944 Turbo

I've mentioned this car in my other thread but I think it's interesting enough that I'd start a new thread to chronicle the project. It's a 1989 944 Turbo with all of the S options. M030 Club Sport package with the adjustable Koni suspension, big sway bars, Brembos, and limited slip transaxle. Pretty cool stuff.



To recap, about a year ago this car suffered a timing belt failure. I bought it immediately upon hearing that the owner had finally given up on the idea of fixing it. It started innocently enough. At first I thought I'd just replace some valves, put the head back on and be on my way, but we all know how that goes. A few days later the engine was out on the garage floor. A few thousand dollars later and I've almost got all of the parts I need to put the engine back together "the right way"... Parts for this thing make BMW parts look cheap.

The block was stripped bare so that it could be thoroughly cleaned. Fortunately the bores are in good shape despite having nearly 200,000 miles. The stamping shows that this is the correct M44/52 Turbo "S" block, originally equipped with all forged internals. Unfortunately the pistons have some pretty deep gouges in them from hitting the valves so hard, so a new forged set is on order. Stock bore and compression ratio with low friction coating on the skirts.









Since the valves cost so much to replace I ended up buying a spare head to rebuild. The head cost just a few dollars more than a single replacement exhaust valve! These heads were cast around ceramic liners in the exhaust ports and they use sodium filled exhaust valves. I was surprised to find out that the exhaust headers, crossover pipe, and apparently the downpipe are made from inconel rather than standard stainless steel. This really was a no expense spared car. My crossover pipe shows signs of a fairly substantial leak so it will have to be repaired or replaced.







The bearings looked decent for the mileage but will obviously be replaced. These crankshafts are forged and induction hardened so it shouldn't need more than a polish. Once the flywheel is resurfaced and the new clutch cover and disc arrive, the entire rotating assembly will be balanced since the new pistons are roughly 100g lighter than original. I went with a stock clutch cover and a Turbo Cup disc since the combination should be able to handle 400lb/ft.







Turbo "S" models used the #8 hot side K26. Mine had a little bit of shaft play so it's being rebuilt and modified to use the larger K27 compressor wheel and housing. This should provide response similar to the smaller K26 with improved efficiency and power potential. The specialist who is doing the modification tells me this combination should be able to make 320-340whp with appropriate supporting modifications to the fuel system. Eventually I will switch over to Megasquirt so that I can play with different blends of ethanol and eliminate the restrictive AFM.



That's all for now. Parts are inbound and the machine shop is booked for a couple of weeks, but I hope to have some big updates soon.