While we were visiting Goodwood Festival of Speed, we managed to head over to Geoff Page Racing's shop. If the name sounds familiar to you, it's probably because Geoff is well known in the U.K for restoring Group B rally and F1 cars and also worked for Brian Hart, who designed F1 engines back in the earlier era of Formula 1. While we were there, we were able to get some insight into a interesting solution to a common problem
If you’re running a high boost turbocharged engine, keeping the cylinder head sealed to the engine block is often an issue and the Hart 415T engine at Geoff Page Racing is no exception. When your cylinder head pressure gets high enough, the block will begin flexing apart, the combustion pressure can escape into the coolant jacket and then it’s all over. Although Hart didn’t invent his solution to this issue he did come up with a pretty interesting one, a monoblock (or monobloc) engine. As the name suggests, there is no head interface between the cylinder head and the block, instead it is cast in one piece. Obviously without a head gasket there is now no potential for head gasket failure.
You may be thinking there must be downsides and you would be correct. Machining valve seats and assembling the engine does become more difficult in that where you would normally drop the piston and conrod assembly in through the top of the bores, you now have to assemble everything from the underside.
That aside, the utilisation of the monoblock design is a great solution to the common problem of head gasket integrity.
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