Early Suffolk Punch 14"

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wristpin
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Early Suffolk Punch 14"

I've recently acquired an early 14" Punch that having read Ian Wallis's article in Grassbox edition 90, I believe that it may be a model 1 or 1a from dating from 1954 -56.

The identifying points are as follows and may assist with a more specific date.

Engine.

Exposed cylinder head and partial engine shroud.

Rope wrap starting pulley - no recoil.

Black painted cylinder block and unpainted sump.

The knurled main jet adjuster for the Zenith carb' is drilled and there is an adjacent small cast and drilled lug on the carb' float chamber  - presumably to take a locking wire to deter unauthorised adjustment.

No dip stick of any sort. If it ever had one of the split pin type the drilled plug has been replaced with a plain one.

Chassis.

Individual left and right height adjusters, no single point micro set screw adjuster .

A pedal cycle type free wheel mechanism in the land roll drive - no dog clutch.

Restore, or clean and preserve?

On the whole the original paint is probably 60% present and , in particular, the Suffolk transfer on the chain case is in good condition .  I think the "red"  on the  engine shroud and fuel tank is original but possibly faded . Does not appear to be the "red/orange" of the later machines.

All thoughts and observations welcome!

 

 

 

 

wristpin
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Progress with the Punch today

Progress with the Punch today. Cleaning the points produced a reasonable spark so moved on to the valves. The exhaust valve was quite badly eroded : some of the damage being down to wear and tear and the rest to the machine having stood for many years with the valve open . The valve face cleaned up reasonably well enough for an "exhibition" machine and the seat likewise. The inlet valve was not eroded but when spun up in the re-facer had a "dip" in it which cleaned up OK. Lapping in the valves produced a satisfactory contact patch although it would ne nicer if a bit narrower and more central on the face. New valves or juggling with the seat cutter angles  would solve that issue but for the use that the engine will get  it will suffice. 

Badly eroded exhaust valve face.

Re-cutting the exhaust seat.

Light spring under the valve lifts it and makes lapping easier.

 

hillsider
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Interesting to see the seat

Interesting to see the seat cutters doing there stuff, I have looked at those a couple of times but they seemed to be quite expensive for a tool that I had no reports of how well they worked and would only be used occasionally.

Do you think that the valves are the same as fitted to later versions of the engine? 

 

wristpin
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I bought the seat cutters

I bought the seat cutters nearly 40 years ago and they were expensive then!. Could only justify them as they were a working tool and refacing the valves and re-cutting the seats were a chargeable item on service and repair invoices. A quick re-face and re-cut would save minutes of attempting to lap in bad valves and produce a reliable result.. My view was / is that if the fine end of the valve paste can wouldn't do the job in a couple of minutes it was time to re-face and re-cut.. Using the coarse paste does more harm than good imo  - grooved valves and rounded seats. As for spinning valves with coarse paste and a drill - not in my shop!!

On the same subject, we would see valve stems that had been crudely ground to achieve the desired clearance with no apparent attempt to hold them square etc. The inlet valve on this Suffolk was still over gapped even after the valve had been re-faced and the seat skimmed !

I bought this old Black and Decker valve re-facer which probably dates from the 1940s, second hand in around 1978, put new stones on it then and bought a spare set at that time but there's still a bit of life in the first set. 

The useful feature is that it has the then optional micrometer stem grinding attachment  - mount the valve in the clamp, dial in the required amount to remove in half thou increments and its job done - square stems and accurate gaps.

One of my favorite books on small engine repairs quotes the following

"Technicians who are valve critical will always have a better record of repair success than those who take a near enough approach"

As for whether the same valves have been used right through the Cast Iron engine production run I think that the strict answer is no, as there are some differences such as some have plain heads while others have screwdriver slots to aid lapping and some have Inlet and Exhaust markings whiles others have none. However I believe that dimensionally they remain the same.  Will be a "wet day job" to go through a pile of parts books and compare part numbers but the fact that at some point the valves were marked Inlet and Exhaust may suggest that there were metallurgical differences introduced during the life of the Cast Iron design, the Exhausts possibly being up graded to a more durable quality of steel?.

hillsider
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You bought wisely when you

You bought wisely when you purchased a spare set of grinding wheels when you did, I don't think they are available now (certainly not from Black and Decker) that coupled with elf and safety concerns and a fall of in work for the machine killed off the one that we had at work. 

They are a brilliant machine though, used correctly they do a good job.

 

wristpin
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A relic from the days when

A relic from the days when every village garage would have one and cars  were in need of a decoke every 12000 miles. I was told that when B and D stopped producing them production was moved to India for their emerging motor industry.  When I bought mine in the late seventies spares were still available through BD in the UK.  

The Suffolk engine was up and running this afternoon.