Anyone driving an SC 930-10 row?
 

I've got a rebuilt '83 sc row on line to drop into my US 83 SC.
Anyone here done the same and driving that row motor?
Would like to chat with you.

I'm driving an 83SC cab RoW, but this is my entry into Porsche ownership and have never driven other 911's.

Where did you score that Pat? I'm 1 digit away with a 930/09.

83 row engine
 

I have an 83 row 911SC. There are known piston issues with these engines. They got me. I rebuilt it as a short stroke 3.2 engine. I do not know for sure, but I think the problem is the 9.8to 1 compression ratio and the factory pistons are cast, not forged as they are in the early S engines. ( with this high a compression ratio). There are several articles about this issue in the Excellence Magazine technical notes by Bruce Andersen a few years ago. My engine still ran great even with the piston issue, but it was a cartoon car that engulfed any following vehicle in a cloud of smoke whenever I went from off throttle to on throttle. Anyway the fix was great but very spendy.

I was unaware of this...any more stories or a link to the article please.....the deal isn't done yet!

SC pistons
 

Here are a couple photos of the Technotes article. Sorry for the poor photos, and you will have to go back and forth a little to read it all. Could not get a full page in and have it legible. Also a couple shots of my 83 row parts. I never heard of this til I experienced it.?http://forums.pelicanparts.com/uploa...1361328444.jpg
http://forums.pelicanparts.com/uploa...1361328479.jpg
http://forums.pelicanparts.com/uploa...1361328521.jpg
http://forums.pelicanparts.com/uploa...1361328556.jpg
http://forums.pelicanparts.com/uploa...1361328592.jpg
http://forums.pelicanparts.com/uploa...1361328621.jpg

Well I ran into this piston problem as well, but I'm not sure its an epidemic or anything... just part failure after 25+years...

http://forums.pelicanparts.com/911-engine-rebuilding-forum/248145-pieces-came-tumblen-down.html

http://forums.pelicanparts.com/uploa...1130391030.jpg

http://forums.pelicanparts.com/uploa...1131083118.jpg

However... I rebuilt mine back to stock. Thing hauls azz. No smoking or anything like that. I have been tracking it and driving it for about 5+ years now with no problems.

The initial diagnosis was bad gas causing some detonation. At 9.8:1 compression the motor is really at the limit of what CIS can do. My motor really needed to be torn down anyway and this was the catalyst to get that done.

It is interesting to note that this is the 1st time I have read or heard of this issue with SC pistons in the 15 years I have owned my car. I believe that it may be simply an age of the equipment issue that is starting to show up after 25 years in service... I'm not sure that there is significant risk of this happening and I would not be put off buying the euro engine by this. Sure its a risk, like buying any used engine, but I would expect if it were a common failure mode we would be hearing a lot more about it here on Pelican.

Enjoy!

It's hard to judge these experiences without knowing about the condition of the ignitiion and fuel systems. I had much more of a detonation problem on the 9.3 c.r. 930/16 engine that I drove for years than on the 9.8 c.r. 930/10 motor which I have also driven for years. Both cars saw lots of autocross but no track use.

A key differene is that maximum advance on the 930/10 is 25 BTDC, whereas it is something like 35 BTDC on the 930/16. When I got my Euro Targa, I found the ignition was set to the US spec - way too advanced. Just saying...

My 930/10 has 180,000 kms and has never been apart. Good head studs, too. I'm sure that I jinxed myself by saying that! :eek:

Concur on the timing issue. Alot of these motors are set timed to us specs. Mine has been going strong for 10+ years with no problems. My only issue when I got the motor was broken head studs and valve guides. After the top end rebuild it has been very robust. I have no clue on it's mileage but it has run strong for many years and had the crap run out of it on the track. Strictly street now. just use the good oil with zddp additives.

BTW, mine was rebuilt by the one and only Howard unrh unrh Freeman

Funny you should say that...the 930-10 I'm buying has also been redone by Howard. I appreciate all of the info from owners and their experience.......almost got scared off but have heard from lots of folks with big miles on their 930-10 cars and it comes down to how the car/motor was treated...properly set up, the right (cooler) plugs, warm up etc and the motors history.
What a great source of input and knowledge.

I remembered wrong on the spec, but the distributor specs are different too. The "timing control" does not tell the whole story. The main point is that the timing is set differently. Also the spark plugs are important. I ended getting a couple of sets in Europe, though there may be someone who sells them in the States.

BTW, a set of SSIs on my 930/10 really livened up the engine. It has a great top end, much better than my 930/16 had with the early style exhaust.

I've been told that the ROW plugs are two heat ranges cooler than the stock 930-16 and that the fuel mixture needs to be set twice as rich as stock 930-16. That and the timing issue stated above in the doc Howard provided may have been part of the problem for some burned pistons.
Interestingly, in that article, many of the cars with the issue were the 930-16 that had lost the bottom skirt of their pistons so who knows....probably a good deal of unknown car history in the background, proper oil changes, driving too hard before warm up....lots of factors.
Some of the shop owners that emailed me had never seen this issue in any ROW vehicle...but they were prop maintained.
I'll take the chance.

Spark Plug Number?
 

I am servicing my 83 930/10 and getting a spark plug number/heat that I can be confident with is had been a bit if a research project. My OEM Porsche CD catalogue has the W3CC Bosch but it is a special order thru Pelican. The US is a WR5D which is a bit hotter for a 9:8 CR motor especially if you drive in high temperature conditions. I am looking at B8 or B9(colder) heat range NGK plugs and factory timing. Anybody have the "MAGIC PLUG NUMBER"?

I am running NGK B9ES which is the correct plug for the motor and one step colder then the plug used in the 930/16.

What about W3DC
 

I found some NOS W3CC. However, I also found the W3DC on some Euro web parts sellers. Anyone know the difference between BOSCH CC & DC? NGK B9ES is also a good number, THANKS!!!

UPDATE: The W3CC & WR4CC are non-projected tips so they did not work well plug & play in 2 different 9.8 cars. An experiment that confirms the project tip works well. Looking at NGK BPR8ES that another 930/10 owner is running. The NGK BPR8ES is a little colder than Bosch W5D. NGK numbers are colder as the number gets larger (opposite of Bosch number system).

The late US 911SC has less ignition advance than the ROW. The difference is the ROW engine is spec'd for 98 RON fuel and the US 87 CLC fuel. The main culprits for the detonation problem are heat and oil dilution. Removing the vacuum retard and getting the hot breather oil out of the intake solves most of the issues on the US model.

So if you are running a 930/10 which requires 98 RON fuel, you should be good with 91 or 93 octane available at Sunoco. I have been running 93 octane Sunoco in my 83 930/10 with good results. Not a hint of pre-detonation or pinging in any gear under any load. These motors pull well from 3K on and will cruise all day at 2.5K up. This calculator will help with the conversion for those not already familiar with it. http://www.csgnetwork.com/octaneratecalc.html

Warren

Depends on engine temperature. My experience is, you really don't know anything until the engine is apart. If you know what to look for, the signs of detonation are obvious.