need advice removing injector on Petter PJ1 diesel

I am continuing my project of restoring a vintage Petter PJ1 air cooled single cylinder diesel engine powered genset of the Petbow brand. I
have obtained a new set of piston rings and have the siezed piston out now and the bore cleaned and prepped with a fresh crosshatch. My attention has now come to the fuel injection system. Yesterday I managed to free up the fuel injection pump and have it all lubed and working apparently. I was able to test it by using a known good VW 1.6 diesel injector and by hand pumping the FI pump on-off lever which lifts the FI pump piston off the cam follower. It works! Now I need to address a bad injector.
Can anyone tell me if it is merely the two studs and flat bracket that hold the injector into the head? I have removed this bracket plate but the injector will not budge. It is being stubborn and I don't want to break it. I have no spare. The tip visible in the middle of the head is badly pitted from rust and the unit does not function. I have sourced a replacement tip from ListerPetter USA. A full injector is not available.
Does anyone here have a complete injector for this engine that they might be willing to sell?
Thanx, Rob
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Well I 'got lucky' as they say and managed to get the darned thing off but I had to cut a small corner off the head (nothing important removed) to clear the inlet connection as the injector body needed to be turned counterclockwise to unscrew. It looks like if I buy a new tip I should be operational. Now at least I can put the head in a mill and take a cleaning cut on the surface with a fly cutter to assist gasket seal. The original surface prep was pretty rough.
I plan to roughen up the surface of the used copper head gasket with #400 grit paper and then anneal it with a torch and cold water quench to make it soft and re-use it.
Rob
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Further examination shows that part of the injector body is still stuck in the head. That is why I had to unscrew it and why it would not pull straight out. I was wondering why it was necessary to cut metal off the head to clear for injector rotation....there shouldn't have been injector rotation! It also appeared strange that the injector came out in separate pieces. Sure wish I had a service manual I must be at the part now where I am having fun.
I managed to take about five thou of an inch off the head this afternoon on a milling machine and now have a nice flat fresh surface for the head gasket to seal against.
Rob
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rcavictim wrote:

There's a couple of good reasons why it is advisable to remove injector(s) before removing the cylinder head. One, it secures the head to a mass which can be needed when extracting the injector, and two, it precludes damage to the injector nozzle(s) that can in a lot of cases, protrude above the cylinder head face.
Tom
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Last night I tried to clean the old injector. Seems a lot of water got into the exposed fuel return line port over the years that the engine sat forgotten outdoors and there is a lot of internal rust damage. I do not think that I will be able to repair this injector. The tip was also rusted beyond salvage.
Does anyone have a complete injector for the Petter PJ1 single they could sell/give me, or know of an establishment that could supply same?
Thanx, Rob
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More progress. Using a slide hammer attached to the two hold down bolt holes on the upper main injector body, and screwing this back onto the stuff still stuck in the head, I was able to yank the lower portion of the injector and the sorrounding aluminum heat dissipator out of the head. Now I can install a complete new injector once I have one. I'll also need to find another aluminum heat dissipator or make one myself.
I may have found an injector from the kind response of an engine collector who kindly emailed me a copy of the manual for this engine.
Rob
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I forgot to mention my engine is now ready to put back together. It has been sandblasted and painted, the valve seats lightly machined, the valves ground and lapped in, the head deck milled flat, the cylinder bore deglazed with fresh crosshatch, standard size piston cleaned, new Hastings ring set acquired and ring gap checked to be within standard spec at largest part of the bore. Bearings look quite good and will be re-used. Sump cleaned and two large neodemium magnets are in the bottom now to catch metal particles. New oil filter installed and new oil pressure gauge fitted. Oil is pumping well. FI pump has been unsiezed, cleaned and tested with a VW Jetta diesel injector as apparently OK.
I am now servicing the brush gear on the attached directly driven power generating alternator/starter. Once my need to spin the engine without piston installed so as to do alternator service is complete I shall put the engine back together. Then I need to make an air cowling for the flywheel fan and an exhaust manifold. These parts were missing when i got the plant. Once running a new base and control panel will be fabricated.
The original trolley-truck-wagon is available if any engine collectors want to pick it up NW of Toronto for offers or trade. Pics available by request.
Rob
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rcavictim wrote:

"new Hastings ring set acquired and ring gap checked to be within standard spec at largest part of the bore." ?
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After my deglazing job with a drill powered 3-stone medium grit deglazing hone I note that the cylinder diameter is smaller at the top of the bore where the poston rings never reached to the dimension at the bottom of the stroke where the rings do the reversal in travel. There was absolutely no ring ridge BYW. There was much corosion to clean up mid cylinder as the piston had been welded stuck at BDC with rust. The cylinder is shaped somewhat like a cone or perhaps a wooden wine barrel. The circumference deviation along it's length is not large however. The ring gap grows about 0.010" as the piston is pushed to the bottom of the stroke. The bore is therefore about 0.0032" larger there. What I was trying to say was that at this larger dimension the ring gap was still measuring within the engine manufacturer's spec for standard bore size.
I am not going to worry about the minor bore irregularity, I am not tooled adequately as a engine rebuilder nor set up to bore with the cylinder under pressure as in using a head plate and this is a slow speed engine. With luck the ring exercise during each stroke will help keep them from becoming paralized wth the usual carbonization. I had to make my own tool to machine the valve seats. This rebuild is on a very tight budget.
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rcavictim wrote:

"What I was trying to say was that at this larger dimension the ring gap was still measuring within the engine manufacturer's spec for standard bore size."
I suggest you give this some more thought.
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Tom,
What are you trying to say?
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I think what Tom means is that it is possibly more important to check that the gap doesn't close up too far in the unworn areas of the bore, though it has to be said that this sort of guessing game is not especially helpful.
--
Nick H



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Nick H wrote:

"Possibly"? That, I don't find particularly helpful.
Tom
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OK, I thought you guys were worried about some cylinder bore taper. I measured the gaps of all three compression rings as supplied at several places along the finished bore using the piston to push them in exactly square. Where the bore is least worn and smallest diameter I have plenty of gap, more than the minimum 0.015" called for by the ring manufacturer (Hastings) for my bore diameter. There is no chance my rings are going to close and get tight from thermal issues at any place in the bore.
My point was that even though I have bore wear and am not overboring or buying a new oversize piston, my ring gap with the standard ring is still within spec of Petter, the engine manufacturer (not too big) at the largest part of the bore. I took care not to hog out too much metal in my bore cleanup operation because I wanted everything to be closer to original spec and not sloppy. If the ring gap gets too big then leakage becomes a factor right? Piston slap doesn't help longevity either.
Paying a shop to machine me a perfectly true, 0.020" over bore size cylinder which would require an oversized piston and oversized ring set is not an option for me at this time. Forget pistons, I am discovering that even basic parts like rings for this engine are incredibly hard to find.
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rcavictim wrote:

From your posts, the ring gap is .010" smaller than the makers specs at the top of the bore. Ring gap is always measured at the unworn part of the bore. Otherwise in worn bores, the ring gap could be reduced to zero with no allowance for thermal expansion.
Tom
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