Smidydevil

Little bram . So what your saying is to run a cvh head reliably at good power it needs full port and polishing work (£300+ ? For a good job) plus a Newman cam and solid lifters (more money) and all the rocker studs needs coils or inserts.. So in your words you would rather stick to a cvh head and spend around a grand getting it to be half reliable and flow enough than use a standard zetec head that will do the same job for £50-100 ... Not to mention the oil problem cvh heads have regardless of what can you use .

I run a rs turbo cvh at "stage 1" spec. And have had endless problems with the engine and parts around it. Resulting in everything except the rings and shells being replaced and iv done 4 rocker studs in my head at this power... And you want to bolt a zetec bottom end to this and push it to 250+ bhp?? Lol everyone has their owns preferences but I'd rather not piss me money down the pan for te fact my engine looks like a cvh to people that don't know what they're looking at.
Hence now building a fully forged zetec turbo engine as I want a reliable and powerful engine that won't rape my pockets 24/7

slammedorion

I love my zetec turbo...
I'd love it more with my focus Rs box fitted to it...

little bram

Good for you mate.

BRAM

iTrader: (1)

If the zetec heads are that much better than cvh heads why doesn't someone phone Norris Motorsport and tell him to build a zetec turbo instead of wasting his time building the 400 or 500 bhp cvh which will eat cams and snap rockers

luke19790_3

£££££

studabear

Do norris not offer zetec turbo conversions then?

mk1turboestate

iTrader: (2)

I've had a zvh for a long time, it's not been on the road a while tho, the engine is now in my mk2 escort, I built it back when you couldn't buy adapter plates etc in or around 1998/99 I think, it also uses skimmed pistons, engine was out of a 18000 mile fiesta rs 1800, and in my rs turbo used to peak boost at 24psi ish and hold 20.
Head has been off and it has no problems whatsoever. Runs a piper 285t cam

Adam.

I went zvh for the simple reason of watching my friends cvh blocks cracking and just wanted a simple 2 minute swap over.

Smidydevil

If you read my comment properly I never said they weren't capable of making big power, and I never said you couldn't remedy the poor oil circulation problem they had.. I said that changing the cam alone doesn't fix the problem, of course you can get big power out of em 90% of engines could with enough money thrown at them, how much does it cost to get a cvh head to a reliable spec for day around 400bhp?? Not to mention all the parts and labour you have just to adapt the zetec block to fit to the cvh head properly.

I didn't say it wasn't possible I said that it seems a silly way to spend a lot more money doing it that way than utilising the full zetec engine for a lot less money an the same performance

Obviously they can produce good power as everyone was building zvh's in the 90's to good specs.. But since people have been showing the potential of te full 16v unit you don't see many zvh built anymore

zetaboostboy522bhp

zetec heads are alot better than cvh heads thats a fact
std cfm for zetec
135.7 inlet
102.7 exh

cnc cfm for zetec
158.4 inlet
125.9 exh

and the st170 cylinder head is even better

std cfm for cvh
95.5 inlet
76.2 exh

cnc cfm for cvh
120.9 inlet
104 exh

now iam not saying that you cant get good numbers from a cvh but i think its a quest by karl norris to see how powerful he can make one which is fine thats how people push boundries and hes got a good reputation for that but ive seen ian howell build a zvh with a large budget and the weak part is the head , breaking rockers pulling studs out etc etc and its had everything done to it . the zetec head is just so much more reliable.

wasnt karl running 40 psi to get 500bhp
if you did that on a zetec you would get 650+bhp but no has never done that as it would be unreliable.
zetec all the way just my opinion

cheers paul

little bram

Did you not see the part where I said zetec heads are better than cvh?? and that you will always get more power?? and where did I say that everyone should build zvh because they are better?? in the 90's zvh weren't making good power and people could saying the same thing about when someone is building a 1.8 zetec