Spitfire Engine swap

[Darren Sharp]

Some of you may remember the Black MkIV Spitfire that I worked on last year in the Magazine . I replaced the rear brakes and repaired a few bits and pieces whilst the owner my friend Matt Knight was away with the RAF for 6 months . This car has never run very well . He has had it for three years now . It rattles and shakes and drains its battery overnight for no apparent reason. It constantly goes out of tune and guzzles Petrol at the rate of less than 20 to the Gallon . Matt is on a budget and he loves the old thing . When I first saw it I pointed out that the single SU carb was just wrong and the engine was from a 1300 Dolomite. The wiring was best described as ‘Scenic ‘ . If you were starting out with a Triumph this car should have had a sign in it saying buy another one! The paint is reacting, the suspension was low at the rear (leaf spring completed knackered) and the bonnet is rotten underneath . It has had new sills and the floor looks good . It’s a Mk 4 and the least popular model . It was about 1 owner away from the breakers yard or a full restoration. As with all our cars it will be a money pit until it’s been gone through from back to front . (And then it will take a regular gulp of cash for ever after). Matt has the ‘Bug’ for sure . On his return home I showed him the knackered spring ,which was rusted out with broken shackles and he replaced it. This gives the car a bit of rake at the moment but it has improved the handling and ride no end . I’ve told him to put a bag of sand or two  in the boot for a couple of months but he just looks at me as if I’m mad ! 

Anyway he is now desperate to use his car and despite my advice to give it to a professional tuner to diagnose its issues once and for all he bought himself a compression tester just to check . He found consistent readings of 70 PSI ! Obviously if correct this indicates that the engine is passed its sell by date. To be continued.... 

[Clive]

Darren, were the compressions done with plugs out ad throttle wise open?

And it may be worth checking the tester against another car, see if it is out of calibration. If the engine is that knackered, I would expect it to produce clouds of smoke....

[Darren Sharp]

That’s in Pt 2 but I did do a compression test on it and his ebay tester was woefully out . 

[Darren Sharp]

On 02/04/2021 at 09:16, Darren said:

Some of you may remember the Black MkIV Spitfire that I worked on last year in the Magazine . I replaced the rear brakes and repaired a few bits and pieces whilst the owner my friend Matt Knight was away with the RAF for 6 months . This car has never run very well . He has had it for three years now . It rattles and shakes and drains its battery overnight for no apparent reason. It constantly goes out of tune and guzzles Petrol at the rate of less than 20 to the Gallon . Matt is on a budget and he loves the old thing . When I first saw it I pointed out that the single SU carb was just wrong and the engine was from a 1300 Dolomite. The wiring was best described as ‘Scenic ‘ . If you were starting out with a Triumph this car should have had a sign in it saying buy another one! The paint is reacting, the suspension was low at the rear (leaf spring completed knackered) and the bonnet is rotten underneath . It has had new sills and the floor looks good . It’s a Mk 4 and the least popular model . It was about 1 owner away from the breakers yard or a full restoration. As with all our cars it will be a money pit until it’s been gone through from back to front . (And then it will take a regular gulp of cash for ever after). Matt has the ‘Bug’ for sure . On his return home I showed him the knackered spring ,which was rusted out with broken shackles and he replaced it. This gives the car a bit of rake at the moment but it has improved the handling and ride no end . I’ve told him to put a bag of sand or two  in the boot for a couple of months but he just looks at me as if I’m mad ! 

Anyway he is now desperate to use his car and despite my advice to give it to a professional tuner to diagnose its issues once and for all he bought himself a compression tester just to check . He found consistent readings of 70 PSI ! Obviously if correct this indicates that the engine is passed its sell by date. To be continued.... 

That’s in Pt 2 but I did do a compression test on it and his ebay tester was woefully out . 

[Darren Sharp]

So Pt 2 started with the discovery that friend and Club Triumph local group organiser Andy Johnson had recently purchased a Spitfire 1500 Donor car . It’s an absolute basket case but came fitted with a 1300 engine that had been rebuilt and a J type o/d . This was the reason for its purchase as a donor for another Spitfire in the family which is a long term resto project. I spotted the engine , removed from the car and perched on a crate and enquired if it was surplus to requirements. It was and I brokered a deal between Matt and Andy . The engined was duly delivered. I was still not convinced that the Dolly engine was as tired as Matt had imagined and during a visit to his house I realised that the reason my own compression tester hadn’t fitted before was because I had covered the head with an adapter to protect it .. doh. I removed the adapter and carried out a quick test and found 150lbs of pressure in No’s 2&4 . I didn’t have time to remove the dizzy and alternator for the other two but I’m fairly confident they would have revealed similar reasons . Matt’s eBay tester was just tatt! . I returned a few days later and found the car bonnet off and half the engine dismantled. Ready for removal . I was a bit disappointed as I’m pretty certain we never really got to the bottom of the tuning issue with the Dolly lump . Good friend and wise Guru Chris Allen has now offered up a very plausible explanation based on the examination of the dismantled lump.
 

With an engine crane acquired all attempts to remove the old cylinder head were abandoned . I’d wanted a look at it in situ and intended to get it off for valve testing and gasket examination before putting it back on to attach the hoist . Sadly it was seized solid on two of the 10 studs which rebutted all attempts at removal . A shame because the others came out easily with no damage . I carried on trying to remove the head whilst Matt and his aptly named RAF mechanic friend Mr Wrench (yes really, nicknamed Spanner’s)  set about preparing the replacement engine for fitting . It was at this point I noticed that the clutch was entirely different with a 21 point splined plate . It was never going to mate with a ten splined gearbox input shaft . Closer examination revealed that the phosphor bronze bush was also missing and the ring gear was also a odd size and half the thickness of the one on the Dolomite engine. Removing both ring gears revealed that the ‘New’ engine was also sporting much smaller flywheel bolts which precluded a straight swap with the flywheel from the Dolly engine. Matt had negotiated the purchase of the starter motor with the new engine and it was a pre engaged type. The clutch plate was also bigger. At this point work stopped for the day but we were left wondering where the Clutch and flywheel were actually from. They were clearly Triumph but not from a Spitfire. On my return Matt and Spanner’s had refitted the engine with a new clutch plate of the correct diameter and Splines . I had liberated the flywheel bush from the old engine and checked with Andy as to how it had gone missing from the new engine bearing in mind I’d had to remove the flywheel to salvage the other one. Andy had no idea but an inspection of the O/D gearbox nose in the scrapper suggests that it was never fitted. The last time the clutch had been changed. 

The mystery of where the flywheel had come from was solved by an examination of the pre engaged starter motor . These were never fitted to any Spitfire’s but were fitted to late Dolomites and Sprints. With the engine back in and the starter fitted , the problem of bypassing the solenoid in the car and wiring up the new pre engaged one had to be undertaken . Despite starting the donor car the pre engaged starter appeared dead and resisted all attempts to make it operate on the car. The old inertia starter would not mesh with the Dolomite ring gear so off it came for internal inspection. Once apart it was thoroughly cleaned and I found that one of the brushes was full of gunk and stuck solid . It was freed off and the solenoid was properly lubricated and it then sprung to life . Refitted with the bolts in the other way round from the back plate forwards (much easier to fit ) the moment of truth came . On the first turn the engine sprung to life . It was dry of water so was only briefly run to set the static timing and a quick look at the dynamic with my timing gun. Matt was keen to get water flowing round it so he topped it up . A second start up to check for leaks and water was pouring from the pump housing . I said “ did you have this apart” Matt rather sheepishly replied that he had swapped the pump off the old engine as it had been replaced . He had not however bought a new gasket or any Blue Hylomar to seal it with . “Oh it’ll be alright he says, just needs nipping up” he then promptly sheared one of the housing bolts... arghh! Off it all came again including the housing and we went off to the chippy for dinner. I advised new gaskets all round and a tube of the blue stuff . Good job he only lives two miles from Rimmers ! 
 

up and running! 

[Darren Sharp]

Just in case anyone wonders how to wire a pre engaged starter to mate with Spitfire wiring it’s all quite simple . The pre engaged starter has its Solenoid mounted on top off the motor whereas all spitfires have inertia type starters and the solenoid is remotely mounted on the bulkhead. The Bulkhead mounted Solenoid is a hub for many other functions but it is easily bypassed for starting by removing the starter wire (red and white) from the ignition switch . This is extended and routed to the bottom terminal on the pre engaged unit. A second wire goes from the pre engaged starter direct to the negative terminal of the coil . Then the big thick wire is detached from the old solenoid bottom terminal and Siamese’d with the top terminal on the old solenoid (this goes direct to the + terminal on the battery) you could cut out the old solenoid altogether but it looks neat and prevents the need to buy new leads . One top tip is the fitting of a discarnect device . This little gem saves a lot of hassle removing the battery connection to work on car electrical’s . I fitted it last year as a solution to a constant battery draining issue on this car. This has now been resolved with the fitting of a new alternator. The diode pack in the old unit had failed meaning it constantly drained the battery . A hard one to diagnose without proper testing gear (and the knowledge) if someone can explain why it does this it might be very useful 

cheers all 

[RichC69]

On 06/04/2021 at 14:37, Darren Sharp said:

Just in case anyone wonders how to wire a pre engaged starter to mate with Spitfire wiring it’s all quite simple . The pre engaged starter has its Solenoid mounted on top off the motor whereas all spitfires have inertia type starters and the solenoid is remotely mounted on the bulkhead. The Bulkhead mounted Solenoid is a hub for many other functions but it is easily bypassed for starting by removing the starter wire (red and white) from the ignition switch . This is extended and routed to the bottom terminal on the pre engaged unit. A second wire goes from the pre engaged starter direct to the negative terminal of the coil . Then the big thick wire is detached from the old solenoid bottom terminal and Siamese’d with the top terminal on the old solenoid (this goes direct to the + terminal on the battery) you could cut out the old solenoid altogether but it looks neat and prevents the need to buy new leads . One top tip is the fitting of a discarnect device . This little gem saves a lot of hassle removing the battery connection to work on car electrical’s . I fitted it last year as a solution to a constant battery draining issue on this car. This has now been resolved with the fitting of a new alternator. The diode pack in the old unit had failed meaning it constantly drained the battery . A hard one to diagnose without proper testing gear (and the knowledge) if someone can explain why it does this it might be very useful 

cheers all 

Regarding the diode pack and alternator,  it is there to ensure that dc power only flows into the battery when the engine is running.  When it fails power can  flow from the battery back through the alternator to ground,  discharging the battery.  On old Dynamo systems the cut out serves the same purpose as without it the Dynamo would run as a motor when the engine is off,  but as it’s held still by the drive belt,  the windings will get hot and flatten the battery or melt the wiring...