76 930 3.0 engine rebuild, where to start?

[infraredcalvin]

I've got a tranny rebuild going on in this thread:

1st Engine Drop and Tranny Rebuild

I'm waiting for tranny parts, and the engine being an oily mess, I decided to pop the upper valve covers off and check my headstuds (famous last words). One one broken, just lying there, the other appears to be gone. Sooooo after a big heart to heart with the wife ($$$$ please), I'm slowly going to embark on an engine rebuild.

This forum is awesome, but I'm a little overwhelmed at where to start gathering information that will lead to a comprehensive part list.

My goals:
Slightly modified, 350-400 hp at the wheels, long lasting, non intercooled weekend driver, occasional DE. I want it to appear roughly stock, but provide a little more umph.

-P&Cs. I'd like to go bigger with a bit more compression (remember the stock 3.0 is lower comp than the 3.3)
-Heads, I'm not against head work as heads can be replaced at a later date for the CW (thoughts on this statement welcome). I'd like to avoid twin plug because of cost (thoughts welcome on this too).
-Cams are a must, but taylor end to my car.
-I'd like to stick with my current Kokeln turbo, and boost at .8 bar (I have a meth injection kit i'd like to put to use as a "just in case".
-Run pump gas (91)

I'm hesitant to call engine builders (supertech and/or turbokraft) as I'd like to do the work myself, and would feel guilty picking their brains without sending them the work. Info on the above is scattered, I haven't found a good book yet. I have the how to rebuild 911 book, but the engine choice/spec section does not really cover the turbo engines. This will be a few month project, but as usual I need to over study before buying anything. Sources, thoughts, encouragement is really welcome...

[Groovie Ghoulie]

People with a little more experience may chime in here, but the 350-400 RWHP takes a little bit more work and I would think more modification. 350+ ish FWHP is probably a bit more realistic.

I JUST completed my full 3.3 rebuild, and those are the numbers (350-400 RWHP) I am hoping for. I have some more break in time and tweaking before I dyno it, but just be aware that is a big power jump goal considering stock boost, and I presume stock exhaust system.

I went a little harder with my build, but your mileage my vary.

Best of luck to you.

[LuftWaffle]

Pat, I went thru a similar process with my '76 several years ago. Started out as weekend project to replace the stock exhaust and 3LDZ for a later style J-pipe exhaust with a K27-7200 and a GHL muffler. (this was before RarelyL8 was around) Made the same head stud discovery and the slope got suddenly steep and slick! Engine ended up down to the crank. My goals were similar to what you express; basiclly stock in appearance but with better performance and drivability. My engine had about 52K miles at the time. The crank and P/Cs all measured well within spec so those got reused. Had the rods resized with new pin bushings, cams were reground to SC profile, heads were reworked to stock. ARP head studs. New rockers/shafts, timing chains, etc. End result is a great driving car. No idea what kind of numbers it makes but is very responsive off-boost and pulls like a proverbial train on-boost. It had a Turbatrol oil cooler in place of the loop cooler when I got it which works well. All told I think it was about a $9K (in 2004 dollars) project and the only work I farmed out was the machine work on the heads and cams and the powder/ceramic coating. Hope this helps! -John

[CKPTAuto]

We are restoring a 76 turbo right now and I just put together a parts list with part numbers I could send you if you need. It's got a pretty complete list of most everything you will need (no stud kits though) and probably a bunch of stuff you won't, but i'm using it as more of a checklist for now. PM me your email and i'll send you a copy.

350-400 should be easily achieved with some bolt on's and decent cams/head work. Twin plugging wouldn't be necessary. Stock 3.0 P&C's aren't available anymore (although if you find some let me know and i'll take em!) You could buy stock 3.3's but if you are going to spend the money you should look into the 3.4 kit~

Oh and get yourself one of these little technical specs books, lots of good info in there~ This one ended on Ebay, but they are available out there if you know where to look~
http://www.ebay.com/itm/Porsche-Technical-Specifications-1976-77-911-Carrera-3-0-Turbo-Tech-Spec-/111244585871?pt=Motors_Manuals_Literature&hash=item19e6b1ab8f&vxp=mtr#ht_22wt_1319

Good luck!

[quattrorunner]

I also rebuilt my 3.0 turbo engine. It also had the stud problem but mine was in boxes.
A couple things I wish I paid more attention to is the case mating process. I have problems with oil leaking around the no 8 nose bearing. You can't rely on the factory o-ring only, Use something else as well there, and do rebush rockers while you do the rods.
You will love that little engine, it revs like a sport bike with a light weight flywheel and aluminum clutch.
I use a Garrett gt30r and it boosts very well indeed. If I did it again, I might choose 964 cams instead of the sc which I have as my turbo boosts so effectively I'd like more power up top but I can't complain. SC cams are great though.
Get a wideband gauge if you want that power level. You'll need higher boost and will get kinda silly over .8bar with no intercooler.
I'll watch this thread.

[jwasbury]

Hi Pat,

The 911 engine rebuild book is an excellent reference, even if not turbo specific. Bruce Anderson's 911 performance handbook is another classic must-have on your bookshelf.

Source parts from people like Henry at SuperTec or Chris at Turbokraft. This is how you can "pay them" for picking their brains. No first hand experience with Henry, but Chris helped me with advice about my DIY rebuild and was very supportive. I purchased my P&Cs from Chris, as well as the ARP headstuds and rod bolts. Later on in the build he help me with 1mm cylinder base gaskets. Maybe I could have saved a $ buying certain parts direct from the manufacturer, but its worth a few extra $ to be able to pick up the phone and ask a question directly...IMHO.

Time to set a budget...think about whether you want to split the case, or not.

I also have a spreadsheet documenting all the bits and pieces (part numbers) and cost for my 3.3 rebuild - happy to share with you if you want

[timc]

Originally Posted by jwasbury

Hi Pat,

The 911 engine rebuild book is an excellent reference, even if not turbo specific.

What is this book that you are referring to?

tim

[jwasbury]

Originally Posted by timc

What is this book that you are referring to?

tim

Written by Wayne Dempsey, CEO of Pelican Parts:
How to Rebuild and Modify Your Porsche 911 Engine

[timc]

Originally Posted by jwasbury

Written by Wayne Dempsey, CEO of Pelican Parts:
How to Rebuild and Modify Your Porsche 911 Engine

Thank you.

[infraredcalvin]

Ok, I'm reviving this thread because I finally got a bit of life out of the way and found some time to start tearing down. This is where I ended up after the weekend:

Man she's an oily mess

[infraredcalvin]

Here is one dilemma, I bought a leak down tester and performed a very cold leak down on all cyl. (Engine has been out and oil drained for 5 months)

Results:
1-3%
2-2%
3-3.5%
4-20%
5-17%
6-58%

This makes sense as my headstud problems are on the right side (4-5-6). It's obvious the engine has been gone through as the heads are marked with dots (like dice) as to the corresponding cyl.

With numbers like my 1-3 seems that I can continue to disassemble to short block, replace headstuds (as long all looks good inside and nothing is pulled) put back cyl and heads and if I get similar leakdown on 4-5-6, continue to button her up for another 40k+ miles. Sound crazy? For $$$ reasons I'm really trying to avoid the WIIT syndrome...

Edit: I should clarify that my intent with the leakdown is to get an idea on the condition of my cylinders/rings. Heads will be cleaned and valves inspected. Leak from oil vent cover will be fixed and case cleaned as well... any and all advice appreciated...

[quattrorunner]

My inexperience says leave the case together. It's all voodoo once it gets split.

[jwasbury]

Hi Pat,

How many miles on the engine (that you know of)? Depending on miles, its probably not a big deal to leave the bottom end alone. Aside from the additional time you'll spend on disassembly/assembly cleaning, once the case is open you're probably going to replace bearings while you're in there, and chances are you'll want to send out the crank for spa treatment. Ignorance is bliss...if you don't go in there, you will probably save 1-2k in parts and sub contract work. An additional benefit of splitting the case is you can verify the function of the piston oil squirters.

With those leakdown #s, assuming the right bank is due to broken studs, you may have some damage to the cylinder/head mating surfaces. Inspect carefully. I'd measure everything and verify within spec, if yes, you could put it back together and run it. consider new rings at a minimum.

This will be your least expensive path to getting back on the road, but won't net any performance gains.

[infraredcalvin]

I suppose I'll have a better idea this weekend when I pull the cams & heads. It's prob wishful thinking that they'll be no damage to 4-5-6.

She's definitely been rode hard and put away wet by the POs, I've tried to make up for it over the 7 years I've owned her, but I'm finding lots of little things that point me to full teardown. 1-2k savings is not what I'm after, it's the 3.4 P&C, port and polish, 964 cams, that I'm worried about .

Unknown history prior to my ownership, 120k miles now (I've put the last 30k). I've driven her appropriately hard, oil changes every 3000k. All previous maintenance under my ownership was with trusted shop. Finally it was the drop in performance, increased oil leakage and consumption, and the lack of cleanliness that drove me to explore on my own.

I'm not looking to push the perf increase too much bec I want to stay intercooler free, but I do have a new meth inj system on the shelf that I'll hide in there for safety margins only.

BTW: Big shout out to Chris at Turbokraft. Back when I first posted he reached out with lots of advice. I appreciate that.

[infraredcalvin]

I'm down to P&C and so far - besides dirty - things look pretty good. I thought there would be a lot more carbon build up in the pistons, they actually look pretty good.



Buildup on #4 is pretty consistent with the rest, cross hatching is visible and no scoring on cylinders. I did see one thing though on #6, can't tell if it's a scratch or a crack, you can see it around 6 o'clock:



Another thing I noticed is a rocker shaft starting to back out, yikes! I suppose this is one of the reasons why the rebuilders suggest the RSR update.



Still on the fence on splitting the case, although it would be nice to clean up the sludge I keep finding in various areas, not much, but while it's apart...

[jwasbury]

I see fully finned cylinders and I think that flat piece of cooling tin that goes across the top of the bank is not original to the earlier engines. Signs that it's been apart before?

Did 3.0 liter cars have the half finned cylinders or did that start with the 3.3 cars?

[quattrorunner]

3.3 cars have half finned cylinders.

[Robbbyg]

A Comparism from a 1977 euro

[quattrorunner]

A Comparism from a 1977 euro

That's not the top. That's the bottom.

[infraredcalvin]

Originally Posted by jwasbury

I see fully finned cylinders and I think that flat piece of cooling tin that goes across the top of the bank is not original to the earlier engines. Signs that it's been apart before?

Did 3.0 liter cars have the half finned cylinders or did that start with the 3.3 cars?

She's been apart before but the tin on top is orig per PET, not sure if it was gone through past heads, although pistons look pretty dang good for 120k miles.

Not sure what a divilar stud looks like, but these look cad plated, threaded on the ends only...

1 broken , one I can't tell, but assuming broken, one unthreaded when taking off barrel nuts.