Porsche 986 2.7l in a VW T3/T25

[bungleburch]

Okay so hear me out,

I've been gifted a 2001 986 complete car with all manor of body issues, so I thought why not?! So I'm taking it apart for parts and engine.

So firstly, is this actually possible?
I've heard stories of people flipping the internals of the 986 gearbox so it will operate forward facing. Is this true?
Is there enough space for the engine to sit right and to not have the drive shafts at a whacky angle to the hubs?

As I've got this car for nothing, and have my own fully equipped garage to do this in, the cost of doing this (i.e. the labour) isn't something I'm worried about because ill end up doing the whole conversion myself and I will be documenting the whole process here. I just wanted to know if something is obviously glaringly impossible with doing something like this.

I've seen a video on youtube with this exact engine installed but no specs on the gearbox used so I'm worried that will be my first roadbump.



Any and all help/resources/counselling welcome. 

[silverbullet]

The Boxster engine has a lot of well documented issues (nikasil cylinder delamination, auxiliary shaft bearing failure) so if it goes wrong, it wont be a cheap engine anymore.
Against that, it uses the Audi inline5/V6 bolt pattern afaik so it should bolt up to a T3SA bellhousing and with an appropriately reworked transmission could be quite nice.
Then you'll need an exhaust making!

[bungleburch]

The Boxster engine has a lot of well documented issues (nikasil cylinder delamination, auxiliary shaft bearing failure) so if it goes wrong, it wont be a cheap engine anymore.
Against that, it uses the Audi inline5/V6 bolt pattern afaik so it should bolt up to a T3SA bellhousing and with an appropriately reworked transmission could be quite nice.
Then you'll need an exhaust making!

Yes I am aware of the issues with the engine however the one I've got is a very nice example and has actually been looked after (believe it or not)
That said, I'm pulling it out and overhauling the entire thing, replacing everything that needs replacing and rebuilding the engine on the stand to mitigate any of the potential issues.

So are you suggesting to use the gearbox in the van already? My T25 it has a 4 speed gearbox and I reckon the ratios wont work in my favour, plus my gearbox is just about toast and needs a full rebuild... and if I'm spending money wouldn't it be better pent on the 5 speed gearbox from the Porsche?

[Dueller]

Ok here's my advice on this, may not be to everyone's taste but here goes...

Just connect the engine to the box in its desired configuration, then fit it to the van. Then drive it. Saves you loads of time this way to getting from nothing to on the road.

Too many of us start with best intentions and get distracted, sabotaged, deprioritised, priced out for months for that one elusive ie expensive part etc etc. I considered a Maserati v8 for mine as you can get almost anything for reasonable money these days but whilst beautiful I didn't want the drama of sorting it to make it work and fit my 'velle. Time is the enemy here of enjoyment to my mind.

All too often the project may get shelved and broken for parts mores the pity

Just fit the engine you have and enjoy it, then you can play with it because after you fit it, you'll want to make changes so why not do it on round 2..?

My engine has a desperate oil leak at the front pulley but I don't care, its going in. I have no history other than it runs, its going in then I will work on it and sort out any issues it has or I don't like that I created as part of the conversion.

My time frame so far is 10 hours for the adapter, 6 hours of running to my 2x engineers and back, 3 hours to collect the motor and 6 hours to have the old motor out and the new one in place, all over a 4 week period so far, vans been off the road 2 weeks this Saturday and will have the motor in and plumbed this weekend, maybe driving too if I can sort an accelerator cable linkage without too much drama. Having a spare gearbox was a godsend for this as I was able to do most of the figuring before i took it all apart and since you have both it won't take you long either.

Enjoy first, always, then plan in more later

Will be watching your thread with interest because I considered similar but rejected it as too costly to overhaul and repair. Far better to spend on the gearbox I'd say as ebay has a guy selling audi boxes reconditioned with LSD's for the v8 guys

All the best

[silverbullet]

If you intend to rebuild the engine first, it should be fine. Not that it will be a cheap exercise! I believe that the usual route is to have the nikasil bores machined out and iron liners fitted.

As for fitting it in the 986 orientation, its a mid engine/transmission tailmost arrangement so in a T3 that means bodyshell surgery.

Its not a popular engine for all these reasons.

Looking at the T3 transaxle options, a 5-speed with a 4.14 (29:7) crownwheel and pinion set would work really well, the engine will have the torque to pull it and you will get lower motorway cruising rpm.

Talk to Neil Fox VW gearboxes in Shardlow, Derbyshire.

[bungleburch]

Okay so things are progressing,





Got the car on the ramp yesterday to take a few dirty measurements to see if it would just fit in its current configuration - obviously with flipping the gearbox internals around so that I have 5 forward gears as supposed to 1 - and from what I can tell I have almost identical space over axle in the T25 when measuring from the axle to the front engine mount by the coolant lines.

I have all the gear to do a full engine rebuild myself, aside from boring the cylinders, but a mate has a setup I can use on the weekend to get that done... Obviously with him watching over me. Never to late to learn something new eh?!

Engine coming out next week so I will update!

When it comes to gearbox flipping anyone have any experience with this? Read online that it's possible... But I gather it's not as simple as pulling out the internals and flipping them around...

Talk to Neil Fox VW gearboxes in Shardlow, Derbyshire.

maybe Neil might know something? I'll give him a call.

[Dueller]

Great to see you've started

I'd contact Tim at Ultimate Engineering as he does kits and parts for the gearbox flip

Would be good to know what can be done as my plan is to go manual with mine due to autobox spares non availability not to mention finding someone to do it

[bungleburch]

Great to see you've started

I'd contact Tim at Ultimate Engineering as he does kits and parts for the gearbox flip

Would be good to know what can be done as my plan is to go manual with mine due to autobox spares non availability not to mention finding someone to do it

Well who knows if I'm not completely killed by the end of this I wouldn't mind lending a hand. I imagine a few custom brackets will be in order, but luckily I've got a CNC Plasma Cutter and a dream ahaha. So I'll keep all the drawings and component 3d files and if you needed a set I can sort something out

[silverbullet]

Neil only does VW T3 091 and 094 transaxles afaik, flipped transaxles don't last long or so I have heard. The driveahafts end up at nasty angles too.

[Dueller]

Have you started yet?