A2 Sport TDI 90 Engine Refresh (SMF)

nick4tl

Member
Hi,
I tried to find this reference again but Im afraid had no luck. Somewhere on one of the remapping forums someone had remapped a 3 cylinder and used a flywheel for a 4 cyclinder. I think because they needed an uprated clutch setup. It worked for a time but then destroyed something. I think the crankshaft or crankshaft bearings or balance shaft gave up.

Theres a discussion on balancing a flywheel using a tire balancing machine to measure the imbalance on the original and then drilling out material on the new to match the imbalance, here https://forums.tdiclub.com/index.php?threads/1-4-tdi-tuning-info.217983/page-10

These guys are running silly horsepower but

N
 

depronman

Member
I am also like Spike very surprised that the engine is not shaking itself to death
The removal of the dmf is not the issue it replacing it with a flywheel for a 4 cylinder engine that is the issue

The fact that you can feel a difference in vibration from before you did the change suggest to me that something is not right
I get the engine mounts are worn but they where equally worn before and the vibration was not present
I fear as does Spoke that there will be longer term problems ahead. I hope I am wrong but I just can’t get my head around why vag would have a different part number for the flywheel on the 3 and 4 cylinder engines which other than the lack of cylinder is the same engine
We all know what vag are like for using parts from the existing parts bins so a different flywheel for the 3 pot engines must mean that there is some difference
Looking at the two there is a scallop of metal removed On The 3pot flywheel, this wasn’t don’t to make it look nice !!!

I hope I’m wrong and you report back with 100k miles on the new setup and no issues but I fear not

Paul


Sent from my iPhone using Tapatalk
 

Joycey

Member
Few hundred miles in and all is well. We all need to bare in mind this is an engine very nearing 200k so any failures could well and truly be accelerated. The biggest change I keep forgetting is how light the clutch is, surprises me every time.
 

Menno

A2OC Donor
Hi,
I tried to find this reference again but Im afraid had no luck. Somewhere on one of the remapping forums someone had remapped a 3 cylinder and used a flywheel for a 4 cyclinder. I think because they needed an uprated clutch setup. It worked for a time but then destroyed something. I think the crankshaft or crankshaft bearings or balance shaft gave up.

Theres a discussion on balancing a flywheel using a tire balancing machine to measure the imbalance on the original and then drilling out material on the new to match the imbalance, here https://forums.tdiclub.com/index.php?threads/1-4-tdi-tuning-info.217983/page-10

These guys are running silly horsepower but

N

Just a thought; in theory, should it be possible to balance a 1.9tdi flywheel to the same spec as 3 pot flywheel using a bubble balancer?
Or would this type of balancing to coarse for use on flywheels due to the high(ish) rpms?


@Joycey , how is the set up holding, still got your teeth? 😁
 
Part of the discussion I can't follow. From the looks of inlet piping I gather this not a ATL 90bhp but a AMF remapped to 90 bhp. So it is supposed to have a SMF, as it is factory fitted with one.
The discussion about putting a 4-cyl SMF on our 3 pot AMF engine is interesting though. If there are no inconvenient or disturbing vibrations there is potential for other owners at a reasonable price.
 

Weetank2

Member
Part of the discussion I can't follow. From the looks of inlet piping I gather this not a ATL 90bhp but a AMF remapped to 90 bhp. So it is supposed to have a SMF, as it is factory fitted with one.
The discussion about putting a 4-cyl SMF on our 3 pot AMF engine is interesting though. If there are no inconvenient or disturbing vibrations there is potential for other owners at a reasonable price.
Post 36 pics show an ATL downpipe
The Tdi engines do look similar to each other
 

Menno

A2OC Donor
Our 3 cyl tdi engines uses a unique flywheel design where a fair chunk of metal is scalloped from the rim on the back face of the flywheel. This is to compensate for the small bobweights on the crankshaft.
Running a conventional flywheel will certainly increase engine vibration so it's worth checking the kit has a scalloped flywheel. Most don't although they claim to be compatible.

Cheers Spike

As I'm in the market for a new clutch for an ATL and would like to make it SMF too I've ordered an AMF flywheel.
Still, I would like the 1.9tdi/G60 flywheel, because it's bigger in diameter and could handle more torque for future projects. It will be connected to a PTW 6 speed gearbox, which is also more sturdy to handle more torque then standard (In the range of 250nm max. standard A2 tdi gearbox).

Now, this scalloped piece on the AMF flywheel supposed to be there for balancing purposes....... But is that a fact? It needs to be there also to get to the bolts of the sump when the gearbox is in situ (for example;get to the oil chain thingy).
If it would be scalloped for balancing reason, why didn't the engineers just drilled a couple of holes, removing weight as it normally would when balancing?
Just some thoughts and questions......

Edit,
Here a picture of a 1.4tdi with scalloped section....... And drilled holes! They're there to make up/balance for weight loss at the scalloped side?

Screenshot_20210224_082442_com.android.chrome.jpg
 
Last edited:

spike

Member
Old link to Audi document explaining the need for the flywheel scallop

Cheers Spike
 

Menno

A2OC Donor
Old link to Audi document explaining the need for the flywheel scallop

Cheers Spike

Perfect! It seems that weight is not "cut out"
But added to the flywheel. @spike ,thanx for the link, especially for the drawing/explanation picture, could you reveal the source?
 

Menno

A2OC Donor
The drill dimples are fine balancing to achieve the correct (im)balance for the triple throw crankshaft.

Agree, but for a 3 pot in general? I'm asking because you see 3 pot flywheels with drilled balancing holes and without them.
 

spike

Member
See SSP 223 in this link - https://www.a2oc.net/community/inde...ther-self-study-course-link.13809/post-311785

Agree the weight shown in yellow on the diagm in post 53 is added to both the flywheel rim and front torsional vibration damper. We just got used to referring to the cut-out or scallop in the rim because it was easier.

Also agree with VAG fool, the drillings in some flywheels are just to compensate for the production tolerances in the flywheel casting

Cheers Spike
 

Joycey

Member
She's still going strong thanks guys, reminds me of the old diesels in the 90s that used to shake alot. Done a few thousand miles now, in hindsight I would fit the flywheel from the AMF as it's heavier just like the one I took off this engine I didn't have any vibration with that unit.
 
Top