Breaking in new Cam and Rockers in an M20

[digger]

Okay, followup question after reading two different opinions (on non-BMW engines). Do I moly lube ONLY where the camshaft touches the head, or do I lube where it touches the rockers as well?

on rockers and lobes to

[Earendil]

Well. Parts arrived. Camshaft looks like it has defects. Any thoughts?

[Earendil]

Okay, followup question after reading two different opinions (on non-BMW engines). Do I moly lube ONLY where the camshaft touches the head, or do I lube where it touches the rockers as well?

[TobyB]

You don't want to go to 2500rpm until the engine is at normal temperature.

The cams I have used have said to go to 2500 as soon as possible. So I do.

I also use either a ZDDP additive or proper break- in oil. I had a cam eat itself
once, and that was quite enough, thank you! It's too cheap to use to NOT use it.

t

[EyExR]

Its where the old mechanical distributor went, drivers side of the engine, just above the pump. A diagram on realoem will help visualize.

This is what I did and it worked. But I have to say, that dropping the hex shaft into the block is a very easy mistake to make when doing this procedure. I lucked out and managed to drop it right back in place but it was nerve wracking!

[digger]

. You don't want to go to 2500rpm until the engine is at normal temperature.

ive seen cam manufacturers recommend to do it as soon as it starts not wait what would probably be 10min

i agree on a performnace cam with stiffer valve springs it is alot more important

[whodwho]

My take on this 8^)

Being it is not a new motor not sure it needs to be primed but never hurts to get good oil circulated thru

First there wasn't mention of if this is just a stock cam or a high lift one. Stock you won't need to be as critical but I think should still be observed. You just don't want it to idle for the first 20ish mins, I'm not sure that it needs to be up to 3k but I hold between 2-2.5k

This also doesn't need to be in one shot, you can fire it up keep it r3vved up and shut it down for whatever reason like address leaks, overheating, change the oil if it is that contaminated and start back up keeping it r3vved up in one or multiple sessions for a total of the 20ish mins.

[jlevie]

You have time to bleed the cooling system while the engine is coming up to temperature. You don't want to go to 2500rpm until the engine is at normal temperature.

[nando]

Its where the old mechanical distributor went, drivers side of the engine, just above the pump. A diagram on realoem will help visualize.

[Earendil]

Even better, remove the cap for the oil pump drive shaft and prime the pump directly using a drill.

(Sorry, hit "edit" instead of "quote")

Procedurally, I have a lot to learn. But I didn't think there was a piece of my car left that I wasn't aware existed, and you just named one. Where is this "oil pump drive" cap, and what is it used for? Google image searching isn't helping me out here.

[nando]

To prime the oil pump, pull the coil wire and crank the engine over. Then replace the coil wire when you want to start the engine.

Even better, remove the cap for the oil pump drive shaft and prime the pump directly using a drill.

(Sorry, hit "edit" instead of "quote")

[digger]

prime the oil pump not the oil whoops

[AndrewBird]

To prime the oil pump, pull the coil wire and crank the engine over. Then replace the coil wire when you want to start the engine.

[nando]

use the throttle stop screw to hold open the throttle while you bleed it. no big deal.

I don't think you need to drive it, in fact I wouldn't.

also, by "prime the oil" I think he means prime the oil pump.

[Earendil]

This may sound a bit silly... but if he pulled the head off etc and is essentially firing this motor up for the first time won't the coolant system need to be bled? How is he going to run the motor at 2500-3k for 20min without overheating... IF the system has air in it? Genuinely curious here!

This guy here! I probably wouldn't have thought to ask that until I was 30 seconds from starting and running through my checklist :)

Perhaps I need to try and recruit a friend to bleed the system while I'm keeping the RPM at 2500?