blown 944

Initially, I was thinking of directing swirl. Then I thought it may actually help velocity at low lifts. I guess I hadn't thought it through that far. Hence the question. I am certainly willing to learn.

Now that you guys have giving explanations, I can visualize that it actually would be comparable to having a massive amount of port work while keeping a small valve ei; way too much material removed.

I've been taking a lot of time to convert over to the 4v. One of my concerns was not losing too much bottom end.

It sounds like I need to either go with the longer stroke (already added displacement via bore) or try to go after a quicker turbo.

I guess we shall see how it goes initially with the same turbo.

Thanks again.

blade7

No I shouldn't have to pay UK import duty when the parts originated from within the EU and as long as all the documentation is in order when the parts are in UK customs and with the shipping agent....... I'd be interested in Wossners part no. if the pistons aren't custom ?

blade7

There are but they lost interest when I asked about custom pistons, plus I dont fancy specifying all the dimensions myself.

67King

K9477D_, where the _ is A for standard bore, 050, 100, 150, and 200 are for 0.50mm, 1.0mm, .5mm, and 2.0mm overbore. http://wossneronline.com/forged_pist...roducts_id=968

It is all right there, too. 2 clicks to get there (from www.wossneronline.com -> Automotive Pistons -> Porsche). If you are SERIOUS, go look on wossneronline. Send an e-mail. Whatever. It really isn't that tough if you are actually looking to get pistons.

Penguinracer

I got my custom Wossner pistons & rods sent to the UK by Karl at Racer's Edge. It was quite a quick process. Karl asked me for the bore, combustion chamber volume, CR & maximum valve lift. A few weeks later I received Wossner's PDF of the blue prints/technical drawings for my approval. I ok'ed the blue prints & the pistons & rods arrived in the UK about 8 weeks later.

Yes, it is weird & inefficient that we're in the UK, Wossner's in Germany & we need to purchase through an agent in the U.S. - but if that's Wossner's dealership structure I can't change it!

blade7

Thanks, been there ages ago looking for 104.5mm, 8v, 8-1 comp, alusil compatible pistons. Still custom with no part number I guess ? I was sidetracked by a certain 3.2 engine car for a while but since that deal has stalled I will continue with my own 3.0 project.

blade7

Sent from the US or Germany ? 2.5 or 3.0. I'm not asking for anything unusual Wossner have drawn/made these pistons plenty of times already. Thanks.

67King

Didn't know you meant a 3.0L bore piston. Those are not a production part. And note that having made something once does not make it a production part. It still has to go through all of the one-off set up and tooling processes. Designing them is pretty straightforward, but the forging and machining processes is very different for a high volume, batch-run part than it is for a single piece.

On edit - Curious to know why you are so hung up on where they are shipped from? Per Karl, they run about $65 to ship to the UK.

Penguinracer

Admittedly the pistons were for a 2.5 but with a 100.5mm bore, standard CC volumes, 8:1 CR & 0.480" valve lift.

blade7

I've heard of shippers demanding 25% + tax and import duty before they would deliver parts if the paperwork wasn't in order.

turbotim3

Hi, Sorry I've not been on line lately. Yes I have had a little problem with my engine, more than likely my own fault. While running the engine on the last dyno session, the engine oil temp was getting very high. This I put down to the new crossover pipe running close to the sump and glowing red hot. I changed oil coolers and I think it got a gulp of air when the thermostat opened and it picked up on number one big end. I am at present awaiting delivery of new parts to put it right and it will then be put back together. I also think the tolerances may have been a little tight between crank and big end shell and with the extra heat involved this may not have helped. I think I will have the crankshaft polished to bottom limit to help this.

I will keep you informed when things start to happen.

Cheers Tim

turbotim3

Hi, Sorry I've not been on line lately. Yes I have had a little problem with my engine, more than likely my own fault. While running the engine on the last dyno session, the engine oil temp was getting very high. This I put down to the new crossover pipe running close to the sump and glowing red hot. I changed oil coolers and I think it got a gulp of air when the thermostat opened and it picked up on number one big end. I am at present awaiting delivery of new parts to put it right and it will then be put back together. I also think the tolerances may have been a little tight between crank and big end shell and with the extra heat involved this may not have helped. I think I will have the crankshaft polished to bottom limit to help this.

I will keep you informed when things start to happen.

Cheers Tim

Duke

It's an interesting build so we're happy that you're sharing. I imagine your ignition is pretty retarded to be able to run that high boost on pump fuel without knock and hence the high EGT's.
What rpm and boost levels on the last dyno session?

turbotim3

Running 99 super unleaded pump fuel. Last session at 7500/8000rpm 18/19 psi boost (around 18/20 degrees from memory) 560 bhp. Can not wait to get it back together.

blade7

Sorted out an intercooler yet Tim ?