Early 1.9 to 2.1 conversion - stop me if I'm being stupid!

[rony4ws]

Hi everybody . Sorry for my english , i m french..
Firstly , many thanks for all your test on DJ pierburg carb !
I have reed all your conclusion but i have questions.
You change the original jet by a 121 size, it s the primary jet ? You don't change the secondary jet ?

Actually i have a full stock DJ with DG pierburg 2e3 and DG distributor.
Many thanks .

[kevtherev]

bonjour mon ami mon nom est Kevin De la messagerie facebook. c'est l'endroit correct à demander.

Your questions will be answered here.

[CJH]

Hi everybody . Sorry for my english , i m french..
Firstly , many thanks for all your test on DJ pierburg carb !
I have reed all your conclusion but i have questions.
You change the original jet by a 121 size, it s the primary jet ? You don't change the secondary jet ?

Actually i have a full stock DJ with DG pierburg 2e3 and DG distributor.
Many thanks .

In fact it is only the secondary jet that was changed. I think this is because the dyno is measuring performance with a wide open throttle, which means that the secondary throttle will be open throughout. I guess there's no point in increasing the primary jet size because if you want more power when the secondary throttle is closed then you just have to press the pedal further!

[itchyfeet]

I have posted this on the WBX group on FB

It would be interesting to hear from people in that group who've dyno'd T25s and have any information on the size of the transmission losses.

Screenshot_2017-11-06-08-35-21 by Paul_Barr, on Flickr

Screenshot_2017-11-06-08-42-13 by Paul_Barr, on Flickr

[CJH]

Thanks Paul - encouraging to read that the atomisation theory wasn't shot down. And drive train losses, and hence flywheel power, aren't accurate - pretty much what I'd understood.

[itchyfeet]

Screenshot_2017-11-06-12-24-48 by Paul_Barr, on Flickr

[CJH]

Presumably that's a nice modern high pressure, multi-hole injection system, so a worthwhile upgrade even without the turbo kit. I wonder what the turbo kit will add to the cost.

Bookmarked for when my numbers come up.

[itchyfeet]

Presumably that's a nice modern high pressure, multi-hole injection system, so a worthwhile upgrade even without the turbo kit. I wonder what the turbo kit will add to the cost.

Bookmarked for when my numbers come up.

Need an MV for the turbo kit I think.
I think the turbo kit is going to be 80% so a stock MV is 95 so up to 170BHP

[R0B]

OOHHH I want a turbo injected engine.

[what2do]

OOHHH I want a turbo injected engine.

Only available to subscribers of Facebook!

[what2do]

Come on Chris join up, you can set your preferances to have no friends and don't write anything on your profile page, then just chat in groups just like on here.

Oh, how the tables have turned Paul. How long did it take me to convince you to see the light?

[itchyfeet]

Come on Chris join up, you can set your preferances to have no friends and don't write anything on your profile page, then just chat in groups just like on here.

Oh, how the tables have turned Paul. How long did it take me to convince you to see the light?

I'm just making your medal now

[CJH]

I've bought an 'N' suffix distributor, from a helpful member on here. Any idea what the shroud around the cap is? Is it some sort if interference suppressor? I'll be using my own (newer) interference suppressing cap anyway, but I've not seen this type before.



I stripped it down, bathed it in paraffin, scrubbed it clean, lubricated it and reassembled it with a new vacuum can and a new seal (I feel like I've written this before...). Since I don't need the vacuum retard function I replaced the old dual-vac unit with an advance-only unit.

I've done a few of these now. The internals seem to differ by the spring arrangement inside and maybe the plastic tips on the weights which limit the maximum advance. This 'N' suffix model has two internal springs of different strength. I removed the springs and the central column (held in place by a screw under the felt pad at the top) so that I could clean the weights and the pivot points better. For reassembly, the the column is symmetrical so could end up 180 degrees out, which would mean the rotor arm points at the wrong plug lead, so I took photos during disassembly to make sure it went back together properly. Good job I did, because the paraffin wash removed the white marker paint completely. You can just about make out a stamped '1' on the base of the central column and a corresponding '1' (inverted) on the baseplate next to the adjacent weight.



The body polished up quite nicely with a brass wire brush attachment in my Dremel.





When I fit it, I'll first need to check the timing on the one that's in the engine now (Itchyfeet's 'N' suffix unit), because this was set at the rolling road. They set it by taking the engine up to fairly high revs. They do this mostly because they're more interested in the maximum advance, but also the timing mark is more stable. So the resulting idle timing may not correspond to any of the published figures. I'll try to measure the idle timing and also the advance at higher speeds, so that I can set my 'new' one up to match.

[CJH]

When I fit it, I'll first need to check the timing on the one that's in the engine now (Itchyfeet's 'N' suffix unit), because this was set at the rolling road. They set it by taking the engine up to fairly high revs. They do this mostly because they're more interested in the maximum advance, but also the timing mark is more stable. So the resulting idle timing may not correspond to any of the published figures. I'll try to measure the idle timing and also the advance at higher speeds, so that I can set my 'new' one up to match.

It was set to 8 degrees BTDC at idle (~750rpm), which resulted in about 27-28 degrees maximum advance. I didn't measure the rpm at which it reached that maximum, but it was above that point by around 2700rpm, which is where I measured it. I've set the new one up to match. I may do a complete trace of the advance curve when I've got more time, but on the road it feels fine.

[CJH]

Something tencentlife said that atuck in my memory...its on this thread

never really understood why as I thought new were flat, I will ask on the fb wbx group

https://club8090.co.uk/forum/viewtopic.php?f=37&t=156409" onclick="window.open(this.href);return false;

You'll need new lifters too, of course, or have yours reground if they were working well, they'll ned to be claeaned and prefilled afterward but that should be done in any event, even with new ones. Regrinding lifters is fine, any decent machine shop can do it, there's no magic VW spell to recite.

Lifter faces can be reground very easily, to a domed profile. Here a machinist will charge $3 apiece.

In my quest for some tappets that don't de-pressurise as quickly as the new KS ones I'm currently running, I've considered buying some secondhand ones and having them refaced (flat). I remembered the above post so thought it would be fine to reface them. But the place I usually go for machining work said not to do it, because the machining will go through the hardness. So who's right - how much can be taken off safely?