The engine was replaced by a 2.5 litre from a 1972 Triumph 2.5PI (less the petrol injection). This was rebuilt by the owner towards the end of 1980, with the help of the machine shop of R. C. Williams of Bachymbyd Garage, Llanrhaeadr near Ruthin, who rebored the cylinders (+0.030″) and reground the crankshaft (+0.010″). This process would involve reboring in 0.010″ stages, finishing to just under +0.030″ by a few thousands of an inch, and finishing by honing (grinding with stones rather than cutters) to precisely +0.030″.
All the moving parts were balanced by Howley Racing of Warrington. The new engine was fitted on the 14th December 1980 (mileage 104,027). All new components were fitted where possible. STP was used to coat all bearing assembies to prevent undue wear until the oil circulates on first start-up*. A parts list appears below (1980 prices, in today’s money £1200+) :-
An article about my rebuild appeared in the February 1981 edition of the TSSC magazine “Courier”. It appears below:
Note about end float, Kas Kastner, in his book ‘Competition Preparation Manual’ cites end float less than 0.010″ as acceptable.
Below are the specifications of the Cylinder head and Camshaft:
* Note, STP contains zinc dithiophosphate as an anti-wear additive. Modern engine assemblers tend to use Graphogen Assembly Compound, which is is a colloidal graphite paste in oil. To visit their website click the image below.
Update August 2025
I have just had the engine tuned by TRBitz in Knutsford and it is running well nearly 45 years after I rebuilt it!! The total mileage done since rebuild is nearly 29,000 miles in total.