3 Litre Turbo Rebuild

[PJMARKOW]

I'am planning to rebuild my 1977 930. I have read Wayne's book and am confident now that the rebuild holds no mysteries. The motor has done 220,000 km, and still runs strong and does not use any oil, however, it has started to make a noise similar to a loose tappet, but all the tappets check out OK. I thought that it must have been a loose tappet on cylinder 4 as the noise was coming from the right rear of the engine, but was more to the centre of the case. The noise was only evident when the engine had warmed up, but now it's there even when the engine is cold. Anyway I was planning to do some improvements to the motor as I've just had electronic fuel injection installed, to replace the CIS system. You may be interested to know that this system is fairly simple to install, and the guy how installed it for me plans on producing a kit with instructions so that anyone with access to a dyno will be able to do the install themselves. It retains the 930 manifold, bybass manifold and throttle body. The CIS injectors are replaced by the electronic variety with fuel rails. There is also a boost controller and electronic ignition system all controlled by a local made Australian EMS Stinger ECU. The system as installed on my car has made a big improvement in driveability, and there is now almost no turbo lag, which is surprising for one of these low compression turbo motors, and this is without the boost controller connected to the ECU (it's still functioning as per factory standard). I will post some photos once we have the installation all completed, now back to my rebuild. Here in Oz I can only get hold of factory original pistons and cylinder sets, so I don't think I will be able to increase the displacement of my engine, however, with this new EFI setup, I thought that if my cylinders are OK, I could choose to go for JE pistons with say an 8:1 compression. I will be upgrading the cams, but now what cam timing would suit, SC cam timing, 996 cam timing, group B cam timng, I'm open to any suggestions. My car already has a 3.3 litre intercooler installed, but I hope to install a custom made job that will cool the inlet charge heaps better. Has anyone used the pistons and cylinder set from a 3.3 litre motor on a 3 litre motor. Is it possible? If you had to buy a new set anyway, you could bump you displacement a bit this way.

[lendaddy]

Unless I am mistaken the 3.3 is a stroked 3.0 not a bored 3.0 so 3.3 cylinders won't do it. I believe Wayne was selling a set of big bore 3.0T jugs earlier this year, I could be wrong. I am very interested in the EFI setup. Please provide as many details as possible! I hate CIS!

[PJMARKOW]

The 3.3 litre is stroked, but the bore is 97 versus the 95 of the 3 litre.
Yes i was getting frustrated with the CIS, as I could never get the car running right after I installed the 3.3 intercooler. If you want more details may I suggest checking out www.pem.com.au. Some of the data may be slightly out of date but the install is almost exactly the same. The guy who does this stuff is only part time at the moment (he works for an airline here). The kit he is putting together will have everything you need including the fuel and ignition maps, so you will be pretty close once you done the installation. You will only need the dyno time to fine tune. He hasn't been able to come up with a firm price, because he is still working on some of the finer points or the kit, but I'am suer he will be more than competitive with the Electromotive stuff over here in the US. The exchange rate with the Aussie dollar won't hurt either. He only did a very conservative tune on my car, due to the number of miles on the engine., but it has really transformed the car. With the CIS it was never really happy in stop start traffic, but now it's a pleasure to drive. The biggest change was in the mid range, and that's where most of us drive most of the time.

[Wayne 962]

Hmm, is there a question in here somewhere?

-Wayne

[PJMARKOW]

Yeh. What are your recomendations for a 3 litre turbo rebuild if the CIS injection has been replaced by a programable fuel injection system. Here in Australia I haven't found anyone with the 3.2 litre kit for these cars. If I have to replace my barrels and pistons, would it be worth using 3.3 barrels and pistons. If my barrels are ok I would probably go for higher compression pistons (JE 8:1). I will be regrinding the cams,but what grind would you recomend. I've read about shaving material of the heads to bump the compression, but would rather stick with the factory deck height and avoid problems with chain tensioners, sealing chain cases etc. The car is mainly used for road with the occasional track day (I believe you call it driver ed in the US). I've had the car for 6 years now and after about 230,00 kms I think it really needs to be treated to a freshen up.

Great book Wayne, it's the inspiration that will be driving my rebuild