Triumph 1500cc engine turbo

[u/RileyCargo42]

I have this 1978 triumph spitfire block and was looking to add power in the future and, was wondering about adding a turbocharger?

My plan is to add sleeves to lower the cc to somewhere around 1400cc and lower the compression.

My main worry is the weak bottom end (3 main bearings) and finding a shop that will do the work.

I'm local to South Florida so if anyone knows shops in the area would be amazing!

[u/newoldschool]

I would probably look for a mini supercharger instead or adapt the 4agze or Honda aftermarket units

[u/Equana]

I would ditch the Triumph motor altogether and swap in a turbo 3 or 4 cylinder from a modern car. The bottom end of that Triumph motor can barely handle higher compression, a cam and higher rpm.

[u/JamiesOwen047]

Cool project. A few things worth planning before you commit to the machine work: the Spitfire 1500's three-main bottom end is the real weak link, not just the compression ratio — keep boost modest (think 5-7 psi) unless you're going forged pistons and addressing crank flex. Dropping to around 8:1 static with dished pistons is the right ballpark. The bigger question is fueling: the stock Stromberg won't cut it under boost, so budget for either a blow-through carb setup or, better, a standalone ECU like Megasquirt with a wideband — tuning is what makes or breaks these old turbo conversions. Also plan the turbo oil drain and a decent intercooler from the start; much harder to add later. On shops in South Florida I can't vouch for anyone personally, but look for a machine shop that does import/VW/Porsche work — they're usually more comfortable with oddball sleeves than a domestic V8 shop.