This is a follow-up to an original article entitled 'A Piece Of String' in the Jan/Feb 1999 issue of the Saab Enthusiast! Magazine. It was all about the Pandora's box of problems I encountered when I had come under the influence of the Trollish spell on the 'K' reg Saab 96 V4 I had bought. The title was a comment on the never-ending work that I felt needed to be done.

It all started on a perishingly cold Christmas Eve in December 98 when in a fit of Saabist enthusiasm, I had been outside in the white cold dismantling and cleaning the cylinder heads. The reason for dismantling the heads was because I intended to have hardened exhaust valve seat inserts fitted and thus be able to use unleaded petrol. I told myself that the costs involved would be an investment because I was preparing this car to be my long-term transport companion.

I have been told that nowadays we no longer encounter 'problems', instead we have 'challenges'. So my first 'challenge' was that having removed the heads I discovered that the valve spring compressor would not compress the springs. When the over-centre lever was operated the tool tied itself into a figure-of-eight knot. The valve collets were stuck in their collars. I managed to free them by supporting the head of the valve on a large socket then putting a suitable sized socket over the collar, but clear of the collets, and giving a tap with a mallet. Result = sweetness and joy. Both visual and micrometer inspection showed that the valve stems had negligible wear.

However, judging by waggling the valves around in the guides the exhaust guides weren't doing much guiding. The exhaust valves had carbon deposits most of the way up their stems, so something was amiss. The Haynes manual says to fit valves with thicker stems into the guide holes in the head that you've reamed to the next size up in a series of possible over-sizes. This would require the purchase of a complete valve set with oversize stems and, having recently been quoted £405.37p for a new Saab camshaft, I blanched at the prospect of buying any Saab parts. (Incidentally, the Saab garage did explain that the camshafts were no longer available but that the sum quoted was the last figure they had for such an item.)

Due to corrosion the exhaust manifold studs needed to be replaced. They would not give in to the heat-plus-Mole-grips treatment so it had to be a trip to the professionals. There were various other threads including the heat shield retaining bolt, which snapped off like a carrot that needed re-drilling and tapping or helicoiling. These things required tools and machining that I didn't have so I turned to Devimead (BSA) Ltd (Tel: 01970 625600) who are on the Glanyafon Industrial Estate at Aberystwyth. They proved to be a great choice. Real engineers who know what they are doing and are used to dealing with engines long out of production. They did all the helicoiling plus taking the lightest possible skim off the heads to ensure that they were flat. They fitted phosphor bronze valve guide liners and honed these to size. Fitted hardened exhaust valve seat inserts. Cut the seats to the correct angle and machined the valves to suit their new seats. I was able to reuse the existing valves. With hindsight, I wish I had used the folks at Devimead for the other engineering work too.

I have found the right hand rocker box oil filler is awkward to use without the help of a funnel because of its proximity to the alternator. I wondered whether anyone has tried transposing the covers by fitting the right hand cover, back to front, on the left hand cylinder bank. The Haynes manual says "Don't do this", but tantalisingly doesn't say why not. Maybe the starter motor would become 'well oiled'. In the end I decided to have a go at making a dog-leg for the stubby, angled, oil filler neck. It wasn't such a difficult task and the result is most satisfactory.

Either from my sixth sense or maybe because it didn't make the familiar alternator-ish noises, I wanted to have the alternator checked. I sent it to P&J Autos (Tel: 01708 500010) who proved excellent to deal with. They reported that it was full of baked mud!! They remanufactured it and it was returned amazingly quickly and looked like new. I was so impressed that I sent them the starter motor to overhaul too.

When sorting out the main lump of the engine Chris Partington advised me to pay particular attention to the water pump end housing and the engine front cover. These parts become eroded by pump cavitation and the efficiency of the pump drops dramatically leading to overheating 'challenges'. It didn't take a second glance to see that the cover was paper-thin in places. Nick Senecal from the Saab V4 Salvage Company found some good condition second-hand parts to rectify this. I dread to think of the frustration I would have incurred in diagnosing this fault at a later date if I hadn't been given that tip by Chris.

The fibre camshaft drive gear was so worn that it deserved to be mounted in a glass case as a lasting tribute to its perseverance in service. Modus Enterprises (Tel: 01280 847189) sorted out this 'challenge' by offering a good price for a set of metal timing gears that are made for Saab in the Netherlands. The small gear is steel but the one that replaces the larger diameter fibre one is an aluminium alloy.

If you ever rebuild a V4 do check the camshaft centre bearing in the block. This is more important then it might appear because it has two uses. First, it supports the camshaft, but secondly, it is this bearing that provides the only route for oil to the valve gear in the heads. The oil is routed into the lower side of the centre camshaft bearing, around a groove in the periphery of the bearing, and out of the top side of the bearing into an oilway that leads to the heads. When the centre camshaft bearing gets excessively worn the oil squirts out sideways into the sump leaving no pressure and little oil to go upwards to the hot and thirsty valve gear in the heads.

As mentioned in 'How Long is a Piece of String' the cam lobes were reground and treated which meant that I needed to fit new followers. Putting worn followers to work on the new shaft would have defeated the regrinding. I was quoted £16.29p each for Saab cam followers. However, Kent Cams (01303 248666) can do a full set for £38. I think the part N0 is CF 10. They are Ford V6 2.3/2.8 cam followers. Their bill for doing the cam grind plus eight V6 followers plus VAT plus Securicor delivery was almost exactly a quarter of the cost of a new camshaft.

The following may be of assistance to anyone seeking crankshaft bearing shells. The standard bearings for the big ends are done by Glacier part N0 B4451LB. The 'LB' suffix is the material and doesn't matter. These bearings are available for Taunus V4 1700ccs 1964-72 number B4451 SE & SC. Main bearing shells come from Vandervell as part number VPM91235. They are also done by Glacier as part number M4219 and are the mains off a V6 Taunus 2.3 of 1968 onwards. (Thank you to Steve at Autella in Honiton for doing the necessary Hercule Poirot exercise on the parts manuals to unearth these valuable numbers.)

Burton Engineering carried out the rebore and fitted new balance shaft and camshaft bearings and thoroughly flushed out the oil ways. I did a repeat of the flushing process myself on the principle that you can never have too much of a good thing. For the assembly of the engine I made a cocktail of one-third engine oil, one third STP, and one third Molyslip. Probably unnecessary, but it made me feel good. I am at the age where I appreciate a little boost from time to time. The crankshaft and flywheel assembly were in perfect balance, but the weights of the rods varied noticeably so they were balanced. I have no scientific figures to back up what I'm about to say, but I am so pleased with the result that I would check the balance of the reciprocating bits in any engine I rebuild in the future. Incidentally, the Volvo pistons were astonishingly well matched for weight straight out of the box - only 4gms covered the spread of heaviest to lightest.

Ford make a useful tool called Plastiguage with which you can check the crankshaft bearing clearances during assembly. It is a great confidence booster to know that all is well. The fitting of the inlet manifold requires that the nuts and bolts are torqued in a particular sequence and in two steps, firstly to 5 lb/ft and then to 15 lb/ft. This is fine except that not many folk have a torque wrench that covers this gentle range. I made mine out of a knuckle bar and a set of spring scales as used by the fishing fraternity. I added a third intermediate stage of 10 lb/ft to the tightening sequence, totally unnecessary I'm sure, but it made me feel good again.

Mark Dunn

Note: This article appeared in the September 2003 issue of the club magazine.