For my next project i want to build an engine for my rst, a local guy reckons he can make 1.8 zvhs for penuts which would be ok if my current one popd and i needed a replacement but i would like to go to a 2ltr zvh instead, thing is apart from the extra torque youd get having lookd into them 2ltr zvhs dont seem that impressive.

For example a 2zvh seems to be make around the 240 bhp mark which would be good but thats at like 17psi but a 1.6 cvh if running sweet can make simular bhp at just a few more psi more.

I dont see how they are suposably 180bhp at realy low boost and only 40bhp more for an extra 12psi.

Can someone explain these engines to me a bit better ther pros and cons.

Thanks Paul.

 

The zvh's always have a tendancy to run more torque than out right bhp due to the longer stroke that the engines come with.
Both the 1.8 and the 2.0 zetecs run an 88mm stroke with only a 80mm piston in the 1.8's and 84.8 in the 2.0.

Where by the cvh is very close as what is refered to as a square engine as the stroke and the bore are almost the same size hence the bhp and torque figure are very similar.

(ie) an rst running a stage one tune cvh lump will be putting out about 160bhp with 160 lb/ft, a 1.8 zvh would be putting out about 180 bhp with 210lb/ft this makes for a smoother drive of boost and very progressive accelleration once coming on to boost.

as you said if you go further and tune these engines you dont get much more bhp in return for your effort but again the torque goes up aswell so the thing will pull like a train which makes for a very fast but yet drivable car .

but if low down torque aint your thing......... and you want that unreal wooooosh and getting throwen back in your seat like sumit out of "THE FAST AND THE FURIOUS" then go with a highly tuned cvh as there good for that, but for me a 200+bhp daily driver i prefer the 2.1zvh as it can be driven everyday with out the worry of a poor little 1.6 spilling its guts all over a A1 coz i aint looking after it or serviced it well enough.


BUT AGAIN TO EACH THERE OWN

 

thats a good way of putting it, torque would be good for around town as i hait the lag sumtimes, i was thinking of maybe going hi comp aswell to acheive a drivability, what would the bhp and torque be of a 1.8 zvh with std pistons and decop plate at 1 bar, i have heard the std pistons are only good for a bar.

I have a modded meterign unit to run 18 psi and big fmi could i run more then the 15psi or more advance or is it that the pistons simply cant take anymore power then a bars worth?

I wouldnt mind going 1.8 zvh decomp plate route as there cheep to make so ive heard so it wouldnt matter to much if it pod as the bottom end would only set me back £100.

Thanks for reply Paul.

 

well i have built a few 1.8's in the past and if ppl what a higher compression for day to day use i dont machine the pistons just leave then as is this will give you around 8.5:1 compression and will allow you to run up to 20psi but i wouldnt recommend it on that sort of compression , however my m8 was addement that he could push it further and is currently running a:

1.8zvh with a home done gas flowed head, kent cam and vernier pulley magnex exhaust, k +n and a std turbo putting out 23 psi it wont last long (the turbo this is) but its putting out 195 at the wheels around 230 at the fly.

But as i said this is not recommended as the max i was recommended was 20psi on unmachined pistons , 14psi on 0.5mm machined pistons

however the 1st engine i built had 1mm machined off the pistons and was running 14psi for over a year by my self and i had no problems either but i had no other mods done to the car and was getting 147 @wheels (around 180 @fly).

If you wish to go down the decompression route with un machined pistons then i would say you could run the 14 too 20 psi range with out any problems as the lower compression will reduce the heat on the top of the piston crowns and will retain reliability when on boost.

and if all its going to cost is £100 all in what have you got to lose as you couldnt even get a set of pistons for a cvh for that sort of money

 

so If i find a 1.8 bottom end what will i need to fit it to a CVH head ? ie leave pistons std and fit a decom plate ? what is the plate and how much does it cost

What sort of power will it put out at 1 bar ?

 

you can get a kit from mad-for-it on ebay for about 150 notes however i would fit a set of 4 taper plugs into the front oil returns as i dont personally like the idea of relying on the head gasket to blank of the oil return galleys as the gasket can deteriate and break down overtime.
also the decompression plates are about 29 quid from the same mad-for-it performance
and from my own experience i can say that a 1.8 zvh running std everything apart from an exhaust and chip to allow 1 bar of boost should give a return of about 180 bhp at the fly and 145 at the wheels.

and that engine came out of a skip with so much piston slap you would think the bottom end was knocking
another mate of mine got 195bhp@flywheel out of his with the same set up but inc. a home done flowed head and kent cam

 

first ill tell the spec of my car then ill ask my question...

1.8zvh using standard unskimmed pistons and no decomp plate.(94 mondeo block)
(basically i didnt lower the compression at all)

stage 3 cvh head (ported and polished, big valve, kent cam)
pace double core intercooler , colllins 220 chip and huge actuator.
standard turbo, all other usual small stuff..

At what boost (if any) is it safe to run this car at considering the compression??????
And what power should it put out when set up????

 

hi guys you seem to know ya zvh's!

ive got a standrd rs turbo running standard boost(how much boost is that?)

im going to take the engine out as it needs an overhaul as its getting very unpredicatable and a general poor drive.

while it was out i wanted to slap the mondeo 2litre bottom end on, my questios are, do i have to have a de-comp plate to lower the compression ratio, and do i have to bore the 2 litre to 2.1 to get it to work?

 

All depends on how much money you have ?

The proper way would be re bore and over size low comp pistons.

however ?

The cheap way is to get a 2.0 bottom end (with a 1.8 sump and pick up) will then fit direct to your CVH head (with the de-comp plate) Mad for it do a full kit, as you need to drill and tap a few holes, for the oil pump.

The De-comp plate allows boost at around 14-15psi (1bar) max. I have now fitted the de-comp kit to the black top ford 2.0 ford bottom end, and it run's 13/14psi and gave a very good, 206bhp, with 222lb of torque. (works well but already i want more boost) so the 2.1 would have been a better idea. (its each to there own really)

Speak to Mad for it, and they will update you on all requiremets on the De-comp plates and whats needed. good luck.

 

anyone know the answer to my question ????? a few posts up

 

i have a full zvh motor for sale never ran still in bits waiting to be built up. This is a good spec engine with all the right bits and everything brand new and genuine ford. Its cost me a fortune to buy all the parts for the build so if anyone is interested pm me. The reason for sale is i want a house basically.