Yet another 930 rebuild begun

[mppickett]

Many thanks to all the Pelicanites for the good advice and pictures of your rebuilds. I'm starting my 930 build. Just test fitted some parts tonight (see pics below) and I still have some more cleaning to do. The basic specs include: an Ollie's shuffle-pinned case; twin-plugged, ported, polished & flowed heads; 3.2 Carrera intake; 42# injectors; K27-7200 turbo; GoingSuperFast full-bay intercooler; B&B headers; dual 6 plug EDIS ignition; and MegaSquirt II v 3.0. I suspect it will be a month or so getting things together and tuned. So here's how it looks during the test fitting:








Mike

[rcwaldo]

Looks nice and purdy. What is that shrouding around the tops of each cylinder?

[sand_man]

Originally posted by rcwaldo
Looks nice and purdy. What is that shrouding around the tops of each cylinder?

Those are the standard 3.3L Turbo cylinders that are not fully finned (on the top). Porsche realized their mistake and the 965 was given fully finned cylinders. On my rebuild, I've opted to go fully finned. Looks nice though.

[mppickett]

Thanks. Figured I'd clean it up so it would transfer heat a little better. By the way, I test fitted the Magnecor wires I got from BoostEngineering and they look good! They have a great price on the 8mm blue wires. I had them make up a custom set for the twin-plugged heads.

[rcwaldo]

Originally posted by sand_man
Those are the standard 3.3L Turbo cylinders that are not fully finned (on the top). Porsche realized their mistake and the 965 was given fully finned cylinders. On my rebuild, I've opted to go fully finned. Looks nice though.

Ahh, I see, thanks. I have never seen Porsche cylinders like that. Not sure what motivation Porsche had to do that?

Thanks for the clarification

[sand_man]

Originally posted by rcwaldo
Ahh, I see, thanks. I have never seen Porsche cylinders like that. Not sure what motivation Porsche had to do that?

Thanks for the clarification

I couldn't agree with you more! When I think of the countless Type1 VW engines and 356 engines that I've built over the years and they ALL had fully finned cylinders, you can imagine my surprise when a high performance, high heat engine like the 911 Turbo is missing these fins on top!!!! I've been told that Porsche thought the air generated by the fan would flow better around the cylinders without the fins!

[beepbeep]

Great setup! Good luck!

[scca_ita]

Originally posted by sand_man
I couldn't agree with you more! When I think of the countless Type1 VW engines and 356 engines that I've built over the years and they ALL had fully finned cylinders, you can imagine my surprise when a high performance, high heat engine like the 911 Turbo is missing these fins on top!!!! I've been told that Porsche thought the air generated by the fan would flow better around the cylinders without the fins!

I was reading the Porsche Handbook last night regarding finless cylinders - It mentions that Ruf built his own P/C (3.4L) because of this issue.

What cylinders could be used? 3L 3.2L?

[WERK I]

Originally posted by rcwaldo
Ahh, I see, thanks. I have never seen Porsche cylinders like that. Not sure what motivation Porsche had to do that?

Thanks for the clarification

Actually....there was a thread on this site about a 917 engine being rebuilt. There are some very interesting photos posted. One of them is the 12 cylinder long block showing the cylinders are half-finned, just like the 930. Porsche may have learned something from their 1000+HP monsters.

[sand_man]

Originally posted by scca_ita
I was reading the Porsche Handbook last night regarding finless cylinders - It mentions that Ruf built his own P/C (3.4L) because of this issue.

What cylinders could be used? 3L 3.2L?

Here's what I know:
-The fully finned 3.2 cylinders can be used...typically they are bored out to 98MM (3.4L) and then replated and supplied with JE 98MM pistons.
-The later style 3.3L fully finned cyliners found on the 965 (964 Turbo) can be used
-The Mahle "Ruf" 3.4L can be used
-The LN Engineering "Nickies" can be used
-JB Racing also manufactures a high-end fully finned cylinder

I just couldn't bare the thought of not doing something about it...I'm not going back into this engine ever again!

[scca_ita]

Originally posted by sand_man
Here's what I know:
-The fully finned 3.2 cylinders can be used...typically they are bored out to 98MM (3.4L) and then replated and supplied with JE 98MM pistons.
-The later style 3.3L fully finned cyliners found on the 965 (964 Turbo) can be used
-The Mahle "Ruf" 3.4L can be used
-The LN Engineering "Nickies" can be used
-JB Racing also manufactures a high-end fully finned cylinder

I just couldn't bare the thought of not doing something about it...I'm not going back into this engine ever again!

So what was your solution?

[sand_man]

As for the OEM finless cylinders...I'm wondering if Hans (the OEM supplier) and Frans (the 930 Porsche engine engineer) made some sort of deal in the beer garden or the golf course to use these things...

[DonE]

Originally posted by scca_ita
So what was your solution?

What is your budget?

3.2L cylinders - approx $1500 from EBS (year ago pricing)
Nikkies - approx $2700
JB Racing - approx $2700

Couple more questions:

What are you going to do with the car?
Why did you choose 42lb injectors?
Why did you choose a K27 7200 turbo?
What max boost will you run?
What cams did you choose?

Very nice work so far. Good luck.

[DonE]

Originally posted by sand_man
[B[snip]
......
...I'm not going back into this engine ever again! [/B]

Ya, that's what I said too - this weekend is the third time in six months I've dropped the motor to "do something"...

[sand_man]

I opted for 98MM JE pistons with new Nikasil 98MM cylinders from Henry Schmidt @Supertec. The price was too good to pass up. Not sure what the origin of the cylinders is (Mahle, or LN, etc), but I trust Henry. We'll see in the next couple of weeks when my order is complete...waiting for JE to do their thing.

[mppickett]

Originally posted by DonE
What is your budget?

3.2L cylinders - approx $1500 from EBS (year ago pricing)
Nikkies - approx $2700
JB Racing - approx $2700

Couple more questions:

What are you going to do with the car?
Why did you choose 42lb injectors?
Why did you choose a K27 7200 turbo?
What max boost will you run?
What cams did you choose?

Very nice work so far. Good luck.

Thanks. My budget is "fluid." Originally I was shooting for around $8K but found that the crank was toast when I opened it up. I ended up buying the disassembled 930 engine that sprbxr had for sale a couple of months ago for parts. My cylinders and pistons measured out fine and I just couldn't justify new ones.

What are you going to do with the car?
- Street and pleasure driving. It is a cab and I don't plan on racing it (I've got a highly modified miata that I race). I'm looking for improved low end torque, strong top end (but not necessarily spending much time above 6000 rpm), reliability, good drivability (no idle problems) and no/few oil leaks ).

Why did you choose 42lb injectors?
- Looking at the rwhp that others are making with similar setups, I decided to set it up for roughly 425-450 at the crank. Using the RC Engineering calculator I decided that the 42# injectors would do the trick (especially since I'm using the Megasquirt and will have a lot of control of the duty cycles, etc). In checking other applications, it appears that I'll be able get a decent idle with the 45#'ers.

Why did you choose a K27 7200 turbo?
- Improved low end boost. I wasn't willing to spring for the HF series (although they look great).

What max boost will you run?
- Probably .8 bar. Just depends on what I see when I dyno it. With the twin-plugs and big intercooler I should be able to run more, however the heads are set up for 8:1 compression and like sand_man, I don't want to make a habit of going into the engine.

What cams did you choose?
- I'm using the 964 camshafts. I was considering the SC cams but John Dougherty says that the 964 cams give you about 25 hp over the SC cams. With the head work (increased compression) and my goal of good idle I was reluctant to go with any wilder cams.

Now if anyone has any fully finned cylinders/pistons they want to give to me before I button it up...

Mike

[Steve@Rennsport]

Hi Mike:

Do you know what kind of power levels you are looking for? Depending on cams, static compression, boost level and such, you might find that 42 lb/hr injectors to be small,.........

Bear in mind that air-cooled Turbo engines rely on the evaporative effects of fuel cooling to help maintain reasonable cylinder head temperatures and "best-power" AFR's are too lean for one of these to survive for long.

DonE asked some good questions that should be considered before making some hard decisions so you do not do this all over again.

Finally, Porsche's finless Turbo cylinders was the result of their efforts to try to maintain more even cylinder and ring temperatures around the circumference of the barrels when the engine was hot. Needless to say, the "experiment" didn't work as planned and most of these engines had leakdown figures that were less than ideal. This resulted in excessive blowby under boost and one noted result was engine oil that became discolored (contaminated) faster than normal.

Porsche followed Ruf's suit and corrected that with the C2 Turbo's P/C's. Thankfully, the replacement 3.3 P/C's are now fully finned for durability and longevity.

[DonE]

Originally posted by mppickett
Thanks. My budget is "fluid." Originally I was shooting for around $8K but found that the crank was toast when I opened it up. I ended up buying the disassembled 930 engine that sprbxr had for sale a couple of months ago for parts. My cylinders and pistons measured out fine and I just couldn't justify new ones.

What are you going to do with the car?
- Street and pleasure driving. It is a cab and I don't plan on racing it (I've got a highly modified miata that I race). I'm looking for improved low end torque, strong top end (but not necessarily spending much time above 6000 rpm), reliability, good drivability (no idle problems) and no/few oil leaks ).

Why did you choose 42lb injectors?
- Looking at the rwhp that others are making with similar setups, I decided to set it up for roughly 425-450 at the crank. Using the RC Engineering calculator I decided that the 42# injectors would do the trick (especially since I'm using the Megasquirt and will have a lot of control of the duty cycles, etc). In checking other applications, it appears that I'll be able get a decent idle with the 45#'ers.

Why did you choose a K27 7200 turbo?
- Improved low end boost. I wasn't willing to spring for the HF series (although they look great).

What max boost will you run?
- Probably .8 bar. Just depends on what I see when I dyno it. With the twin-plugs and big intercooler I should be able to run more, however the heads are set up for 8:1 compression and like sand_man, I don't want to make a habit of going into the engine.

What cams did you choose?
- I'm using the 964 camshafts. I was considering the SC cams but John Dougherty says that the 964 cams give you about 25 hp over the SC cams. With the head work (increased compression) and my goal of good idle I was reluctant to go with any wilder cams.

Now if anyone has any fully finned cylinders/pistons they want to give to me before I button it up...

Mike

OK

The opinions below are based on my experience and are only here for you to consider - it seems you've put a lot of thought into this already and I am in no means questioning your logic/budget/build/etc.

Turbo - it WILL run out of breath at 5500 rpm with your new set up. I would reconsider the HF.

Cylinders - I would reconsider getting fully finned cylinders as you have quite a nice engine that will create a fair amount of heat - more than what the stock cylinders were designed to take.

Injectors - consider the Bosch 52lb injectors. Great low end and drivability because of spray pattern. Can supply up to 600 hp at the crank when you turn up the pressure.

Again, very nice and good luck.

[Steve@Rennsport]

More REALLY good advice from Don,....

The last thing I'd add is that I sincerely hope that this engine gets mapped on a dyno (not inertial) by experienced personnel so that you do not put all those expensive parts at risk.

[mppickett]

Great advice, guys! I really appreciate it. I know the engine can put out more hp, but I'm going to keep the boost purposely low since this is just a "fun" car that I'm not going to race (although 600 hp would be fun to experience). Steve, great advice on the dyno mapping and I agree completely. This is too much of an investment to fry on a bad tuning guess. I have a dyno guy that I've tuned with for several years that I'll work with (I'll be shooting for 11.5-12.2 to 1 air/fuel ratios).

Having taken several engines to the ragged edge and then backed down the outputs to "sane" levels later, I'm trying to find the right balance on this one at first. I hope I'm not wrong about living with the stock 930 cylinders but I guess I'll find out. I'll keep on the lookout for fully finned cylinders for a future top end transplant.

Mike