bonerp
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| posted on 27/4/04 at 12:02 PM |
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New Pinto Head
I've just bought a new complete head off ebay for £30!
Its unleaded but not for the injection model.
Now what I would like to know is I know that the inj head is ported better
than the carb one but will I really know the difference?
If not I will fit it!
Paul
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flak monkey
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| posted on 27/4/04 at 12:09 PM |
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There are 2 differences in the ports between the injection and normal heads.
The first and major differnce being the short turn (the curve from the floor of the port to the valve throat) is much smoother in the injection head.
But you could modify your new head your self and smooth off the turn if you can be bothered. This is where the major flow gain come from in the
injection head.
The other difference is (and is not always the case) the injection head has a slightly larger inlet port (38mm over the standard head having 36mm).
But even at 36mmm the port is big enough for hard tuning.
Hope that helps
David 
Sera
http://www.motosera.com
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NS Dev
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| posted on 27/4/04 at 04:24 PM |
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Just out of interest, whereabouts are you? If you are in the Leics area then I have the kit to do a proper job on the porting of your new or old head,
let me know if you are nearby?
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Peteff
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| posted on 27/4/04 at 04:37 PM |
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Read Dave Andrew's site on flowing the Pinto head. If it's still on there he had an article about it describing the shaping of the valves
and everything, very informative. Apparently for serious tuning the first step is to reduce the size of the inlet ports to increase flow.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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NS Dev
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| posted on 27/4/04 at 05:02 PM |
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Yes, Dave Andrews site is full of informative stuff. Interesting with the pinto inlets because when you look at them you can see the reasoning behind
making them smaller, as they are pretty huge! Many tuners swear by this technique (although welding/devcon putty are not that easy to do really, I
don't want the hard putty going through my engine!!)
However, HT Racing, who built the largest percentage of race winning pinto's, used to open the ports up!!! I have just sold a pinto with opened
up ports and it made very good power.
I am not arguing because logic and science would seem to suggest that the ports are too big but then practice and race success (and power outputs,
some of HT's 2.0 pintos running on petrol were putting out 220+hp on the dyno, and I know of a 2.4 putting out 270 hp on the rolling road) seems
to maybe conflict with this?? I dunno I'm no expert, as usual though there is more than one way to skin the metaphorical cat!!
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flak monkey
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| posted on 27/4/04 at 05:05 PM |
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Surely at 38mm the port size is perfect for Webers? Since the choke size for a 2 litre pinto is 38mm, if the inlet manifild matches that, why not make
the ports the same size?
Cheers
David
Sera
http://www.motosera.com
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NS Dev
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| posted on 27/4/04 at 05:15 PM |
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Again logical, but airflow around a bend then over a valve is not quite that simple (makes it sound like I understand it which I don't!)
The port velocity is critical to the way the air flows over the valve. With the tight "short side turn" in the port, and the wide opening
of the port, the main bulk of the airflow does not meet the back of the valve at the optimum angle, and increasing the velocity together with changing
the angle apparently helps, though I am no expert on this. (on porting jobs I have done, as long as you decrease the short side turn angle somewhat,
and aim to direct the flow "across" the back of the valve rather than down over it then it seems to work well. Hey ho who knows, not I!!
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flak monkey
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| posted on 27/4/04 at 05:20 PM |
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OK, i think i understand what you mean. Anyway in my pinto tuning book it says that the standard port size is plenty for all stages of tune. But they
recommend smoothing off the short turn, just to smooth the flow up a bit.
Cheers,
David
Sera
http://www.motosera.com
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NS Dev
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| posted on 27/4/04 at 05:28 PM |
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Yes, that's basically what I would do on the pinto head if I was doing one now. The amount of port work is not huge, basically do what you say
to the short side of the turn, reduce (remove if going to bronze guides) the guide boss, and most importantly, reprofile the back of the valves to a
"flatter" profile (less conical).
That's about the limit of my knowledge on this engine's inlet port/valve!
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scoobyis2cool
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| posted on 28/4/04 at 07:35 PM |
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What tools do you need to port a head? Is it easy enough to do yourself or is it a job best left to the pros? Wouldn't it be easier to just swap
it for an injection head?
Also, can anyone tell me the address of Dave Andrew's site, sounds like interesting reading?
Pete
It's not that I'm lazy, it's that I just don't care...
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macspeedy
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| posted on 28/4/04 at 07:40 PM |
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b+q do a dremil equiv tool which is ideal ibought the one with the extension and a stand and a whole load of ends/ stones etc for around 35 quid which
ain't bad broke it twice took it back twice, replaced no problem! can't say fair'r than that, also it is easier to get a copy of des
hammils book (rather than explain the ins and outs) as it covers a lot of information not just head working techniques ebay sometimes has them cheap.
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NS Dev
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| posted on 28/4/04 at 07:52 PM |
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There are various tools for the job. The dremel type tools are fine for final polishing and very detailed work around valve seats etc. but they would
take forever to do the heavier duty stuff like smoothing turns and removing guide bosses.
A proper electric die grinder (the air ones use loads of air, make a big mess and get very cold!!) is the ESSENTIAL tool. They are around £175 + vat
for a decent variable speed one which will slow down enough for paper finishing at a push.
sccobyis2cool - You have U2U regarding the above (you are not too far from me and I have the equipment to do this work, needless to say not at
"professional" cost!!!)
[Edited on 28/4/04 by NS Dev]
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JH
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| posted on 15/5/04 at 10:14 PM |
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What is the address of Dave Andrew's site?
cheers
john
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Peteff
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| posted on 15/5/04 at 10:42 PM |
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Don't let the Robin Hood put you off.
http://hometown.aol.com/dvandrews/index.htm
There are several interesting downloads and good info on ford stuff. I've used the quickshift a few times and have thanked him for his
efforts.
[Edited on 15/5/04 by Peteff]
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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jolson
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| posted on 15/5/04 at 11:03 PM |
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New pinto Head - references
The Des Hamill book is avialble online.
It can be downloaded thanks to the Russians at:
http://faq.ford77.ru/info/manual.htm
33.9Mb, the link is near the top of the page
I've got David Vizard's book here, if you need any info from that. He has diagrams showing the actual full-scale shapes the ports should
be altered to.
Cheers
John
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