zetec head spec for 500+
 

Hey,

I've got a zvh s2 just now, running around 480bhp, now looking to go 16v,, probably using a silver top head as a base, just had no idea what sort of spec the head would need to be to support 500+ bhp like cam choice valve sizes amount of physical work on ports etc themselves,,

any info appreciated :grin:

480bhp from a ZVH :wow:

yea, got a bit carried away with it :oops:
good fun tho!

its surprisingly easy to get carried away when building a car :grin:

I must admit I thought the same , heard it's possible but still 480bhp Jeesh

hey,,

haha yea i know,, a lot of people struggle to believe it,, ill try get a dyne sheet up,, it was built by sitech racing, its the engine he had in his red s2 to start with but with a few changes, 2ltr CGI block, cosworth pistons, can't remember rod type, GT3076R 4" anti surge ported shroud, tial stainless 0.82AR exhaust housing, ems stinger management, and loads more that ill struggle to remember!

Just out of curiosity how come you want ZT, just more power or ?

its really down to i think ill get a smoother power delivery, although it isn't that bad at moment, but at same time would like a bit more power for no reason other than i can! but if i was to want to push more through the cvh head i WILL need to go roller rockers etc from titan or whoever, as I'm probably already on borrowed time! so rather than through more into cvh head i thought it would be more beneficial in long run to go ZT route?

yeh would imagine it would be more reliable with 16v head. still can not believe you got a 8v to that power, impressive.

Good job on the ZVH. What torque figure does it produce?

ill get back to you with torque figure! it made 480.2 bhp at 6632rpm, text simon at sitech to get back to me with torque figure! :oops:

Sounds a monster as it is!

Seen your car at sitech when it was getting mapped. Don't zetec heads have problems with spark plug treads at this power? Are you doing a full new engine?

hey, cool, how far away are you from sitech? not sure,, but i do remember reading about that somewhere!

no won't be doing a full new engine, but there is a few things,, if i go zt ill be getting either a jenvy inlet or possibly speak to someone about getting one made, and prob go dry sump or external oil pump as still using standard ford pump and not sure if thats a good idea!!
theres a million things I'm still keen to change but funds are tight just now and nothings cheap!! :grin:

How impressive is your ZVH...What gearbox have you got in it...

Hey,
Thanks, its a bit of an animal,
Its a st170 6 speed, with an atb and custom shafts from sitech,
Not a fan of the ratios really, looking at quaife gearkits, but not sure which kit would be the best ratio wise!

It's about a 3hr drive for me. Can't simon sort you a head out for it or are you doing it your self? Don't know what the valves would be like also? you might need to change them. Have you looked into focus rs head they might be a good place to start ie valves mite be ok.

Yea he could! I was just tryin to gather info and maybe some parts,, yep thought about rs head,and im sure st170 heads are really good flowing heads as standard,
Then at same time im sure simon said he was looking into designing titanium roller rocker type set up which i could use for zvh if was going to push it more, decisions haha!

I Can't believe you want more power in an RST, you must be as mad as Simon!
I'm sure Simon has built some 500+ Mk1 Focus before.

I bet you've surprised a few people on the road.

I know what you mean, my cabrio did 293bhp at the flywheel and its absolutely nuts, so I dread to think what 450bhp+ is like in a escort.

hi mate the silvertop head needs cnc port matching (mild porting) by cnc heads which are the best in the business , 1mm oversized valves uprated guides etc , standard exhaust cam , custom inlet cam . if you use standard cam followers you are very limited in which cams you can use in terms of how aggresive the profile is if i remember right as it was a few years ago now lol. you would need to speak to ian howell or a cam company to make you one but i know ian used piper cams to make his custom cams and they would not remake them for anyone else. kent cams and cat cams said they couldnt make it if i remember right for my engine which is why ian got cnc heads to machine the followers to a larger hole so he could fit larger hydraulic followers from the ecotec engine which then opened up the choice of cams profiles to use , this cost around another £400 on top of the £1300 cnc big valve head. i chose not to have this done and stuck with the standard size followers and it still make great power 522bhp @30 psi. my head did not reach choke point either it was still making 38 bhp per 1 psi of boost but we decided to stop at 30 psi because of the headgasket etc.
the st170 head is by far the best head in terms of flow to use and already comes with 1mm oversized valves as standard or the silver and blacktop heads so you could gave 2mm oversized in a modded head. but you would need to mod the cam belt system if your on a silver top block which again causes headaches then theres the warping issues that surround the st170 head so the choice is yours really. also the focus rs is a blacktop head so again you would need to mod the cam belt system.

iam also finding it hard to believe that a zvh has made 480 bhp knowing how hard it was to get the power from the zetec engine. as i am also very good mates with ian howell (the man who invented the zvh engine ) he has a customer called sid who chucks money at his car like its going out of fashion , that has the best of everything and that has only ever seen around 380bhp at a sensible boost say around 26psi and that is always breaking , rockers smashed , pulling studs from the rockers etc and i know it one of those projects ian wants to get over 400 bhp from and he even has trouble. it been on the engine dyno about 5 times lol
i know the karl morris red s2 ran 400 bhp on a 1.6 cvh but i also heard that it was running 40 psi which is why it always broke.

hope this helps

cheers paul

Thanks a lot for taking time to reply!
you basically told me everything i was wanting to know! :god:

A lot of people do wonder about it, but I'm certainly not in the game of claiming it beats lambos and going for top speed records lol, I'm looking to get a dyno sheet from sitech to put up , the one I've got is a photo on taken from phone of comp screen when it was on rolling road---shite photo.
Don't think simon comes onhere very much either or he could've answered a few questions

thanks again for your helpful reply! :clap:
scott

No probs mate I don't want to sound like a non believer etc and iam not slating you or Simon so please don't take it that way but I know what it takes to get to 500 bhp and the cost . iam sure it must be a real handful lol and if there is anything I can help with then please let me know.
I would say around £1500 for a top head from cnc heads , £1600/2000 for jenvey inlet , injectors , fuel pressure reg , £250 + throttle body so a few quid but worth it Imo .
It's an old picture but here's my engine now fitted with the jenvey inlet quality piece of kit.

http://i457.photobucket.com/albums/q...230_134044.jpg

Cheers paul

No worries mate! :)
Haha and belive me i know to well about the cost,, got to carried away with myself! But i enjoy doing it! :)

Love the look of that inlet, what Tb is that youre using?
Cheers
Scott

its a 67mm cosworth one that bolted to the st150 cosworth inlet manifold but i dont think you can get them anymore. ive also got a 67mm cfm throttle body on my st170 and that made very well and a little bit cheaper aswell.

cheers paul

cheers, found the cfm ones look pretty good!

are you still developing you're engine or happy?

scott

Last spec was
2.1 litre
H beam rods
Arias Pistons
Big valve head
Ian Howells inlet with x4 650 cc injectors
Aero motive fuel reg
Home built unequal length header exhaust manifold over gearbox type
Turbonetics t61 turbo
Tial 44 mm wastegate
67mm throttle body
Wet sump
Modified breather ports on engine
Standard ford head gasket
Standard ford head lots

New spec will be added to or replacing old parts

Full dry sump system
New homemade tubular manifold equal length headers (maybe twin scroll)
X1 extra wastegate if going twin scroll
Jenvey inlet manifold with long runners
X4 extra 450 cc injectors on top of the 650cc
Extra porting work on the head
Machining of head to allow use of ecotec followers
Custom exhaust cam
Engine block and head machined for m12 head lots
New turbo yet to be decided
Plug on coils
Back on dyno

Iam in no rush most of the engine parts are here so trying to build the car then the engine and diffs , gearboxes etc

Cheers paul

We have now seen over 400 from sids on our dyno 405 iirc
And I would advise getting some bigger cams particularly on the exhaust as running standard is just silly. The cylinder pressure would be through the roof and won't help with the weak zetec head as it is!

stay with what you have mate, i remember simon after finishing your car said he could push more past the 500bhp+ with a few more parts also you have the engine that will suprise everyone when you tell them what it is haha

Thanks mate :)
Yea well that was the main reason i liked having the zvh was that alot of people as soon as they hear zvh automatically slate them, if there thrown together to a low standard they probally are pretty shady, but thats like everything i guess!
Seems to all be about head work and a good cam which makes a huge differance!

Cheers
Scott

What sort of bhp & psi does the standard silver top head start becoming less efficient and need work?

how does the head stay togethe ron the standard parts , i had sme problems as sid , id snap rockers 2 at a time , snapped caps, colets coming off, dropped a valve a few times, pulling studs out head stripping threads off studs that was at 360bhp? 21 psi , now im on roller rockers with inserts in the head ive not had a problem , do u not have problems with head lifting ?

https://passionford.com/forum/genera...dvantages.html

David Baker did the head I believe?

If im going to fully honest im nervous about it, its not had a hard life at all since built as bodywork has been getting work aswell as alot of suspension changes, brakes etc etc
So in all fairness those problems could still be fully possible and likely! Hence why i was thinking about 16v swap over, rather than carry on with cvh head,but im now already keen to remain zvh and get roller rocker set up etc which simon was developing,
Cheers
Scott

If youre asking about my head simon at sitech did it

Cheers
Scott

Speak to Lee at Devil Developments, he built the more powerful Zetec turbo in the country. He fits M10 head studs to stop the head lifting and machines the head to fit Cosworth style spark plugs.

Is Ian howell open again? someone said he closed doors?

yes jimbo cams will be on the way , to be fair we was only going for 480bhp @ 27/28 psi and it was me saying to your old man fuck it stick some more boost in that we did over 500 bhp , i probably would of gone for a little more tbh if the duty cycle on the injectors was at 90% lol.
i know its each and everyone to there own but ian is my engine builder and iam sure it was fit for the power we needed (480 bhp) and if theres room for improvement it will be made.
tbh ive never heard of spark plug issues apart from you saying which i believe as scs is a great company and have probably dynod more zetec turbo than anyone else.
the only problem i had was on my first head which had modified plug holes to accept cossie plugs and kept having misfires due to the plugs sitting in the head slightly lower thus not allowing the plug leads to clip on the plugs properly and unclipping themselves .

i take it you mean lee at devil uses m12 bolts

and no ian howell is shut but still helping loyal customers


cheers paul

Was just pointing out to someone higher up abouve that high power zvh's have been seen before :top:

Ahh i see!
Yep they certainly have, theres others that have around +/- 400bhp up here, but not everyone uses forums etc so always under the radar!
They can be very good engines if built right!

Cheers
Scott