Classic TR4A Engine Re-build

At TRGB LTD we recently received a seized TR4a engine for full rebuild.   

We firstly proceed by methodically stripping the unit down ready for appropriate machine work and chemical cleaning. Upon stripping the unit down it soon became apparent the cause of the engine being seized.. look at all of the silt and gummed up water ways!!  

With all in house engine re-builds, we always acid dip each block to thoroughly clean all sediment/ corrosion from all areas to stop future silt or hot running issues! We often see engines that have had a substandard re-built which have hot running issues! This is often caused by sediment from engine blocks which gets picked up then blocks waterways and cooling radiators! This Is a worthy process whilst stripped down!

After chemical cleaning and all machine work has been done we are ready to paint and re-assemble the unit! We use a local machine shop who we have used for nearly 30 years! 

The crank shaft after being re-ground, balanced, de-bunged and cleaned! Note the rear scroll has been machined to take our rear oil seal conversion! 

Pre installation of the crank shaft to check crank end float and main bearing clearances! 

Getting ready to fit the pistons and liners! Don't forget to use some stag well seal on the figure of eight gaskets! We only fit steel figure of eight gaskets as the copper type can squash to much when torqueing the cylinder head down!


Checking the cylinder liner height before fitting the pistons and con rods.

After the liner heights are checked and the clamped in place we check and gap the rings! Never assume the rings are pre gapped correctly!

After the piston crowns have be weighed, balances and the maxpeeding con rods fitted, it's time to fit the piston set!

After the piston set has been installed we always double check the big end bearing clearances with a plastiguage! 

Now it's time to fit the cam shaft and do the cam timing! Note: essential cam lube and uprated cam sprocket! 

Now the cam timing has been done it's now time to fit the oil pump, sump and top end! 


Now we are close to fitting the high port cylinder head. Note: we only fit high quality composite head gaskets! We highly recommend installing phosphated cam followers and new head studs and nuts!

High port cylinder head after crack test, pressure and re-face! The head has also had hardened valve seats, new valves and guides fitted!

The fully re-conditioned cylinder head is fitted, torqued to the correct specification and reconditioned rocker shaft assembly fitted! Now it's time to bolt on the fuel pump, distributor, thermostat housing and the narrow belt conversion kit! We would also recommend having the fly wheel faced, slightly lightened, balanced and fitted with our trusted borg and beck three piece clutch kit!


The final finished product! Note: we always keep the manual fan extension! This allows you to fit a front facing electric radiator fan and still keep the original manual fan! Thus increasing engine cooling efficiency, especially in summer conditions! We would also highly recommend fitting a spin oil filter conversion and lumenition optronic ignition system! We always run our engines in on dynolite 20/60 engine oil!