From : 
"Gerald Stanley" <>
To :,
Subject :  Re: 3.5 motor
Date :  Mon, 30 Jul 2001 11:23:20 -0400
Hi Doug,
Just got back from the Porsche Rennsport Reunion at Lime Rock. Fast & Loud
cars. Yeah.
The 535 motor is a drop-in with the following notes:
- The end of the camshaft has a Motronic-only drive on it. If you plan on
using carbs, you can get a conversion nut for $60 from Metric Mechanic --
this would also necessitate using your old upper timing cover, distrib,
distrib drive gear.
- Your old carb manifolds bolt right up, as does the old thermostat housing.
Use the Bav exhaust manifolds, as the 535i ones are 60 degrees different on
the downpipes connections.
- Use the old brackets from motor mounts, A/C, PS, alternator. The mounting
holes in the block are identical.
- Auto cars did not have a pilot bearing in the back of the crankshaft. The
input shaft of the manual tranny rides in this. Make sure you install one.
- Your 4-speed, clutch, flywheel, throwout bearing, clutch slave cylinder
will bolt up fine. On the old blocks, there's an aluminum reinforcing
bracket in front of the slave cylinder. The 2 mounting holes do not exist on
the new block. I drilled & threaded the block and used it -- most folks just
leave it out and do fine that way.
- Be aware of the fuel tank return line needs if going Motronic. Other
people can give more detail on this.
- '88 head has no Mech fuel pump drive, so you'll need and electric pump and
a requlator in the trunk.
- There is no coolant return port on the Left-rear of the new block. On carb
blocks, this connects to you choke-heater coolant lines. If going with 32/36
carbs, get electric chokes @$25/carb.
- If using carbs, use your old valve cover and associated studs.
- Use the 535 oil pan. Just snip the oil-level sensor wire.
- If going Motronic, I think the big E3 brake booster is too big --others
can confirm/deny.
That's about all I can think of off the top of my head. Feel free to ask
more -- I'll advise if I can.
Shoulder is healing well, but will probably be another month. Waiting for
insurance folks to look at the bike.
I'll copy this to the list as others may have more to add.