ahebron

Hi Bernie Can I ask you some technical questions regarding the Lagonda Rapier engine. More than happy to do it on the forum so more will learn from my troubles. There is also a Rapier for sale here in NZ, the link might disappear if the car sells https://www.trademe.co.nz/a/motors/cars/other/other/listing/3985966210 Thanks Adrian

Thanks Digger I am almost convinced it is not a Magneto issue. I rotated the leads and adjusted the timing and it made no difference. Looking into oil getting past the inlet valves. I will try Bernie.

Hi all I am working on my parents 1934 Lagonda Rapier and have an unusual problem that I think is magneto related. The car when they bought it had an impulse mag that was wrong for the car so it was fitted with a BTH more in keeping for the car. So far work on the engine has included getting rid of the restrictive hockystick exhaust manifold and fitting headers and also removing the old SU H2 carbs and fitting 28mm Amal Concentric carbs on the original inlet manifold. I recently redid all the valve caps to get the correct gap for the double over head cams, they were all over the place. During the carb set up we fitted NGK BP5HS plugs as the original kept fouling, I have refitted the original cooler spec plugs. I noticed when the car was running that the front cylinder header was not getting as hot as the others, the spit test. Using a laser thermometer I discovered the temps to be cyl 1 140 degrees C cyl 2 245 degrees C cyl 3 250 degrees C cyl 4 170 degrees C Remove the plugs and cyl 1 was wet but as I had the inductive pickup for a digital tach it was still generating voltage down the wire. Cylinder 2 and 3 where dry and a nice colour and 4 was between 1 and 2,3. While the car was running pull the lead from 1 and almost nothing noticeable changed, when replaced the engine would pick up a little. This was the same with lead 4. Pull either 2 or 3 and the engine would die. But it idles smoothly with all four leads attached and revs happily. Luckily I know some vintage airplane mechanics so mentioned to them and they said bring the mag in and we will test it, I took 3 in, the BTH, a Simms and a Lucas. The BTH passed the test on their spark tester but they thought its magnetism was low, the Simms passed with flying colours and the Lucas failed. Unfortunately the remagnetiser had been sent to another branch but I was welcome to take the BTH over to get it zapped which I did. The mechanic who zapped it wasnt that impressed with the initial remag so gave it another go but it didnt improve much. I refitted the BTH but the faults with spark still existed so I fitted the Simms. The car started the best it ever has with the Simms and runs fine but all the issues with cylinders 1 and 4 still remain, cool exhaust pipe temps, damp plugs etc. In desperation I removed the inlet manifold, 4 nuts and slides off and using a carb balancer with a length of vacuum cleaner hose I did a crude suction check and all the cylinders drew evenly. Eyeballing down the inlet the valves are working as they should. Engine compressions are all acceptable 135, 135, 140 and 135. Everything has been changed out from the original BTH setup, new plugs, new leads and new mag (Simms) All gaps are in spec. To me as fuel is getting to the plug then it must be a mag issue. Carbs are balanced and mixture set. Twin carbs with carbs feeding cylinder 1 & 2 and 3 & 4. No obstruction between the carbs and inlet ports and the carbs are central on both ports. The old SU carbs were shot This is getting frustrating Thanks Adrian

Rapier Lagonda Rapier Talbot Rapier Sunbeam Rapier and probably a few more Adrian

Lets correct a few points here. Spitfire never had the 948cc engine. It first came with the 1147cc with twin carbs Triumph Vitesse was the same body and chassis as a (mk2 chassis) Herald saloon and convertible with no factory coupe or estate built. Running gear was very similar but certain components modified or strengthened. Many Vitesse have been rebuilt using Herald body, chassis and mechanical parts . It first had a 6 cylinder engine of 1600cc which was a sleeved version of the Mk1 2000 big saloon and estate, this was the Vitesse 6. Main external body difference is the twin headlight front end, aluminium bumpers and stainless steel side trim going the full length. Interiors had wooden door tops and a few other differences though the first 1600 had the the same dash as a 1200 Herald, latter ones got a rev counter After the 1600 came the 2 litre which had a similar engine to the Mk1 2000 big saloon and estate but a bit more power. Retrospectively named the Mk1 2 litre A major Vitesse redesign came with Mk2 and this had a new front grill, rear boot inlay and rostyle wheel trims. The mechanical improvement was the rotoflex rear suspension which helped tame the handling and the fitting of the motor similar to the Mk2 big saloon and estate cars. Overdrive was available as an option on all Vitesse and made them into a better car for highway use otherwise the 6 is spinning at nearly 3000rpm at 60mph. The TR5/6 engine has always been 2500cc and while similar was never commercially fitted to the Vitesse. Vitesse 6 with the 1600cc engine was sold in the States as the Sport Six and wasn't a great commercial success. Thanks Adrian