Boss Racing get 1950s Coventry Climax engine race-ready with Ultraseal sealed cylinder head

Vacuum impregnation sealing and pressure testing services

Boss Racing get 1950s Coventry Climax engine race-ready with Ultraseal sealed cylinder head

Race team and specialist race engine builders, Boss Racing, recently worked with Ultraseal Slough to seal a cylinder head for a special race engine build project.

The engine in question, a 1950s Coventry Climax, was an advanced engine for its time; all aluminium, lightweight and featuring an overhead cam.

Housed in a Lotus Elite, a car that was built in 1957 and pushed the boundaries for a GT of its time with its aerodynamic silhouette, shaped out of glass fibre reinforced plastic monocoque bodyshell, the Elite generates a drag coefficient of just 0.29.

With the Elite being prepared for entry into a classic sportscar series, Boss Racing were tuning the engine from its original 75hp into a race-ready 140hp performance engine.

With power output being close to doubled, Boss Racing knew that sealing the 60-year-old cylinder head was essential to ensure the quality and reliability of the engine.

Ultraseal Slough processed the cylinder head through their vacuum impregnation system, firstly placing the part in an autoclave, where Ultraseal’s impregnation sealant fills any porosity within the part as a vacuum draws air out of the cylinder head.

The Coventry Climax engine

The cylinder head was then drained and placed in a hot cure for the resin to set and provide a permanent seal to any porosity in the part, operator Colin Pinkney then hand washed the cylinder head to ensure any excess sealant was washed away.

Pressure sealed, the cylinder head is ready to be re-fitted back onto the Coventry Climax aluminium engine block.

Trackside and ready to race

Ultraseal Slough are a trusted partner to many race teams, classic car restorers and automotive manufacturers throughout the UK. The service at Slough is also regularly used by private individuals undertaking their own car and motorcycle restoration projects.

When we look to maximise the performance out of any engine we know that sealing parts like cylinder heads is essential. With Ultraseal’s vacuum impregnation service we know we have a reliable, sealed part


Boss Racing offer service, race car set-up and support for track and road cars, to find out more about Boss Racing services got to: