Big Inch Shovel - Build Thread
- Thread starter jayzedkay
- Start date
Oldguy
Club Member
Re the lathe, an old Harrison L5 takes some beating, worn? Yup. but you learn to drive it like an old flathead--
The main difficulties with the old round pillar mill/drills is the lack of a true register, as long as that is understood, they can do good work.
Primary considerations with a lathe are the spindle bore size, swing over the bed and does it have a gap bed.
With the first two parameters, size does matter.
The main difficulties with the old round pillar mill/drills is the lack of a true register, as long as that is understood, they can do good work.
Primary considerations with a lathe are the spindle bore size, swing over the bed and does it have a gap bed.
With the first two parameters, size does matter.
devon.john
Club Member
was given a mending bench dill years ago brilliant ,i keep the belt a bit on the slack side so it can slip if hitting something it doesn't like
that and my Boxford lathe and my old mig
that and my Boxford lathe and my old mig
kiwidave
Registered User
This has been quite an education. Thanks for teaching us all in forensic detail.
And.... you're so right about old-timer engineers in their own workshops. They become your best mate in a bike build when there is things you just can't do. Pride in their work, attention to detail. You are DEFINITELY going to be one of those blokes sooner or later.
And.... you're so right about old-timer engineers in their own workshops. They become your best mate in a bike build when there is things you just can't do. Pride in their work, attention to detail. You are DEFINITELY going to be one of those blokes sooner or later.
jayzedkay
Club Member
kiwi', yeah, Paul, who i use is a rareity on this planet i think. he grew up around engineering, his father was an mech/elec engineer/consultant. plus a model engineer. Paul was on lathes/mills as a child. adolescent years modifying cars, engines, as we all did. he was just on another level due to facilities available. involved in motor sport, mainly motorcross, but an engine is an engine, undertsand the principles of one, you know them all, yeah?
not only machining, but fabrication skills are outstanding, to me they are in the realms of 'art' from spinning-metal to constructing aluminium tanks, covers. There isn't anyhting he cannot do if it involves metal. Plus, not that money is ever discussed and it doesn't really matter, as the work is primary. Hourly rate is unbelievable really. i think less than half of a typical commercial machine shop?
not only machining, but fabrication skills are outstanding, to me they are in the realms of 'art' from spinning-metal to constructing aluminium tanks, covers. There isn't anyhting he cannot do if it involves metal. Plus, not that money is ever discussed and it doesn't really matter, as the work is primary. Hourly rate is unbelievable really. i think less than half of a typical commercial machine shop?
devon.john
Club Member
I have a good frend thats an engineer ,,,,, if i have something that beyond me i take it to him ,
i just say ' not sure if you can do this ' like red rag to a bull ... very clever man
i just say ' not sure if you can do this ' like red rag to a bull ... very clever man
Paul P.
H-DRCGB Archivist
Not totally on topic but I think along similar lines - one of the videos from YouTubes best firearm historian (Forgotten Weapons) was on our army's first purpose made sniper rifle. It was two mates in a shed trading as Accuracy International and they submitted their weapon just to test the response, to their surprise they won and the Ministry of Defence wanted to meet them. They quickly rented a small industrial unit, got together as many serious tools as they could (lathes and such) and roped in some mates as "employees". The MoD came, were given a don't look too closely tour and hurried to the pub where they are claimed to have said "well we are quite happy, we only needed to make sure you weren't just some blokes in a shed"!!
jayzedkay
Club Member
update on this.
So, after fettling the pistons a couple of times; file, assemble, not enough, disassemble, file, assemble etc.
i'm now happy with the clearances. i was at about 40 thou' prior to last fettle.
60 thou' worth of feeler-blades in the gaps around teh piston/flywheel at BDC.
you get the idea.
i'll likely dress-up the filed area prior to final assembly with some wet-n-dry and oil just to polish it up to match the surrounding area.
interestingly i weighed the pistons after filing, just to see what differences there was.
the front bare piston was 565g and the rear was 559g, 6g difference.
now i haven't removed that much material no way.
what that difference is, i'm sure, is the the rear piston relief cut into the skirt to clear the front piston when both are at BDC area.
I'd have thought in manufacture, more material was put into 'reliefed' piston to compensate that relief? obviousl not.
they appear to be idential forged 'slugs', just one is machined more.
now, i believe that 6g, a little over 1% difference won't make any odds when almost 2 litres of ridgid-mounted combustion-volume is surging down the road in a series of inductions and explosions? but i will investigate it?
So, after fettling the pistons a couple of times; file, assemble, not enough, disassemble, file, assemble etc.
i'm now happy with the clearances. i was at about 40 thou' prior to last fettle.
60 thou' worth of feeler-blades in the gaps around teh piston/flywheel at BDC.
you get the idea.
i'll likely dress-up the filed area prior to final assembly with some wet-n-dry and oil just to polish it up to match the surrounding area.
interestingly i weighed the pistons after filing, just to see what differences there was.
the front bare piston was 565g and the rear was 559g, 6g difference.
now i haven't removed that much material no way.
what that difference is, i'm sure, is the the rear piston relief cut into the skirt to clear the front piston when both are at BDC area.
I'd have thought in manufacture, more material was put into 'reliefed' piston to compensate that relief? obviousl not.
they appear to be idential forged 'slugs', just one is machined more.
now, i believe that 6g, a little over 1% difference won't make any odds when almost 2 litres of ridgid-mounted combustion-volume is surging down the road in a series of inductions and explosions? but i will investigate it?
jayzedkay
Club Member
next i had a look at valve-clearances w.r.t cam-lift and piston at TDC.
from doing this before, i had some bits in my stash to make it easy.
i replace the valve-springs with small springs, slipped over the valve stem enabling the valves and collars to be installed and take measurements at installed heights an dbe able to easily open the valve for checks.
the lower collars supplied with the heads have a larger ID to allow them to fit over a seal.
These are supplied by other manufacturers, such as manley as part of their hi-lift collar sets.
but are infcat the same as late shovel-collars, post 79 is it, not sure, but the same anyway.
pre-79 or whatever collars have a smaller ID and 'sit' on the guide. significantly impeding 'lift' capability if seals are utilised.
anyway, the valve-spring install height, i.e. the length between the collars is measured at 1.535"
and the length between the upper-collar, at valve-stem and the top of the valve-guide is 0.9"
These will dictate maximum lift with 'no' modifications.
first off, i measure valve-spring coil-bind, that will dictate maximum lift available before anything else is considered.
placing both valve-springs with collars in the vice, wind it up until the spring binds and measure the length of the spring compressed.
here for ease i measure the complete width, then measure collar widths and subtract that to obtain spring-length, yeah.
after subtracting upper collar widths i get spring length of 0.790"
i subtract this from my install-height, leaving 0.745"
this is the maximum travel before spring-bind. i haven't factored in a safety-margin, additional clearance for teh spring at this point.
now, i havent decided on the camshaft, but i have three in the runnings.
the largest lift out o fthe three cams is 0.651", and it's likely the one i'll use.
so 0.745", subtracting my 0.651" leaves 0.094" clearance prior to 'bind.
the general minimal margin is 0.060", so i have clearance to spare, happy with that.
there is a school of thought that too much clearance is not such a good thing, as approaching 'bind' helps dampen the springs and prevents the potential for the spring to surge. But i take this sort of stuff manily relevant to high-rpm operation, race/drag whatever and not stooging around on an antiquated thumper, so i don't consider stuff like that. nearly 0.1" clearance is ok for me.
so my spring is ok at 0.651" lift, what about the collar-to-guide?
i have 0.9" between collar and guide. subtract the intended 0.651" lift, that leaves me 0.249" spare for safety-margin and seal-protrusion.
seals typically come in the OEM steel-clad types or hi-temperature viton variants.
the OEM types i consider to more of a 'wiper' than a seal and they are a lower profile that the viton ones, allowing more lift, but it's kinda marginal.
i took the various seals that i have and measured the overall height of teh seal,
then the internal-depth to guage the protrusion of the seal above the guide.
i found the following
OEM steel clad had a protrusion height of 1.44"
Viton ones varied from 0.149" to 0.209". so the lowest profile viton was only marginally taller than the oem type.
so, taking my 0.249" spare-travel, fitting seals would give me lift-clearance i.r.o 0.04" to 0.105",
with the shallow-viton seals giving 0.1" clearance, optimal is they'll give a proper seal, as opposed to a 'wipe' and have the 0.060" safety-margin with room to spare.
Thing to note here, typically when fitting viton seals, they do not fit 'flush' to the top of the guide. the body bottoms out on the guide-collar and takes up valuable room for lift. In the past, what i have done is simply work out how much to 'trim' off the base and get the dremmel out.
here's one i did for the S&S heads on my 98" some time ago, replacing the fitted oem type for viton types.
ideally, it'd have been a little longer to get maximum body length.
but with my new mill, i'll be able to trim them perfectly this time.
next i check the valve-to-valve clearance and valve-to-piston at TDC.
from doing this before, i had some bits in my stash to make it easy.
i replace the valve-springs with small springs, slipped over the valve stem enabling the valves and collars to be installed and take measurements at installed heights an dbe able to easily open the valve for checks.
the lower collars supplied with the heads have a larger ID to allow them to fit over a seal.
These are supplied by other manufacturers, such as manley as part of their hi-lift collar sets.
but are infcat the same as late shovel-collars, post 79 is it, not sure, but the same anyway.
pre-79 or whatever collars have a smaller ID and 'sit' on the guide. significantly impeding 'lift' capability if seals are utilised.
anyway, the valve-spring install height, i.e. the length between the collars is measured at 1.535"
and the length between the upper-collar, at valve-stem and the top of the valve-guide is 0.9"
These will dictate maximum lift with 'no' modifications.
first off, i measure valve-spring coil-bind, that will dictate maximum lift available before anything else is considered.
placing both valve-springs with collars in the vice, wind it up until the spring binds and measure the length of the spring compressed.
here for ease i measure the complete width, then measure collar widths and subtract that to obtain spring-length, yeah.
after subtracting upper collar widths i get spring length of 0.790"
i subtract this from my install-height, leaving 0.745"
this is the maximum travel before spring-bind. i haven't factored in a safety-margin, additional clearance for teh spring at this point.
now, i havent decided on the camshaft, but i have three in the runnings.
the largest lift out o fthe three cams is 0.651", and it's likely the one i'll use.
so 0.745", subtracting my 0.651" leaves 0.094" clearance prior to 'bind.
the general minimal margin is 0.060", so i have clearance to spare, happy with that.
there is a school of thought that too much clearance is not such a good thing, as approaching 'bind' helps dampen the springs and prevents the potential for the spring to surge. But i take this sort of stuff manily relevant to high-rpm operation, race/drag whatever and not stooging around on an antiquated thumper, so i don't consider stuff like that. nearly 0.1" clearance is ok for me.
so my spring is ok at 0.651" lift, what about the collar-to-guide?
i have 0.9" between collar and guide. subtract the intended 0.651" lift, that leaves me 0.249" spare for safety-margin and seal-protrusion.
seals typically come in the OEM steel-clad types or hi-temperature viton variants.
the OEM types i consider to more of a 'wiper' than a seal and they are a lower profile that the viton ones, allowing more lift, but it's kinda marginal.
i took the various seals that i have and measured the overall height of teh seal,
then the internal-depth to guage the protrusion of the seal above the guide.
i found the following
OEM steel clad had a protrusion height of 1.44"
Viton ones varied from 0.149" to 0.209". so the lowest profile viton was only marginally taller than the oem type.
so, taking my 0.249" spare-travel, fitting seals would give me lift-clearance i.r.o 0.04" to 0.105",
with the shallow-viton seals giving 0.1" clearance, optimal is they'll give a proper seal, as opposed to a 'wipe' and have the 0.060" safety-margin with room to spare.
Thing to note here, typically when fitting viton seals, they do not fit 'flush' to the top of the guide. the body bottoms out on the guide-collar and takes up valuable room for lift. In the past, what i have done is simply work out how much to 'trim' off the base and get the dremmel out.
here's one i did for the S&S heads on my 98" some time ago, replacing the fitted oem type for viton types.
ideally, it'd have been a little longer to get maximum body length.
but with my new mill, i'll be able to trim them perfectly this time.
next i check the valve-to-valve clearance and valve-to-piston at TDC.
devon.john
Club Member
Hes going to glue some glass paper on the fly wheel just in case
i will get my coat !!
jayzedkay
Club Member
yes, they will expand. that 0.060" is enough to factor that in and be left with room to clear.
but also the rods will expand and effectively grow taller, raising the piston away from the flywheels.
but also the flywheels will grow too, effectively gaining a larger diameter.
but this clearancing lark factors all that in and 0.060" is considered the 'go to' number for pretty much all safety-margin clearance; pistons. valves etc. do not confuse this safety-clearance with tolerance-clearance, yeah.
Ron
Club Member
Looking at your piston clearance to flywheel pictures, in the last one is a good view of the chamber that the oil "scraped"/flung off the flywheels is collected in. Would taking the oil drain from the rear head to this chamber be a practical way to move the pipe to the rear of the motor and more out of sight?
Clutching at straws time, take the front drain into the front exhaust pushrod tube?
Clutching at straws time, take the front drain into the front exhaust pushrod tube?
jayzedkay
Club Member
during cam-shaft operation, there is a period at TDC that both valves are open.
the inlet having started to open and the exhaust coming to a close.
At this point the valves are closest to each other and we need to check they do not hit.
moving away from TDC, before or after the valves have a greater separation.
camshaft parameters specify how much this lift is, i need to check that the heads can handle it.
here i use some brass-collars that slip over the valve stem and can be nipped tight with a screw.
ideally i'd change those those stainless caps for brass or nylon screws.
but they only need to be nipped by hand and i have ground the ends to a ball so not to damage the stems.
i make sure the valves are closed, i have the head sitting on a ball of taped-up paper in the combustion-chamber to push the valves closed.
then i rais the collars so i have the lift at TDC between the top of the guid and base of collar.
So, when the collars drop and stop at the guide, i am at camshafts specified TDC lift.
lifts in question here are 0.218" on the inlet valve and 0.200" on the exhaust valve.
i them measure to make sure i have the obligatory 0.060" between the valves.
here i have a 1.5mm (0.059") drill bit passing between the valves without any friction.
i'd ordered a descent 32 feeler-blade set and not had it delivered when i took this photo.
i revisited it and it was on the nose at 0.060"
so i consider good with the valve-to-valve clearance.
next i want ot make sure i have enough clearance from the valves being open at these lifts with the piston at TDC.
for this i have the heads setup with my small-springs, as shown earlier.
simply place the head on the cylinder with piston at TDC and push the stem down until piston contact is made and not the lift.
here, as before, front exhaust valve closed, install height.
valve pushed down, to piston contact.
i repeat these measurements, as i do all of them to get some repeatablity and an acceptable result, one off measurements are no good.
anyway, i subtract the 'contact' measurement from the install-height measurement to get the valve-to-piston measurement.
in this case i get...
0.333" for the inlet valve and 0.299 for the exhaust valve.
going back to the cam's TDC lift; 0.218" for the inlet and 0.200" for the exhaust.
i'm left with clearance of 0.115" on the inlet and 0.099" on the exhaust. both in excess of 0.060", so good there.
so at this stage, all looks good with heads/pistons for the camshaft intended.
if i go with one of the other choices, the lift is less, the TDC-lift is less. so all clearances increase. .
the inlet having started to open and the exhaust coming to a close.
At this point the valves are closest to each other and we need to check they do not hit.
moving away from TDC, before or after the valves have a greater separation.
camshaft parameters specify how much this lift is, i need to check that the heads can handle it.
here i use some brass-collars that slip over the valve stem and can be nipped tight with a screw.
ideally i'd change those those stainless caps for brass or nylon screws.
but they only need to be nipped by hand and i have ground the ends to a ball so not to damage the stems.
i make sure the valves are closed, i have the head sitting on a ball of taped-up paper in the combustion-chamber to push the valves closed.
then i rais the collars so i have the lift at TDC between the top of the guid and base of collar.
So, when the collars drop and stop at the guide, i am at camshafts specified TDC lift.
lifts in question here are 0.218" on the inlet valve and 0.200" on the exhaust valve.
i them measure to make sure i have the obligatory 0.060" between the valves.
here i have a 1.5mm (0.059") drill bit passing between the valves without any friction.
i'd ordered a descent 32 feeler-blade set and not had it delivered when i took this photo.
i revisited it and it was on the nose at 0.060"
so i consider good with the valve-to-valve clearance.
next i want ot make sure i have enough clearance from the valves being open at these lifts with the piston at TDC.
for this i have the heads setup with my small-springs, as shown earlier.
simply place the head on the cylinder with piston at TDC and push the stem down until piston contact is made and not the lift.
here, as before, front exhaust valve closed, install height.
valve pushed down, to piston contact.
i repeat these measurements, as i do all of them to get some repeatablity and an acceptable result, one off measurements are no good.
anyway, i subtract the 'contact' measurement from the install-height measurement to get the valve-to-piston measurement.
in this case i get...
0.333" for the inlet valve and 0.299 for the exhaust valve.
going back to the cam's TDC lift; 0.218" for the inlet and 0.200" for the exhaust.
i'm left with clearance of 0.115" on the inlet and 0.099" on the exhaust. both in excess of 0.060", so good there.
so at this stage, all looks good with heads/pistons for the camshaft intended.
if i go with one of the other choices, the lift is less, the TDC-lift is less. so all clearances increase.
.
softail898
Registered User
Very, Very Impressive. 
jayzedkay
Club Member
Ron, i hear ya, but i think going into places like that or the pushrod/pump side of the motor complicates it and can make it more cluttered?
though undecide, they will go into the primary side case, likely either side of the timing hole, or possibly make a passage through to the cylinders, then oil could provide additional cylinder lube, dunno.
that takeouts for the drains on the head come out on the primary side, sort of inline, but underneath the exhaust rocker nut.
this gives an idea. i think hard-lines routed/shaped with some thought and symmetry will look ok?
red-lines would be to like either side of timing hole.
the yellow-line, is where the drain could route into cylinder.
i've not really givcen this any significant thought at this stage.
it'll probably be the last thing before final assembly?