What can you get out of this 55bhp engine when tuned to within an inch of it life?.

Are they capable of 90bhp also?

Ball

I reckon they'd easily be capable of 100bhp and beyond with DCOE/Bike carbs, Port and Polish head, schrick 276 or higher in addition to an aftermarket ignition module to provide accurate ignition timing, Stainless 4-branch exhaust manifold with a decent system (straight through), high compression pistons and high octane fuel like V-power or BP Ultimate. Of course, you wouldn't want to do these mods and leave out a lightened and balanced crankshaft/flywheel. It's just a case of ticking all boxes, they don't work at their best if one is missing.

I think with what Danny lee has decribed would easily achieve 110bhp....

They can be tuned to over 150bhp! screaming 9k engine 8)

A chap near me had his gt running on side draught weber 40's and that was 110 bhp with just carbs and a lightened flywheel. The compression in the coupe s bottom end it slightly lower and presumably the camshaft has a higher lift. But apart from that the two engines are very similar.

So yeah, up to 170 bhp N/A with lots of money spent... that mk1 polo in pvw last year for instance.

Cheers for the scary and surprising info.

I never would have thought that the kind of power figures your talkin about could be produced by this tiny little engine.

Well i best get my spanner out once i have sorted my body and suspension.

Cheers lads.

Ball

not your spanner, more like your wallet. unless you know someone or have trade connections yourself and can do the work yourself, thats list dannylee gave is going to be one expensive way of getting power into your polo.

expensive but much better than going the normal way of dropping a gt in,

You're going to have to try very hard to get anywhere near that kind of power from a 2 valve per cylinder 1.3. Assuming the capacity is fixed you can only get more power by increasing the volumetric efficiency, increasing the compression ratio and increasing the revs. A GT works by having a higher compression ratio and better volumetric efficiency at high revs using multi point injection with wide bore inlet runners in the manifold (and different cam timing?). That only gets you 75BHP compared to 55BHP for a Coupe S and the compression ratio is already close to the limit. The GT inlet is already pretty good in terms of flow at high revs. A bit of gasflowing on the head and a better exhaust might add 10BHP. So if you get 85BHP at 6000rpm, 7000rpm gets you 99BHP, and 8000rpm 113BHP. The higher figures assume you can maintain the same volumetric efficiency at these higher revs. (Engines peak torque is the point of maximum volumetric efficiency, say around 3000rpm. As revs increase the power goes up but the volumetric efficency drops off. Eventually the drop in volumetric efficiency (ability to breathe) drops off so much that the power stops rising. Hence the big drop off in power after 6500rpm or so.) I think you might get up to 115BHP with a lot of work but it will probably idle badly and be gutless at low revs.

Got you,

I completely understand what your sayin.

I use my car everyday and cant afford for it to be a lumpy idler and stuff. possibly go 50% mental on the engine then, a compromise.

tbh if i have 55bhp at the moment, I'm happy with the performance for £430 so, if i do spend some cash on the engine i think it will all be relative and work out ok.

O and ye i do know a few people here and there about the motor industry(Parts peeps and mechanics, body places and so on).

One of the reasons i bought this car is to learn sooooooo. I'm all ears tbh, thanks for the advice and stats as well.

Ball

GT cam, ported and polished head, 4 branch manifold, full exhaust and a different carb (dunno what would be best suited) would do you nicely I'd have thought.

You could have more or less as engines get old and tired.

So yeah, up to 170 bhp N/A with lots of money spent... that mk1 polo in pvw last year for instance.

I think it is highly unlikely that the car in question had as much as 170 PS, as every other 145-150 PS+ Polo I have seen the spec sheet of have wilder cams and higher CR than that engine