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Fowler Petrol Engine Resources Restoration Tips (30/01/04 - Mainly text but picture will be added when I get the time to take example photos) Through restoring several of these engines I am familiar with some of the pitfalls that may be encountered whilst working on these engines. Hopefully the following information will assist in your projects and will help avoid further problems at a later date. This information is based on my own experience and is in no means meant as acurate instruction for restoration - I cannot accept any responsibility for any damage or injury which may occur as a result of reading my experiences! Dismantling Unless you purchase a restored engine the chances are you will have to carry out restoration work on your engine. The best place to start is to take a few photographs of the engine which will help when rebuilding at a later date. It is also good to have some 'before' photos to show to people when you have finally restored your engine, if you don't take them now you can never show people how much work has gone into the restoration ! This is also a good time to take a not of the engine details from the nameplate, or if this is missing the engine number and model spec. can usually be found stamped on the flywheel crown adjacent the keyway. Some emery paper will help reveal these details if the crown is rusty. A couple of decent boxes and some plastic bags are worth having to hand to store all the parts as you dismantle them. I usually put nuts/bolts for particular parts in labeled bags for cleaning and refitting at a later date to ensure they go back on to where you removed them from. I start by removing all external fittings such as fuel tank, carburettor and exhaust. To remove the magneto you will need to remove the timing gear cover to gain access to the spindle nut. Hold the flywheel and loosen the nut with a ring spanner but don't remove it as yet. Loosen off the magneto mounting bolts and then carefully tap the nut on the end of the magneto spindle to loosen the gear from the shaft. The gear will usually come off allowing the magneto to be withdrawn. I usually refit the gear to the magneto loosely to protect the magneto spindle and prevent the spindle nut and oil seal from being lost. Dealing with Mazak Castings Once the main external parts have been removed you will now be at the stage where the main castings can be removed. If these are Mazak it is worth checking the condition of these before starting to remove them. Warped crankcase doors and poorly fitting governor housings are a sure sign of problems ahead. See Production Problems for further information. The oil filler, crankcase door and magneto will usually come off the engine with ease (and with luck in one piece!) however it is often the camshaft bearings that can prove tricky to remove. Camshaft Removal The camshaft is keyed onto the cam gear and can usually be separated completely. I have found that the camshaft has to be separated from the cam gear to allow complete removal from the engine, and this is where it gets tricky. Start by loosening off the two bolts on each camshaft bearing and remove the tappet block from within the crankcase. Remove all the bolts from the camshaft bearings and using a soft faced mallet gently tap the cam gear in the direction of the camshaft bearing on the flywheel side. With luck the bearing will start to move and will pop out of its housing. Repeat with the other camshaft bearing but be careful as the cam gear will foul on the cylinder and you won't be able to completely tap the bearing out of the housing. If the bearing has started to move, some twisting by hand will usually see the bearing slide out of the housing. The tapping of the gear will often cause the gear to start separating from the shaft automatically. With both bearings removed the camshaft can be separated from the gear and withdrawn through the RHS cmashaft bearing hole. The gear will drop out and can then be removed. Carefully note the position of the key and slot on the gear. I have seen camshafts with one keyway and gears with two slots cut in them. You need to mark the correct gear slot if this is the case or there is a risk of the valve timing being incorrect if reassembled wrong. If the camshaft bearings won't move at all we have a problem ! This is usually caused by the Mazak material expanding over time and siezing the bearings into the housing. You may find the engine difficult to turn over which could be a result of a partially siezed camshaft. Most engines I have seen or worked on with this problem end up with the bearings being destroyed during removal. The outer flanges are usually first to break as people try and lever the bearings with screwdrivers etc. Once the flanges have broken the bearings are basically destroyed and the best solution is to literally smash the bearings out and try and obtain good replacements or make new bearings from brass/bronze stock. I have in the past chain drilled the remains of the camshaft bearings to aid removal but you have to be extremely careful not to mark the camshaft running surface with the drill. Once drilled all the way round the bearing can be punched out and the camshaft removed intact. Again take note of the position of the camshaft in relation to the keyway in the camshaft gear. Flywheel Removal With the camshaft removed the next major part I usually remove is the flywheel. This can either be an easy job or very difficult. You may find the key will come out with ease but you may also find someone has already 'got at it' and snapped the head off the key which can lead to problems. If the key is intact I always ensure the key head and surrounding area of the crankshaft keyway are absolutely clean and rust free. I usually run a sharp point up the corner edges of the key way to ensure no burrs or rust is present. The key can be removed using a number of techniques. These can include using wedges, punches or custom made pullers. See Technical for further information. I have successfully used a flat plate puller in the past for many engines and it usually always works a treat. The photo below shows my puller after significant use. Basically a thick flat steel plate with three threaded boly holes (M10 I think!) and a hole cut in the middle suitable for sliding over the crankshaft and key head and then using the bolts to exert pressure. A combination of lateral pressure and tapping from a hammer usually gets the key to move with success. If this key won't budge the most successful (but drastic!) method I have used to remove keys is to weld a long slide hammer onto the protruding key head. This method is also excellent if the key head has snapped off. The puller is basically a flat bar with a notch cut out one end, filed to create a tight fit over the key. The other end of the bar should have some heavy box section or angle welded on to it to allow it to be struck by a hammer in the opposite direction from the key. The weld onto the key should have good penetration and fill to ensure the joint will not break. When the weld has cooled a sharp strike with a hammer on the angle/box section in the opposite direction from the key should see the key loosen. The effect of heating and cooling the key through welding helps significantly in loosening the key off. Once the key has been extracted it can simple be cut off the flat bar with a hacksaw and reshaped with a file. For further information on key removal see Technical for further information. Main Bearings Fowler 1PA and 1PD main bearings are of the ball race type. This makes them easily replaceable compared to white metal bearings but a number of points should be noted when assessing whether an engine needs the bearings replaced as new bearings are expensive and sometimes tricky to find. Rumbling when turning over and lift of the crankshaft is a sure sign of worn bearings. Often, replacement will be the only option however I have successfully re-used bearings which were deemed ok for rally purposes. I usually strip the engine down fully and carry out a visual inspection of the condition of the bearings immediately after removing the crankshaft from the block. If the bearings look rusty or have orangey sludge stuck to them I have found that this is an indication that the bearing surfaces have rusted which will mean the ball race track and the ball bearings themselves will be pitted which will lead to rumbling noises in operation. Following this I thrououghly de-grease the bearings and polish up the crankshaft to aid a sliding removal of the bearings which probably have not been removed since new. I usually apply heat to the inner part of the bearing to expand this from the shaft and aid removal using a large brass or aluminium punch. Unfortunately I don't have a large enough three jaw puller and access to a proper hydraulic bearing press is a limited luxury ! With care I have been able to remove and re-use bearings by gently heating and tapping off the shaft. Once cleaned and lightly oiled you will be able to tell if the bearing is re-usable. Holding the bearing in two fingers spin the outer race over to guage the level of wear and the noise it produces. If the bearing feels rough and the outer ring is loose from the inner ring and it makes a high metallic grinding noise the bearing is beyond recovery. If movement is minimal and the noise is 'smoother' the bearing may be ok for further light use on the rallyfield. I have actually found that old bearings once cleaned, packed with grease and well oiled will actually quieten down after a period of running. My engine No. 11812 is an example of this. If you require new bearings please let me know as I may be able to assist in supplying new (unbranded/reconditioned) bearings at a reasonable price compared to buying new branded (SKF/RHP) bearings. For rally field purposes the bearings I can source should provide years of trouble free service at a fraction of the cost. For example I was recently quoted over £90.00 UK for the large bearing and around £75.00 UK for the smaller bearing! Prices like these are not worth paying as they well exceed the value of most Fowler engines in my opinion ! Fowler Bearing Details Large Bearing, Flywheel Side -
Crankshaft Oil Seals These can be another restoration problem area if
you do not know where to source new seals. To be honest I don't
know where to get the either but they can be made from dense felt
material of slightly over a 1/4" thick with
ID of slightly under 1-3/8" to fit 1-3/8" crankshaft
(approx 1.370inches) and OD of 1-7/8" (approx 1.87inches) Water Jacket Drain Taps Original Fowler style drain taps can be difficult to find so if your engine still has the original fitted treasure it !! My advice would be to leave it in position providing it is not already loose or damaged beyond repair. Even heating the fixing bush to release the brass tap body is not good enough and can risk snapping the tap in-situ. If the tap can be removed with ease fair enough but if it has 'that siezed look about it' I would leave well alone. By all means remove the tap internals to clean, polish and grease but the best option would be to clean the tap body in-situ and mask off for painting. Exhaust Silencers As we have seen a range of silencers were fitted to the Fowler 1PA range but by far the most common example is the vertical unit with fishtail atmosphere pipe. To construct a new silencer a length of thin wall steel pipe is required - 10" long x 4" diameter. A top and bottom plate is welded into the pipe ends to form the main silencer. The top plate is chain-drilled to cut a circle to accept a further length of 1.75" diameter x 5" long pipe which can be welded in place. To make the silencer look original I weld a small split collar of larger diameter pipe around the outlet pipe and further weld this onto the top plate of the silencer. A further enhancement is to use an extended outlet pipe which protrudes 3" to 4" inside the actual silencer - this makes for quieter running. A flange can be fabricated to suit and welded slightly off centre into the bottom of the silencer - a further chain-drilled oval hole is required in the bottom of the silencer. If your engine has the remains of a silencer the flange and outlet pipe is likely to be perfectly re-usable and will help save time as you won't have to fabricate a new flange. The pre-wd silencer can be constructed using a new Wolseley WD2 silencer as a starting point (these can be picked up at most rallies). I was lucky to have most of the remains of the original I could use as a template, in fact the original nut, washer and stud were reused in this case. Silencer construction is fairly simple, involving welding a large washer in the silencer half in which the outlet pipe passed through. The outlet pipe is trimmed so that the two halves join once more. A blanking plate and stud needs to be welded to the end of this pipe and the back half of the silencer should be welded to the pipe. With care and exact replica can be made as the photos below illustrate.
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