Will be getting a spare cvh head soon to do some playing around with so was wondering if anyone has done there own porting etc. Its only a little experiment, something to do at work when i should be doing other stuff, so it dont matter if it doesn't work out. Im pretty handy though so cant really see that it will go wrong.
So if anyone has got busy with the dremel on a cvh head then let me know what they did and how they did it. Looking to put it on a 2.1 zetec bottom end if all goes well and yes im on a budget

 

you will well and truly fuck it up mate and it will end up flowing less air than when you started .

 

For it to be done properly you need to know the correct shape and size to port them to or you can make it flow worse then before you started!! Experience counts for a lot here!!

"There are certain things that absolutely must be done to portshapes to get the CVH head to flow to its full potential. The area around the valve guide where the port bends is critical and this must be straightened out and shaped to blend nicely into the valve throat. You MUST remove the valve guides to get at this area so any head which just has a bit of polishing and no real constructive port work will not show much of an improvement"

 

thanks for the comments it seems ill probably pay someone to do it, although id like to give it a go, i know the results wont be as good as if i take it to a cvh head specialist lol

 

if i was going to try it i would just take off any rough bits, to make and smooth and then just give it a very good clean

its got to flow more air than standard surely

 

But do you need to flow more air than standard? Have you thought of the negative consequences of carrying out this work?

 

what could be negative?

i didnt realise there was a downside, i always thought the more air the better

 

yes thats what i thought also, as its going to be part of a 2.1 bottom end with 350bhp i reckon ill need it stage 3'd at least. What are the downsides of having work done on the head Christian?

 

do you really think you can diy port a head and get 350 bhp????????? do you even no what turbo you would need what fuel pump what injectors what bore exhaust system ect??? and how much all this will cost.

 

didnt realise at first it was 350 bhp

and i did put a confused face as i was only guessing, as he said it was 'a spare cvh head soon to do some playing around'

but if i was aiming for 350 i would get someone else to do it, it does sound a bit risky at that sort of power

 

stage 3 hybrid turbo, uprated cosworth pump, bosch 803's, 3 inch exhaust, maybe need to change the 803's as they are on there limit at around that sort of power, as far as cost is concerned, around 500 quid for head work, 500 for turbo, 100 for injectors, 200 quid for pump and already have the exhaust.
On top of this, going with je pistons, eagle rods, 500 quid for the lot and around another 300 for other bits and bobs.

Ł2100

 

double that and you mite get close to the power you want ! and a stg 3 what ?t3 ? and the greens will max out about 280bhp

 

how do you work out 4000 for 350 horse mate? im doing the build myself minus headwork and machining of block

 

because ive been there and done it mate.

 

i dont argue that you haven't done it but 4 grand is way over the odds.. in my opinion. I have tallied up the costs and the 2 and a half grand figure is what i have come to.... there is no way on earth that it is going to cost more.. it cant.

 

unless there are some costs that i havent taken into account

 

Have a go at the head work. There is plenty of literature out ther on head porting, some even specific to cvh heads.

Have a read and then see how you get on. Everybody starts somewhere so don't listen to the others. They are stick in the muds who aren't brave enough to try something new.

Good luck and keep us updated.

 

thats the fucking spirit, thanks alot mate, I am a keen petrol head that mounts intercoolers on the front of my bumper knowing it looks shit but want lower temps. I absolutely agree with getting stuck in and people on here not really wanting to get there hands dirty. I want big horse power and want to learn along the way. Anyone can throw money at a garage and tell em what they want but I just want to get my hands dirty.... ill have a look at the cvh head work and get stuck in!
Shame this mentality aint more common!

 

hers what i think and this is just brief
block Ł100
new oil pump Ł75
new bearings heavy duty ones Ł130
rebore Ł80
rods and pistons (usa) Ł600 the pound isn't that good at the min
head gasket and head bolts and all other gaskets Ł100
crank grind Ł80
skim fly wheel Ł30
clutch Ł300
proper ported head Ł500
newman cam and solid lifters Ł300
and Ł200 to have them set up
fuel pump Ł150
injectors Ł300
turbo my choice gt 2876 Ł1000 with all accessories
vernier pulley Ł80
oil return in the sump Ł30
fiesta efi inlet manifold Ł50
intercooler Ł350
thats over 4k and
then theres management and dyno time on top .

 

make sure you do plenty of research into this before you start mate as i'm sure it would be very easy to see a negative effect
agree with garage above though go for it but don't forget setting it up and getting it as useable power is quite expensive as well

 

yeah mate thanks for the advice. Im definitely going to research it before i spend a single pound. I got some cleaning up to do with my s2 before I start on the engine. Its running 16psi at the minute and it already feels slow people that go in it with me and they ask me to floor it always tell me how quick it is but I want more power and feel that a zvh or full zetec turbo is the way to go.

 

I Think crazycage is quoting a little on the cheap side to be honest for that kind of power for a reliable engine, I would expect to pay more than 4k these days.
You also have to consider that there has been no mention of the gearbox or clutch to handle 350 BHP, and you have to think about stopping the thing

 

Research is the key! I have taken my daily driver inlets out to 31mm removed the valve guides for the work and shaped them as per what I read up. The exhaust ports were opened but kept the same shape, which is vital on the cVH (D Shape). The maniflolds were port matched. I am not saying that cosworth have been on the phone for advice or anything but it has made a noticable improvement in both power and response! It has not been on the rollers so I cant quote figures.

For what it cost me do do I was made up but as for it being the pinical of CVH head flowing I very much doubt it. It depends what you want.

 

if you don't mind me asking were did you read this about cvh head porting etc

 

yeah im interested in where you read about that mate, can you post a link or reference as to where you obtained the information?

 

Some very good information can be found here....

http://www.pumaracing.co.uk/CVH.htm

 

I would do it for you if i had the time

Just do plenty of reading and most of all, take your time. Most people just concentrate on smoothing the ally and losing the valve guide but all this will be pretty much in vain if you do not open up the valve seat diameters to allow for the extra gasflow. Getting this correct is vital, too big and you will run the risk of losing your valve seal area.

 

If your building a big spec CVH they key is the head. If your aiming for 350BHP get it done properly. The head on my old engine was home ported by the lad who had it before who is an ex machanic/enginneer and the car always felt laggy. Comparing it with my Vulcan head I`ve got now I think he removed far to much material and made the head worse.

 

lol @ Ł2100 what box management,clutch are you goin to use to run that power safely also who you gonna get to map it to fit within budget, goog look though.

 

hi mate good luck with the build but i think your figures arent correct. i agree with crazy, ive just done a zvh to 300bhp and its cost me over Ł6000, thats with management gearbox adn a proper set up by ahmed bayjoo. if your going to do it do it properly the first time in my opinion.
dont skimp on the things that matter most. if you want to power make sure the car can stop and its got a good suspension set up. and youll also want to keep track of what is going on in the engine bay and quality guages arent cheap. good luck anyway.

 

one key factor is to leave the inlet rough ( DO NOT SMOOTH INLET ) won't create the right air / fuel ratio