Hello All. This is my first time on this forum. Bought my '08 R56 a little over a year ago, and a couple of weeks ago on my way home from work, car dies out of nowhere. Towed it home, no codes, spark is good, fuel pressure is good. Removed my valve cover, and found what I was afraid I'd find. Upper guide is broken and laying inside the timing chain. The chain had actually jumped off the intake sprocket.

After doing my research, I have geared up for my first head rebuild. I know my intake valves have to be bent, and for good measure, I'm purchasing exhaust valves also, as well as guides and valve stem seals. Thankfully, I found some very detailed videos from a guy on YouTube detailing how to replace the timing chain and remove the head. However, he sent the head to a machine shop for the rebuild. I'm not into paying someone else to do work I can do myself (although if I had the cash I probably would...).

My question is, is there anyone with experience rebuilding an R56 head that has any pro tips they would like to offer? This is new territory for me. I'm assuming the rebuild is pretty simple. I'll be cleaning all the carbon build-up, reusing the valve springs, and replacing everything else already mentioned. Is there anything else I need to be aware of here involved in the rebuild. Any reason I should be sending this to a professional rather than doing the work myself? Any feedback would be greatly appreciated.

Thanks in advance!

 

Before you make too many decisions, get the head off and check for other damage --- you might not want to repair if pistons or block is damaged.

Assuming no other damage, you'll need a Bentley service manual for torque specs, sequence, and putting the front end into the service mode --- very helpful for creating a little more working space. Then there's special tools for timing, chain tension, FI seals, and possibly more, depending on your ingenuity. You'll need a good set of torx sockets, male and female, and maybe a spark plug socket, depending on what you have already. My old valve spring compressor, from the '60's, won't touch these Mini valves --- possibly another tool you'll need.

Gasket sets and replacement stretch bolts will set you back $300 more or less --- on top of valves, timing chain kit, and whatever else you find to replace. Be sure to check our vendor sponsors for the kits --- lots cheaper than individual parts from the dealer. PS --- valve stem seals are included in the head servicing gasket kit, while the head gasket itself is separate (two thicknesses are available).

No comment on valve guides --- beyond my experience.

 

Thanks for the reply! I was trying to avoid forking out the money for the manual with the fact that the entire project is looking to be over $900 with the specialty tools - found a good deal on the cam locking tool to service the timing chain and found a valve spring compression tool that approaches the springs from the side rather than the top - but rather than trusting a video to get my torque settings right, I think you're right about purchasing the manual. Everything else you mentioned I've accounted for, except FI seals. I'm assuming fuel injector seals? Didn't realize they needed to be replaced. Gotta add that to the list! Thanks!!!

 

Before you pull the head off, do yourself a favor, install a new top chain guide and realign the timing chain to spec, ive seen it many times timing skipped, but not causing damage to the valves, there is a big interval before it hits the valves. you might be lucky. Also after you reset the timing to specs do a leak down test before you start taking the head apart. You have a cooper s or a cooper? sorry if I missed it. I used to be a mini tech, before last fall, worked for dealership. Ive seen So many tow in's not even funny. Most timing related. Customer runing these cars with no oil. When top chain guide brakes, cams slap, it will skip but has to be driven like that for a while to actualy take it as far as bending valves. If top guide is braken it makes sence for the engine to run funny and stall, cams slap and cam sensor readings go off.

 

Lorenzo, I initially thought about putting on a new upper guide, setting timing, and giving it a shot, but the intake cam was way off in relation to the exhaust cam. Also, when removing the crank pulley, the crank turned over and I heard an obvious clunk. I may be totally wrong, but I've been told this indicates a bent valve. I'm just a little skiddish about trying to fire it up again without taking off the head to at least see the valves. I'll update the condition of the valves after I get the head off this weekend.

Btw... it is a Cooper S.

 

OBW, forgive my ignorance but what is the difference between the two thicknesses for the head gasket?

 

Sub, it's my understanding that the thicker gasket is a good option when you've had your head resurfaced. The thicker gasket helps to avoid increased compression...? OBW may know better than me, but I've also heard of using a thicker head gasket to reduce compression when upping boost pressure.

 

This's a good suggestion --- clean out all the broken stuff, reset timing and do the leak-down test, you might get lucky. Probably ought to replace the chain, remaining guides, and tensioner anyhow, but shouldn't need to pull the head to do this. Here's a procedure to measure the chain for stretch using the tensioner tool. Use it after you ensure the head is OK.

And yes, FI is for fuel injectors --- there's a teflon seal that needs to be compressed so it can be installed. --- each injector has one.

Head gaskets are available in two thicknesses --- OEM is 0.9mm and the optional one is 1.2mm. I've read that the 1.2mm is for a JCW, but haven't verified this.

 

Yes, a thicker gasket will reduce compression, but not by much (how much is beyond my knowledge --- SWAG is 0.1 - 0.2CR). Frankly, I prefer the higher compression gasket --- makes for slightly better power. Altho it can be overdone, as I recently posted --- https://www.northamericanmotoring.co...e-deadest.html My head rebuild is to be shaved just enough to ensure flatness, and the block is also to be shaved after a Cylinder Support System is installed and rebored. Both are in process, and I'm leaving the shave amount to the specialists doing the work --- I only specified "minimum shaving". A 0.9mm gasket is planned, but not yet obtained.

 

Thank you both for the answer

 

Set the timing. do a leak down test after, will show if you have bent valves.
Its totaly up to you, as you know better the situation...cheers

 

Where did tou remove the crank pulley from, 3 E12 bolts or 18mm big bolt?
If you heard a clunch when you removed you might removed it from 18mm big bolt, wich is holding the chain sproket at the crank. If you free that bolt, cams will spin the sproket. As valves want to close. Now might be too late. But never late to check forward. This is what you should do.
Dont spin the engine if you think its of, remove chain tensioner,remove the cams(intake and exhaust) remove the chain cassete...you have to do this anyway to install a new chain, but since you there its easy to check...use the big bolt to rotate the crank after, this way you can rotate the crank and be 100% sure wont hit any valves(no cams, valves are closed) at this point you can get every piston to tdc and do the leak down test it. Safe way..
make sure you follow the manufacture instruction when doing the job on install new chain.

 

Thanks for the advice, Lorenzo. I was turning one of the three pully bolts. Probably should've waited to lock the crank and removed the cams first. Lesson learned. I'll definitely try this and do the leak down test before tearing apart the head. Thanks again.