Exactly £ for Lb/ft a Pinto is not a bad option at all, i do a bit of Sprinting and Hill Climbing, i weighed up all the options and the Pinto came out top, to stay in a Road Saloon class, it has to be Ford and an engine fitted to the car model.....so Zetec and Duratec was out, the only options were Twin Cam, Xflow, BD or Pinto........then i thought ok i'll maybe move to Mod. Saloons and run a Zetec....but the competition in that class is pretty fierce.....dont have the budget.
The only thing i dont like about a Pinto is : 1. the weight 2.the valve gear.....it even looks vulnerable....spray bars, ball studs, rockers.....it works though, just!
A 2.2 Lotus 8v is a very good tuneable, light engine that not many consider
I think by now the Pinto Engine must be getting to the end of it`s development, we keep hearing about modern Cam profiles etc, there`s only so much that can be done with the opening and closing of the Valves, surely all the permutations have been covered.
A well respected Engine Tuner I know with over 40 yrs service, building Historic DFVs, BDGs, and many more has only recently seen 202 BHP on the Dyno off his Historic Rally spec Pintos, that`s 25 BHP down on what some builders are claiming.
Downdrafting and Tubing the Pinto Inlet Ports is n`t a Job for the faint Hearted, sealing the Tubes when the Water Jacket has been broken through will be a massive problem, reliability is always the no1 priority.
With 2,0 Duratec now a cheap Engine to obtain it would be interesting to see what it would take to get 220 BHP out of one on Carbs on a limited Budget.
8 Valve Pintos are now in the same class as 16 valves on some Events.
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Downdrafting and Tubing the Pinto Inlet Ports is n`t a Job for the faint Hearted, sealing the Tubes when the Water Jacket has been broken through will be a massive problem, reliability is always the no1 priority.
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We'll see...but I really don't expect to have any problems sealing my downdraught head. If it leaks and can't be cured (doubtful) I'll just do a conventional big valve 1600 head for my 1700.
if this were an engine for myself, i would be inlined to try down drafting, to make it really work i think you would have to go really radical and bring the port up through the upper face of the head, weld up some of the long turn in the port to avoid a dogleg, and consider a tulip shaped valve
in days of old it would of been brazed, as braze takes well to cast iron, rwd jason found a mig wire that supposed to be the bee knees for welding cast
It seems like a lot of work and expense to Jig Bore and Tube a Cylinder Head for for it to leak on the coolant, the only ones that seem to a down drafted the Pinto with success are the Swedes.
Good luck with yours Mempphis, keep us all informed on your progress on your Down drafted Head.
A NA Cosworth Head is of semi down draft, but seems to give Bugger all Power and Torque for all the Money that needs to be spent on the Engine.
the problem with the cosworth, is its nothing like as downdraft as it needs to be in addition to the ports being very small, to make it really flow you need to open the ports out to the point where you are about to break through everywhere
Scan from Streetmachine magazine Sept. 1986 ...
Good to see a decent 2.3 build
I would be thinking the larger the inlet valves the better, aim for big port flow rather than high port velocity as the stroked bottom end will demand a hell of a lot of air anyways, increasing velocity, also your rather small rod ratio will make the pistons draw very hard towards the first half of the intake stroke, going this route I would use a cam with Huge overlap and as much lift as possible
GTS4 is a Prime candidate for an off the shelf cam, forget about HT1 it is shite for a 2.3+ build take my word for it GTS4 will make at least 10bhp more on a dyno, it simply has really low lift and the duration above 10mm is way too low, upper lift duration with GTS4 is quite good for a non roller cam, there is no other cam I have tested that can beat it for this kind of build
RC31 may be a decent Ish choice but is has a shit load of duration, it will work with TB's I am sure, GTS4 is a more modern profile with asymmetrical profiles, I can PM you a graph I made of the profile if you like
HT1E is ok but not suitable for this kind of build
About long rods, they DO make more power, BUT the combination has to be right
Longer rods, short pistons, "small" high velocity ports, great low lift flow decent high lift flow and big cylinder ramming, low overlap duration and lift, high valve lift, low duration, small exhaust primaries and secondaries, WIDE power band
All of the above is a perfect match for rallying especially and a lot of racing applications too
Short rods suit big inlet and exhaust ports, large exhaust primary and secondary pipes, high overlap duration and overlap lift, Narrow Cam LSA, Narrow Power Band
With this combination the short rods make the pistons move a lot faster around TDC, a lot of the cylinder filling takes place before the piston is half way down the bore
Works well with high cc bottom ends with 8V heads because any heavily stoked and bored 8V is moderately to severely choked in terms of airflow, port and valve size is now small in comparison to the bottom end
Fit long rods into the second engine setup above and you will see little to no gain
All of the most powerful 2.0 to 2.1 pinto engines are using 136 to 145mm rods, the insanely powerful ones are all running 145mm, not saying that YB length rods cannot produce power they can for sure, however every few hp and lb/ft adds up, the difference between 128.5mm YB and 145mm rods is rather huge in length, not so huge in terms of power gain but it all counts in a full on engine, I would expect to to see a solid 5bhp difference between 127mm and 145mm rods in a 220bhp engine at least, we are talking a high max power rpm around 7500 to 7600rpm, not a stroker engine
About the compression ratio
If you use under 12 to 1 SCR and a lairy high duration cam the DCR will be low for sure
I would aim for at Least 12.5 to 1 SCR, 13 to 1 would be so much better and easy to achieve with a 2.3 bottom end
Pinto's need all the compression they can get
However all in all Air flow is the main thing to get a 2.3 to rev and make decent top end, I would use at least 46mm inlet valves, 37 to 37.5mm exhaust is plenty
Have a good Xmas
"Horsepower sells cars, torque wins races" - Enzo Ferrari
you are correct of course, but it need to remember you still have a bigger volume of trapped gasses in the cylinder.If you use under 12 to 1 SCR and a lairy high duration cam the DCR will be low for sure
heres one example bmw s14, the 2.5 engine has a lower compression ratio and hotter cams than than its smaller brother but actually made slightly more power in terms of bhp per litre.
Yes higher cylinder pressures in the 2.5 (increased torque) translating to more bhp
But add more compression to the 2.5 and it will make more power
I would aim for a solid 12.5 to 1, that will be relatively easy to achieve with a 2.3 engine, 12.5 to 1 in a 2.0 is just a dream without raised top pistons but will make more power, especially when combined with a long duration cam
Best of luck with the build, sure it will be very powerful and super high torque from even 3k upwards whatever cam you decide on
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Interesting, a few things from that build don't add up, 2 inch twin box exhaust system, std valve springs and 0.550" lift = not possible, you would need titanium Everything to make that even a possibility without severe valve bounce, no surprise really for a magazine article, often the spec sheets have inaccurate information, however I do believe the 322B crane profile, some of the old Crane profiles were the best there was at the time
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Was it Vizard that did Tuning Articles in Fast Car Magazine in the late 80s about the Pinto from very fast road to Full Race? Brilliant reading at the time before the Net!
yes it was vizard
Thanks Graham!
when dave walker started publishing in ccc he was the only reliable source of non bullshite since mr vizard.
Any updates Graham?
just waiting for the steel rods to turn up
Yes it is very nice to use, when the current and feed rate are set right it sounds and flows like a normal mild steel weld, sticks to the cast really well, pre heat and post heat is needed to reduce risk of cracking when welding something solid that doesn't want to give, if welding something where one of the two parts being welded can either A. move closer to the other part or B. welding a light steel plate that can pull closer to the cast part as it cools then the risk of cracking is zero
Royal 44-30 is the brand 0.035" gauge, Nickel-Iron-Manganese mig wire http://www.crownalloys.com/products.php
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Royal 44-30 is the brand 0.035" gauge, Nickel-Iron-Manganese mig wire http://www.crownalloys.com/products.php
Hi Jason , Have you ever personally used this mig wire on a race pinto head ?
I have not yet filled any inlet port with this "yet" but have repaired items etc, here is what the weld looks like, welding an old pinto head, its the best filler material and welding method for cast iron bar none imho
As you can see it takes to cast Very well, looks like mild steel to steel weld pool and flows like it too
Haven't strapped a set of cam towers with this yet but my best guess is it would be a piece of piss with this mig wire tbh
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Looks good, what sort of temp are you preheating to and what the penetration like? I've only ever welded cast using arc but am interested in trying with mig, I guess you need high power for any decent penetration on a cast head?
Current I use is 140 to 175amps, 140 is plenty unless welding something very heavy, same current you would use for welding say 6mm mild steel plate with 0.60mm wire, no more current than welding mild steel really and adjust feed until the weld pool looks nice, penetration is good, you can belt the weld with a hammer and it won't move, pre head and post heat not sure what temp tbh, too hot to touch but nothing excessive, the test weld above was with no pre heat or post heat, no cracks anywhere, would be very suitable for welding chambers etc I am sure, and can weld steel to cast iron which is handy, have welded some really light cast with it and had good results, it is a little expensive but if using it for regular welding rather than filling it lasts for a long time, won't use it very often but when you need it, it is very handy to have, I wouldn't attempt cast welding with arc tbh unless I really had to, mig puts a lot less heat into the material + you can see the weld pool as it forms and the filler is soft like mild steel rather than brittle, a good strong weld
"Horsepower sells cars, torque wins races" - Enzo Ferrari
rods arrived last week,
it looks like ive decide on a cam.
my gut feeling (and i tend to do a lot on gut feeling which doesn't usually let me down) was to use a kent RC31, yeah i know it has some serious duration but that never hurt my bmw engines. the only really odd thing to me is why it should have more exhaust duration than inlet, anyway ive now decided.
this isnt the only engine im looking for a cam for right now and im looking for a supplier of performance cams, so its kinda ironic that my decision was forced by one supplier not even bothering to return my calls or emails, i wont say who it was but ive now ruled out the RC31!
after a chat with ken at newman we are going to modify the P5 (now called P6) i used in dave whites pinto, ive asked them to grind me one with a bit more lift and duration on the inlet lobe
oh mr. Graham....any news?
not really, ive just taken delivery of a couple of 1600 heads to use.
even with a 2.3 bottom end a 2.0 head still wants a lot skimmed off it to get 12.1 or more compression, and thats without any chamber mods.
and i know theres some power to be had there, but have never really investigated that avenue before for fear of loosing too much compression
flow wise the 1600 head is not as good a starting points as an injection head, but that does rather depend on where your looking for the airflow, an injection style port does loose out at very high valve lifts.
i shall be looking to raise the ports a bit, and am considering offsetting guides, although i have to remember that at this stage shooting for the ultimate isnt required, and reliabilty is most important so there wont be any welding or boring through water jackets, we will leave that for another day, because i have my own ideas there, which include welding up bits that no one else seems to of tried
Last edited by Graham; 08-02-2014 at 11:24.
Hi graham..following with interest...when you move the guides what plans do you have for the rocker studs...when i moved my exhauste valve moving the guide was fine but moving the stud caused more hassle than the guide...at one stage i almost didnt move them.. cheers mark
i was only planning on a very small move 0.5mm or so another possibility is move the guide over slightly and change the angle a bit.
dave used to straighten the valves up slightly, it give you more material to play with on the short turn
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