Darylbrookes
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 posted on 29/7/12 at 07:15 PM |
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Pinto problem
Hi all thank you in advance for any information/guidance you can give.
I have 1984 2L pinto running on twin 45 webbers
Electronic points, motorcraft, no engine managment system other than this
The cam seems to have markings HR 320
I have had this engine tuned by mikechanics in congleton on rolling road as the carbs were in balanced and spitting back, 150 bhp was recorded on the
graph at 5700 rpm after tuning, but the carbs are still occasionall spitting back. I have checked the timing as this was adjusted during rolling road
tuning
With vacuum pipe on timing is 26 btdc and with the vacuum pipe off goes down to 12 btdc
I have compression tested all cylinders while engine warm and the throttle fully open and all four cylinders grace 11.75 bar each, which after a quick
search seems to be good
Oil pressure cold is about 65psi but as the engine gets hot drops a little to 50psi. When on the road/track prolonged high reves 5000 rpm and on
motorway doing 70mph the oil pressure drops down to just over 30psi
The engine is noisy (sounds like a transit) and I have hot oil mist comming from the oil filler/breather I also get this from the dip stick tube when
the dip stick is removed. The pcv valve is still intact but is not connected to the inlet manifold, just a pipe that drops under the car body. I have
checked this several times and is as dry as a bone?.. I have even removed the pcv valve altogether and no blow by gasses and more importantly no
oil??
I am thinking of fitting an oil catch can to get rid of the mess the oil breather is making of the engine, but I am worried that there is something
more fundamentally wrong with the engine.
Here's hoping for a lot of help and advice, im pulling my hair out, but I'm wondering if any of the above problems are related
Thanks again Daryl
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avagolen
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| posted on 29/7/12 at 07:22 PM |
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Hi, I would think that the PCV not being connected to the inlet manifold is part of your problem.
They require a negative pressure to open them and 'suck' the oil fumes from the crankcase.
As this is not happening, you are getting the 'messy' engine described.
Put an oil catch tank in and if you use the pcv valve to connect the Catch tank to the engine, modify it
by removing the 'valve' within it.
HTH,
Len.
The Answer for everything, but never the last word....
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mark chandler
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| posted on 29/7/12 at 07:56 PM |
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As Len says, PVC requires vacumn so you have effectively blocked crankcase ventilation by just taking to the ground, remove the valve and loop to a
catch tank keeping the loop of hose high so blown by oil can drip back where it belongs.
30psi @ motorway speeds and noisy, good Pinto's are quiet, sorry it sounds like ringing and shelling required.
12degress BTDC..... it should be around 36degrees at 4000 rpm and above, vacumn off and idle between 6 - 12BTC when everything is connected, something
does not sound correct, at what conditions are you talking about, full load, idle RPM etc.
I suggest you get a copy of David Vizards book on tuning Pinto engines and have a read up.
Regards Mark
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Darylbrookes
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| posted on 29/7/12 at 08:02 PM |
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Hi Len
thanks for the reply, I'm unsure if I can connect the pipe from the pcv valve to the inlet manifold as I have been told that this will throw the
oil/mixture into one carb and could upset the mixture, this seems to be a non no.
I have taken the pcv off completely and ran the engine and no oil/smoke comes out even if engine is revved?
I will definitely be fitting a catch tank ASAP, but it just seems something else is amiss
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Darylbrookes
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| posted on 29/7/12 at 08:07 PM |
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Hi mark thank you also for your reply.
I checked the timing both at idle
Everything connected 26 and vacuum off 12 btdc (idle 1100 rpm)
Thanks for the book advice will have search and order a copy cheers
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snapper
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| posted on 29/7/12 at 08:08 PM |
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Compression is ok, for a standard engine
150bhp is good
Cam I have no idea but may be radical if your getting 150bhp and this may be why your compression is 170 psi
Spitting back is due to lots of overlap on the cam, no biggy just what radical cams do
Oil pressure should be at least 7psi per 1000rpm
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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Darylbrookes
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| posted on 29/7/12 at 08:16 PM |
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Hi snapper thanks for the reply, I have to admit the car (Ginetta G27) goes very well and seems to have plenty of torque. Thanks for clearing the spit
back issue that's one ticked off.
The oil pressure dropping on long runs, couple of hours on the road is a little worrying, thought it was the grade of oil, so flushed and replaced
with 20/50. I have thought that the oil is getting to hot, thinking I need a oil tem gauge just to get this one ticked off too
Thanks again
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britishtrident
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| posted on 29/7/12 at 09:11 PM |
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Check the vale clearances, the valve gear is the weak point of the Pinto engine, in the Cortina era the camshafts were only lasting 30,000 miles or
so thank fully better quality cam and follower material and oils made a big inprovement. An old fashioned 20w/50 mineral oil will not do your
engine the damage any favours to camshafts and cam followers occurs during cold starts. use at least a semi-synthetic a 5w/40 or 10w/40 if you
must a 5w/50 or 10w/50.
To get the oil temperature under control fit an oil cooler connected through an oil thermostat you want the oil temperature within about 10 to
15 degrees of the coolant temperature.
Apart from oil pressure the more important reason for keeping the oil temperature under control is the formation of varnishes and black sludge in
the oil.
Mineral oils start to break down and form sludge and varnishes at lower temperatures than synthetics and Pinto engine is particularly prone to
sludge and varnish blocking the oil feed holes in the camshaft spray rail.
A change in oil pressure (either downwards or upwards) is a symptom, a high oil pressure is not an aim in itself. The oil pressure
generated by the pump has next no no effect on the oil pressure within the bearing.
[Edited on 29/7/12 by britishtrident]
[Edited on 29/7/12 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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chillis
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| posted on 29/7/12 at 09:43 PM |
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HR320 is a lairy cam, you will get some spitting back off cam.
You'll need to vent the crankcase and rocker cover into a sizable catch tank.
The lairy cam will be quite noisy compared to a normal car engine.
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Darylbrookes
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| posted on 29/7/12 at 10:05 PM |
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Thank you chillis, I have tried to search for the hr320 cam to get some date but unsure of the manufacturer. It is noisey and when revving higher it
almost becomes a whine, perhaps I can also tick this one off the list too thank you
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Darylbrookes
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| posted on 29/7/12 at 10:19 PM |
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Thanks britishtrident,
I have had the rocker off and all seems well from a laymens point of view. All cam lobes look reasonable no tell tale signs of wear. I gave the old
girl a flush with wynnes oil flush and replaced with the 20/50 as this was also mentioned on few sites about the oil grade to use. I will try your
suggestions, and see if the pressure remains constant.
I was concerned as my son I laws car oil pressure seems to increase with engine speed, so I was expecting the same and this concers with the 7psi per
1000rmp. So this maybe the oil temp and as you say I may need an oil cooler, although i can't understand why the oil is becoming too hot (please
note not sure it is. Don't have oil temp gauge) water temp is fine so the engine isn't overheating. And in all fairness the engine is
basic, except for the twins, and cam upgrade?
Thank you
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snapper
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| posted on 30/7/12 at 04:39 AM |
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Check the noise is not detonation (pinking), if running a distributor it is likely that the idle advance is adding to much all in advance
The ideal advance should probably be a bit higher 14 to 16 staying flat to 1400 when it should rise to 36 degrees at 3,600 then flatten, you could peg
all in advance at less and see how it feels
Vac advance should only come in on closed throttle or very light load
Oil pressure can be addressed by fitting a high capacity, high pressure pump, an easy fit on a pinto and not a lot of money.
Oil cooler, I fit a 16 row with thermostatic take off and would recomend the larger pipe fittings and pipes, 5/8 or 3/4 as opposed to the standard
1/2" for better flow and use swaged fittings, I had 1/2" pipes blow off under pressure when fitted with Mikalor clips
[Edited on 30/7/12 by snapper]
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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Darylbrookes
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| posted on 30/7/12 at 08:10 PM |
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Thank you snapper,
I'm looking into the oil cooling and you have given me some great advice cheers, i have seen temp strips you can place on the oil pan to give me
an idea if this is actually a problem. I'm going to check the timining again and see what readings I get throughout the rev range and post, prob
won't be until tomorrow eveining now.
Many thanks for all the valuable information
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