Rebuilding the 1600 long block

1st August 2009

The small block I started last month seemed to be a distant memory as personal changes in my life were at the fore of my mind and I was finding difficulties in locating the parts I needed for the long block.

I had sourced the 1600 barrels from a very good friend in return for a bottom end rebuild he wanted me to do for him. I negotiated that it would be better if I told him how to do it, so I was going to show him when he was ready to get it done and hopeful pass on some lessons I had learnt on my first rebuild.

The Barrels were in reasonable condition for their age

with three of the pistons in good condition with the third showing some significant mark on the surface. I decided this would have to be replaced and placed a thread on Vzi to locate a replacement . I cleaned the barrels up using a degreaser gunk and then with a wire brush. I used 600F degree VHT black paint to paint them. The barrels seemed easy to find unlike the Marle piston rings that seem to be disappearing sadly from the shelves of GSF and many other VW suppliers. I hope this is just a problem with the import and does not mean we are losing them as I still favour Marle above other makes. You can see pictured right I have checked the alignment arrows on the piston surface that face the flywheel and placed a circlip pin in the same end so that I could not mistake the direction that the gudgeon pin had to be driven in. I eventually found some Marle piston rings and started to fit them to the pistons. Generally this is much easier to do if the piston is covered in oil. The packet of rings is normally divided into three sections with the rings for the bottom middle and top slot all held together. Starting with the bottom ring position nearest the connecting rod. The correct ring can be identified easily as its the widest one and usually consists of a spring device or frame, cover two separate side rings or a frame that fits over the spring frame. I have seen both types of bottom ring oil seal in Marle kits so it is good to be familiar with the different types. My Marle kit contained the undulating frame and two separate rings The undulating frame is colour coded to allow it to be correctly placed together. Personally I think it is better to fit it and try overlapping either way to ensure that its profile fits nicely together. The two thin rings sit either side of this to ensure a good oil seal. The undulating frame keeps them separated and sprung. The next ring up is a much larger ring and you must be careful to get it the correct way up by finding top marked on it. This can be slid over the piston crown in much the same way the other thinner oil rings were introduced. More care must be used though as its large size makes it more brittle. The top ring is also marked on one side 'top' be sure to also get the orientation of this ring correct. Slipping it onto the piston in the same manner used before. With all three rings on the piston great care must be used to ensure the gaps in the rings do not line up. Generally speaking I put these at 90 degrees to each other so that no gas could escape past them. The ring assembly procedure is then repeated for the other four pistons.

With the rings in place you can insert the pistons into the barrels I have tried many home made devices to fit the pistons in but to be honest they do not work as well as the piston ring compression tools that are on the market and can be bought for as little as £10.00. The only disadvantage of these cheaper ring compressors is that you have to remove the gudgeon pin to take the ring compressor on and off. With this in mind the piston ring compression tool can be slid onto the piston and the ratchet then ratcheted up to pull tight against the rings. It is important at this point to ensure that the piston ring compression tool fits around the piston with the top of the piston flush with the skirt of the piston ring tool. Also if the piston ring tool is made of spring steel rings ensure all the rings are flush. Lubricate the bore of your cylinder. Place the piston upside down on the neck of the barrel. With a piece of wo0d placed inside the crown of the piston, knock the piece of wood , whilst holding the piston ring compression tool and piston centrally over the barrel. A few short taps should place the piston in the barrel. Make sure the skirt of the piston is protruding from the barrel so that you can re-insert the gudgeon pin.

The barrels can be then placed on to the engine block. You must start with the cylinders nearest the flywheel end of the engine. If you tap the gudgeon pin so that it slightly protrudes inside the piston, you can locate the gudgeon pin in top of the con-rod. so that it can then be tapped home with a round drift like a socket extension so that it sits comfortably against the clip. Place the clip in the end of the piston to secure the gudgeon pin taking care not to spring it inside the engine. A piece of cloth can be draped over the engine apertures to ensure this does not happen as a complete rebuild is needed to remove it!. With the two barrels nearest the flywheel in place the other two barrels can be placed in the same manner remembering the securing clips for each. As you work putting the barrels on you may need to rotate the engine to get the con rod out far enough to make the connection to the piston. With all the barrels on the short block tap them with a mallet so they sit firmly in the case. Fit the air deflectors to the underneath of the barrels - these clip in between the barrels and fit on the bottom of the barrels blocking the air flow from pushing straight past the barrels.

With the barrels and pistons sourced and fitted I was left with the task of finding some 1600 heads. The answer again came from a friend Huw from vZi who drove them down to me. It was very nice to meet him face to face. When buying replacement heads it is important to check that the heads have no cracks in them. The spark plug areas are notorious for this and need cleaning to ensure they are crack free. Also check the fins are intact and the threaded areas are good and not stripped. The heads were in very good condition and did not take much cleaning to bring them up to good condition. You can see pic right that they didn't look like they had more than 500 miles on them as they still carried the lustre of new heads. I cleaned them down with spray-on-Gunk rinsed with my favourite garages jet wash. This was particularly funny as it was tipping down with rain and instead of getting wet from the jet wash I was soaked from the rain too I must have looked comical. Once I had them back I covered them with carburetor cleaner and wiped the remaining residue off with a cloth. I left them to dry before assembling. I was very pleased with the heads after cleaning them up. I removed the tired exhaust studs from the heads as I always think it is fool hardy not to as they are very inexpensive to buy. They can be removed by locking two nuts onto each other on the stud and undoing the lower nut. This process will remove most studs but invariably there is always one or to that you need to apply heat to so that they will start to move.

Before installing your heads you should check that you have the correct fitting kit. Some heads need a copper washer to be fitted but others like my 1600 heads require a straight fit. You also need to gather the push rod tubes push rod seals and push rods as you will need all of these to fit the heads onto the barrels. Personally I always use new and fit the seals onto the tubes with grease up front to fitting on the heads. You should firstly fit your heads as a trial fit to ensure they go onto the studs and fit snugly onto the cylinder heads. If you are using older heads then it is better to grind the heads to fit the barrels. This can be achieved by using valve grinding paste on the surface of the barrel and rotating it in the head until it finds a flat seating. If you have to grind your heads ensure both parts are cleaned thoroughly to remove the valve grinding paste (Very important.).

The head install is a four handed job that requires a balancing act of the push rods and the heads. Personally I start with the head placed onto the studs. After greasing the ends of the push rod tube I then place each push rod tube in situ. I use the push rod to poke through the tube so that the tube is supported and does not fall out and is held on the push rod this is repeated for one side four in total. With everything in position you can try to slide the head into its final position as you do this keep an eye on the push rod tubes and ensure that they stay seated into the concave recess or the engine case and head. Once you have the head on far enough you can use two of the nuts to wind it in further checking again that you have not trapped the push rod tubes. You can now start to torque up the heads. This needs to be done in a precise order so that the heads are pulled on evenly to the barrels. Start by torquing the nuts up to 7ft/lbs or 9.0 NM ensure you have a washer behind the nut follow the 7ft/lbs diagram (Far left) in order to tighten the bolts in sequence. Once you have torqued up the nuts change the setting on the torque wrench to 23ft/lbs or 31 NM and re-torque the bolts in the order of the 23ft/lbs diagram (far right above) Note there are two different sequences for tightening the heads this is important. During this process check that the push rod tubes have not moved and are seated properly. This procedure must be repeated for the other cylinder head.

The end float must then be calculated for the crankshaft to allow the flywheel to be fitted. The tolerance for this needs to be between 0.07" and .012". It is generally easier to do this with the front pulley wheel removed. Both the the mating surfaces on the flywheel and the crankshaft must be thou roughly cleaned. You must then ascertain whether you need a paper , metal gasket or o-ring seal and no gasket. I was using a 200mm later flywheel with an o-ring that used no gasket and just needed the o-ring replaced. With this done check the dowel pins in the end of the crank are good and straight and load the flywheel onto the end of the crank. Be careful you may need to support it with a block of wood as it is fairly heavy. You then need to pull the flywheel onto the crankshaft tighten the flywheel nut and torque it up as high as your torque wrench will go. With this done you can start to get a feel for how much end float you are dealing with by pulling in and pulling out the flywheel to see the extent of this movement. To measure this you either need a DTI and magnetic support arm or a vernier gauge with a dial indicator on it to improve its resolution. The vernier gauge has a depth gauge on the lower half of the gauge and it can be used to measure from the surface of the flywheel to the engine case. Start with the flywheel pushed back towards the back of the car as far as it goes. Use the DTI or vernier to measure this distance. Pull on the flywheel as far as you can get it out measure again from the surface of the flywheel to the case. Subtracting these figures will give you the gap that your flywheel moves. This will need to be packed with three shims that will reduce this gab to the correct tolerance . Shims are available in 0.24", 0.30", 0.32", 0.34" and 0.36" only. Select three shims that give a total width that when subtracted from your gap brings the end float back into tolerance as near as .07" as you can get it. Once you have the three shims remove the fly wheel and place the shims on the crankshaft. Replace the flywheel and test to see that you have good end float. When you are finally happy remove the flywheel and fit the fly wheel oil seal into the case. This may need to be driven into the case with a block of wood. refit the flywheel and torque it up to 230 ft/lbs.

Once this has been completed your long block is complete. The only exception being the rockers and valve covers both will be covered fully in the next article.

Parts Used.
-------------
FREE Barrels & Pistons.
£10-15 1 x Replacement Second Hand Marle 85.5mm piston.
£120-£150 per pair Second hand 1600 cylinder heads.
£20 - £25 - Marle 85.5 mm piston rings.
£10 Piston ring compression tool.
£20 Push Rod Tubes and seals.
£10-15 Engine Gasket set.

N.B All Prices included as a illustrative guide only.

Engine small block rebuild

30th June 2009
The idea of rebuilding the bearings of a beetle engine to most people is something best left to the technical amongst us. To be honest this may be true as you get a more accurately built engine , however it is not something that cannot be done in your own garden shed.

Principally the hardest part of rebuilding an engine is changing the main bearings. There are many problems with this as cases are sometimes line bored to accept slightly larger bearings. With this in mind you must be sure which bearing set you need to order. Most good suppliers are only to helpful with this and armed with the correct bearings and your bearing saddles not having any strange grooves or lumps out of them then you can fit the bearings as detailed below. If the bearing saddles are pitted , scored or otherwise trashed you will need a line bore through the bearing saddles so that the bearings can be seated properly. Generally speaking if you are having a line bore its best to order the bearings through the company doing the line bore to ensure you have the correct ones.

The next problem most people encounter is to remove the bearing that sits between the camshaft drive and the number 2 rod shoulder. This is something I have always had done in the shop but to be honest its not as difficult to remove as you would think. To remove the bearing you will need either a three pronged puller or a proper crankshaft bearing puller which unfortunately are fairly expensive. The other thing you will need is plenty of heat , now we are not talking about a paint stripping gun. We are talking about a butane torch that will heat the bearings up to a temperature that they will expand enough to slip of the crank shaft. When you have both of these you can remove the oil slinger by removing the wood ruff key with a screwdriver and hammer to tap it out this will give access to remove the circlip use a screw driver to prise the circlip of the end of the crank. The bearings can then be heated and heated some more until they are hot enough to enable the puller to pull the camshaft gear and distributor gear off. Be careful when they are off as they will still be very hot.

With the camshaft drive off you can slide the old bearing of the crankshaft. You need to check the bearing surface for any defects. Now putting them back is not the same procedure as taking them off. Ensure that you put the new bearing on with some bearing compound such as Joe Gibbs Assembly lube grease, which will help bed the bearing in. The next important thing much overlooked is to ensure the camshaft bearing goes back on with the two dots facing towards the end of the crank. The curved in side of the drive needs to go next to the bearing. Now to get the drive back onto the crank you will need to heat up the camshaft drive again. The easiest way of doing this is to pop down to Tesco and buy a cheap saucepan and fill it with engine oil and put both on a camping stove. Watch for bubbles appearing from the drive. When you get this the drive is hot enough to be dropped back onto the crankshaft. Be warned get it the right way round! Also don't go hotter or you will set the oil on fire. Fit the racer spacer next and then use the same process to heat up and fit the distributor drive. Finally the circlip can be replaced. The oil slinger must then be placed back onto the crankshaft it may be necessary to remove the pulley wheels wood ruff key to enable to fit the slinger the concave side must face outwards.The other bearings can then be lubed up and placed on to the crankshaft bearings with the exception of the middle one which must be fitted to the case.

Personally I did not fit my crankshaft at this point but instead checked the play in the con rods which in my case was considerable. The tolerance for measure this is done by inserting a feeler gauge down the side of the con rod. There should be no more than 0.016-inch min by axial measurement. The bearings can be bought for very cheaply and can make a considerable difference if the crankshaft saddles are in good condition. Ensure that you remove and re fit the con rods the same way up. All the notches should face up and the con rod marks should appear the same side for the top as for the bottom. The con rod bolts need to be torqued up to 23lbs. The new bearings made an impressive difference remember to lube them in using the same pre-assembly lube as the crankshaft. With the rod bearings fitted the crankshaft can be fitted on to the bearing saddles. remember to check the dowels are in situe and are in good condition. The bearing need to be aligned so that they fit onto the dowels and the crankshaft will drop into place.

I decided that I wanted to fit a higher lift camshaft to the engine and had previously chosen an Engle W110 for this engine. I used a Billet Alloy camshaft gear that I had from a previous test comparison. This had been balanced on a lathe as its original casting was poor. The camshaft and drive can be fitted after the cam followers have been lubed and inserted into the case. Ensure that the top of the cam followers have also been lubed. the camshaft bearings are press fitted into the casing on both halves. The larger shouldered bearing fits nearest the drive and the bearing decrease in size towards the flywheel. The camshaft needs to be meshed against the Camshaft . The two dots on the drive gear should nestle neatly either side of the dot that is on the cam gear. This is the correct synchronisation of the two gears and is vital for the timing of the engine.

The two half's of the crankcase can be mated to test for binding on the crank. If the crankshaft is free and able to be moved the two half's can be separated and the camshaft seal can be glued with sealant into the case. I used blue hymelar as a case sealant as it stays tacky whilst your assembling. The six central nuts can be tighten remember to diagonally tighten down. Check the crankshaft can still move by placing the front pulley wheel in situe and then place the peripheral nuts and bolts around the case.


The oil pump can then be fitted into the case a soft rubbermallet can be used to push the oil pump into place. YOu must remove the gears before doing this as they need to be keyed into the camshaft. With the oil pump in place the small block is almost complete rebuild was almost complete. I needed to purchase a full flow oil pump cover as I had decided to go full flow.

AS41 Magnesium Alloy Case Welding the tricks

23rd June 2009
The Magnesium/Aluminium case design of the AS41 case i renown for being one of the lightest design engine cases even by today's standards. This was the brilliant invention of the VW factories in Germany who originally built the engine to power planes. The downside of this design is that the Magnesium/Aluminium alloy was a mixture that was hard to weld. The obvious risk of this being igniting the Magnesium whilst welding so that the hole part you were welding burned with a large flash eating away its form. Traditionally welding these materials takes a great deal of experience as the welder needs to be aware of the composition and must apply only enough heat to weld and not combust. It is also paramount that you have a hammer with you available to beat the crap out of the area you are welding so as to knock the burning magnesium out of the area. The downside of this is that i can leave a larger hole than you start with. Crucial to the weld is also the composition of rod that you use and traditionally the flame is better controlled by a tig welder. Most people believe wrongly you need an Aluminium rod with a Magnesium content to weld the AS41 case. The result of this I found out quite quickly was not the answer and the shop that I asked to weld the case up produced the hole filled and taped but not surprisingly the plug they had welded in did not bond to the case and was simply able to be pulled out.

The correct welding rods to weld an AS41 case are in fact Magnesium rods with a low percentage of Aluminium. The actual percentage being 8% Aluminium to 92% Magnesium. These are available from Armour supplies Ltd in Hastings, East Sussex UK .

Withe the case welded so that the main gantry was plugged I was able to get the case re taped with the 3/8" NPT tap. I used a workshop for this and had to remove all the engine main studs so that it could be mounted in their mill. you can see from the photograph that I decided to have the area made bigger so that the thread had a good fetch into the casing.

The finished plug looks stronger and more durable than the original. I am very suprised this can be done and it blows a large rasberry in the faces of everyone that says it cannot be done or to put it a better way the people that have kept this a secret from us for a long time are now all aware we all know,. I look forward to seeing a lot more cases re welded in the future.

As the answer is a vertible YES!!!!!!!!!!!!!!!!!!!!

Fan housing design and overturning traditional ideas

14th June 2009
With the disaster of my engine case I had to find a company that could weld and re tap the oil gantry. This was a difficult task and in the meantime I turned my attention to the other parts of the engine that needed cleaning up. I had two companies that I had approached to do the case work but both were taking time to come back to me.

Originally I had thought that I would just cut weld and chop of the air outlets from the fan housing but a friend had put a thread on Volkszone about this and surprisingly there had been some technical testing done by Jake Raby's research into engine temperatures and fan housing design. That indicated that the Fan housing design was constructed to have integral vanes that directed the air flow inside the housing separating air flow from the engine and diverting it to the housing outlets. It appeared from the discussions that the general consensus including my own that simply blocking of the vents would cause air flow turbulence in the coursing that would effect the fan housings overall ability to cool the engine.

I have included a picture of the internals of the VW fan housing courtesy of www.offroad.net which is also a source for the information here in comparison. The scat housing picture courtesy www.newlancsvwclub.co.uk is definitely missing some of the internal vanes and although seems to produce adequate cooling there must be reasons why VW included the extra vanes in the first place. The solution suggested by newlancsvwclub seemed to be to cut the whole outer edge of the fan housing down to remove the air channel that would cause the air buffer. This in practise was a very easy option and the rough shape can be seen on the following picture. The internal structure of the fan housing that directs the air to the vents can be un tacked from the fan housing and pulled out to make a new curve that follows the new line of the housing as detailed by the green line.

I started on my fan housing removing first the air outlets with an angle grinder and thin cutting disk. The outlets came of fairly easily and from the holes that were left I was able to see the internal vane that was going to become the outside of the new housing. It is important to leave about 2" of metal at the top of the housing to keep the two halves held together in the correct alignment. With a flexible ruler I marked a line on the outside of the housing. With one side cut away the front side could be trimmed to ensure it was closer to to the vane. The rear section was then cut away and the vane pulled out to meet the new curve. It can be seen from the picture that the vanes do not meet the top of the fan housing. I cut pieces from the cutoffs to make material to fill these gaps. Obviously you could bend the internal vanes to make any new shape you desired, however I was attempting to get the best cooling possible from the design and though that the curved top lended itself to this application.

With the design and metal work cut and established the fan housing needed to be welded up . This is not as easy as it looks as the thin tin ware is quite thin. I used a MiG welder to tack up the housing at opposing points around its perimeter . This gave the construction a better stiffness that allowed the perimeter to be tacked up. The result of he welding process is not as neat as the original design and it as obvious that I would need to prep the housing before painting. After Angle grinding the surplus weld of the housing I decided to try p38 filler to smooth the outline. Discussions with a friend regarding this pointed out that the files likely to chip off from the housing during its use and that I would be better to have the outside prepared by fibre glass. I took the fan housing to a Friend Ash who created a mold from the housing and re profiled it to make a better curve. This was then bonded on and the whole housing was painted and primered. I painted the rest of the tin wear in primer and needed to get a nice cool day to buy some 2pac in spray cans so that all the tin wear could be blacked up . The tin ware was looking excellent and I needed now to get the case repaired. This was looking very interesting as most posts found on Volkszone said it was a potrntial arsonists or pyrotechnics dream come true as the Magnesium base AS41 case just would turn into a large roman candle. Was it going to be possible or was I just going to have to purchase another case or complete engine?


Some pictures courtesy of www.newlancsvwclub.co.u and www.offroad.net.

A new 1300 dual port engine

5th June 2009
I had started to realise that with the break up of my relationship that my new 2L engine was going to be something further distant that I had planned. I was planning to have the engine in by the end of this year and with the custody fight and various other depressing events I needed to find a solution that would get the engine situation resolved as my friend had been very good to lend me his engine lump but obvuously I wanted this resolved. I managed to purchase a 1300 dual port lump that had been dry stored in a lockup for some years. Although the engine had some end float outside the allowed parameters generally it looked in good condition.

Initially I decided that the engine would need stripping and the piston rings would need replacing , but I also found that the con rod bearings and crank bearings really could do with renewing. I really had not planned for this and had decided against renewing at this time until i was placing the pistons back on to the case and pung one of the pison ring clps accidentally into the casing.

This normally would have been a disaster but to be honest I was already considering stripping the block down and decided that this was now had to happen. You can see from the diagram that the gudeon pin clip was lodged beneath the camshaft and was totally uneccessable from the oil plate. I took out the crank hsaft and camshaft and cleaned the engine parts thourougly with gink and then jet washed them off to remove any final engine residue.

The engine casing parts cleaned up fairly well and without the use of a dishwasher I was unable to get them as clean as I had with the other cases I had worked on. I couls ssee from the bearing journals that the crank had not damaged the casing and the case was in good condition. I decided whilst I had the case apart that I would full flow the oil system so that it would be able to cope with any future upgrades. This consisted off tapping the casing outlet of the oil pump for a 1/8" NPT thread and tapping the main oil gantry to provide a return a 3/8"NPT thread. The oil pump casing was quite easy to tap and this can only be done with the negin in half. The 3/8"NPT main return thread was a hole differant ball game. The thread would not take in the casing and instead just powdered up and dug a hole . This was a disaster as there was not much room in the casing to put in a case saver. I new that I would have to delve into the world of case welding something believed to be a Pyrotechnics black art.

Whineing Fan Housing and Drag Torque Bar

31st May 2009
After nearly a year of the Drag Bar Linkage setup sitting in my garage I had to take the temporary engine out I was using as I was getting a very large wine noise from the fan housing. The engine was a single port 1300 engine which had a surprising amount of talk. Some months back I did not have time to write the dynamo failed and I had fitted my alternator from my previous engine. The problem with this was that there was not enough depth in the single port fan housing to take the fan and alternator backing plate. I presume from this there must be four different types of backing plates although I have only ever seen two. The result of this was the back of the fan was scraping on the fan housing an emitting a horrible wine. As a result of this I decided to remove the engine and at the same time fit the drag linkage kit.

The drag linkage kit fitting was described here http://martinsswbratrestoration.blogspot.com/2008/10/installing-csp-torque-bar.html

If have to add to this that the new rhino mounts that I bought to remount the gearbox where firstly not exactly what I thought they should be . The rear mounts looked very similar to the urethane ones and the front mount was missing the tab that fits into the chassis on the back of its bracket. In addition to this the rear mounts fitted extremely tightly in to the gearbox mount to a degree that made them very hard to fit. I new from fitting the gearbox that the gearbox strap was very tight to bolt into the frame arms for this propose I changed over the brackets first. The downside of this is that you cannot move the bracket to help get the mounts in. After struggling , Jacking up the gearbox etc I found a solution that worked. I used a clamp to clamp the bell housing to the bracket . This had the result of pulling the gearbox down onto the mounts . With the combination of a screwdriver in the mount bolt hole I was able to slowly tighten the clamp enough to allow the bolts to be placed in situe.

The fan housing issue in the single port 1300 engine was not so easy to resolve. I have tried the pack the front of the backing plate with small washers to push the front of the fan away from the back of the fan housing . If this fails to work I would have to find a temporary twin port engine to run in the buggy.