Making 3.0 to a Turbo Engine

[Nitrometano]

Hi guys.

What I need to know and to do to make a normal aspirated 3.0 engine to a turbo engine.

I need to change the CIS stocks pistons for turbo pistons?
I need turbo CIS injectors?

Thanks.
Nitro.

[afterburn 549]

lots have done it,you just need to figure which way to go bling, or bling bling bling!! get a older 930 sysytem complete or go with a stand alone system that way you have a safer ignition/boost system. Electromotive ,S.D.S., mega squrt/ promtive/ ect.

[350HP930]

Go efi, get some low compression pistons, a decent cam and intercooler and you easily got yourself over 350 HP

[afterburn 549]

If you ....double plug and stay around 1 bar I think you can run 8.5 c/r with a proper sys.

[dweymer]

Buy the book "maximum Boost" by Corky Bell; it tells in detail what is needed and what is not; not porsche specific, but a very good resource. What is the highest octane available in PR?
Change out the CIS for an EFI system, I am not sure what the C/R is on a stock 3.0, but if it is 8.5 you should be able to run about 7lbs boost on 92 octane; or 12-13lbs on 100 octane. I believe pelican "sammyg" has done this to a stock 3.0; do a search on his username. If you are using an intercooler you can run more boost safely, or run on lower octane fuel.

[iamchappy]

Just read through this thread it will tell you everything you want to know. 8 to 9lb turbo fabrication with fuel enrichment and boost timing retard MSD ignition system without intercooler works just great and it can be done for less than a pair of pmo carbs.
I ran 9lbs last year on my 79 3.0 stock engine and it works just fine it will give you around 300hp and is very gratifying.
I have added an intercooler and will raise the boost to 11lbs any more than that the heads have a hard time with the extra heat generated, so I am told. I was planning on trying for 1bar but really would need better suited pistons and 930 heads to reliably handle the heat. Running 9lbs is a lot of fun and will make your car very fast.......not scary fast but fast enough for most.
911SC Turbo

[dweymer]

I was hoping someone who has been there done that would respond. Thanks chappy

[Nitrometano]

Yesterday I tear down the engine. The pistons looks good and the cylinders still have the cross pattern inside. The matching surface of the heads looks in perfecto condition. For a simple view the valve looks good. Any way I need to precise measure all the parts to know if they still between the tolerances. I will split the case today. Maybe I found surprises in the bearings. The engine have steel head suds. I will change it to Raceware or ARP head studs and rods bolts and nuts.

I have right know a new set of Evo GT 2 crankshaft with new valve springs and titanium retainers.

There the things that I'mplanning to do:

Electromotive Tec-3 engine management system.
One of this two: TWM throttle bodies or carrera intake manifold (I like the TWM).
T4/60-1 or T70 turbocharger ( For the moment I preffer the first one).
Half moonig the cylinders.
Boat tailing the engine case.

Finding 7.5.1 forged pistons for a 3.0 engine. Do you know were I can find this pistons?

[afterburn 549]

if you are staying 1 bar or under with a good stand alone system you do not need to drop below 8.5 c/r as I understand it

[Nitrometano]

I split the crankcase yesterday and found that the first main bearing (at the flywheel) and the nose #8 bearing are worn. The other main and rod bearings looks tired. The drive shaft bearings are totally worn, you can see the cooper. The layshaft it self don't look good at all. The wrist pin bushings at the rods are worn too. I will replace all that parts wit new parts. The next wheek I will take the crankshaft to the machine shop to make a micropolish (or grind it to use oversize bearings), a knif-edge modification and balancing (include flywheel, rods and pulley) When I found the pistons I will balance it and make the half mooning to the cylinders.

For the moment this are the problems:

I don't find low compression pistons for the 3.0. You know a source that sell 7.5.1 pistons for the SC?

I can lower the dome of the pistons to reduce the compression?

The stock Mahle pistons they are forged or cast?

Is necesarry to change the head studs and the rods bolts and nuts to Raceware or ARP hardware or I can use the same head studs and new original bolts and nuts for the rods?

[350HP930]

Unless you will be running this thing at red line all day long save yourself the money and don't bother knife edging the crank, mooning the cylinders or other windage related mods.

The money dumped into those mods would be much better spent on something that can actually give you some extra power.

[dweymer]

You must use new nuts and bolts for the rods, they stretch when you torque them, steel head studs should be fine for normal boost. I am pretty sure JE will make any C/R you want.

[Wayne 962]

I find it easier to start with a Turbo motor and modify it versus turning a NA motor into a forced induction one...

-Wayne

[Nitrometano]

I'm doing my homework finding the proper turbo for the engine. For the moment is a T4 the proper turbo. That is because the numbers that I can get from the pressure ratio and other stuff calculations and looking at the compressor maps. I will still searching.

I dont have the book Maximum Boost indeed I have Turbomania. I think that the turbo theory are the same for the selection. Is not let me know and I will try to get the other book.

I do not take the things personal, but I don't know what's wrong with sammyg2. I don't have the right to make questions? Also where in the other replies I have told that I will do the boat tailing, half mooning cylinders and knife edge crankshaft? I only make questions to known the opinions of the members of this forum. And to know what the experience told to that people that have do the engine conversion.

[350HP930]

A T3/T4 hybrid like a 60-1 would be a good match for a porsche motor.

I am going with a garrett GT37 myself.

[dd74]

Originally posted by Nitrometano
Hi guys.

What I need to know and to do to make a normal aspirated 3.0 engine to a turbo engine.

Thanks.
Nitro.

You need to listen to Sammy, and Chappy. Sammy's been a huge wealth of information as I decide if I might go this route with my 3.0. If you want all the OEM fixins, take heed of Wayne's word. He has a definite point there as well. Wayne's advice is much more cost effective than opening up a 3.0, sourcing all the correct parts, etc.

[RarlyL8]

It makes no sense to open up a N/A motor and turn it into a turbo motor.
If you are going to spend the time and money to rebuild an engine why not use a 930?
Stock SC engines make a fine platform for a bolt-on system.

[dd74]

Originally posted by RarlyL8
It makes no sense to open up a N/A motor and turn it into a turbo motor.
If you are going to spend the time and money to rebuild an engine why not use a 930?
Stock SC engines make a fine platform for a bolt-on system.

That's right! Plus, I've seen some turbo motors going for $6,500 or less. This is really not too bad considering the cost of a rebuild could rise to $10K. No, it's better to stick with the devil you know, right Rarly? Now, as far as that devil goes, what preventive measures would you take to secure that the turbo doesn't damage a NA 3.0. I'm thinking off the bat possibly ARP bolts. I imagine it depends how much boost one runs to necessitate that.

[rudy]

I payed $6000 for a 78 euro 3.3 complete, And sold my 3.0 for $4000. I thought about putting a turbo on the 3.0 but for $2000 I felt like whats the point? If I had more time and motivation I might have considered building a 3.0sc turbo motor.

[ChrisBennet]

Originally posted by Nitrometano
I split the crankcase yesterday and found that the first main bearing (at the flywheel) and the nose #8 bearing are worn. The other main and rod bearings looks tired. The drive shaft bearings are totally worn, you can see the cooper. The layshaft it self don't look good at all. The wrist pin bushings at the rods are worn too. I will replace all that parts wit new parts. The next wheek I will take the crankshaft to the machine shop to make a micropolish (or grind it to use oversize bearings), a knif-edge modification and balancing (include flywheel, rods and pulley) When I found the pistons I will balance it and make the half mooning to the cylinders.

Try to avoid grinding the crank if you can. Unlike a "normal" crank, it's hardened and getting it rehardened is a bit of a pain.

The layshaft bearings and the thrust surface of 1st main bearing seem to wear a lot faster than the other bearings for some reason. The ones I have seen usually have copper on those bearings even when the other bearings have plenty of life left.

#8 bearing can often be reused. I don't reuse them but it is so common that main bearings sets don't include #8 usually (unless you buy them from the Porsche dealer). It sounds like your motor either had a hard life or has a lot of miles.

I also think (and I'm no expert) that knife edging the crank and doing the airflow mods is a bit overkill on a (relatively) low RPM dry sump motor but life is too short to try to make everyone else happy. Build your motor the way that makes you happy.

Good luck with your project.
-Chris