1200 Challenge enginebuild(s) - Sinnbefreites tuning

[Airspeed]

Is there any interest in sharing my 1200 engine build(s) for this weird yearly (dyno)Challenge?

I know 1200 tuning is totally useless for all practical reasons, so its no use to anyone really, so thats why I ask beforehand.

Background: I usually participate each year (its mostly held in germany at a dyno location) and at least its not type 4  (and still usually the best weekend of the year for me  )

[Erlend / bug66]

Sure! Any engine configuration that’s not a type 4 is an enjoyable read 

[Airspeed]

Sure! Any engine configuration that’s not a type 4 is an enjoyable read  

I thought as much  

First I maybe need to explain what 'sinnbefreit' means: its a german phrase for 'completely free from any logic/meaning'. Thats what my german buddies call this 1200 tuning. Its sums up it up pretty well.

You also need to know that the 64mm 1200 crank is way weaker then a 69mm cross drilled crank. It has straight drilled oil channels without chamfering and less cheek width, so less dynamic rigidness... they evn broke in stock engines now and then, or so I've heard.
The 1200 rods are also a lot weaker. Width is between a type 1 and a type 4 rod, so nothing aftermarket fits...(even though it still has 55mm bearing diameter.
Pin is 20mm..

Fortunately, we can (and do) use 1300 DP heads as they are 77mm bore as well and flow of course much better then 1200 singel port heads. Problem is most all 1300 DP heads *europe only, never sold in the US) are cracked. Badly.
Still, most cracked heads seem to run pretty decent we have found out  

Some history:
This is going on since 2009 (yearly dyno contest) and we only have 2 classes: N/A and blown (supercharger, turbo, NOS)
Other then it needs to be 1200 cc's (1192cc), only first oversize (77,50) allowed, making it a max of 1208cc.

In practice, due to all inherend weakness of the parts and mostly because of the small bore, which makes stock valve size of 35x32mm already run against the cylinder bore wall, getting hp from these engines proves pretty darn difficult!

At this time the N/A record is 100,65 hp, which has not been broken since 2010 iirc.
Blown record is at 203 hp (last year), which was reached at 1,85bar of boost and on a used (free) W110 cam  

[Erlend / bug66]

Are there specific rules on parts etc?

How about a industrial 1600 engine, destroked to 64mm with 2” rods?

Then cylinder adapter rings and 1200/1300 long block parts 

[Airspeed]

Are there specific rules on parts etc?

Nope, basically, there are no rules  

How about a industrial 1600 engine, destroked to 64mm with 2” rods?

Then cylinder adapter rings and 1200/1300 long block parts  

Yes, people have thought about this, but 69 - 5mm is indeed 64mm, but your rod journal get 55-5mm - 50,00mm IF you grind without ANY loss in roundness or otherwise. Then you still have a stock type 4 2 liter rod (not a 2"rod), but in type 1 width (type 4 is way wider), so although 'everything' is possible, it gets expensive really quickly. And because there is no use for such an engine otherwise (torque will be low always),  usually mostly stock or upgraded stock parts are used. We therefore like it a lot that AA has made new 1200 cylinder sets. They work pretty well, but a motorcycle piston would be cool of course...

For last season I went a little further and had a set of AA 043 heads welded up to be able to seat the 77mm cylinders. It was a lot of work (new seats and all), but they flow a little better and the longer (type 4) spark plugs work well and cracked heads are a thing of the past with those.

My 1200 with EFI with VWSpeedshop TB's and a W110 on 4 degrees advanced, but with very low CR (because turbo later) made 70hp at 6500 RPM in 2020.
I used Mazda pistons for this engine, but although they use 20mm pin, we had to cut grooves for circlips in the piston pin holes.


Also reused my rebuild original rods, where I used Ford (cortina?) ARP bolts to gain a little extra strength. They are also shot peened. You can also see the added oil grooves like 1300/1600 cranks:


That engine is extremely short (-12mm per side iirc) because a lot of flycutting and the much lower pin on the Mazda pistons. The engine tin and shroud are shortenend to fit.


Dynorun N/A:
https://www.youtube.com/watch?v=WCt_hOuxsVs

With a turbo that same engine made 203hp at 1,85 bar boost on petrol and a big inboard (under the decklid) air-air intercooler ;-)

Turbo engine:


Dynorun boosted:
[youtube]https://www.youtube.com/watch?v=crasGgeW5Sg[/youtube]
https://youtu.be/crasGgeW5Sg

For this year I bought a lightweight buggy where the 1200 engine actually makes sense  
Busy redoning the 'old' engine in an attempt to crack the current N/A record..
Later more about that.

[Airspeed]

This is the lay-out for the N/A 1192cc engine. Before anyone asks: the pictured manifolds were a one-off from a mate, so they are not for sale anywhere, sorry..



Cam will be a W125 I got for free from another mate (in true 1200 Challenge style) and runs on 53g tool steel lifters from Thorsten.
Now, the W110 with 4 degrees advance was already a little crazy on the 1200, I can only imagine how the W125 will be like... but the heads will be flycut 3,7mm again after the 3mm last time, so hopefully I can get to at least 9-9,5 CR. fingers crossed. Heads are still out, so haven't been able to measure head cc yet.

Another flywheel (200mm from a 1500 type 3 engine) has just been machined as well. I needed another one as the engine comes into my newly acquired buggy with a stock VW gearbox. Before, the 1200 engine ran in my 1303 attached on the G50 gearbox with a 215mm flywheel (from a vanagon), opened to 228mm, so a G50/Mendy 9" plate could be used. I didn't want to grind out the stock buggy box for the 228mm pressure plate, so back to stock 200mm parts.


I a week or two the heads will be ready 

[ibg]

That flywheel is seriously chopped, nice finished weight.
are you staying with 4 dowels?

[Airspeed]

That flywheel is seriously chopped, nice finished weight.
are you staying with 4 dowels?

Yes, the flywheel is seriously lightenend, but my type 4 flywheel with this kind of modifications was just 4,5 kg, so its not even that light. Still, it will do ;-)

Yes, I am very stubbern in that way that I think the clamp is mainly from friction through the flat surfaces and drilling more holes only reduces that surface. If you have to rely on the dowel pins for sheer, you're usually done anyways. We have had that discussion here before iirc. There are different opinions about this for sure.
I put my trust in a much better bolt and much higher clamp force (as all high hp builders do as standard these days), but without the extra dowels. The turbo engine had 203 hp and also no extra dowels, but I have no clue what is ultimately best or strongest for type 1.
For this 1200 N/A engine, even if it makes 101 hp, it will surely hold easy peasy this way ;-)

[brewsy]

Is there any interest in sharing my 1200 engine build(s) for this weird yearly (dyno)Challenge?

Hell YES!
A good engine build is a good engine build 

[BeckyCalderon]

Sure! Any engine configuration that’s not a type 4 is an enjoyable read  

I thought as much  

First I maybe need to explain what 'sinnbefreit' means: its a german phrase for 'completely free from any logic/meaning'. Thats what my german buddies call this 1200 tuning. Its sums up it up pretty well.

You also need to know that the 64mm 1200 crank is way weaker then a 69mm cross drilled crank. It has straight drilled oil channels without chamfering and less cheek width, so less dynamic rigidness... they evn broke in stock engines now and then, or so I've heard.
The 1200 rods are also a lot weaker. Width is between a type 1 and a type 4 rod, so nothing aftermarket fits...(even though it still has 55mm bearing diameter.
Pin is 20mm..

Fortunately, we can (and do) use 1300 DP heads as they are 77mm bore as well and flow of course much better then 1200 singel port heads. Problem is most all 1300 DP heads *europe only, never sold in the US) are cracked. Badly.
Still, most cracked heads seem to run pretty decent we have found out  

Some history:
This is going on since 2009 (yearly dyno contest) and we only have 2 classes: N/A and blown (supercharger, turbo, NOS)
Other then it needs to be 1200 cc's (1192cc), only first oversize (77,50) allowed, making it a max of 1208cc.

In practice, due to all inherend weakness of the parts and mostly because of the small bore, which makes stock valve size of 35x32mm already run against the cylinder bore wall, getting hp from these engines proves pretty darn difficult!

At this time the N/A record is 100,65 hp, which has not been broken since 2010 iirc.
Blown record is at 203 hp (last year), which was reached at 1,85bar of boost and on a used (free) W110 cam  

[PPRMicke]

This is the lay-out for the N/A 1192cc engine. Before anyone asks: the pictured manifolds were a one-off from a mate, so they are not for sale anywhere, sorry..



Cam will be a W125 I got for free from another mate (in true 1200 Challenge style) and runs on 53g tool steel lifters from Thorsten.
Now, the W110 with 4 degrees advance was already a little crazy on the 1200, I can only imagine how the W125 will be like... but the heads will be flycut 3,7mm again after the 3mm last time, so hopefully I can get to at least 9-9,5 CR. fingers crossed. Heads are still out, so haven't been able to measure head cc yet.

Another flywheel (200mm from a 1500 type 3 engine) has just been machined as well. I needed another one as the engine comes into my newly acquired buggy with a stock VW gearbox. Before, the 1200 engine ran in my 1303 attached on the G50 gearbox with a 215mm flywheel (from a vanagon), opened to 228mm, so a G50/Mendy 9" plate could be used. I didn't want to grind out the stock buggy box for the 228mm pressure plate, so back to stock 200mm parts.


I a week or two the heads will be ready 

Ok it will be good 60 foot times with such light things
On our 1600 challenges, we go the other way
As heavy flywheel as possible 180 mm are the heaviest since 4 kg pulley on the other side so the time creeps down to 60 foot
Engine just sighs a little
When we tested with light things, they lost 2500 rpm in the start
/// M

[Airspeed]

Wintertime is wrenching time, so off and on with the 1192cc engine for this summer.
The 1200 dyno Challenge event will be at 26 August this year (2023) held at HRengineering in Doesburg, NL on their superflow rolling road ('heartbreaker') dyno.

Had my pushrods made to length: very short, because 64mm stroke, 130mm rod length and over 6mm flycutting  



straight HD alu rods from Thorsten Pieper, love them already (48,9gramm at this length- ~259mm)!

To give an idea why 1200 tuning is so much "fun": Because of the flycutting, the stock intake valve size hits the cylinder edge unless you 'clearence' the cylinder tops...:

https://www.youtube.com/shorts/R89ro2KWhzU