has anyone got any decent pictures of a properly ported and polished zetec cylinder head?
Im doing a DIY job on mine as I've totally blown past my turbo budget already

I know about gasket matching etc. Just wondering if anyone has got any more info.

Also, what hp level does the head become a major restriction? I have read about it causing compressor surge because it cant flow enough air at higher horsepowers.

My setup is ripe for about 400-450hp so I know I will need to improve the head.

thanks

 

Is it Blacktop or Silvertop?

 

Silvertop mate. Forged pistons and conrods etc
still collecting parts but getting it stripped next week for the build

 

Personally I would change to a Blacktop and you will see 400 bhp without any porting work on the right set up.

Just need a set of Cat Cams valve springs then! 'Budget' and 450 bhp Zetec don't really go hand in hand as oil pumps beging to be an issue!

 

It's got to be a Silvertop mate as its a Silvertop 1.8 turbo I'm running already. Budget isn't the right word...! Ive spent well north of 3k on bits so far and I haven't built it yet! got tubular exhaust manifold , 800cc injectors ordered. turbonetics to4b hybrid. I know about Oil pump risks but I'm going to fit an Oil pressure warning alarm and see how it goes. Can't afford dry sump at the minute! And some oil pumps have been ok...

 

1.8 for over 400bhp? Dont think so mate!

 

No mate!. I'm currently running a 1.8 zt dynoed at 249hp on a dyno dynamics.
I'm building a 2.1 (or a bit under cc wise) with forged internals and all the bits, for 400 hp or a bit more. The turbo will flow for what I need, I just want to know if the head will....
I know most tuners won't reveal their secrets understandably, was just seeing if anyone has done a zetec head themselves.

Also, what cams should I use? I have read the inlet cam needs to be more agressive. Not sure about exhaust? Anyone got any turbo cams they are flogging?!

 

some pics of various zetecs at various stages that i have done, they're pretty easy to make a half decent job of

 

As shown above most improvements will be in valve throats, don't go mad on ports as it not there its needed

 

on mine, im using a rover turbo tomcat inlet manifold. i made an adapter plate, then filled the standard zetec injector cut-outs with ally weld, then matched everything together so there are no gaps or drops. then ported and polished and had 3 angle valve seats cut.

 

Thanks mate. Those pictures are very helpful. What would you say the most important areas to address are? bearing in mind I don't have any access to engineering machinery...

 

No worries. To be honest im not really the best person to ask. I just thought on the princable of to get the engine to rev quicker, air needs to enter and exit quicker. So first i made the adapter plate for my manifold, and made sure the ports were identicle to the head. Then i took the head toba machine shop and had the injector cutouts filled with ally weld, then put the adaptor playe back on, then got my files out, many hours later they matched. Then i just bought a porting kit from demon tweeks and did it myself. Just dont go too mad, a mirror finish is no good. Then i got the machine shop to cut my valve seats so it disperses the fuel over a more widespread area. I dunno if it will work or not, its a big learning curve for me. Il keep you updated though!

 

Had a head ported for my 1600 rally car engine by cylinder head developments made a fantastic job of it and we're very knowledgeable worth a ring

 

ok cheers

MDCOS - many thanks also for the excellent pictures mate. Some really good stuff to digest there.

nevsrevs - roger that. Will focus on the valve throats. Seems harder to f*ck that up too lol

 

Looks damn good to me Tom if its your first go

Zetecbeast - best thing you can do is to get your machine shop to machine some metal out of the throats when you get the seats cut. it cuts out a hell of alot of hard work! I usually work to a size for my porting work, my zetecs are 25.5mm inlet port, 24.5mm exhaust. just grind an old valve down to that size, or find a washer that size and stick it on a long bolt. when you can stick it all the way through the port, you're done

I'm no expert really, i just work in a machine shop for a living so love to tinker but you can probably get about 95% of the gains of a professional job by having a go yourself!

Only word of warning though, there is a waterway that goes through the exhaust port inbetween the valves, so be careful not to remove too much metal from that area

as for cams, stick with standard for that power level!

 

oh, and another thing... http://www.autosprint.co.uk/?p=p_48

awesome valves at an awesome price! i know alot of the fast vauxhalls run them no problems

 

cheers mate. Great info
Are you saying I need to go oversize valves as well? or just a port and polish?
cheers

 

You don't need them, but just thought i'd mention them as they're a good deal

 

my 2005cc ZT made 396bhp/386lbft and had more to go.

headwork was just mild port and polish, i port matched to the gaskets but that was it.

deffo go for oversize valves tho, i used a piper cam kit with a cosworth BD16 grind on them

i also kept revs to 7k rpm limit

 

What C/R do you estimate you will have? If it's lower than 8-1 use a 115 exhaust and a 130 inlet, if it's higher use both 130's (imo)

 

thanks chaps.
Anyone got any idea how much I'd be looking at to get the oversized valves fitted?

 

Also try aldevelopments

 

just had a look, there is a nice guide on porting a head on their site! its an ST170 head, so gives you a good idea of what the other zetecs should look like

http://www.aldevelopments.com/Head-Work-Guide.php

 

ALD also did clarky5700 head on his zetec turbo

He's does the heads at a very good price also

 

cheers lads.

SiZT , its going to be 8:1 mate. Thanks for the cam advice

Thanks lads for the ALD advice It's going to cost Ł150 for a die grinder so will have a think on it..

MDcos - mega nice guide, cheers for the link mate

 

My 2ltr turbo head:

This is a ford racing cnc head, hand port and polished, flow tested and hand lapped.

 

Very nice mate...!!! cheers

 

Martin,
I can't remember Has my head had any work done?

 

i think it had the throats cut out a little, 3 angle seats, modified valves and a reface, but not 100% sure