Starting the 930 rebuild today
 

Well after just 2 months of ownership and about 4,800 "drive it like you stole it" miles, armed with just 3yrs of wrenching on my old H1 Hummer, Viper v10 and Indian chiefs, I will be dropping and breaking down my motor for a complete rebuild once I've decided on the final "plan" . I was hoping it would be later than sooner but I feel the hard driving has taken effect. Not to mention my clutch began slipping pretty bad so the motor had to come out anyhow. I'm staying CIS for now, perhaps nexttime I'll go EFI.

My plan is to extend my existing mods in the process. I've studied everyone else's rebuilds and have come up with a list. I'd appreciate any input from anyone here that would like to give me advice on my project.

The current "plan"
(3/27/06)

ARP bolts/studs
New bearings/gaskets/chains/tensioners/valve guides
964 Dougherty cams
100mm finned Nickies/custom JE's 7.5
8:39 Ring & Pinion
41mm heads/intake
Headers (advice? GHL/Goingsuperfast/B&B??)
Muffler (advice? Fabdual or york/B&B/Borla/Ruf quad??)
Twin plug
mod my K27 to HFS style
Fidanza
Centerforce
Tial 46mm WG/ C2 bov
Imagine fuel head(delete Andial enricher)
EVOM intake


existing mods:
Andial IC & enricher
1bar
full euro exhaust
SC cams
K27 7200

Looking forward to the words of ingenuity that this forums members are sure to bring me. Hopefully I won't get into much trouble using Wayne's two invaluable books:) wish me luck brothers!

Not sure what your plans are for the car/engine, but I'd be reluctant to go with 100mm Ps&Cs for a turbo street engine. If I'm not mistaken the case (cylinder spigots) will need to be machined to accept them. The 98s are "drop in". Nickies are nice, though.

I've heard that for a CIS street engine, the SC cams work better...better low end to mid range power and that the 964 cams work well at higher RPMs. I think the SCs run out of steam at about 5,500 RPMs. Having said that the 964 cams might be better when or if you decide to go with EFI.

Best advice I can give you is to find a machine shop that you can trust that eats and breathes Porsche engines. The "bolt-on" stuff is all great, but unless you've got a solid foundation, you're asking for trouble. The majority of my budget was spent with the machinist.

Maybe you mentioned it, but how are you planning to fire the additional plugs? What ignition?

Also, if this is a track engine that will see regular high RPMs for extended periods, you'll need to think about race valve springs and Ti retainers. Not much benefit though (unless you feel the need to spend $$$) to go with this stuff for an every day driver.

mainly hot street/some track, I know they're dropins but I figure, if you're gona openit up, might as well go all out, (well as much as your pocket allows anyways)
my SC's do run out of power at 5700, but the 964s are better suited for me since Im porting the heads up to 41mm and will get raelly good bottomend, and a broader powerband

how much did you run up with the machinist?

not sure yet, was looking for the right setup, any ideas? My research shows up as Electromotive tech3. Im dualplugging simply for insurance, just wish it wasnt so darn expensive.

As for the machinist and how much I spent...I'M EMBARRASED TO SAY!!! Let's just say that the guy went through EVERYTHING! It was all measured, tested, fitted, etc. Every oil galley plug in the case was drilled out and everything was clean enough to perform open heart surgery on! I've never seen anything like it.

As for twin plug, I'm going with Electromotive XDi. It's good enough for my purposes. Another nice option to look into is the twin plug dizzy mod that Henry Schmidt of Supertec Performace does.

I thought a valet driver wrecked your car?

Sand_man, got any pics of yours so far that you car to share?

I'll post some soon. I've got my Ps&Cs installed and will be putting the heads and cam housings on tomorrow. Seriously, my parts looked new when I got them back.

it was hit yes, but it looked worse than it was with no structural damage. The Bodyshop of Barrington took a look at it. They slapped a new fender,new a-arm, windshield, re-tracked and aligned it to specs and that was it. It still needs a new paintjob but I needed to hightail down to AZ for my job.

If you plan on going EFI later on you should just have things twin plug ready and run plugs on the lower spark mounts in the heads. Going to a twin plug dizzy isnt cheap and the Electromotive's I have heard of, seen and read about plenty of problems. Some have had great success but others not so much.

I agree that going 100mm on a forced induction motor is calling things rather close. I have a set from charles at 100mm for a super fun little 3.3 that I am building with my dad. The case register must be opened up to accept these cylinder and the skirts begin to get thinner than normal. From 98 to 100 you dont gain a whole lot. I simply went this way because everything else on this motor is being changed, wanted to try something different and I think this combo has great potential to make some awesome power in NA form, also I can put in a 3.2 crank later on and get a 3.5.

Your upgrades that you are looking at are tried and true. On your exhaust are you planning on running heat? That has a big part in your header decision. Also, if you plan to run EFI in the future and if you go with a 98mm bore on top of your other mods you can get away with a higher static CR. As of now with cis you are somewhat limited as well as with a dizzy. As always with projects compromises much be reached in order to stay reasonably close to a budget. I say this because things begin to get way out of hand really fast.

Another route for EFI on a forced induction motor would be to utilize the 3.2 intake like many others have done, get a 964/993 dizzy modded for you, andial signal splitter and have at it. Seems like a very rugged tried and true route.

As far as racing springs with Ti retainers that all depends on your cam and rev range you will be running. I went that route and bought a set from John Dougherty at an awesome price along with my cams. A set of performance springs doesnt run too much and you would have a little more piece of mind if you feel stock springs are not up to the task.

Kennedy Engineering makes Porsche clutch parts at great prices. More often than not you will simply need to upgrade your clutch disc. The Centerforce clutch kits I have driven were not awe inspiring to say the least.

Anyways, best of luck to you and your endeavours.

Eddie,

With regards to your purchase of a 8:39 ring & pinion, you may want to reconsider if you happen to need to a rebuild of your transmission. I was in the process of rebuilding mine when I also got the bright idea to put an 8:39 ring & pinion in. After re-assessing the total for rebuilding the tranny ($1,800) and ring & pinion ($1,600) coupled with needing a new clutch kit ($1,500) needed to support my 600+rwhp I decided that it would make more sense to go with a G50/50 kit from Patrick Motorsports ($9,500) and sell my 930 tranny. Ends up costing more, but I think it will make the most sense in the long run.

David
1986 911 Turbo

I want/need heat.
Will prob skip twin plug altogether for now, tight budget.
964s are from DC, will pick up his retainers too, thnx
Going with 3.4's now.
Kennedy makes a hd clutch kit?

David,
my budget is too tight for a g50/50. still got that WUR?

bodywork update:

Im in AZ right now, just found a great bodyshop, Stuttgart Southwest, car will be going in to get tracked/aligned properly to meet factory specs and then totally repainted. Not sure if I want to stay black/black. I also will be going with the Ruf CTR bumpers from Souk and his 911R tail lights.

My advice...keep the OEM color - whatever that might be.

it's blk/blk

I think the 98mm cylinders are a more reliable option.

I decided not to do the 8:39 R&P since I've heard 1st gear becomes too short with mega HP. My plan is to finish the engine, see how it runs, and then decide whether to change the tranny gearing or spring for a G50.

It sounds like you're opening the intake ports to 41mm to match the Carrera intake which is a good idea for a future upgrade. The injector pockets are bigger on the Carrera so you'll need to match up an intake when porting the heads. The seal area on the intake ports to the intake becomes thin after these mods so you may consider having some welding done on the outside of the intake ports. After doing all this you might as well go EFI while it's apart. :D

125shifter,

I'd like to just dump CIS and go EFI, but its waaaay to much $$ now. In a couple years it'll come down. yes the 41mm is for the Carrera setup. Ill prob being skipping the 8:39 although Im on a limited budget so I cant swap for a g50/50, even though that is what I really want to do.
anyone selling their g50/50 for cheap? :)

From my investigation, the G50 is only about a third of the cost.

I was on a limited budget about 22 months ago. That didn't last long. ;)

how much did you pay?

I was looking into clutches a while ago and got same advise from other's on centerforce. ...go Kennedy.

What year is car? ...didn't see euro injector lines on your list.

Regarding springs, I've heard 962's ran same springs as 930's. I was okay with that.

Regarding twin plugs, you could just have them twin plugged (not that much) and put plugs in them and not use'm. Keeps you from needing to take apart later.