What should I do to my 3.2?
 

Hello all,

I have a 1984 3.2 with 220,000 miles on it. The car pulls well and runs 3-4 on the oil presser gage and 210-230 deg. Car does not smoke but it does lose a little oil.
I just found a single head stud when I pulled the valve cover.
As such I know I will be “doing the heads” and replacing the head studs. As such I’m in the “whilst your there” stage. That’s where I need some advice. If I do end up doing a full engine rebuild what do you think I should do?

Option A is build a stock motor just like it was 1984.
In not too keen on that as I’m thinking “if I’m spending all that money why don’t I upgrade”.

Option B is build a 3.2 but build it with more power.
I like this idea but what would I do to get more power and what would it cost. I’m thinking I would have to up the compression but how high can I safely go running one spark plug and using CA gas (91 Oct/95 RON)? Would I have to replace P&C if I up the compression? If so what P&C should I use? Also the CAM’s would get work. I read a lot of people putting in 964 Cams but it seems to me that only gets you power higher in the rev range. Don’t know about you guys but I don’t redline my motor (much ) so is it a loss to do this, what is a better cam for low/mid-range? So with the valve job I could change the springs, is it worth doing? New plugs and leads. Anything I’m missing here, I know I am so what is it?

Option C build a 3.4 /3.5
But what type? Can I run single plug or do I need to twin plug it (keep in mind the fuel, 91OCT/95RON). What other differences are needed to support a 3.4/3.5 over Option B?

I look forward to hearing your comments and suggestions on part suppliers.

Have you looked in Wayne's about build combos? He has a pretty good list of motors/upgrades. Frankly, I never went too far across that chart as I have a 2.4.

Here's some discussion that kind of supports what I've heard over the years about c/r and plugs: single plug up to 9.5:1 and dual plugs, estricted timing and/or race gas above that.

If your crank and rod bearings are OK (they probably are), buy a set of slip in 98mm P/C kit n(10.5 compression), and you get a 3.4L. Then ad a set of good cams, (Dougherty, Elgin, WebCam can all advice you). If your budget allows, extrude hone the intake and bore out the throttle body. Also get a better exhaust system, the original "steals" at least 10Hp. Then get a Steve Wong chip for that specific build, and you will have 250 to 270Hp easy, with plenty of torque in the low end!
However, it's no secret that all Porsche flat six engines like to rev high, and that they come "alive" above 5,000rpm. Like with any Porsche, you should red line it every time you take it for a spin, and red line it as often as possible. Don't drive it like a Camry!!!

I'm not posting this in a mean spirited way, but I never red line my Porsches and have never heard anyone recommend this. It seems like such an odd recommendation. :confused:

I would take Fly's advice with a big dose of caution.

I can't see building a strong top end on a worn down bottom. You re going to be asking for another rebuild and it's going to be way more than a set of bearings.
Bruce

So build up the top end, leave the bottom end alone and then redline the car Everytime you drive it?? Great advice!!! While your redlining your motor do it in a school zone near the end of the month with a full beer in between your legs.

Cracking an Al case doesn't have quite the impact to your wallet as a Mg case. So, what is he looking at inside the case, Bruce? Verify the crank is in spec. Check lash on the IM although from what I've read, this doesn't have too much impact. Possibly upgrade the 4 rib oil pump to a turbo but 4 rib is fine, no? That leaves bearings which are relatively inexpensive. Have the case cleaned and the piston squirters checked. Other stuff like mains shuffle pinned and boat tailing cranks are for race builds. Seems to me like cracking the case is a no-brainer.

Budget?

Weak bottom end notwithstanding, nothing wrong with redlining your car. It wouldn't be the redline otherwise. I think Fly was trying to make the point that you should fully enjoy your car.

I just did a 964 Cam swap and proper timing is the key. Even with my 3.2 Cams I had great top end with SW Chip but timing was way off.

Now all around the car is ALIVE, bottom, mid & top. I bet when you tear her down check the timing, you might be surprised how off it may be due to worn components.

Only caveat is the idle will need to be bumped up to accommodate for sub-dips at motion

Assuming you meant your 85, how did you adjust the timing?

Using a timing Z block and Dial Gauge, and adjusted to close to 1.26 as humanly as possible.

Here is my journey: http://forums.pelicanparts.com/911-engine-rebuilding-forum/918126-964-cams-swap-journey-2.html

Prior to removal of my 3.2 cams I triple checked and my timing was 1.08 d-side and 0.83 on P-side :eek:

Option A: This would probably run you around $2000 if I remember correctly from our host's engine rebuild wizard. If you haven't already, I would give that a look. (Warning, it is a bit lengthy)

Option B: As long as your cylinders are Nikasil, you would only need a new set of pistons to bump up the compression ratio. I've mostly heard people using J&E which would run you about $1100 I think, but there are a few other manufacturers (wossner and carillo?). Opinions differ, but you would probably be safe at 9.5:1 on pump gas and single plug, which gives you a whole point of CR over stock US spec. As for cams, I think those usually run around $1k, and each of the manufacturers can help you select the right cam for your use and engine setup. I read on hear a little while ago about a guy who had Dougherty make custom profile cams to give better mid range performance at the cost of slightly less top end power since that fit his driving style. I believe several other Pelicans have since purchased that cam grind. Finally, you definitely want to get a new chip that is programmed to accommodate all of the engine changes. Steve Wong seems to be the go to, however, since I have an SC, I can't comment either way on chips.

Option C: This is my personal favorite. First off, no, you should probably not run single plugs on 91 if you do this option. Like you said, you can go 98mm p&c's for a 3.4, or go 100mm p&c's for a 3.5.
-Since you already have the 3.2 95mm cylinders, building a 3.4 is a much cheaper option. You can have you cylinders sent to EBS who will bore them out and have them replated in Nikasil by Millenium Tech. I don't know the price on that, but I think it was around $600-700. From there add in a set of 98mm pistons at you desired CR and a matching cam.
-The 3.5 will be a lot more money because you will have to source the 100mm cylinders. If memory serves, the original Mahle cylinders don't have enough thickness at the base when they are bored to 100mm and are prone to failure. LN sells slip fit cylinders which means the case doesn't need to be bored to allow for bigger cylinders. However, those cost a pretty penny: $3740 for cylinders and $4780 for p&c set. Once you have a set of cylinders, the process is the same as the 3.4: pistons and cams to match. The pistons don't really change price for the different sizes, so it is mostly the cylinders that affect the price.
-Twin plugging: You will certainly want to consider twin plugging if you go for the big bore. I've heard of people running single plugs with a 98mm bore, and certainly the Max Moritz setup did, but those pistons also had a special dome design to help the burn front. For protection, most people tend to go twin plug. Plus, with twin plugging, you can run higher CR. The downside is that it will probably cost about $2k to twin plug. I won't detail the various setups for this, but I can find a few helpful threads for you if you want.

Also, upgrading your exhaust is another way to get a little bit more out of the engine. Debatable on whether the power bump is worth the money, but that's a personal decision.

Hope this helps at least a little.

I only went 964 cams with SSI exhaust on my engine when I did the rebuild. Now I experience very much the same behavior up to about 4000 rpms, once the cams come alive, my engine has the same sensation of a power band kicking in on a two stroke engine. Very much like an extra thrust of power.
I agree with DRACO, dial in the timing and you will be amazed at how well the engine will run.

If you are planning on doing much in the way upgrading you might want to replace the rod bolts with ARP bolts. They tend to be the weak point in the bottom end of these motors. They will stretch then come apart usually as a result of an over rev caused by a missed shift. Cheap insurance.

+1 on what Ken said. Your engine has the slightly smaller (I think was from 10mm bolts to 8mm bolts) connecting rod bolts. If you plan on doing any upgrades that result in either an increase in power, or plan to build for a higher revving engine, you will want to consider getting rod bolts that are stronger than the OEM.

911 engine rebuild advice - books to get
 

buy 3 books: SmileWavy

Wayne's - Pelican Technical Article: Time to Rebuild? - Part II

Bentley - Porsche 911 Carrera Service Manual PELP989 - PEL-P989 | Pelican Parts

Bruce's - 1989 Porsche 911 Carrera Coupe - Books & Technical Documentation - Page 1

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Why are some of you afraid of running your car to red line?

Cheers

+1
Red line is the guarantied safe rpm limit.

I've meet people that upgrades their engine for more power but never go above 4000 rpm.... :confused:
Most stock Porsches make peak power around 5800, if you don't go there your leaving power on the table. It is in fact good for the engine to be run hard from time to time.
However I'm not recommending to shift every time at 6000, for example around town, that's just stupid and makes other people want to shot you.