My "Stroker" project

[Pisobiker]

I'm finally ready to report my FIRST STAGE STROKER PROJECT.
First stage becase for the moment I will be running the already existing RS2 turbo, intake, exhaust and ECU management system.
This report is not meant to say I did the perfect job and anything different isn't right. It just tells my way of managing it and related problems that arose while collecting, prepearing and fitting the parts.

[Pisobiker]

CHAPTER 1: PLANNING

Following is the list of my starting standopints:

a) Engine mostly for road use;
b) Use of pump fuel, therefore max 98 RON;
c) Power level in the range of 480-500 crank Hp;
d) Strong low rpm pull, and quick throttle responce;
e) Lowest possible boost treshold.
f) Use of the ADU aux systems, ECU and 1 coil per cylinder ignition.

To combine together all these features it appeard to me best choice being increasing displacement, which could go either by increasing bore or stroke (or both).
The research over this subject lead to the decision it wasn't safe to go much over the 81.5mm bore at high boost applications, unless the use of some tricky metal headgasket which I didn't want to use. This left the stroke increase solution which was offering the 95.5mm stroke crank+block coming from Audi's Tdi engines with a total dispalcement of very close to 2.5L.

Planning ended up with the following key features:

1.1) AEL/AAT tall block+cranckshaft, featuring pistons oil squirts and needing only a few modifications to make it perfectly compatible with the 20V turbo head and aux systems;
1.2) Custom longer conrods able to withstand up to 800 Nm max torque;
1.3) Custom specs forged pistons providing 8.6-8.7:1 CR and good for up to 700 Hp;
1.4) Optimization of head ports, valves and combustion chambers;
1.5) Single mass flywheel (dual mass is sayed to be too weak for big Nm applications);
1.6) Sintered metal clutch good for at least 700 Nm;
1.7) Crankshaft balancing;
1.8) Big front mount IC;
1.9) Custom front mount TB IM;
1.10) Catch tank;
1.11) Custom made tubular exhaust manifold;
1.12) Ball bearing turbocharger;
1.13) Custom 3.5" turbo back exhaust system with racing cat converter, muffled to a resonable loudness level;
1.14) Uprated fuel system (injectors, lines, pump);
1.15) Uprated oil cooling system (bigger or additional oil cooler);
1.16) Uprated MAF;
1.17) Uprated engine management.

Eventual other issues, like cam timing and lift or water cooling system, would have been taken into consideration once project was finished and tested.

[Pisobiker]

So my project was thrown into next step:

CHAPTER 2: FINANCIAL ESTIMATE

This is one of the most important steps of the whole project. Most precise and complete estimate as possible will avoid beginning a project that might cost well beyond what firstly planned.
Prices showed are approx what I've payed for the parts, and of course will vary with different brands, material or supplyer. Where price isn't showed is where I did the job myself or already had the part:

2.1) Block: 300 Euros (used block from scrapeyard);
2.2) Conrods: 800 Euros (Pauter 4340 Chrome-Moly Rods);
2.3) Pistons: 950 Euros (JE forged, moly + ceramic coating);
2.4) Head work: ---- ;
2.5) Single mass flywheel: ---- (used a MN flywheel I already had, modded to suit my needs);
2.6) Clutch (pressure plate+sintered metal disk): 600 Euros (Sachs racing);
2.7) Crankshaft balancing: ---- ( will pay something for the use of the machinery. Don't know how much jet);
2.8) Intercooler: 350 Euros (600x300x76mm core, bar and plate);
2.9) Silicone hoses and plumbing for IC+IM: 400 Euros;
2.10) Custom IM: ---- (will try to make my own ASAP);
2.11) Catch tank: ---- (making my own custom one, using an AC dryer/separator);
2.12) Custom EM: ---- (will try to make my own ASAP);
2.13) Turbocharger: 1200 Euros (GT30R);
2.14) Custom exhaust system: ---- (will try to make my own ASAP);
2.15) Uprated fuel system: 1000 Euros;
2.16) Uprated oil cooling system: ---- (have an additional cooler out of a Lancia Delta, if needed. Modding OEM system myself);
2.17) Uprated MAF: ---- (trying to make my high flow MAF);
2.18) Cone air filter with induction optimization: 200 euros;
2.19) Uprated engine management: 600 euros;
2.20) Complete head+block gaskets, seals, studs, bearings, cambelt+tensioner: 800 Euros;
2.21) Machine shop: 300 Euros (I did most of the work myself.....).
2.22) Engine assembly: ----.


So far, whitout eventual other upgrades (like camshafts, adjustable cam gears and whatever else needed) total is 7500 euros + all of the parts and labour I didn't monetize.

This kind of work is meant to have a potential of pushing the engine up to 700 Hp and 800Nm, maybe more, no matter if I actually will ever go so high or stay to a milder and porbably better streetable 500 Hp setup.
At this point it is only a matter of choices, being the difference with going with an higher output only a matter of bigger turbocharger, bigger and different exhaust layout, injectors, engine management and maybe bigger IC, as well as wilder head porting and cams; all this probably costing only a few hundred Euros more.
Going higher with torque and power will of course drive attention to some other aspects which might become weak points, such as cooling system, gearbox and drivetrain strenght, chassis..... etc.

[Pisobiker]

Lets now go more in depth in the project:

CHAPTER 3: CILINDER BLOCK and CRANKSHAFT

3.1 Selection of a suitable item:
The selection of a scrapeyard block is a critical aspect, since you won't be able to say if it will be good until you disassemble it and take micrometrical measurements on journals and main caps. In my case the block (AAT) came off a car who broke the cambelt bending some valves. before buying it, I took the head off and checked the cylinders where fine. Pistons where as well with only a few small marks of contakt with the valves, so I had good chances block and crankshaft where fine.
Once checked at the machine shop both crank and main caps showed some sign of wear, but still whitin tolerances.

3.2 Block work and modifications:
The AAT block (which AFAIK is identical to the AEL one) differs form the 2.226L gasoline unit for the following aspects:
3.2.1) water line from flywheel side (#1 on picure) which comes plugged in the casting, therefore needs to be opened to accomodate the plug, together with the threaded hole for holding the plug in place.

3.2.2) cranckshaft position pickup bracket is different (only one plug, #2 on picture) but the casting is the same as the gasoline unit, therefore accomodating in the same place the two pickups with theyr bracket whitout mods.

[Pisobiker]

3.2.3) deck has an additional oil return hole in the flywheel side (#3 on picutre) which needs to be plugged (I'm using a water plug for this).

3.2.4) deck doesn't have enough material next to a oil return passage for the 20V turbo headgasket to seal it (#4 on picture, already fixed). Weld some material before skimming the deck, using the 20V turbo headgasket as a template.

3.2.5) Block doesn;t have the crankshaft vent plug, therefore the plug (#5 on picture) needs to be replaced with the right one.

[Pisobiker]

3.2.6) Block doesn't have the turbocharger water return line, so the plug in the middle (#6 on picture) needs to be replaced with one having the tip.

[Pisobiker]

3.2.7) Deck is of course higher. Should be around 16mm higher, but I didn't measure it and didn't care, because made my measurements for conrods and pistons using other parameters.
3.2.8) TDi uses M12 x 1.75 head studs vs. M11 x1.5 of the 20V turbo engines.

Everything else seems so far perfectly suitable with the 20V turbo aux systems.

The cranckshaft has same main journal and big end journals as the 20V turbo one (of course is 95.5mm stroke vs. 86.4) beign perfectly compatible with ADU big end and main bearings.
Belt pulley and cambelt gear are different, but crankshaft is not, so no problem in using 20V turbo stuff.
Flywheel mounting is the same as well.
I didn't plan lightening the crankshaft, not having the purpose of building a racing engine. A nice balancing with flywheel, pulley and bobweights (after having computed bobweights mass) is a must, anyway.
Will cover this aspect later on.

[Pisobiker]

CHAPTER 4: PISTONS AND CONRODS

My calculations over CRs produced the following results:

1) pistons needed to have 11cc more dish volume on top;
2) conrods needed to be 155.8mm center to center long.

So the parts where ordered accordingly. I choose JE Pistons and Pauter conrods.

[Pisobiker]

Conrods are not rifle drilled and have an oil pickup hole on top of small end for wrist pin lubrication.
Pistons have moly coating on skirt and ceramic coating on top.

Had some misunderstanding with the pistons supplyer when giving my specs: my +11cc dishhaving been understood as total of 11cc negative volume. Had to have new ones made. So make sure manufacturer has exactly understood what you want.
I also didn't like the finish of the outer edge of intake valves recess, very sharp, so, after someone on the forum has experienced problems with melted edges, I decided to cut them off:

[Pisobiker]

CHAPTER 5: HEAD


Plan was to have all the sharp edges removed, the ports radiussed and perfectly matched with the gaskets and manifolds.
Combustion chamber and exhaust ports finish at a mirror finish (the best I could) and the intake ports at a rougher finish

[Pisobiker]

....

[Pisobiker]

Head was then skimmed 0.02mm to clean and flatten mounting surface up.

Seats have been reworked, valves received a three angle job, guides remained standard.

Studs holes have been enlarged to 12.5mm to accomodate TDi specs head studs.
For this purpose I've used M12 x1.75 studs of the A2 1.4 TDi (AMF) engine, cut back 20mm.

[Pisobiker]

CHAPTER 6: FLYWHEEL, CLUTCH AND PRESSURE PLATE

Since I planned the engine should have run 700 Nm (and over, if possible), I needed to go for a single mass flywheel. didn't have a 3B one handy, so decided to use the NM one modded to exact specs as 20V turbo engine as for TDC pickup point. While there I also slightly lightened it. At the end flywheel+3B specs pressure plate where around 3Kg lighter than OEM dual mass+pressure plate assembly.

I decided to go for a SACHS racing sintered metal clutch and uprated presure plate which should be rated at some 120-150 Nm more than OEM assembly.

[Pisobiker]

CHAPTER 7: CRANKSHAFT BALANCING

Couldn't find any machineshop with the knowhow and experience on balancing the IL5 crankshafts in the neighbours, so decided to do it myself. After having computed bobwight mass, I had to build them out of aluminum.
This is how I proceeded:

a) built the bobwights at my calculated mass;
b) balanced each bobwight by itself, at the precise weight computed;
c) balanced the crankshaft by itself;
d) balanced the crankshaft with the bobweights, flywheel and armonic balancer fitted;
e) balanced the above assembly with clutch's pressure plate fitted.

After the whole work crankshaft's journals have been polished.

[Pisobiker]

CHAPTER 8: REASSEMBLING

Swapping the engines took about 5 full working days. Pretty long, mostly caused by many small problems arosing while taking the old engine out, like auxillary parts to be cleaned up, fixed or replaced. Quite a big part also took the modding and adapting of the auxillary parts and systems to the taller block:

8.1) OEM cambelt is 151 theet (150 on some ADUs I think), wile I needed at least 153 theet. Couldn't find any of the right size so had to modify the belt tensioner.

8.2) Taller deck produced half a theet of timing difference on the camshafts which makes about 13 crankshaft degrees (way too much to make it usable). So I had to build a custom pulley having the right phasing not only for the camshaft position but also for the hall sensor disk's slot.
Here is my first solution, but I'm already building a much better one with the possibility of choosing among 0, +2, +4, +6, -2, -4, -6 degrees camshaft phasing.