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zvh?
mrwibble - 25/8/09 at 09:32 PM

can someone explain to me the advantage of using the cvh head on a zetec bottom end? It seems quite a common conversion, but i cant find out WHY people are doing it.

Is it only the turbo heads from the rs fiesta's that are used?

regards, wibble.


jpindy3 - 25/8/09 at 09:50 PM

more turqe


MikeRJ - 25/8/09 at 10:37 PM

The only sensible reason for doing this is so you can use the complete turbo installation from an RS turbo.

Dave Walker was commenting in PPC the other day about what a waste of time these conversions were.


matt_claydon - 25/8/09 at 10:52 PM

Basically because you can, and it's easy. And somebody in a pub once told somebody else in a pub is was an amazing upgrade and gave them a squillion more bhp.


AdrianH - 25/8/09 at 10:53 PM

A probable dumb question then for you more knowledgeable on here.

I believe the Zetec is based on the bottom end of the CVH lump, or so I have read in some pages. You can fit a CVH head on a Zetec block. ...... So does that mean you can fit a Zetec head on a CVH block?

The 1.8CVH was done for economy, not for performance, but with a Zetec inlet and exhaust would it breath better and be able to perform better?

This is probably one of my more stupid questions.

Adrian


MikeRJ - 25/8/09 at 11:02 PM

quote:
Originally posted by AdrianH
A probable dumb question then for you more knowledgeable on here.

I believe the Zetec is based on the bottom end of the CVH lump, or so I have read in some pages. You can fit a CVH head on a Zetec block. ...... So does that mean you can fit a Zetec head on a CVH block?



The pistons would be completely the wrong shape for a 16v head. By the time you've replaced them you might as well have slung a complete Zetec in to be honest.


blakep82 - 25/8/09 at 11:04 PM

quote:
Originally posted by matt_claydon
Basically because you can, and it's easy. And somebody in a pub once told somebody else in a pub is was an amazing upgrade and gave them a squillion more bhp.


really?! where can i get one? any cheap on ebay just now?!




AdrianH - 25/8/09 at 11:26 PM

quote:
Originally posted by MikeRJ

The pistons would be completely the wrong shape for a 16v head. By the time you've replaced them you might as well have slung a complete Zetec in to be honest.


A good enough answer, worth asking in my case.

TA

Adrian


blakep82 - 26/8/09 at 06:14 AM

i guess with a lot of work and a turbo, you'd have something similar to the cosworth.
theres probably better engines to start with now though, like the duratec.

as said its probably a case of 'coz you can' and because its something different.

after all, why are we all building cars, and not just buying a new car?


omega0684 - 26/8/09 at 08:38 AM

quote:
Originally posted by blakep82
after all, why are we all building cars, and not just buying a new car?


because we are all a sandwich short of a picnic!


Jenko - 26/8/09 at 09:33 AM

I also read Dave W comments and obviously he doesn't have too much experience of them.

The main reason is much of pluming carbs, inlet, exhaust (i.e. all the bits that cost a fortune when you are doing an engine conversion) can remain the same, therefore, for a bit of work, you get an instant hike in cc....

But for those not in the know, the CVH head actually flows fantastically well, and with a little head work can match a zetec but (as mentioned) with more torque.....

I Have what is effectively a 2ltr Zetec block under my cvh, and am currently running 203bhp, and 192lb/ft torque (not a turbo)- the engine really does pull like a train, so, if you can put the work in it is a worthwhile conversion......

So, don't believe everything Dave Walker says!.


MikeRJ - 26/8/09 at 09:55 AM

quote:
Originally posted by Jenko
But for those not in the know, the CVH head actually flows fantastically well, and with a little head work can match a zetec but (as mentioned) with more torque.....

I Have what is effectively a 2ltr Zetec block under my cvh, and am currently running 203bhp, and 192lb/ft torque (not a turbo)- the engine really does pull like a train, so, if you can put the work in it is a worthwhile conversion......

So, don't believe everything Dave Walker says!.


That's far from a standard head and cam though, you could have applied that to the Zetec head and probably got even more power.

The CVH head can be made to flow well, but it still suffers from chronic valve geometry problems. A high lift cam isn't going to have a great life expectancy.

As Dave Walkers suggestions regarding manifold lengths etc. have managed tp extract 275bhp from my friends 2.0 N/A tarmac rally car I can't help feeling he knows exactly what he's talking about.

[Edited on 26/8/09 by MikeRJ]


Jenko - 26/8/09 at 10:29 AM

Agree - It is ported and uses a cvh27 Cam with solid lifters.....

I'm not suggesting for one second that a cvh is a better engine then a Zetec....

Point is, DW said whats the point, and I think the point is, if you are willing to get your hands dirty, you can have a very torquy engine with as much punch as a zetec for less money than actually converting to zetec....It works because as standard CVH flows well, and has large valves....It would be interesting to see a comparisson of a standard 2ltr Zetec vs a 2ltr CVH.....

The valve thing becomes a huge problem if you don't look after the engine and change the oil often...the cam is oiled via some tiny hols that drip oil to the cam, if these are not clear, the cam will chew the lifter up in no time.....I've done plenty of miles and track days now, have had no issues...but will admit to changing oil 3 times/ year!.

Paul.


blakep82 - 26/8/09 at 03:21 PM

quote:
Originally posted by omega0684
quote:
Originally posted by blakep82
after all, why are we all building cars, and not just buying a new car?


because we are all a sandwich short of a picnic!


exactly! we do it because we can, and we want something unique. i think thats the reason right there