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3.4 Upgrade


Stardust

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This has to be one of the best cost breakdowns I've yet seen of a 3.4 upgrade.

 

If only we can get something like this for sub $25k in Aussie land.

 

Am I dreaming?

 

http://forums.pelicanparts.com/porsche-911-technical-forum/768929-3-4l-upgrade.html#post7633210

 

Or you can get this car that has had the upgrade rebuild

 

http://www.carsales.com.au/private/details/Porsche-911-Carrera-1984/SSE-AD-149394/?Cr=22&sdmvc=1

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I know a bit about that car as it was built by my spannerman.. Can't believe it hasn't sold for around $50k

I been lucky to have had two 3.4 converted 911's, both with the unfairly maligned 915 gearbox. it's a great way to bump up the power and torque. One had 9.8 pistons and was on CSI, the other 10.3 pistons on PMO's. The latter was faster, the former more civilised. Both great fun.

Sometimes it seems that carsales can kill a car if it sits too long.

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This is something I am planning to do in a couple of years. I had a quick chat to the engine builder at K Tec here in Perth and he indicated between 15 - 20K. Depending obviously on what exactly I would want for the engine.

Does anyone have a price breakdown for Australian delivered parts??

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You need new cylinders and pistons.

 

The 3.4 cylinders bolt straight on to a 3.2 case. Same bore size, different wrist pins on the piston to accommodate a longer crankshaft.

 

Your SC needs to go to a 3.2 short stroke - it needs boring out. The 3.2 Pistons can't be bolted on like above because of the longer stroke of the 3.2.

 

I'm guessing the 3.4 upgrade goes anywhere from 250hp to 270-ish hp if you want to maintain streetability/engine life - and keep the motronic efi. The link I posted shows 275 rwhp.

 

I had a conversation with JustJames once where he said "how fast can you afford to go"?

 

Nice summary is here:

 

http://forums.pelicanparts.com/911-engine-rebuilding-forum/147128-quick-faq-3-0-3-2-upgrades-3-2-3-4-a.html

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Sure turbocharging is cheap hp. But, for me, I'm selfish and I'm after power and throttle response.

 

I agree with you that 25k for this amount of power increase is a crazy investment. That's why it's a pipe dream at the moment and why I asked the question about pricing in AU. It's something I'll probably do one day but happy to tootle around in my 3.2 in the meantime.

 

Much cheaper to fix the loose nut behind the wheel.

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Great info thanks.

You need new cylinders and pistons.

The 3.4 cylinders bolt straight on to a 3.2 case. Same bore size, different wrist pins on the piston to accommodate a longer crankshaft.

Your SC needs to go to a 3.2 short stroke - it needs boring out. The 3.2 Pistons can't be bolted on like above because of the longer stroke of the 3.2.

I'm guessing the 3.4 upgrade goes anywhere from 250hp to 270-ish hp if you want to maintain streetability/engine life - and keep the motronic efi. The link I posted shows 275 rwhp.

I had a conversation with JustJames once where he said "how fast can you afford to go"?

Nice summary is here:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/147128-quick-faq-3-0-3-2-upgrades-3-2-3-4-a.html

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Most people wait until a rebuild is needed anyway and then opt for the 3.4 on the basis that its no dearer than a standard rebuild. I certainly wouldn't tear into a perfectly good 3.2 just to give it an extra 200cc, whereas with a turbo conversion at least you can take it all off when you sell the car. I've always found it easier to buy the right car first up, rather than build something unusual that will turn into a money pit. Each to their own, and I admire those who have the skills to make a special 911 in their home garage. Not something I can do unfortunately.

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With a current EFI/ turbo tech there is 100% no reason you can't have both.

 

Yep your right there Uncle, no lag in mine any where in the rev range.

 

My new sports exhaust has given it instant throttle response and a sound to die for, it no longer has that typical Turbo sound.

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"To upgrade a stock 3.0 Engine to a 3.2, you need a special "Big Bore" kit.

This kit turns your 3.0 into what is known as a short-stroke 3.2. The stroke remains the same at 70.4mm because you're not swapping out the crankshaft. Instead, you are installing what are known as "Big Bore" pistons and cylinders which are 98mm wide (as opposed to the normal 95mm for the 3.0). These are special pistons and cylinders that were never a factory kit available from Porsche (as far as I know). There is no Porsche part number for these - they are an aftermarket kit available from Mahle. These are also sometimes known as the Max-Moritz kit. They are available in various compression ratios - I have a set that is 10.5 and resembles the original RSR setup in design. These sets are "plug-n-play" and do not require modifications to your case or heads. The piston pin offset in these kits is specifically made to work with the 3.0 crankshaft, and these will not work with the 3.2."

Hmm did anyone read this? Same process stated for 3.2 to 3.4. Here I was thinking some special modifications where required and its just a big bore kit with respective 3.0 or 3.2l crank?

Lets just throw in cost of headers, cams and tuning for argument sake. Sounds like you could halve that budget provided your not upgrading anything else.

Needs further investigation but that's sounds right with other platforms.

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