roadrunner
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| posted on 5/2/07 at 08:44 PM |
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PINTO HEAD
Has anyone fitted bigger valves and ported there pinto, if so how did it go, fancy doing it myself, fairly cheap power if i get it right.
Has anyone got a spare unleaded head kicking around, just incase i bugger it up i still have my car running.Beer tokens awaight.Cheers Brad.
Also , what tools do i need.
[Edited on 5/2/07 by roadrunner]
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mark chandler
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| posted on 5/2/07 at 08:57 PM |
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Years ago on a 2.0l pinto.
1.75 inlets only, fettled the ports to vizard tulip spec.
skimmed the head 60 thou + decent exhaust with standard cam on vernier made around 140bhp on dyno.
Costs less than £100 to do, no fancy carbs et al.
later on built a 2.1, cost around £800 with bigger everything, 285 piper cam etc, did not seem any better really, just harder to drive as it was
irritating in town, first/second/first ...
Hope that helps.
Regards Mark
Oops sorry, shgould have read the question.
Tools for the £100 build, valve seat cutters, got one bit a smaller than the 1.75 valve and drove it into the head to cut the port, slightly larger
one for the seat, burrs to grind the ports, paid for the skim and vernier timing wheel, set the cam around 5 degrees advanced.
The other was all machined as a 2.1 kit so just bolted up. I think the head was overdone hence the poor show, ports opened too much.
All this was with the joys of leaded fuel so no hardened valve seats required.
[Edited on 5/2/07 by mark chandler]
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Catpuss
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| posted on 5/2/07 at 09:01 PM |
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Hi,
I've currently got 3 2.0 liter heads. The one I got from you, then fucked as one fo the zorts studs was sheared off in the head and two
unleaded ones.
The one in the engine just has a rather badly drilled out zorts stud hole so not end of the world. A local place in Coalville will do unleaded
conversions for SFA too.
If you do have problems getting a spare head I'll almost certainly end up with at least one spare as I don't think I can turn 3 pinto
heads into a 12 v system 
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roadrunner
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| posted on 5/2/07 at 09:03 PM |
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quote:
I don't think I can turn 3 pinto heads into a 12 v system
And i thought you was a clever fella.
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Catpuss
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| posted on 5/2/07 at 09:20 PM |
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quote:
Originally posted by roadrunner
quote:
I don't think I can turn 3 pinto heads into a 12 v system
And i thought you was a clever fella.
Oh its not the conversion thats the problem, just lots of rolls of gaffer tape and some string. Its just getting the carb to feed all the inlets at
the same time.
Oh and it should be 24v so I guess I'm fecked from the start
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Andy S
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| posted on 6/2/07 at 03:12 PM |
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About 80% through porting one as a bit of an exercise- not planning any large valves but giving it a full race port as per Vizards book on the
SOHC.
Cost depends on what tools you have as a start. If you have compessor die grinders burrs and points already then its just time.
If you have to buy all the equipment to do a proper job them expect the bill to run to at least the price of a large valve ported head. £450 or so.
for info there was a good article by Dave Andrews but the link I have no longer works.
Big inlet valves 3 angle seats and the head skim will cost around £150. But after the porting you will have a head capable of some very good power.
Expect the porting work to take - a good couple of weekends to complete.
Andrew
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roadrunner
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| posted on 6/2/07 at 06:46 PM |
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Is it possible to use a good Dremil type tool to do the porting, i thouht i could purchase one , and get a local garage to fit the larger valves, or ,
am i being naive.
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flak monkey
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| posted on 6/2/07 at 06:49 PM |
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If you just want to smooth the ports off and not enlarge then a dremel type tool is fine. However you really need a die grinder (either air of
electric) to remove any major amounts of material.
David
Sera
http://www.motosera.com
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roadrunner
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| posted on 6/2/07 at 07:28 PM |
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To David.
Did you use a dremel on yours or a die grinder, and did you use bigger valves.
Brad
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flak monkey
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| posted on 6/2/07 at 07:30 PM |
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Hi Brad
I used a 150w dremel type thing on mine to clean the ports up and a die grinder to smooth off the short turns and open up the port throats. Valves are
still std size at the moment.
David
Sera
http://www.motosera.com
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Andy S
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| posted on 6/2/07 at 11:25 PM |
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Have not tried a dremel - I had the compressor so I bought a long reach die grinder - trouble with electric devices is that if you stall them they
burn out - no such issue with a air tool.
I dont know if the dremel can run a 6mm shaft and a 25mm carbide on cast iron but if it can I doubt it would not be for very long.
Following the Vizard book there is a great deal of metal removal - the throats come out from 36 to 39mm and all of the valve guide boss is removed and
the majority of heads with good data on flow appear to follow the same criteria more or less.
Cleaning up the exhausts is the more difficult because of the angle of the port - lots of jamming until metal is removed to get some extra volume in
the port so the stone can get a clear run.
Vizard makes it quite clear that there are no quick fixes for this head and to get good flow takes a lot of work and typical tuning tricks reap no
benefit - so unless you are going to go in with conviction - as above with driving a cutter into the throat then leave it alone as there will be no
good benefit apart from making it a bit shinier.
Andrew
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