xrsi

iTrader: (1)

Right basically my local machining shiop has just called me to raise a possible issue they have with the large valve i dropped off with them to be machined into the head.

I ave brought from autosprint a set of large valves which included +3mm over sized exhaust valves specially for the black top zetec which i am using to build up a zetec turbo engine, the machine shop, who do alot of work for rally cars and other performance cars as well as normal every day cars, gave me a call this eve when i was on the way home saying that the valve looked to big for the head and that if they machine it the insert would be likely to fail (i presume they meant the seating insert...... as i was driving at the time and he was on my car kit and didnt have the best signal)

Question is, has anyone else had +3mm exhaust valves machined into the head and also has anyone come across this porb or can you get larger valve seats to machine into the head?

AustenW

31mm valves will fit with new seats

30mm valves will fit the standard seat

If they are not confident to fit new valve seats grind the valves to 30mm and recut the standard seat

xrsi

iTrader: (1)

they are 30mm...

they said it would leave very very little material on the actual insert (presuming seat as that is all they can really mean!)

i think they want me to double check with auto sprint they are the correct item before doing the work so they cant be held liable for damage to anything else if the lack of material did cause it to fail.

they are cutting 3 angle seats if this makes any difference? can larger seats be brought do you know as this may be an option if its do-able!

AustenW

standard valves are 28mm

30mm valves will fit fine, I've done two zetec heads with larger valves over the years

First used 30mm on standard seats current head uses 31mm on modified seats

xrsi

iTrader: (1)

so i should just tell them to cut them into the seat and stop being a big girl about it then?

Pob

Do you buy these valves as part of a cam kit? I'm looking for future refernce for parts, but everywhere only seems to sell kits ;-(

xrsi

iTrader: (1)

no i rought them from autosprint that advertised in fast ford...

i was going to get a set of nitride coated valves sent from the usa but these worked out to be cheaper and was next day delivery.

Turbo Zetec

iTrader: (1)

i have PERSONALLY cut seats to fit autosprints zetec valves and i can confirm that although the 45 degree angle is on the very outside of the seat (if done properly), there will be no problem with it at all. if they are using a 3 angle cutter, one of the angles will be cut into the aluminium, although this won't be a problem at all as it isn't the actual 'seat', it's just there to improve flow around the valve.

xrsi

iTrader: (1)

thats exactly what i wanted to know mate! thats helped loads :d

the bloke who does the head work at the place is off untill monday now (booooo hisss) so i wil give him a call first thing mon about it and tell him that aswell as to stop being such a big girl and fit the bloody things to the hed as i wanted it back today

mk3cab

can i ask how, much you paying for the machining.

xrsi

iTrader: (1)

bout 150 plus the dreaded

Turbo Zetec

iTrader: (1)

fuck me! Mine cost nothing!

xrsi

iTrader: (1)

yeah but i havent got the equipment to do it myself otherwise i would....

also for that i am getting the head ported, and the exhaust ports polished, along with the valve guides cut back.

so for what they are doing not a bad price i dont think!

Chip

iTrader: (3)

To make use of 2mm oversize valves it requires some skilled porting, id be talking to someone like Karl who is a specialist at this sort of thing, but obviously you wont be getting it done for 150 quid, lol

Turbo Zetec

iTrader: (1)

agreed! although, the inlet valve size isn't much different to standard, so won't require much porting there.

the exhaust ports seem to be very restrictive though, they go very small on the curve all the way to the throat.

is this going to be on a turbo car?

pa_sjo

It's not so much valve size on a zetec that needs sorting, it's just the port shape.. a 28mm valve on a YB can flow an awful lot!

Personally I think 3mm oversize is ridiculous on a zetec.

Turbo Zetec

iTrader: (1)

exhaust valve on a cossie is 31mm

i'll agree on the port shape, although the inlet side is pretty good, the exhaust side is awful!

pa_sjo

Oops. Fuck knows why I had 28mm in my head

Turbo Zetec

iTrader: (1)

fuck knows

mine's having the 33.5/30 combo, decided it was a good idea as most of the bigger powered turbo cars have valves around that size

xrsi

iTrader: (1)

yeah it is.

i have asked them to open it up alot on the exhaust and then on the inlet just smooth ii and open it up slghtly as well as knifedging the aera where it splits between left and right valve.

got to give them a call in morn and make sure they have done everything ive asked and when it will be ready! going to make sure als when i pick it up that its all done right

Turbo Zetec

iTrader: (1)

just be careful around the exhaust ports, there's a waterway that runs between them... Try to take too much out from between the valves and you'll go straight into it!

xrsi

iTrader: (1)

can anyone recomend a place that can fit the bloody exhaust valves!

they are being girls about it and also have cut the one valve in and said there is no seat left so i am "going to have a look" ie to pick the bloody head up and tell them to stop fcuking around! will also be looking how well the porting has been done before paying for that also!

not going to be paying Ł150 i can tell you that now as i told them it was needed last weekend and they have only called me today to say it still aint done! :x

AustenW

Ian Howell at Area Six / Fiesta Frenzy