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The Ford Capri Laser Page


Engine Rebuild

The time had come to refit the cylinder head.  I had purchased a cylinder head gasket set for £13, and a full set of torx bolts from the Capri Club for £20.  Fitting the head was made easier using a trick I picked up from a friend.  I cut the heads off two of the old head bolts and cut a screwdriver slot into the top.  These were then screwed into the block to act as guide pegs for refitting the head and the gasket.  It worked very well and once the other eight bolts were in place  I was able to remove them with a screwdriver.

I made a decision to use head gasket compound.  I don't know if you should or shouldn't but I can't personally see the harm in it.  If you do make sure that it is compound designed for head gaskets as not all are.  In my case it was Red Hermetite and I applied it to both surfaces of the gasket using my finger to give a thin and smooth layer.

With the gasket sitting in place I used the final opportunity to set the camshaft sprocket so both valves were shut on no 1 cylinder and no 1 piston was in its topmost position.  This way I knew that the timing marks were in approximately the correct place (the vernier pulley does not have the 'factory' markings).  The head was gently lowered onto the pegs described above and each bolt was fitted in turn.  I sprayed each bolt with WD40 and applied some copper grease to the top of the bolt to ease torqueing.

The tightening procedure must be followed completely and is usually listed on the box that the bolts come in.  It is also explained in Chapter 13 of the Haynes manual.  You do need a good quality torque wrench to do this job properly as you have to tighten them VERY TIGHTLY.  The first stage is to tighten each bolt in turn to 28 pounds foot, then second stage is to tighten to 53 pounds foot.  After a wait of five minutes (to allow the gasket to settle down) the bolts are in turn retightened another 90°  This last stage requires a lot of muscle power and it is quite worrying because you are convinced that the bolts will snap.  But they are designed to stretch a little making them a permanent fit.  My arm was visibly shaking after doing this job!  Unlike the older bolts (12 splined variety) there are no further stages to the tightening procedure.

With the head back in place the rebuild really started to take off.  First on the list was the refitting of the inlet manifold which had been gently shot- blast to make the aluminium nice and shiny.  As an additional step I port matched the inlet manifold with the inlet ports on the head.  This involved marking the metal overlap using the new paper gasket and then carefully grinding the excess metal away with a drill and grinding stone.  In all I removed approximately 3mm of metal on the diameter of each hole, which took quite a bit of time and patience.  Finally the ground out port was cleaned up although I did not polish the metal as the rough surface assists with the mixing of the fuel and air by causing turbulence in the chamber.  I have no idea if port matching helps improve the performance but many people say that it does and it is a cheap DIY mod.

The inlet manifold was attached to the head using a new gasket smeared in blue Hylomar sealant.  Each bolt was in-turn tightened to the correct setting and the engine breather pipe and vacuum brake pipe were reattached.  Finally the carburettor was refitted using a new spacer and new gaskets, again smeared with Hylomar.  It is important to get the spacer the correct way around and there are arrows stamped on it.  With the carburettor bolted in place, the various hoses were refitted in their noted positions and the throttle cable was bolted down and reconnected.

The right hand side of the engine was now complete apart from fitting the base for the new K & N performance air filter.  This plate was bolted down with cap screws fitted with spring washers - I can't imagine what would happen if one of these worked loose and flew into the carburettor!

The next big job was to fit the new performance exhaust system.  I checked that it would mate up onto the studs and it did.  As before the 4 individual gaskets were fitted using red high temperature gasket sealant and the manifold was bolted down in stages.  The bolts were torqued to 15 pound foot although I had to repeat this several times to make sure the gasket had settled fully.

The rest of the exhaust was not much fun to fit being as I only had about 8 inch of clearance under the car.  I decided to have a practice run and loose fit the pieces before clamping.  The middle box section was clamped and fitted to the hanger on the underside of the car.  Even loose it was very hard to fit the middle section of pipe as it wasn't quite bent enough for a smooth fit.  I persevered and slid the wheel arch section up and over the back axle.  This was only made possible by lowering the back axle right down off the jack to make some extra space.  After a lot of pulling and tugging the exhaust finally looked as though it was sitting correctly.  I applied a generous smear of Autostick cement to each join and pushed them home one by one.  Each clamp was then tightened in turn around the slotted section of the tube so that the metal was pulled inwards and gave a tight fit.  The final section required a bit of pulling and tugging to get it poking out of the back of the car in a straight line and not catching on the metal work.

The exhaust I fitted was from the Capri Club and cost £95 for the exhaust system and £66 for the manifold.  I was impressed at the build quality; all the welds were neat and tidy and the middle silencer was fully skidded as extra protection.  It was a great relief when it was finally fitted!  The only minor concern was that the speedo cable now touched the manifold  so this was relocated away using a large cable tie.

With the main parts of the engine rebuilt I refitted the overhauled distributor and alternator.  I also replaced the water pump which is described fully in my work section.  A new timing belt was fitted taking care not to move the pulleys out of alignment.  Next was the refitting of the radiator and surrounding cowling, and the various cooling hoses were refitted and clamped down.  With the drain plug refitted into the block I was able to refill the cooling system with a new mix of 50% antifreeze and water.  To make this job easier I first detached the hose from the automatic choke which is the topmost part of the system.  The water was then filled to the top of the radiator and the air was allowed to escaped from the hose termination.

With the cooling system refilled it was getting close to the big day when she was ready to start.  I had put the battery on a charger for several days to make sure it was a peak power.  Before the electrics were refitted I turned the engine over several times to listen for any strange noises and to allow the carburettor to refill with petrol.  This was done with the spark plugs removed to make it less hard work on the battery.  I also wanted to make sure that the oil spray bar was working properly and no holes were blocked.  The timing marks were rechecked again and again to make sure no mistakes had been made.  Finally it was time to refit the rocker box cover, not before applying some grease to the lobes of the new camshaft.  A new rocker box gasket came with the head gasket set.

Last but not least a new set of spark plugs were fitted and torqued to 20 pounds foot, and the  ignition leads were attached and checked (I did manage to fit two of them the wrong way round to begin with!).  Next the the points were set up on the distributor with a 0.45mm gap.  This was later checked electronically with a dwell meter later to make sure the dwell was 50 degrees.

The moment of truth - key in the ignition and ready to turn.  With several worried looking spectators and a fire extinguisher at hand I cranked the engine over.  Nothing at first but after a few cranks she started to feel like she wanted to start.  Then on the fifth attempt she started and revved straight up to 2000rpm.  Wow what a noise!  The new exhaust roared deep and throatily and the K & N air filter sucked air loudly.  After a few moments the paint on the exhaust started to burn and clouds of white smoke billowed out of the engine bay.  This was quite scary I can tell you and my heart was literally in my mouth.  Various strange smells were emitted as well.

During this initial start up I was running round the car like a madman checking and listening.  My wife Pam was responsible for keeping the throttle pressed and watching the temperature gauge like a hawk.  As the temperature came up I felt the thermostat open and the radiator became nice and hot.  Everything was looking good.  I was especially pleased with the sound of the engine which had settled down after a shaky start, and the noise from the rocker box was surprisingly smooth and mechanical rather than the metallic clattering heard before the rebuild.

The instructions for the cam shaft said that the engine should be run for a minimum of 5 minutes at over 1500rpm to allow the cam lobes to bed in.  At the end of this period the engine was nice and hot and most of the smoke had dispersed.  The problem now however was that the engine just would not tick over - as soon as the throttle was closed the engine stalled.  This made setting up the timing and dwell extremely difficult so it was time to call in the experts.

With the tick over adjusted so that the engine stayed at around 1500rpm I was able to drive her, but only just.  It was enough to go for a quick spin around the block.  The car was not running optimally at all.  In fact she drove more like a tractor than a Capri.  But I didn't care - at least there were not strange noises coming from everywhere.

Following the engine rebuild I replaced the timing belt cover which proved to be more complicated that I expected.  The vernier pulley was found to be slightly wider than the original and when I started the engine there was a horrendous grinding noise from within.  Several hours later and the incorporation of several spacer washers I managed to get the cover sitting in place so it didn't foul any rotating parts.

I decided not to service the Capri until after the rebuild so any bits of metal and contamination would end up in the old oil.  So the weekend following the rebuild was spent changing the oil and filter and other service items.  The K & N air filter was cleaned and re-oiled with special K & N oil.  The car was now ready for the rolling road....

 

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