putting the F back in a model F

[zeppelin builder]

been spending a lot of time honing out the 1918 harley barrels this week
stripped the motor and found it was a mix of mismatched junk had a look at the bore with a scope and it was in prettty bad shape, got new forged high comp +40 pisons from merica
it was 30 0ver higher up the bore but its tight at the unworn bit at the bottom , so with that evened up the rest will clean up reasonable , note must get an old van noman for rebores

 

[frank horton]

nice honing head......
more pictures pls....

 

[zeppelin builder]

nice honing head......
more pictures pls....

its a delapina standard hone i got at a church auction for £30 it has the 3 mt drive shaft an a couple of othe adaptors fortunately the cylinder has a big bolt in the middle i could secure in the vice ,,its a geared drill im running and is very powerful on the lowest speeds and has tbrown the vice out the door before
i have a couple of smaller hones for big end races i think the standard hone is almost 1k £ now stones are £100 a set super diamond ones about £450
crazy when the indian ones are about £80 complete bores are cleaning up ok and another boring session should see them ok

 

[zeppelin builder]

more progress on the model F barrels back on and turning nice and freely had great compression on front cyl but back was lacking could hear a faint hissing so taped up an old glove on the inlet port
voila inflating , turned out it was the inlet cage not the valve passing .
the seat that the cage bears on was badly pitted so spent ages with
valve paste lapping the cage/ cylinder joint with a battery drill till an even unbroken ring , job done
leaks cured .
thats an old adjustable walking stick bolted to the crankcase to take the weight , new it would come in handy !

 

[Erie Fred]

I was told the air cooled aircraft engine cylinders a "choke honed" to be tighter up top, so when
they heat up, they would be straight. Is that the same here ?

An old mechanic I used to hang around ground valves & seats, he would test the seal with a few drops of gasoline, puddle it around the valve and check for leak thru.

 

[Ali]

Do you have the rest of the bike? Yours or a job for someone?

 

[zeppelin builder]

yes i have the lot a job for a friend
going through the whole thing been a collection of bits

 

[Ali]

yes i have the lot a job for a friend
going through the whole thing been a collection of bits

I’m that case, more pics please and keep us updated! Not too often you see these older HDs in the UK

 

[zeppelin builder]

I was told the air cooled aircraft engine cylinders a "choke honed" to be tighter up top, so when
they heat up, they would be straight. Is that the same here ?

An old mechanic I used to hang around ground valves & seats, he would test the seal with a few drops of gasoline, puddle it around the valve and check for leak thru.

the hone tends to take out minor hollows and unworn bits , i think these would be simply bored on a lathe when new as there is a big thread in the centre of the heads that would accept a bar to spin them , and an area ner the bottom flange a steady could be utilised there is a gramaphone face on the flanges too that would be done to keep the flange square to the bore
with regard to the bores i imagine they will probably change shape as on one side you have a bigger mass of metal , these ones had about 8 thou wear near the top and very little on the non ring area at the bottom
compression ratio at 3.5 would help keep the heat down no doubt
the petrol in the port is a well known trick to check seats

 

[zeppelin builder]

I’m that case, more pics please and keep us updated! Not too often you see these older HDs in the UK

heres it in one bit

 

[zeppelin builder]

so off with the magneto its an early Nos,

bosch ze2 which was originaly a 180 degree which i have moved the cam lobes tosuit the 45 degree firing order bit of a compromise that requires a lot of wizardry to get near to 2 sparks of even power
bosch made the zev2 with staggered pole pieces to get round that .joe lucas was more a cheapskate and even used a modded 180 on the mighty vincents
with the one and a half spark syndrome, despite using this bodge most v twins run ok
early german bosch are the best of the best before ww1 with platinum points and a unique slip ring thats multi directional , however ohms were
poor at 1.8 k ish so ripped it apart and rewound it now showing over 4 k
with a 10 000 turn secondary
has to be baked next

 

[slim_boy_fat]

^^ I admire work like that , I just wish I understood it.

 

[zeppelin builder]

heres an update on the model f had compression escaping from rear cyl inlet port not from the valve but due to a small crack in the casting communicating with the hot side it was breathing in out enough to partialy blow up a rubber glove taped to the port, dye pen showed up a deep pore where bubbles were emerging from i countersunk the pore and with tig put a small spot of ni1 wire and peened it all well and holding now , matched manifold to carb messy job with carbide burrs mrs said i looked like garry glitter i joked well i believe he was an expert in that field !

had 3mm step and made a new suction valve spindle and boss
so it has no excuse to not run now

 

[zeppelin builder]

the patient lift / overhead crane came in handy , fired up no problem albiet was a bit fiesty with timing on full advance , moved it back to a happy medium (timing will be fixed as i mentioned before i have set the cam ring permanently to get 2 sparks of near even intensity .

the rear screw in ring that holds the inlet valve cage in was a very sloppy fit in the head ,apparantly when they blow out the rocker can puncture the fuel tank and cremate the bike.

after many stupid repair suggestions
from boffins and armchair experts
a simple fix was had, i have a box of various boiler tube expanders and a few turns on a suitable one expanded the ring to fit perfectly
saved a lot of machining !

work continues exhaust system next
hand oil pump
clutch
and loads more
tried to get videos up but too large
to process it said
???

 

[Ali]

Looks like you’d need long arms with that on full lock

 

[mtt.tr]

Very very cool.

Good work.

 

[zeppelin builder]

got the exhaust cobbled up yesterday out of mostly scrap silencer is a repro

 

[zeppelin builder]

started out to have a good look at the clutch , alas we had about 6mm up and down play on the drum its held on by a large lh hex nut and interestingly it works opposite from most other clutches in that the mechanism pulls inward to disengage it . clutch now off off there was about 3mm play between shaft and sleeve gear and threads on shaft were barely there .
out with gearbox to investigate

turns out there was a split bush had been omitted and a rummage through some old spares found us a shaft with intact threads and the missing bush so another bit done
gears are well worn but substantial things , and way superior to the sturmey archer stuff the brits were producing at the time ,so might last another century if not abused large roller bearings abound and it seems to be a real quality thing not bad for a scottish exiled blacksmith

 

[zeppelin builder]

put it all together afer gringing a spare shim for the layshaft to get the gear over as far as possibleto engage first gear deeper to give it a sporting chance with whats left of it all moving and engaging good now came across a www1 field repair a plate shaped and riveted where the kickstart gear had caused a bit of mayhem in the past also the big bearing screwed in retainer lock ring theads were badly damaged so plate was fitted and a spot of weld locked the plate in
just the indent plunger to make now as its awol too
the wee plunger on last foty is for when the k start quadrant jams up
push it down and it moves the gear to a more favourable position

 

[Rannsachair]

Thanks @zeppelin builder great thread, love to see the design of old bikes, interesting mix on the old Harley, quite a contrast to what I work on.