Thinking of buying some from the US for my silver top using the exchange rate should it ever get nice and low again. Thing is. How doi know they'll fit the engine run the right compression etc?

Mmmmmm - sounds like a question for Uncle Albert...
Sure he'll be along in a bit

There's quite a bit on this on the various ford forums. I am in the process of sourcing a zetec to put into my plus 2. The st170 engine is a factory tuned zetec with forged pistons and fancy rods as standard.

elan_fan
Can you advise which forums to look at in particular?

Turbosport, locostbuilders and passionford are a few. Google zetec st170

elan_fan
Some of those guys on turbo sport reckon 300 hp from a zetec block and st270 head combo. Is that really realistic?

I guess that would be turbo charged. I think 200-220 is more realistic and that is with headwork, cams and throttle bodies. Also a good exhaust seems to be a must. They seem good value to start with but they would quickly get expensive when looking for big power. I was looking at a 2 litre black top to fit my 40 dcoe carbs to, giving around 160bhp to put in my plus 2. I'm going to use my 2000e gearbox and so big power would break that quickly.

Eugene runs a 2L Black Top, with Twin 45 Webers, and outputs 210 BHP...

I love it!



Great torque, and a very robust engine...
And still feels and sounds like a cross-flow

The Zetec is a 4 cylinder engine. The ST 270 was a 5 cylinder engine. How will that work?

Are you sure about that?



I've never heard of a 5 cylinder Zetec, and the ST 270 is a Zetec, isn't it..?

The Mk1 Focus was the ST170. It ran with what was basically a Zetec Blacktop with VVC and a different injection system. The bottom end was slightly stronger and just to confuse everybody Ford badged it on the cam cover as a Duratec but it has no link whatsoever to the engine that Caterham fit.

The Mk2 Focus ST came in several flavours. The standard one was the ST240, the ST270 was a tuned version. Both used the 2.5 litre 5 pot Volvo turbo engine was called the T5 in early Volvo applications). The same engine was used in the Mk2 RS but that had even more power.


There has never been a 5 cylinder Zetec and the ST270 was not a Zetec, simples.

Ah!

Eugene
Well ive confused matters with a typo. This should have read st170 not 270. These guys are making a bitsa engine. They appear to run a st170 (focus) head on the zetec silver top block. The head appears to have better breathing. Then they've ported it added cams and pistons and make nutty numbers if they are to be believed. Hence the query. No turbos in sight

To fit a Blacktop Head (which is what the ST170 is) on a Silvertop head is not a simple bolt on job. The cam pulley arrangement is totally different and machining needs to be done to put the pulleys in the right place. Basically due the totally different location of the waterpumps in the blocks the cam belts have a totally different arrangement.

Considering that the likes of Dunnell and Raceline have been tuning Zetecs for about 20 years now and have never claimed figures like those for off the shelf engines I find it very difficult to believe. Not saying it is not possible but you would need some very special porting and very special cams and some serious revs which would require more than a standard modified crank, this is work that takes time, rarely do people get it right first time out.

I had a 2.1 Zetec in mine for about 4 years, produced 208 bhp on Jenvey bodies and was great engine until the oil pressure relief valve stuck, blew out the oil filter O ring and dumped 5 litres of Motul on the tarmac. Stck a bog standard Silvertop in to get me back on the road, took a couple of days. After a few weeks I came to the conclusion in normal road use it was just as quick, possibly quicker since I was not changing gear as much. Bought a brand new Blacktop from Raceline and that is even better, no modifications (other than a nice exhaust and the Jenveys) but loads of torque and slightly more power.