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200tdi dynamic timing advance kit


reb78

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So the thread that @RRC200Tdi started earlier in which I incorrectly interjected an answer got me thinking. 

These dynamic timing advance kits (https://stegs4x4.co.uk/product/dynamic-timing-advance-spacer-kit/) seem, according the dyno outputs on @NRS91 's website, provide a decent increase in power output.

My pump has been overhauled by DieselBob and setup with what he described as a slight advance on the timing so that it is better suited to run SVO.

Will one of these timing advance spacers still be a benefit on my pump? It performs well since the overhaul (did so before) and has had the normal tweaks on the boost pin and slight increase on the pump pressure screw.

I would be keen to hear peoples thoughts.

Edited by reb78
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Haven't got a clue, I put one one mine when I had the pump off to do the shaft seal. Put it all back together and it is more responsive, and also smoother when above 2.5k revs which is nice. But unsure whether the responsiveness and power was due to be having adjusted settings slightly without meaning to, or if it is due to the ring. 

 

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To my eye it seems to be doable in situ, albeit a little cramped. I am planning to do it that way and will let you know how it goes. I'll grease up the parts a little so they hold together when I am fitting back in. Maybe others will chime in before I get a chance to do mine and offer some input if they've succeeded/failed doing it in situ.

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It can be done in situ but people do struggle with one of the bolts and some recommend a hammer and chisel to get it started moving. The bolts are replace with longer ones anyway. I did it on the bench as had my pump off to change a seal. If you have the timing kit with a pulley holder it doesn’t take very long to take the pump off.

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Quick observation on this - the dyno results started from backing off the fuelling, then adding the advance kit and increasing fueling so missing out a vital data point that would show if the advance kit was responsible for any improvement 

On my old Isuzu 2.8 conversion, which aside from more cc's is a very similar engine, the bosch VE pump had a timing advance solenoid built in - so I could flick a switch on the dash for cold starts and get a few degrees advance. Was hoping it would be like a superboost button leaving me pinned to the seat under acceleration, but all it did was change the note of the diesel knock slightly - no noticeable difference in power 

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I think even if it provides no more power, or to put it another way if it extends the torque curve,  or if it widens the usable rev range a little it'll be a useful addition. Particularly when towing I find myself sometimes doing a lot of gearchanging if the slope varies slightly - it would be good to be able to just hang onto a lower gear. People seem to focus on the maxima  - not unreasonably - but the overall shape of the curve is important - as anyone who has driven a very 'cammy' engine will know. I think the 200/300 tdis have the opposite problem, a strong bottom end but it tails off quite rapidly.

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1 hour ago, cackshifter said:

I think even if it provides no more power, or to put it another way if it extends the torque curve,  or if it widens the usable rev range a little it'll be a useful addition. Particularly when towing I find myself sometimes doing a lot of gearchanging if the slope varies slightly - it would be good to be able to just hang onto a lower gear. People seem to focus on the maxima  - not unreasonably - but the overall shape of the curve is important - as anyone who has driven a very 'cammy' engine will know. I think the 200/300 tdis have the opposite problem, a strong bottom end but it tails off quite rapidly.

This is what I am hoping really. I spend a lot of time on the motorway and with the overdrive engaged that sits me at around 2300-2800 rpm but there isn't much happening if you put your foot down then. I don't want pin me back in the seat sort of acceleration but just a bit more response.

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2 hours ago, Eightpot said:

Quick observation on this - the dyno results started from backing off the fuelling, then adding the advance kit and increasing fueling so missing out a vital data point that would show if the advance kit was responsible for any improvement 

On my old Isuzu 2.8 conversion, which aside from more cc's is a very similar engine, the bosch VE pump had a timing advance solenoid built in - so I could flick a switch on the dash for cold starts and get a few degrees advance. Was hoping it would be like a superboost button leaving me pinned to the seat under acceleration, but all it did was change the note of the diesel knock slightly - no noticeable difference in power 

Haha. You are right though - plus that disco was smoky as anything - I am not sure I would put that forward for an MOT without turning it down first! It would have been interesting to see the dyno run with just the timing advance on standard fuelling and then the fuel tweaks

Edited by reb78
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@reb78 what is the situation with your boost pin? How has bob set it do you know? 
I am not advocating swapping the pin for anyone’s super pins at all as sometimes they need more setting up and spacers yadda yadda or sometimes you end up with no power off boost and loads on.

On mine I gave the top torx screw 1 turn clockwise which has given much better pulling away and off boost power. Then turned the factory boost pin so the profile is facing forwards. This made a massive difference and it is so much more drivable. I haven’t played with the max fuel screw as don’t want the smoke. 

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Thanks Jon. I sent the pump to Bob as preventative maintenance really (it was on about 200k miles at this point) and asked him to set it so the performance was similar to when I sent it to him. The boost pin was set with the deepest profile pointing forwards. When it came back, the performance was pretty much identical to when it left me so I confess I haven't opened it up to look at the pin. Its out of warranty now so I could take a look but don't necessarily need to adjust it as I don't want to produce more smoke. I think its at a point where performance is very goos but more fuel will make it smoke. 

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I fitted one of these to my Defender 200tdi at the end of last summer when I did the VNT conversion. The bolts are tight and a bit fiddly but its pretty easy to do in situ.

Make sure the area is nice and clean before you attempt - i used petrol and a tooth brush to get it nice and clean before I broke into the system.

As regards the performance gains - Its difficult for me to measure as I changed a few things at once. - one thing I have noticed is that I get a fairly big puff of smoke when pulling away in 1st - it was never bad before I changed the turbo etc. So I'm actually planning on removing the ring to see what difference it makes to the smoke, general running.

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10 hours ago, Maverik said:

I fitted one of these to my Defender 200tdi at the end of last summer when I did the VNT conversion. The bolts are tight and a bit fiddly but its pretty easy to do in situ.

Make sure the area is nice and clean before you attempt - i used petrol and a tooth brush to get it nice and clean before I broke into the system.

As regards the performance gains - Its difficult for me to measure as I changed a few things at once. - one thing I have noticed is that I get a fairly big puff of smoke when pulling away in 1st - it was never bad before I changed the turbo etc. So I'm actually planning on removing the ring to see what difference it makes to the smoke, general running.

The spacer wont affect how you pull away and the cloud you leave. The spacer only makes a difference about about 2400RPM.

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I just want to toss in my two cents on what my expectations are for the timing advance spacer and shim and mention how I mean to address the fueling curve as it has been mentioned in this thread.

I am installing both the dynamic timing advance spacer/shim and shimming the governor spring. My understanding, and please correct me if I am wrong, is that timing advance will advance and shorten the injection event as RPM increases. This expected to improve combustion (particularly at higher RPM) when the FIP has been tuned to increase fuel. If this holds true, then it should have a positive influence on economy and EGTs, which is my goal for adding this timing spacer and shim. 

I am shimming the governor spring to alter the fueling curve. This will increase the RPM at which fueling begins to decrease. From the factory, the fueling curve is conservative and the governor intervenes at low RPM, in my case around 2400-ish or before. One of the consequences of this, is that when I shift up to the next gear, the RPM inefficiently drops out of the power band. My goal is to have better cruising power and shift the fueling curve to optimize and match the power band. 

To my mind, these are safe and beneficial improvements, further refining an engine that was tuned conservatively to provide reliable performance in a wide range of dynamic conditions without the benefit of electronic sensors and controls, and there is much room for individual optimization. 

When I get a chance to install these components I will provide my subjective impressions.

As always, I acknowledge that I have been on a steep learning curve and may be wrong in my understanding of all matters diesel, and I welcome criticisms, corrections and input 🙂

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2 minutes ago, reb78 said:

Interesting stuff. Can you do a 'how to' with pics when you shim the governor springs? I would be keen to see how to access it all and what you do. 

Absolutely, more than happy to! I am just waiting for the shims to get here 

 

 

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20 hours ago, reb78 said:

Interesting stuff. Can you do a 'how to' with pics when you shim the governor springs? I would be keen to see how to access it all and what you do. 

Without pics.... but basically if you look for the throttle shaft o ring replacement that's dotted around, once you are that far into the pump the governor springs are looking at you. There cage just needs twisting 90 degrees and lifting out.

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Don't think advancing the injection shortens the event, it just brings it forward. From my limited reading, the injection event is shortened by using larger nozzle holes so the same measure of fuel enters the cylinder in a shorter period of time? Guess same applies for increasing the injection pressure? 

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1 hour ago, Eightpot said:

Don't think advancing the injection shortens the event, it just brings it forward. From my limited reading, the injection event is shortened by using larger nozzle holes so the same measure of fuel enters the cylinder in a shorter period of time? Guess same applies for increasing the injection pressure? 

Thank you for correcting me, it is true that the timing advance kit only advances the initiation of the injection event and does not shorten it. It is very important that we all correctly understand how each one of these adjustments influences fueling of these engines. Sorry for the confusion!

Also, it is definitely true that using larger injector orifices will shorten the injection event. This is why I think switching 200Tdi injectors to 300Tdi would be beneficial to a 200Tdi.  

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  • 2 weeks later...
On 2/10/2021 at 10:23 AM, vulcan bomber said:

Without pics.... but basically if you look for the throttle shaft o ring replacement that's dotted around, once you are that far into the pump the governor springs are looking at you. There cage just needs twisting 90 degrees and lifting out.

@simonb has a great post detailing the removal and refit of the throttle housing for replacing the spindle o ring. This is exactly how I added shims to my governor spring. I will add some photos and description in the shimming the governor spring thread.

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I finally installed the dynamic timing advance spacer and spring shim. I started by cleaning around the dynamic advance plate.

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Note the number stamping is oriented upwards, the plate is not symmetrical from top to bottom, there is a relief molded into the top. I decided to do it in situ, but it is not much harder to remove the pump and install the spacer that way. My main reason for installing it in situ, was to not have to hassle with spilling diesel and priming the system. For some reason, the finger lever on my mechanical lift pump does not supply any pressure so priming is a PITA in my case. I need to replace the lift pump ASAP.

 

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The plate is fixed with T30 torx bolts.

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I used this small ratchet to break them loose, then used the torx bit by hand to fully unthread the bolts 

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Here is the plate removed and the supplied shim for the springs. My kit was for a Cummins and the spring shim did not fit the alignment pin in the plate. I measured the shim and it was 2.80 mm. I found some galvanized m8 x 16 x 1.5 mm washers in my collection which fit perfectly. The measured thickness of two washers was 2.90 mm, which is .1 mm thicker than the shim, but as I do not currently have a bench vise, using the galvanized washers was the easier choice. Furthermore, I am not convinced that the shim that came with the kit is even the correct thickness for the land rover engine, and unlike the machined shim that @NRS91 sells with his kit, this 'shim' looks like an ordinary 1/4" washer. The thickness of the timing spacer is roughly 5 mm (I neglected to measure it before installation), so as it sits right now I am getting a total decrease of around 2.2 mm in spring preload. I am planning to order some shims and fine tuning the thickness over time as R&R is super easy in my 200Tdi. 

There are factory shims already installed, so I removed the small ones to install the aftermarket shim.

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There are two sizes of shims in my FIP that correspond to the two springs. The inner spring has additional shimming, so installing the aftermarket shim before the small shims ensures that the the relative difference in preload between the two spring is maintained. I installed them in the above order (1-4). 

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I  coated the new o-rings with some grease to lubricate and hold them in place during assembly.

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Installed the o-ring into the dynamic timing advance spacer

 

 

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assembled with the springs (don't worry I wiped down the parts before installation 🙂)

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I then loosely assembled the parts back on the FIP.

 

 

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I used a 5 mm hex bit to thread the bolts finger tight, then used a hex key torque them down. Since these are sealed with o-rings I only used enough torque to ensure that the bolts would not back out, I would estimate around 5 -10 nm. So far, no leaks 🤞.

In total, removal and reinstallation took less than 20 minutes, excluding the time spent finding the correct washers I used for shims. At least in a 200TDi without air conditioning, in situ installation is simple and fast. If you have a timing tool kit it'll take a little longer, but will be less fiddly, and it would give you an opportunity to check and reset your static timing 🙂

Before I installed the dynamic timing advance kit, I had installed a shim in my governor spring. This adjustment raised the RPM at which the FIP governor begins to intervene, the result of which is a different fueling curve and higher EGTs. The improvement in driveability and performance is significant, however. When I installed the dynamic timing advance kit, EGTs decreased considerably, though not quite to where it needs to be. I will be refining fueling to resolve this, but it is pretty close and totally driveable as it is. I was really surprised with how much the dynamic timing advance kit reduced the over-fueling issue without any other adjustments.  

With all of the adjustments I have made, the 200Tdi now has good power from idle to beyond 3400 RPM (I don't know how far as I shift at 3400 or less) and stays in the engine's power band while shifting under hard acceleration--an absolute revelation. Shimming the governor spring was a brilliant improvement, but increasing the dynamic advance increases efficiency, which mitigates the rise in EGTs. In my opinion, these two modifications are complimentary and are marvelous.  I can't say that I detected any seat-of-the-pants performance improvement with the installation of the dynamic timing advance kit alone, but i provides additional room for increasing fueling under boost conditions. I suspect if your FIP is factory tuned this modification may not enhance performance.

For additional context, my 1989 Range Rover has 265/75r16 BFG Km2s on tornado wheels. I can't remember how much each wheel/tire weigh, but I think it is above 70lbs multiplied by 5. I have a HEAVY homemade winch bumper (fully boxed 1/4 steel--comical overkill) and I habitually carry a steel land anchor in the factory spare tire well as well as some recovery gear. I don't remember exactly how the vehicle was equipped at the time , but it weighed in at ~5400 lbs with the aluminum 3.9. My static advance is set to 1.60 mm of lift at TDC and I have a higher spec 'Race' turbo CHRA with a billet compressor wheel with boost limited at 18 PSI. I am using an aftermarket boost pin, which increases the rate of fueling as boost increases and, importantly, the relative difference between off-boost and max-boost fueling (which I think is a bit of a trade off unless you choose to live with smoke under max boost).

 

 

 

 

 

Edited by RRC200Tdi
pictures not posted
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