Rebuilding My 930 - Page 4

krazyman · 11-25-2004, 04:54 AM

Don E
Are you sure those are correct Porsche 993 studs??? I bought 993 studs when I did my rebuild and they either had a coating in the middle of the stud or only the ends had threads, can't remember which I'm too near 40 y.o.

But I am sure they did not have threads all the way on the stud.

Jeff

DonE · 11-25-2004, 09:46 AM

Yes - check out Wayne's rebuild book for more info. Rgds

krazyman · 11-25-2004, 10:43 AM

Ah, right you are. I guess mine were the 993, I remember the coating more than the threads going all the way. Do you know what caused the rust? How long ago was the rebuild?
Jeff

350HP930 · 12-12-2004, 07:33 PM

Here is something I picked up this weekend for the 930.

350HP930 · 12-12-2004, 07:36 PM

And a little side by side comparison for those who are unaware of why many people make this switch.

MichiganMat · MichiganMat's Garage

wow, that is dramatic

arrivederci · 12-13-2004, 02:49 AM

Does the opening for the throttlebody look smaller on the carrera intake than the TB itself on the 930 intake?

How do they compare weight wise?

briankeithsmith · 12-13-2004, 04:03 AM

Weight wise the carrera intake is much lighter than the 930 intake!!!

Brian

DonE · 12-13-2004, 05:47 AM

Really? The 930 is magnesium and the Carrera is cast aluminum. My carrera manifold is heavier than the 930 monifold, ....but it really doesn't matter to me.

350HP930 · 12-13-2004, 01:50 PM

The carrera manifold appears to weigh just a little more than the 930 manifold.

I wish I had a bathroom scale to give you an exact number with.

Even though my new manfold didn't come with a throttle body I didn't mind since both manifolds use the same sized bolt pattern and opening.

briankeithsmith · 12-13-2004, 02:30 PM

The way I am looking at it is this. If you are going with the carrera intake, you are replacing the old CIS fuel head. So if you weigh the carrera components for intake/fuel vs the 930 components for intake/fuel, there is a pretty decent weight difference.

Brian

350HP930 · 12-13-2004, 03:15 PM

So true.

It looks like I will be using megasquirt II for fuel and spark control which will eliminate a lot of other stuff so I will be shedding a lot of weight in the rear.

For this reason I will have a lot of goodies for sale, including an Andial fuel enrichment system, J&S Knock Controller (very effective BTW), Permatune box, and a modified air lid that allows one to use a cone filter instead of the full airbox.

Oh yeah, I also have most of my old exhaust and intake stuff for sale for anyone who is looking for 930 plumbing.

beepbeep · 12-14-2004, 10:40 AM

hint: you could swap your 3.3 choked heads for 3.2 Carrera heads. I bet it would cost you nothing and you would have perfectly port-matched intake/head instead of having to fiddle with dremel.

Just sell those turbo heads to somebody who believes that they are made of magic stuff and pick some Carrera heads off E-bay

350HP930 · 12-14-2004, 03:02 PM

The intake choke is easy to remove with a mill. The dremmel is just for fine tuning.

My plan is to reuse all of the motor with the exception of cams, induction, exhaust and ignition.

Porting and a compression bump will be my only internal engine mods.

I got more time than money right now so hacking up my 930 heads and making them a personal work of art works better for me than swapping them for carrera heads.

beepbeep · 12-14-2004, 04:19 PM

Quote:

Originally posted by 350HP930
The intake choke is easy to remove with a mill. The dremmel is just for fine tuning.

My plan is to reuse all of the motor with the exception of cams, induction, exhaust and ignition.

Porting and a compression bump will be my only internal engine mods.

I got more time than money right now so hacking up my 930 heads and making them a personal work of art works better for me than swapping them for carrera heads.

Whooa, hold it there. It's not so trivial.

Just making oval hole bigger is easy, but port-matching the injector notch isn't.

Take a look:

930 head in pic #1 has material to be removed outlined by green color. Removing the material to make hole isn't hard, but 930 head has less material between lower stud and "injector notch" (take a look at small inserted pic of Carrera head).

This means that you will need to do some fill-in with epoxy (like on pic #2, to the right of red area) to make good flange seal (in case you do a full poprt-job on the notch) or keep the notch little smaller, which will disturb injector spray-pattern once Carrera intake is bolted-on.

350HP930 · 12-14-2004, 04:35 PM

There is an easier solution beep. Instead of adding epoxy to entend the injector notch area its better to mill down the flange a couple millimeters instead.

That gives you aluminum to work with instead of bonded plastic epoxy and a better aiming position for the injector.

beepbeep · 12-14-2004, 05:05 PM

Hmm...yeah, you can do it that way as well.

Only potential problem is that injectors will be placed lower down the throat, which might and might not be a good thing. It all depends on spray-pattern of EFI compared to K-Jet injectors. Keep us posted!

350HP930 · 12-19-2004, 08:18 PM

Well, after many hours of working on my heads during my lunch breaks and some finish work this weekend in my garage I am nearly finished porting and polishing the exhaust ports on my head.

Its hard to get a good photo of the improvement in shape, size and finish, but if you look at the untouched intake ports it gives you a good idea of what I started with.

Once I finish boring out the intake port inlets they will be getting the same treatment.

DonE · 12-20-2004, 06:01 AM

Nice job. Are you going to polish the exhaust ports? This seems to help in evacuating gases and the polish reflects the heat to keep the gases as hot as possible to the turbo. You probably already know not to polish the intake. Did you also flow each port?

The 3.3 heads can't be all that bad, when in stock form they can produce over 400 rwhp with a CIS attached.

350HP930 · 05:44 PM

I am going to polish them once they are back at the shop and I have access to some more powerful dremmels and buffing wheels.

The smooth surfaces are for the purpose of reduced flow resistance and also to reduce surface area which will reduct heat conduction into the head. Once the engine has run for a few minutes there will be enough carbon black in the ports to eliminate all reflective capabilities.

I will have to wait till I replace my guides to flow test them, but I am confident that they should all flow evenly.