theasphaltgambler

After purchasing my (first)'85 targa creampuff last month with 97k; the cam chain(s) started to make noise occasionally. Since I'm an seasoned ASE master tech with lots of European exp (except for Porsche) I put it off for a later major service. Guess what? While on a recent outing the noise got very loud. Irregular whacking /knocking . As I tried to limp home 150 miles away, one let go then I lost oil pressure. I then immediately pulled over and had it towed.
Since I'm unsure how much damage was done I'm going to pull the engine out and tear it down. As long as I'm in there (and learning) I'd like to know what the OE static compression is and bump it to 9:5 by either piston change or milling the heads /barrels. As far as cams I here that either SC or 964 grind works well but which one? Also who is a reputable at extrude honing the intake manifold and cylinder heads? This engine was tight (seal-wise) and used maybe 1qt for 700 miles and carried good oil pressure. I hope that this will be just a freshen up and chain/guide replacement.
I'm an experienced performance engine builder and am looking for one source for tech info and problem areas that should be addressed. Any and all experienced advice is welcome. Thanks!!!

fixnprsh

Get this book at Pelican Parts

I tried building a 930 by it just for the hell of it and its better than a factory manual and has all tech specs you need.

As far as cams, with motronic 964 is the way to go.

as far as raising your compression, where do you live? what gas do you have. I thought about trying a bump on my 3.2 but decided against it due to wonderful CA gas, smog, and cost for pistons. you can cut the heads I've heard but then you have issues with chain, housings lengths and manifolds, and tensioners.

as far as extrude honing, go for it but take some 80 grit and rough them back up slightly as extrude honing leaves them too smooth and gas beads up, heads leave alone.

you can measure and replace rod bearings with out spliting the case but if your chain is damaged you'll have to split it anyway. upgrade the fasteners and use some high grade head studs and dump the dilivar. Its expensive, but so is everything else so this is the last place to save money.

as far as heads, all new guides and springs are a must. aftermarket guides are apperently better than O.E.M. guides. the cost of drilling and tapping the heads for twin plug while they are stripped is like $500 if you ever plan on spending the $$$ for the rest of the setup later, the hard part is already done.

theasphaltgambler

I live in Va, and 93 octane is everywhere here. Where I live there is very lax emission standards. I need to find out what the '85 3.2 static compression is so I can then make a decision. I know by experience that anything past 9.5 in any aircooled engine is a risk. I also know that there is very little performance to gain (on the street) past this point. But if the stock compression is say 8.0-8.5 raising it to 9.5 coupled with the basic mods is a big increase in torque and efficiency. Who would be a good source for purchasing cams and pistons? I have access to WorldPac and can buy at my shops cost but they only supply OE parts.

JackOlsen

Not to cross-promote inappropriately, but Pelican Parts has a forum in their BBS that's specific to 911 engine rebuilding where you'll get a lot of input.

fixnprsh

in 85 your at 9.5:1 stock, that was 207hp from the factory.
an 85 in europe was at 10.3:1 and was 231Hp stock,
you can source higher compression pistons to bump it but your looking at running 93 all the time and hope your government officals dont decide to start smoging cars like here in CA as most other states are starting to do. It might/might not pass, its hard to say. I think the formula is a 10% gain per point you go up as the general rule of thumb.
We need someone to chime in who has experiance raising the compression on these cars.
I have a friend with a GTI that had a 3.1L with a large compression ratio. it would throw down 230 hp to the wheels NA. but he was always having to fill it with a mix of 91 and 100 octane to get it to run right here in CA.

r911

raising the compression is best if you twin plug - you will also want a good reprog'd chip

theasphaltgambler

I'd like to keep it simple. If it came with 9.5 stock and the pistons spec out well then I'll re-ring and bearing it, set the minimum deck height. and install the 964 grind cams. Any other suggestions?

fixnprsh

have the P's & C's and heads zyglowed for cracks. Check the gaps between the compression ring and the piston ring groove, if you arent cutting the heads, or changing pistons/cylinders, you wont need to reset deck height. make a note of the shims that come off the bottom of the cylinders (usually just one shim .25mm) upgrade your hardware though. You would hate to break a head stud within a few thousand miles and half to tear the top end back off. or worse a rod bearing.
Building these motors is alot of fun. just take your time and be thourough.