zetec
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| posted on 9/3/07 at 10:59 PM |
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DIY Head Porting.
I've just got hold of a spare 2ltr Zetec engine. I fancy trying a spot of DIY tuning. Jenvey suggest a good start is some Piper 285 cams. These
are OK in a standard engine but give best results with a ported head.
Anyone tried porting a ali head. I've gathered some info on what I should be aiming for but have a few questions.
1) Some people seem to leave the valve guide in place and blend it into the port, other remove the guide and then replace it once the porting is
done...any advice on pros/cons.
2) Where can I get cutters and grind stones to do the work.
Any advice greatly received!
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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balidey
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| posted on 9/3/07 at 11:39 PM |
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Removing and refitting guides is a PITA and not easliy done DIY.
Proper porting really needs a flow bench, but anyone can take 'a bit' off the head and generally it will improve flow slightly. Biggest
improvement comes from removing rough casting and machining marks, but I bet the Zetec engines are pretty good from the start.
As for tools, a carbide burr set will get the big amounts of material off, then use 80 grit emery rolls.
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Chippy
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| posted on 10/3/07 at 12:20 AM |
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As said ^^ polishing out the rough areas is a good improvement. I always leave the guides in, and work the ports around them. The other thing is to
ensure that the manifold ports, (inlets and exhaust), line up with those in the head. If you really want to get the absolute, then get the head done
by the profesionals, aint no substitute. HTH Ray
To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy
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dl_peabody
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| posted on 10/3/07 at 12:20 AM |
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quote:
Biggest improvement comes from removing rough casting and machining marks, but I bet the Zetec engines are pretty good from the start.
I heard of a company that used wet sand under high pressure to do this.
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ayoungman
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| posted on 10/3/07 at 01:18 AM |
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Health warning. Aluminium grinding dust will do you much harm if you inhale it ! A serious mask/extraction system is a MUST. Be warned from someone
that knows !
"just like that !"
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oadamo
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| posted on 10/3/07 at 12:16 PM |
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hi when i done my head i bought a air die grider from machine mart a carbon cutter and a few flap wheels 30mm dia course and fine. the lot came to
about £30 if you take the guides out you have to get the seats recut to line up properly thats why most leave them in or just turn down a bar and
hammer them out they come out very easy. first use the carbon cutter to take the alloy away then use the course then fine to smooth it out dont woory
if you get dips with the carbon cutter you can smooth them out if there not to bad just take your time its a wee easy i sectioned an old head so i
could so how far i could go.it makes it a bit easyer if you use a bit of wd40 when useing the carbon cutter aswell
adam
[Edited on 10/3/07 by oadamo]
[Edited on 10/3/07 by oadamo]
[Edited on 10/3/07 by oadamo]
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Cousin Cleotis
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| posted on 10/3/07 at 09:36 PM |
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"cleaning up" the ports will make a small gain, proper valve seat job and back cut valves will make more of an improvement, any more than
that without checking results with a flow bench could do more harm than good.
Paul
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oadamo
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| posted on 11/3/07 at 09:39 AM |
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well i just opened the f**ker right up and it the ports was 30mm after i finished they was about 40mm didnt notice any idle issues just more top end
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