The heart of any car and what makes this a comparitively unusual competition Midget. The Triumph 1500 engine is much maligned for its weak bottom end. All I can say is that mine (and several others) survived a pretty tough season and, when it did break, it was a piston and not the crank.
My engine was built with for the Luffield MG Championship standard class which restircts modifications but the ones it does allow can make quite a big difference. Standard the 1500 produces 71BHP at the flywheel and mine came with a print out showing 75BHP at the wheels . Since then I’ve added a few bits and would hope to see closer to 80. There is lots of variation on the web about how much power is absorbed in the transmition (you would need to know this to calculate the flywheel BHP) – some talk about 25% which seems like a lot – I don’t think my car is making 100+ bhp BUT we’ll see when it goes on the rollers.
My car is fitted with intake trumpets and ITG filters, to get the air in quickly and an extractor manifold to get the gasses out. I’ve also got electronic ignition which was made to my spec (not difficult since the spec is virtually standard) but it set records using standard points.
The most significant change was to have the crank balanced with the flywheel and front pulley. This should allow the engine to rev without tearing itself appart. This might be a problem! Watching the onboard with the unbalanced engine I was changing up at about 5600 rpm – just because that sounded and felt like a lot (too much going on to look at the rev counter on most events) With a smoother engine I was changign up at around 6000. This could explain why I keep running big ends and, most recently a main bearning. I’ve promissed myself to keep the revs down this season. We’ll see how long that lasts!
An electric fan should free up a couple of horsepower too. People laugh at my looking for 2bhp here and 2 bhp there but 4 bhp would be 5%!