So I am finally putting my r56 S engine back together after a complete rebuild. My only unsure issue is setting the crankshaft to 90 deg BTDC. I have the pistons all even across the bores but I understand there are two complete revolutions for a complete engine cycle. I have the cams locked but I know I might need to remove them if needed and honestly that's easy enough. So how do I verify this? I originally asked the machine shop that installed the pistons to do this but they didnt so now I need to. I do have the locking tool for the crankshaft to the flywheel. I have not installed the flywheel as of yet but that is coming soon. I have the timing chain and all the crap that goes with that installed but not torques down as of yet till I know everything is in the right spot. I could take it back to the shop and have them verify my crank placement but I would rather learn and do it myself at this point. Any assistance would be appreciated.

 

The pistons will all be at the same height twice for each full crank revolution, and there are two full crank revolutions for the cams one full rev. Flywheel can only be mounted in one position --- it's keyed --- and there's only one crank locking hole to use. Your task is to install and lock the crank without turning the already locked cams. Then install the chain, set it's tension and complete the assembly.

Easiest way from your current re-assembly process will be to observe where the locking pin hole is located as you mount the flywheel. If it's on top, the crank needs to be rotated another 180 deg. This means removing the chain so the cams don't turn. If the locking pin hole is on the bottom, near the pin install hole, you're good to go. It might require slight crank movement to align the hole for the tool, depending on how accurately the pistons are set to all the same height. ANY crank movement should require the chain be removed so the vanos isn't disturbed. Be sure to not mix up one of the flywheel balance holes with the locking pin hole while making this observation.

Hopefully you're using the Bentley manual --- one of the "rules" is --- "only rotate the crank CW", looking at it from the chain end. I'm guessing CCW screws up the vanos. There's also the use of the chain tensioner, which isn't in all the other manuals. Also torque specs / sequencing, 1-time only bolt ID (TTY or stretch) and other great info.

 

Thank you. I'm trying to get as much done on the engine stand but I'm about to move to the hoist and I'll put the flywheel on then. I ended up placing a straw in each spark plug hole resting on the piston then turned the crank clockwise. I was able to watch piston 1 and 4 lower and 2 and 3 raise then stopped when 1 and 4 rose to where all were in line then locked the timing in place. I think that is good to go but I'll double check once I put the flywheel on.

 

It's pretty easy. Insert flywheel locking pin, verify pistons are level and that the part numbers etched on the cams is pointed up. Install cam locking tool and have fun.

 

thanks. I think I am about there now. I just needed confidence I was doing it right. Now I am 99% sure I did. Hardest part of any job is getting started. I tend to over think things and want to know exactly what and why I am doing something so I really research it till I understand. Might slow me down but I learn a lot and usually get it done right the 1st time. I have people laughing at me because I am putting a paint mark on every bolt I torque so I know its done but I can tell you I will not miss one lol. Tonight I am pulling the engine off the engine stand so I can get the flywheel and clutch on. I am about to set the engine back in the car Frisday or saturday. Its really not that hard if you just take your time and keep it organized. I placed all bolts in bags and zip tied them to all the components. That really helped. I am also cleaning every bolt before using them. I was really nervous taking this on but looking back I have had a lot of fun, learned a lot and made some new friends on here along the way. Once I am all done I will post my pics I have taken since day one. Again thank you for your help! Means a lot.

 

I got it!! Thanks guys. Once I put the flywheel on it all went together perfectly. Only needed to slightly wiggle the flywheel to line up the tool. Now the process makes since to me and I learned a lot. I made this a lot harder than I needed to. I appreciate the help. I am almost finished now!

 

Nothing wrong with paying attention to detail. Love the engine and transmission mounts. Is that paint, powder coat or anodizing?

 

Thanks. It's paint for now. Did the calipers to match but I think later I'm going to go with anodized but for now this worked. I'm so ready to be done lol