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#75
by
carrizog60
on 29 Dec, 2011 02:57
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regarding the cold start lever side of the piston the spot were the lever touches is deeper than the piston top(were it hits the cover) so maybe a little trimming could be possible.
dont know what would it do with static timing settings...
edit:see posts below,trimming is not an option as said before by dieselstink.
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#76
by
Alleslowbuged
on 29 Dec, 2011 03:27
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Hi,
first of all, thanks for your pic with the flywheel governor, this looks really tight, so i think i have to reopen
my pump to check if i have i can have a collision there.
As long as you stay with the stock camplate, the adjustment value for static timing stays constant, so
you can shorten the advanced timing piston at the cold lever side and still use the stock adjustment value
for the static timing.
The adjustment value in [mm] (or inch) is an equivalent to a specified rotating angle of the pump before
TDC. At least, the real parameter (which is adjusted) is the time in sec. between start of fueling and
TDC, which must correlate with the speed of sound (of the fuel) and the length of the injections pipes.
As the length of the injections pipes and the speed of sound stays constant, also the time between
start of fueling and TDC has to stay constant and the rotating angle has to stay constant. If you change
the camplate to another type with a different helix angle, you have to find the plunger stroke in [mm], whichs
results at the equivalent rotating angle of the stock camplate with the stock adjustment value.
I have take a look in my old measurements and find that my VP cover cap "only" allows 4 mm more stroke,
as i understood your post, you cap would give 8 mm more stroke (if the cap would be the only restrain)?
Best Regards
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#77
by
carrizog60
on 29 Dec, 2011 03:54
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you are right,the maximum allowed by the cover is +-4mm as the piston wont enter the cap hole at the bottom,just the spring.
the stock cap dont have this recess so we have more 4mm of travel than stock.
since piston hits the wall before reached those 4mm protusion i need a limiting bolt that can give me that 1mm(or a bit more just to be safe).
2.5mm over stock would be a good increase right?
next is a pic of the piston before hittinh the pump wall,but on the cold start lever side.
as we can see the only way to allow the movement would be to get a spacer as the lever hits the piston inside before the edges hit the cover.
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#78
by
carrizog60
on 29 Dec, 2011 03:59
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new measurements:
piston hole(for spring) is 20,26mm
VP cover hole is 16,08mm
if the spring lenght fully compressed is 17mm than (assuming that the pump can generate force to compress the spring) the spring is for sure not the limiting factor as fully compressed she can be inside the piston without protusion.
maybe with VP spring that wouldnt be the case but the advance would work slower due to higher tensile strenght from the spring.
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#79
by
carrizog60
on 29 Dec, 2011 04:35
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alles,did you tried the 1.6 spring?
my plans were using one but i am concerned about it being loose when advance is low...
i could add a fair amount of schims but that would also affect the tension so using that or the vp spring maybe be ending the same thing...
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#80
by
carrizog60
on 29 Dec, 2011 12:02
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it looks to me that the piston edges dont touch the cap of cold start side.
the lever pushes the piston not by a straight motion but using a ramp like rod.pulling the lever it rotates and pushes the piston by forcing a pin to go up on that ramp.
i am hopping that alles can give me a number of degrees and rpm that can be achieved just by adding the cap and vp spring.(more 3mm from stock)
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#81
by
Alleslowbuged
on 29 Dec, 2011 13:44
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Hi,
@Dieselstink
You are right (for sure), the pump must re-timed after changing the static position. I have tought about writing that, but thought it would be clear.
As mentioned i have changed the static position 3 mm (to the cold lever side) and can assure that still the same timming belt position can be used.
As been written here serveral times, there are many versions of timing pistons. The one in my pump and also in another pump, which i have build for
a friend (Jetta II with a 1.6 TD) and the pistons in my BMW pumps all stops at the end cap on the cold lever side. By shorten the piston approximate
1 mm could be gained, i my pump built i have grinded the lever and also eliminate the thrust bearing, which brings another 2 mm.
@carrizog60
Thanks for your pics, i like pics and measurements in threads like this.
Just as rough numbers, in my pump i would have need 11,4 mm shims with the 1.6 spring, which would allow 12 mm stroke due to the spring. But
i would not wand to have the spring nearly to solid length, so i would say, stroke should be limited to max of 10,5 mm due to the spring.
Just for mention it, the VP37 (i have used) comes with 11,4 mm stroke as stock.
In my mind 3mm more would help a lot, and would be good enough. I assume that your pump has have stock ~ 9 mm and not ~7 mm as the older
ones.
Best Regards
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#82
by
Alleslowbuged
on 29 Dec, 2011 13:46
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...
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#83
by
Alleslowbuged
on 29 Dec, 2011 13:46
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....
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#84
by
Alleslowbuged
on 29 Dec, 2011 13:47
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...
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#85
by
carrizog60
on 30 Dec, 2011 04:31
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my pump has a 9mm head but now its 11mm.
since its a 1.9 with a tdi gearbox and bolted to a passat 35i i dont plan to rev it past 5000,maybe once or twice but i like to know that if i rev it beyonde that its still working hard.
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#86
by
Alleslowbuged
on 30 Dec, 2011 05:13
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Hi,
what i meaned was the stock stroke of the advanced timing piston, not the diameter of the high pressure plunger.
I have take a look in my old measurements and find out, that a pump for a friend (a very old one with the smaller
LDA pin) has hat only ~7 mm stroke instead of ~9 mm.
Best Regards
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#87
by
Alleslowbuged
on 30 Dec, 2011 11:01
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Hi again,
so can we agree on that point, a 2 mm or 3 mm spacer (no need to work on the casing slot) would be the finest and best solution.
Than take a VP cover cap plus the VP spring and my "limit pin" and you would have enough stroke for all idi engines and could
make the mod without open the pump.
Best Regards
Alleslowbuged
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#88
by
carrizog60
on 30 Dec, 2011 12:57
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its the safest way at least.
i am going just with the vp cover and spring,sure it can provide advance till 5500 or near right?
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#89
by
Alleslowbuged
on 31 Dec, 2011 03:57
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Hi,
yes that would be the ultimate tuning set for advanced timing.
A spacer for the cold start lever side (2 mm) and a new cap for the spring side, which gives another 2 mm stroke and also compensates the
changed static position for the spring, so that you came out with the same pre-stress as before.
I have an excel spreadsheet with my measurements and will put that figures together and make a screen shot for here, to find out if this
would work plug and play and what would are the final numbers. If i find time pherhaps i can make a 3D Modell and ask a machine shop what
would be the manufacturing costs. The bigest challenge would be the sealing of the spacer, because it is not thick enough to just take a second
o-ring.
Best Regards