"Bentley" Pump Timing Spec. N/A's 1.15mm..... Questions???

[Greenthings]

Anybody know why the "Bentley" Rabbit Diesel (77-80) has such "HIGH" timing #'s for the 1980 and later  1.6 N/A engines. It says 1.15mm for 80 and later.  83mm for 77-79 moters. I thought this would be a " Very High advance even for the Turbo motors (1.05) suggested timing. Most post I see have peolpe setting there N/A's from the mid 80's mm to 1.0mm. Why is there such big jump in the Gap? I've been trying to get my timing right on my N/A that's running with a Turbo pump. Injectors are N/A 135 psi. Should I be advance beyond the 1.15 (N/A) with the higher Turbo Injector pump pressure on the N/A injectors. Still getting alot of white smoke, heavy fuel smell at start-up. Last for atleast 10 minutes with studder and slight surges or so at idle. Runs fine when warm with a very light white puff when punching it. I'm at 1.05mm now. Was at .98mm N/A performance spec. in Bentley (Vanagon) with smoke. I realize that I could have some worn injectors at 65k but I would like to settle this(official) timing dispute before pulling them. 

[Greenthings]

Wanted to add that this smoke was there before my Timing belt slip mishap. No issues since the re-set.  Car runs good after warm-up. {Anybody} understand the reason for different timing #'s in different Bentleys?

[theman53]

If I remember they had different injector opening pressures. That changes when things open and is why they had different timing #s.

[Greenthings]

All VW diesel (1.6 N/A) injectors open at 135psi and All 1.6 Turbo injectors open at 155psi....Right? Anybody run there N/A at 1.15mm?

[rabbitman]

All VW diesel (1.6 N/A) injectors open at 135psi and All 1.6 Turbo injectors open at 155psi....Right? Anybody run there N/A at 1.15mm?

Actually it's in bar not psi, one bar = 14.5psi. I'm about positive that my rabbit's injectors are 125bar, newer (mk2) I think went up to 135bar and yes turbo ones are 155 unless they've been tampered with.

[theman53]

But I am pretty sure the 1.5 had some different pump settings. Just from what I read in some of saurkrat's threads. I have never had a 1.5 or real early 1.6 so I don't know for sure.

[wolf_walker]

All VW diesel (1.6 N/A) injectors open at 135psi and All 1.6 Turbo injectors open at 155psi....Right? Anybody run there N/A at 1.15mm?

Wouldn't bet my life on that, Bosch has several different part numbers for what popular wisdom says should be the same injectors.
And nobody, including Bosch tech support, has been able to definitively explain it.  I ran late NA injectors on an early pump and things
were funky, early "correct" part number rebuilds from big B fixed the funkyness.  Who knows.. 

That being said, aren't the high pump setting for the "yellow dot" pumps?  Who knows at this late date what they were doing, or trying to do, with timing curves and advance rates.  They seem to have backed off static timing over the years, but they still listed a "performance setting" that was a fair bit higher than the "stock" setting.  I think it's all about half out the window on an old pump myself.  Line the marks up and then move it till it runs right.  This being a variation on one of my aged and wise Father's favorite pieces of advice, being "tighten it till it smokes and then back off a quarter turn". 

[rabbitman]

The "yellow dot" pump probably has weirdly calibrated internals making the timing odd ball, it would be neat to find one and tear it apart and compare pump guts.

[wolf_walker]

Yeah, it's a damn shame we are so in-frequently privy to engineering goings-on with cars.

[Rabbit on Roids]

1.5's came with 175 or 180 bar injectors. (i think) and they only came until 1980. thats the reason for the high timing spec.

[Greenthings]

O.K.    Good timing on the 1.5 pump timing thing. I just recieved a Bosche VE 1.5 Pump from an e-Bay auction. Was re-built at some point, but a shop "shelf" sitter also. For $13 and $10 postage I could'nt leave it there.  Probally leaks more than I pee, but just for the " heck of it", I'm going to install it on my 1.6 n/a with 135 bar injectors, after I let it sit a week or so filled with ATF. I'll start at 1.0 mm go up from there. Main reason for buying the pump is to make it a "home-made" injector tester. Neat video on YouTube of "Bubba" technology VE Pump injector spray tester. Seems like a pressure gauge could be installed between the pump and injector to get some readings. I'd also bolt-through the pump sprocket holes with wide washers and long lug handle instead of a permanent weld on. I know it's a little "hokey" but it should show common or inconsistencies in spray patterns of a group of injectors. later