Nuffield m4 petrol/paraffin

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Damo
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Joined: Sun Nov 10, 2019 11:59 am
Australia

Nuffield m4 petrol/paraffin

Post by Damo » Wed Jan 08, 2020 10:10 am

Hi all.
I am in the process of slightly modifying my m4 petrol/paraffin nuffield. I am converting it to petrol only no longer to be run on paraffin, has anybody in here had success with this and any pros and cons.
I am going to be running a single barrel down draft stromberb carburetor and a custom intake and separate exhaust manifold.
I will obviously be bypassing the governer and managing my rpm via throttle stop and a taco.
I would also like to get some more rpm, however being governed to.2000rpm does anyone know what these engines are capable of doing safely. I have heard the flywheels I'm these can not handle rpm above 2000, if so if there a compatible flywheel and perhaps clutch to change to.
Thanks in advance
Damo 👌



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Jamie Davis
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Re: Nuffield m4 petrol/paraffin

Post by Jamie Davis » Sat Jan 11, 2020 8:24 am

Moved to the Nuffield section as i think you’ll get better response there.
Jamie Davis

Past - Nuffield 10/60
Present - Nuffield 460 & Nuffield 4/65

mike.l
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Location: london ontario
Canada

Re: Nuffield m4 petrol/paraffin

Post by mike.l » Sat Jan 11, 2020 1:17 pm

Hi not sure why you want to use a different carb, these old tractors were run on gas only through the main carb and tank right from new in Canada and New Zealand. the only difference is the heat box needs to be removed or it will vaporize the fuel to early. The old solex carb and the governor were a good set up bit on the thirsty side Mike

JohnM
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Re: Nuffield m4 petrol/paraffin

Post by JohnM » Sun Jan 12, 2020 2:49 am

I take your point about the heatbox Mike but I don't think this would be an issue as Damo in the first post says he will be using a custom intake and separate exhaust manifold. I guess that these old engines were not deigned for too much performance as they would have a very low compression ratio to prevent pinking (knocking/pre ignition) when running on paraffin.

What is the main reason for wanting to do this mod, is it the availability or price of the fuel?
I have always assumed the reason that TVO engines were made was to save paying tax on fuel in the UK. If our overseas friends don't know road going fuel has always been highly taxed, petrol in the UK costs around 1.25 pounds and 28 second heating oil (kerosene) is around 50 pence

This thread has brought back memories as I used to drive one of these tractors in the UK as a fourteen year old in 1964 on a small farm where I worked. I can remember considering it much more high tech than the Allis B that I also used as you had to get off and switch off the paraffin tap then open the petrol one to switch over.
The Nuffield had the changeover on the choke, fully in for paraffin, out a bit for petrol then fully out for choke. If the engine wasn't hot enough to run on TVO you simply pulled the choke out a bit, if you made the same mistake with the Allis you would have to drain the carb and start again.

How different things are today, I am getting a bit off topic now but I follow a guy who repairs mac computers on YouTube, he shows how he repairs macs that Apple say cannot be done. He has recently joined and is lobbying for the right to repair movement in the USA. He says that modern tractors with all their electronics are preventing farmers doing their own repairs, even if a part could be obtained and replaced it would still need a laptop running software exclusive to the manufacturer to instruct the control unit that the repair has been done. He says that John Deere are the Apple of the tractor world.

Damo
Posts: 3
Joined: Sun Nov 10, 2019 11:59 am
Australia

Re: Nuffield m4 petrol/paraffin

Post by Damo » Mon Jan 13, 2020 1:45 am

Hi guys thanks for the replies,
As far as the carb changeover, the solex carb seemed almost a flood fuel type delivery, under low rpm solid fuel was wasted out of this carb, I will have the new manifold with separate exhaust and I take to lower intake temp. I'm aiming to combine this awesome vintage tractor with a little modern tech to get the better of both worlds so to speak, also kerosene is a lot more expensive the the best fuel from the pump here,
This tractor will be used for vintage type tractor pulling so a full days work on the plough isn't going to be normal conditions, hense the reason I am also hoping to get some more revs if anyone knows what they are capable of doing safely.
Thanks again lads

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