Pop-bang-phut .....

I thought I'd worked enough for a while, so dedicated yesterday afternoon to starting a few engines & watching 'em run.

First, the Petter A1 - always a first time starter. Pull the cover off, turn on the petrol (now at least two years old) flood carb, wind handle, bang pause bang, bang, bang & off it went.

Next the Bernard SIMEL that let me down in the winter at the Wessex Mince Pie Crank Up. Changed the plug, splashed a drop of petrol in the tank, wrap-and-pull & away it went - bap-bap-bap.

Now the Petter Universal Two, the single horizontal air cooled cylinder job. No compression - ah, now I remember, I had it running last year and it just stopped on me. This engine has little compression anyway, so needs all it can get. Stripping off the cowling and the cylinder head could not have been much easier, the exhaust valve was OK, but I lapped it in anyway with fine paste. Under the inlet valve face was a tiny (1mm across) flake of rust. Remove, trim inlet manifold gasket to open out the hole in the centre (why do people not do that??) so it's the same size as the port and remove a small pile of rust flakes lurking on the floor of the port awaiting use (!). Grind in the valve with coarse & fine paste, reassemble & dribble some Plus Gas onto the valve faces. Disappointed to find the inlet valve still leaking very slightly, but suspect it actually needs a new guide and reseating but there isn't much meat left. We shall have to manage.

Re-assemble, splosh some petrol in the tank and turn the handle through the minimal compression. Tuf. Oh, really? OK then, swing. TUF.

Fiddle with carb, swing - and it's running. Why Mr Petter should want to build it with the carb so remote from the cylinder is beyond me, it is hard to adjust the mixture with an inlet tract over a foot long.

I turned it off and as expected, the compression is very much improved. I noticed that one of the valve caps had a deep hole in it and will drill & tap to fill in the recess which will make some difference.

I reused all the old gaskets, but the head seal appears to be without one & this I re-assembled with blue Hylomar.

So, there we are then. At one time, I had four running, as I pulled a Norman T300 out blinking into the sunshine to join the noisy throng. After I enjoyed a nice cup of tea and some plain chocolate covered ginger biccies in their company, I returned them dry float to store before the neighbours came home and started banging their back doors at me.

Regards,

Kim Siddorn E-bay. You know what really pi**es me off? the ill-educated previous inhabitants of the Chinese province of Wan - King that think "Stationery" is spelt "stationary"!

Reply to
Kim Siddorn
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Perhaps because its half a PU8?? The Norman T600 and Douglas FT35 share this highly undesirable "feature". As for your sig/PS; perhaps we might have a tw*t of the month award and maybe an award for the most oragonial spelling of original :-) ....and of course the shill prize for mates/family members bidding on each other's stuff :-( ttfn Roland

Reply to
Roland Craven

Kim,

Re: your postscript.

I'd never noticed before; it's amazing what you can find if you do a search on 'stationery' - thanks for the tip. :)

Mark

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Reply to
mark.howard10

I'm not saying that this is a design feature but a step change in the inlet tract has been shown to have advantageous effects. This is due to the step change causing fuel that has settled out on the port wall to be reintroduced into the air flow. The step can be a sudden change as in a deliberate increase in area generally where the inlet manifold meets the larger cylinder head port, or a series of microscopic surface irregularities due to a course ground finish. The other advantage of a step in the inlet tract is to reduce reverse gas flow along the port wall. This is usually caused by the use of high performance cams with significant overlap. Now that all modern engines use fuel injection, carburettor confusing turbulence in the inlet tract isn't a problem. The correct fuel is injected regardless of the gaseous confusion. As a result, more radical cams are used. The inlet ports are designed not only for good forward flow but have poor reverse flow characteristics as well to improve low speed running. Gas flow a modern inlet port as we used to in the 60's and you can actually loose power. Probably no of this is applicable to a Petter though.

John

Reply to
John Manders

wrote :-

Would 'station*ry' not cover both eventualities?

Reply to
Nick H

Yes, I've added it to my search list!

Mark

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mark.howard10

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