Classic Fords, Kit-cars, Race Cars, even boats; the good old Pinto (OK, Ford OHC) is still going strong. However if like me youâ€™ve got a Pinto that has been extracted from a neglected Sierra, it will almost certainly have the classic Pinto problem of a worn cam.
Mine had a double problem. It had been run on unleaded petrol by a previous owner (I used Valvemaster), the valves receded in the head and the cam follower clearance disappeared. This is the wear on the base of the cam!
Of-course it also had the classic cam lobe wear caused by sludgy oil blocking the holes in the spray bar and starving the cam of lube. The Pinto needs regular changes of quality oil.
Well time to restore lost performanceâ€Śâ€Ś..and add some more for good luck by the fitment of a performance Cam Kit from Piper. Of course the job was going to need a gasket set, new head bolts and cam drive belt which came from Burtons. I also managed to get hold of a head from an injection Pinto, which apart from having hardened seats to cope with unleaded, also gives another few bhp due to better inlet port design.
OK, Time to get stuck in. Using the standard timing marks on the crank pulley, I set the engine to TDC.
This, by the way is the mark used to line up the cam if you retain the standard cam drive pulley. Its not exactly precise to rely on what someone working for Uncle Henry did with a centre punch, but later on you will see that Iâ€™ve chosen to fit a vernier pulley. There is no point in fitting a performance cam and loosing some of the benefit through poor adjustment!
Before I started the strip down, I marked the position of the rotor arm in the distributor because once the cam drive belt is off, the auxiliary shaft that drives the distributor and the oil pump is free to move. The ignition timing will have to be reset with a strobe once the engine is running again, but it will be close enough to start.
In this shot you can see that I have removed the thermostat housing so that I can remove the cam belt tensioning pulley. I am just pulling-off the alternator drive pulley. This needs to come off so that the cam belt can be removed. Yes it really did come off this easily, I was expecting to have to use a puller.
My engine is fitted with the later Torx cylinder head bolts. I bought myself a set of Â˝â€? drive Torx bits (Its the T55 size you need for this job), knowing I would also use them on other Ford components such as the Sierra Diff.
So its off with his head! Actually you shouldnâ€™t just whip the head bolts off any old how. Back them off a Âź of a turn at a time in the reverse order to the tightening schedule shown in a workshop manual until the tension is off. I suppose on a cast iron lump like the Pinto this is not so critical, but with aluminium alloy heads, and other modern lightweight designs, you need to take care. Distortion is possible.
Right the head is off, and the engine is stripped as far as it needs to go. So time to find true Top Dead Centre (TDC). You can see here that I have mounted my dial gauge to work on number 1 piston, and mounted the timing disk that comes in the Piper Cam kit on the crank. I’ve made up a pointer out of a wire coat hanger and mounted it under a convenient bolt head. Then followed the instructions in the kit to find and set the timing disc / pointer to read TDC. Which is the point I have just arrived at here. Spot the mistake………yep I’ve refitted the crank pulley without putting the new cam drive belt on first. So I’ve got to take it apart and go through the setting process again! It is worthwhile taking some time over this. I found that the standard crankshaft timing marks were slightly more than 1 degree out.
Now onto the bench for the strip of the head. Donâ€™t just plonk it on a flat surface, as until the cam followers are removed, some of the valves will be protruding beyond the face of the cylinder head, and you wouldnâ€™t want to bend them. Two parts are going to be re-used in the rebuild 1) The cam follower retaining spring assembly and 2) the ball pin locking nuts. So look after them. If yours have seen better days, replace them.
One of the advantages of stripping the head on the bench is that you can get a couple of spanners on the ball pin and locking nut to slacken them off. When carrying out clearance adjustments with the engine in situ, space limitations can prevent this. There is a special locking nut spanner available from the usual sources to help with this â€“ see inset photo.
Right, so thatâ€™s the cam followers removed, now to take the cam out. First the drive pulley has to come off. There are bosses cast onto the camshaft that you can put a wrench onto so that you can undo the centre nut.
The drive pulley comes off with the belt guide plate. Again I was lucky as I didnâ€™t need to use a puller, a couple of taps with a rubber mallet had it free. Needed to be careful that I didnâ€™t bend the plate, but lets face it, neither are exactly pretty. So another good reason for a smart vernier pulley!
Once the cam thrustplate is removed, the cam is ready to be withdrawn through the bearings. Careful you donâ€™t damage the bearings in the process, the edges of the cam lobes are sharp!
In the gasket kit should be a new camshaft oil seal. The old one prises out quite easily, and here I am pushing the well oiled new one back into place. To make sure it was well seated I used a large socket and rubber mallet.
The next job is to fit the new valve stem oil seals. Again use plenty of oil, but as you can see here, they are a tight fit on the valve guides and it is important to check that they are sat fully in place. This one isn’t…………..
……and needed a sharp tap with a suitably sized socket to get it to snap into place. These oil seals can come loose if not properly fitted and they then proceed to move with the valve, pumping oil down the guides in the process. You don’t want that!
Next comes the refit of the valves and springs. The Piper kit comes with new valve springs which are matched to the needs of the wilder cam, so don’t reuse the old ones. You will need to reuse the old spring retainers and collets. I’m using my trusty old school valve spring compressor which can slip-off, so I took great care when fitting the collets. Fiddly so and so’s. As you can see on the inset, these are the standard Pinto ones with the twin ridges that match the two groves in the valves. If you have after-market valves yours may need to be different.
Valves all fitted, so it is in with the new ball pillars.
These need to have the cam follower retaining springs refitted, which can put up quite a surprising struggle.
Closely followed by the new cam, followers, cam thrust plate and retaining springs.
Which just leaves the follower to cam clearance to be set. In the cam kit comes a sachet of cam lube. Use this copiously on any wearing surface you can find i.e. cam lobes, bearings, ball pillars, cam followers etc. This lube is all that is between you and disaster on first start-up before the oil fills the lubrication system. However I have a tip to help with this later on.
The cam kit also comes with a new spray bar, an item that many people feel should be replaced at each oil and filter change. I have also fitted the new vernier pulley and positioned the cam so that it is in a similar alignment to when the standard mark on the head is used. Once on the block I donâ€™t want the valves clashing with a piston crown.
Back to the block. Make sure the block to head faces are scrupulously cleaned of old gasket to ensure a good seal. I guess we all have our favourite scraping tool, but make sure you don’t leave scratches. The gasket in the Burton top end set is of good quality, and yes the holes in it aren’t the same size and shape as those in the head and block. They are designed to control the water flow rate through the block and head so there are no hot spots, so don’t mess with them. Turn the engine so that No. 1 piston is 90 degrees before TDC to ensure no clashes. New Torx bolts need to be fitted.
These stretch when fitted, and so should not be reused. The advantage over the old style head studs is that they do not have to be retightened after the engine has been run for a while. Use the tightening sequence in the manual, this involves two torque settings and after a 5 minute rest a final 90 degree turn. Here you can see me setting the degree gauge so that I can accurately measure the final 90 deg. turn. What you donâ€™t get to see is the scene 30 secs later with the camera man holding the engine and stand steady and me with veins standing out as I try to get the final few degrees on!
Now comes to time to fit up the cam drive belt. However before you do so, I recommend putting some oil into the engine and spinning the auxiliary shaft at a few hundred RPM with an air wrench or similar until oil sprays on to the cam showing the lube system is fully primed. Then set the crank to TDC, the auxiliary shaft so that the rotor arm is pointing at the mark on the distributor and fit the drive belt. This is a heavy duty one from Burton. I used the 90 degree twist test to check the tension, which despite the recommendation in manual to use a special Ford gauge, is the way many professionals do it anyway!
At this stage the cam timing is only set approximately, and itâ€™s now time to use the vernier cam pulley to set it spot on. Here I have mounted the dial gauge so that it acts on the No. 1 cylinder inlet cam follower.
The engine is now turned until it is at the position of maximum lift for the cam. In this case for a Piper 285 cam it is 108 degrees ATDC.
Then with centre of the pulley loosened, the cam is set to the point of maximum lift on the dial gauge, and the locking screws re-tightened. The centre of the pulley has a pointer against vernier marks on the outer (hence the name!!), which shows where the optimum set point is. Record this so you don’t have to repeat the process in the future! In my case the cam was 2 degrees out from where the standard marks would have set it. Well that is the interesting part done, so the rest of the rebuild is straightforward reassembly. Can’t wait to see how it goes, but first the new cam needs to be bedded in as per Piper’s instructions to avoid premature wear. This is an engine run of 25 minutes at not less than 2500 rpm.