key in the crank keyway,using the same fit between key/keyway in crank and also in timing gear as at the flywheel end. Fit timing gear temporarily onto crank. Also use a bit of 0.004"shim offcut to ensure timing gear is not riding on the top of the key then remove timing gear and key and put to one side.

Fit all clutch components minus the driven plate (the one with the splined hub)to flywheel,including all 12 springs, 3 toggle levers,pins and posts. I am assuming all the clutch and starter ring gear have been looked over/refurbished as necessary,including new friction linings. It's not much use having your engine balanced if you have worn starter ring teeth. Some people fit a Speedi Sleeve stainless sleeve on the flywheel boss to use in conjunction with a modern spring loaded lip seal. I have never used one as I have just polished the boss on the flywheel for the seal to run on. Make sure the 6 off 1/4"BSF clutch cover screws are all the same length for consistency when assembly is dynamically balanced.

The crankshaft/ flywheel assembly can now be taken to be dynamically balanced. Take along the starter dog because this will be needed to locate the assembly in the balancing machine. Front timing gear and all bearings are not required. I have used John Noble Tuning, Chatsworth Road, Chesterfield for 4 cranks now, the most recent (2015)costing around 100. They usually have a turnaround of 2 weeks ish.

Before fitting crankshaft into crankcase

I am assuming that you are happy with the 5/16" BSF block to crankcase studs ie there is no evidence of them pulling out of the tappings in the case. Best to take them out with 2 nuts locked against each other and then slightly countersink the tapped holes in order to allow the block to seat better. Also ensure the oil pump blanking plate is oil-tight in its seating, is not proud of the case top surface nor below the top case surface as this also is a potential oil leak difficult to rectify when everything is assembled.

Check all other crankcase tappings are sound at this stage and ensure that all oil galleries are scrupulously clean. One frustrating problem is when you have installed the engine in the car and then attach the bacon slicer starter housing to the crankcase only to find the tappings for the unit in the top of the crankcase are not as sound as you thought. So it is worthwhile assembling starter unit to engine on the bench to test that all is well.

Oil pump and relief valve. As they are very cheap, put in new relief valve ball and spring,and new pump vane springs. Note that the 2 vanes have a chamfer on one end and none on the other. The chamfered end goes into the pump first, the chamfers clearing the radii in the base of the pump. The vanes should be level with the top of the pump body and no gasket is required between pump and the pump lid.

Check that the abutment lip at the bottom of the front bearing housing is sound. It is very weak and is easily damaged by brutal assembly of the front bearings. If it needs work one of the cherished "Friends" suppliers can do this but they will need to machine the case and fit a steel replacement washer where the lip used to be. I have done my own using a scrap crank with a hole drilled in the front web which is then fitted with a lathe single point tool, the whole assembly mounted in the case on old and slightly relieved in the ID of the main front and rear crank bearings. I then hand turn this assembly using a crude handle attached to the flywheel, machining off the remains of the old lip .It is a pain to do and takes much messing about so may be best to let one of the above suppliers do it for you if necessary.

Fitting the camshaft and setting camshaft end float

You need the camshaft, front bearing and camshaft timing gear pre-assembled on the bench in order to set the camshaft end float.

First of all the location of the camshaft in the crankcase with the original design is poor and can be improved by throwing away the special square headed screw with locating peg which fits in a clearance hole in the top of the front bush. Tap out this hole in the bush to 5/16" BSF and use a screw which goes through the slightly opened out originally 5/16" BSF tapping in the crankcase and is long enough to engage your newly tapped hole in the bush. Make sure it is not so long that it locks up the camshaft when the screw is fully tightened. You will then have a more positively located front bush in the crankcase this way.

You are after a working end float of no more than 0.004" so initially tighten the timing gear on the camshaft to see what end float you have, using a feeler gauge between timing gear face and bush front face. It will probably be much more than the 0.004" required so remove gear and apply fine grinding paste on the taper until you end up with the required endfloat when all is tightened up. If you overdo this you can remove a little material from the bush face which points into the crankcase.

You can now trial fit the front cam bush on its own into the case. If it is sloppy you can assemble it with loctite when the time comes.

Fitting camshaft in crankcase

Fit rear camshaft bush in crankcase ensuring it is the right way round with oil holes in bush and crankcase lining up and the chamfer on the bush clearing the pump gear. Don't forget the gasket. Put a small amount of engine oil on front and rear camshaft journals.

Feed camshaft with centre rollers stuck to the camshaft journal with very sticky grease. This is a fiddly business, the rollers falling off the camshaft just at the crucial point. Some people use elastic bands here wrapped round the rollers but it never works for me.

Now before fitting front cam bush, degrease hole in case and cam bush OD. I use cellulose thinners. Apply loctite to front bush OD. making sure you don't get too much loctite near the oil holes of bush and crankcase and fit in hole and onto camshaft ensuring that the tapped hole in the bush is aligned with the hole in the case and then fit the new 5/16" BSF locating screw using loctite as a sealant. Rotate camshaft a few times to ensure there is no loctite sticking camshaft and bush together. Don't fit timing gear at this stage as it is difficult to stop the camshaft rotating when tightening the timing gear nut.

Fitting crankshaft in crankcase

I am assuming you are using the 1 1/8" front roller and deep groove ball bearings at the front so with the crankcase you are using we don't need to go into the intricacies of angular contact bearings and housing depths and which way round to fit the bearings.

Feed the bare crank through the rear main bearing hole, being careful not to damage the oil jets. So with case on the bench, timing gear end uppermost, find a piece of wood which is thick enough to allow you to fit the front bearings, roller bearing first (inboard) and ball bearing last without damaging the lip as you gently tap the bearings onto the crank journal. The piece of wood goes under the flywheel end of the crank. I heat the case up for a few minutes,quite gently with a hot air gun, not concentrating the heat in a particular spot for too long which allows easier fitting. You can heat the bearings up to make it easier to fit on the crankshaft (see rear main fitting below)

Fitting the rear main bearing onto the crank journal

I have a small saucepan with about 1 1/2" of clean oil in it which I sit on my open vice jaws and heat up with a blowlamp. You only want to heat up the inner race which you can do with the roller bearing because the outer race slides off. You will be heating up the rollers and cage as well because they are permanently attached to the inner race.

When hot enough (I usually get the oil almost boiling but not quite as we don't want a conflagration) the inner race should slip onto the crank with a gentle push. Let this cool down before the next stage.

Now fit the rear main steel bearing cartridge after you have fitted on the bench the separate rear main outer race into the cartridge. This outer race goes hard up to the lip on the cartridge. Make sure you align the bottom oil drain holes in cartridge and case. Don't forget the thin paper gasket between cartridge and case. Again, a bit of hot air gun application makes this easier.

Fit front bearing housing washer,using locking tabs on the 1/4" BSW screws. These screws are quite delicate and can be easily sheared off.

Fit crank timing gear and its key, starter dog and locking tab. This now locates the crankshaft axially in the crankcase. To aid tightening the crankshaft starter dog, put a substantial piece of wood between crankshaft and crankcase wall to prevent the crank turning. Be careful not to damage the delicate oil jets.

Fit rear aluminium seal housing with integral lip seal after first fitting the original oil thrower washer (top of dish shape facing towards flywheel) This washer is trapped between inner race of rear main bearing and flywheel boss and rotates with the crankshaft. Ensure that it does rotate with the crankshaft rather than digging a nasty stress-raiser groove in the crank by dimpling the trapped part of the face with a blunt centre punch or suchlike. Don't forget the gasket between steel bearing cartridge and seal housing. Tighten the 4 off 5/16" BSW rear main bearing screws and use lock tabs.

Aligning oil jets – Important!

This is quite messy and involves a paraffin-filled squirty bottle with a short (3") length of thin wall rubber hose which will fit over the end of the oil jet when you expose them by undoing the 1/4" BSF hex jet covers in the oil gallery. You will need a small tray under the crankcase to catch the paraffin.

With all this lot on the bench,sump face towards you squirt paraffin into the jet via squirty bottle and rubber hose and check that the trajectory of liquid is going straight into the oil trough on the crank. Try and maximise the length of arc that the liquid is squirted into the trough by carefully bending the jet inwards towards the crank. I use a piece of steel tube which just fits over the OD of the jet at its base. Don't try bending the jet using wire inside the jet hole or it will be damaged. Do this for both jets of course.

The jet cover screw thread in the case is delicate so don't overtighten them when replacing. Fibre washer required between case and screw head.

Don't fit the flywheel at this stage.

Fitting camshaft timing gear

Align the markings on cam and crank gears and fit cam key and gear, tighten nut with tabwasher underneath. You can now stop the camshaft rotating as you tighten the cam gear nut by putting a substantial piece of wood between crankshaft and crankcase wall as previously when tightening crankshaft timing gear.

Fitting block and pistons onto crankcase

(Assuming you are satisfied with the previously fitted valves,springs etc.) Degrease top face of crankcase and bottom of block. Put crankcase sump face down on bench top,oiled crankshaft big ends horizontal inside case.

Assemble pistons/conrods in block, pistons facing correct way round in bores, ring gaps all set rotationally so no gap in line with another gap,big end caps removed,oiled white metal in conrods, big end bolts in conrods but no nuts attached, oil baffles roughly in their correct orientation on the conrods.

I use normal thin paper gasket and Blue Hylomar or Loctite SI 5990 copper silicone, so I would sit the gasket onto case top face after applying goo onto the case top face and block bottom face. Some enthusiasts use better quality Loctite 518 gasket maker without the paper gasket if you would prefer it. There are now available silicone block to crankcase gaskets which I will try the next time I have the opportunity. By all accounts they are excellent.

Lower block assembly onto crankcase, feeding conrods onto crank journals and aligning oil baffles on crankcase top.

Attach nuts to 2 opposing crankcase studs and fasten down. Turn engine on its side, sump opening towards you and attach oiled big end caps, ensuring that the big end bolt is correctly located in the conrod. The corner of the bolt head sometimes digs into the conrod and doesn't seat properly.

Check that bolt head and conrod seating face are in full contact by trying to poke a 0.001" feeler gauge between them.

Now, looking up the bores and with all big end caps fitted you hopefully will see that the gaps either side of each conrod and between the piston gudgeon pin bosses is roughly equal, proving that the new crankshaft is correctly located axially.

Fit all block/crankcase nuts and spring washers and fully tighten down.

An improvement to aid tightening block to crankcase is to fit elongated nuts at front and back of block as the elongated nuts used inside the tappet chest.

Flywheel and seal axial alignment

Fit flywheel on crank taper and check that oil seal lip is fully engaged on flywheel boss. This can be adjusted by moving seal back and forth in the aluminium housing.

Fit flywheel, nut and tabwasher. To tighten flywheel nut,use the piece of wood between crank and crankcase wall method and don't be tempted to stick a screwdriver in the flywheel periphery wedged against the bell housing or the crankcase may crack.

Also check that the flywheel tabwasher is not catching the domed inside of the clutch driven plate.

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