Big Bang Theory: Oettinger 2500E rebuild

[silverbullet]

A while back, my search for an 82mm crank to go with some 98mm pistons and barrels resulted in the unearthing of a genuine Oetti 2500 wbx sat in a festering 1988 Carat Auto on the continent.
It has sat around in the workshop for a while and was high time that I at least washed off all the oily grime (the auto had been leaking for some time) and saw what i had really bought.
I knew that it was the real deal but that didnt stop me poking a wire down a plug hole to check...82mm...phew!
So far all I have done is stripped off the loom and boxed it, removed the entire exhaust (binned) and felt smug. Up on the spare engine stand, wash it down with some paraffin and then brake cleaner to degrease and lift the inlet manifold off.
Looky here:

The exhausts have been worked out to the gasket line too:

The final mark of authenticity, buried under all the grime:

Not forgetting the all important label on the engine cover

The next step is to get inside it and see what cam and rods they used to fit...

[jes*b]

Very cool this is . Has anyone every driven one then ? What is known about performance , maintainance etc

[mm289]

Ooooooooh, you've got me interrsted on this one. Bit more fun than a standard WBX build

You guys are like rabid squirrels the way you search out stuff from all over europe then store it away for a boring winter night!

Good on ya

Cheers

MM

[silverbullet]

Cheers Paul. It wasnt cheap but looks like I bought the right one.
I think that its in the 140hp/200Nm bracket on the DJ system so should be nice once on modern management, but that will be a steep learning curve.
I have seen recent pics of a turbo 2500 in a doka too...

[DSM]

Okrasa is my kind of porn. More pics please as you delve in? Been waiting for you to do this since I saw it in the corner of your workshop.
Is it destined for the Syncro?

[silverbullet]

Happy to oblige Duncan! Yes this one is destined for the syncro, should make for a nice drive with a sensible tyre choice on the ARC's
PS I have a plan for a bigger volume cast alloy plenum too...

[mm289]

So are you gonna take the plunge and use MS on it?

Thats what i am planning for a turbo'd Aircooled, but at some point it would be fun to turbo a DJ with MS. But as Jes will tell you i am long on projects and short on time nowadays

Cheers,

MM

[silverbullet]

MS would be the one, for a daily driver Digijet doesn't cut it these days, got to be lean and clean.
One coil per cyl, no half measures

[AdrianC]

should be nice once on modern management, but that will be a steep learning curve.

Can't wait for that thread - I've got MS sat here for a project, but it's the least of those requirements at the mo... I _think_ I've got the basics of injection fairly straight in my head, and it shouldn't be too hard to get a basic map to the point where it can be auto-tuned.

[ELVIS]

Ian, There is a guy a stones throw from you who is a MS expert/guru in VW circles. Will dig out his details when/if you need them

[silverbullet]

Not Ian at Wolfsburg Performance? He moved to S.Wales last year...

[ELVIS]

No, guy called Eddie. Main man in Golf circles.

[silverbullet]

PS I am tempted to go for downdraught throttle bodies and my own design twin plenum induction system, but that might be a bit too frisky...would be quite cool though

[silverbullet]

Nibbling at the job, had to make a tool to get the triple pulley off so having seen what the proper VW one is like, I made something simpler that still does the job:

My technique for cracking 350Nm on the engine stand:

I use 3/4" drive for the hefty jobs, a T-bar and 4 foot of keeclamp handrail always works for me

[silverbullet]

Having a little think about plenum chamber volume... most of the current thinking for good performing road engines suggest anything from 0.8 to 1.5 times engine displacement is needed for adequate induction air. I have looked at the late 80's-mid 90's efi engines that I have here and it doesn't look good for the VW one.

The 170bhp 2.3L 7A has a plenum of around 1.8L so definitely at the lower limit. An old Rover 3500 Vitesse V8 (not knowing for being a great breathing engine due to small head ports) has a Lotus-designed plenum circa 4.5 litres for its modest 190bhp, putting the ratio at about 1.3

The DJ plenum by my best estimate barely holds 1100cc...I think that we can do better. The thottle body placement really restricts air flow into cylinder #1 so this limits the potential performance of the engine as a whole.
The worked heads should work well with the standard (but oversize) inlet runners and it looks like a plenum around the 3000cc size should fit inbetween all the ancillaries.
So...do I go billet or cast with a nice Oetti sheild logo on top?