C63fora2w1

I just read through this thread and saw guys talking about replacing one bolt at a time. Isn't there a specific torque sequence on the bolts ? That's how it is on SBC's and most engines I have dealt with in the past. Also if your going to remove the entire valve train and replace the head bolts it would be a perfect time to pull the heads and send them out for a port and polish. For those of you interested I did some Google searching and found this company that offers work to Mercedes engines with out the usual AMG tax. http://www.dprracing.com/smercedes.html The company also makes custom cam shafts. My gut tells me that the M156 would respond really well to a more aggressive cam profile. Its basic hotrod stuff Heads, Cam, Intake, Exhaust if you combine that with EFI and a custom tune it should reward you greatly. If you use the LS platform for comparison even modest cam upgrades yield 50-70hp improvements and that is on an old pushrod style V-8. The M165 uses OHV, quad cam design and therefore should be much more efficient.

BLKROKT

You have all of these "gut" suggestions that have already been tried many times, and most have failed.

Camshafts = not a good idea, do a search
Head porting = heads are super efficient from the factory, do a search
One bolt at a time = has been done countless times with no problem as long as the HG is ok, do a search

Blah blah blah custom tune and EFI...... blah blah blah LS this and LS that..... seriously, do you just like to pollute threads? Did Eurocharged stop answering your calls?

C63fora2w1

Thank you for your kind and thoughtful response. Your wealth of knowlege will serve the community well. Have a nice day.

Jasonoff

Yes, but it's mainly for compressing a new HG.

It's quite a bit more effort to pull the heads. Probably close to double.

jptaylor

i would agree with that statement...swapping the head bolts or changing to studs with the heads in place is big job but not a bad job.....but when you talk about pulling the heads you bring SEVERAL more factors in....such as having to remove the lower cam gears which lets the chains fall limp, which allows the tensioners to fully extend(as in past there wear pattern) and then youve got to get all that lined back up as well....and as has been stated earlier these heads are pretty much optimal from the get go.....and dont get me wrong, im not hating, i LOVE the LS motors as well but there is one helluva difference between a mass produced, assembly line LS and a hand built/assembled engine with bespoke parts fit to it for premium performance. If you wanted the LS statement to have any validity here then you should have specified LS-X or LSA as THOSE engines i would feel comfortable saying are much more in line with the M156 as far as optimized out of the box goes....

Boris's c63 AMG

interesting

Boris's c63 AMG

hey thanks for those pictures, they helped alot! so i will be able to pop he cover off without touching the timing chain right?

Boris's c63 AMG

that last picture shoes the timing chain on the cover off of the engine. Would i not be able to just leave the chain on the engine when i remove just the cover?

Jasonoff

That's just because the heads are removed in the last picture.

Rovel

In case anyone still needs head bolt replacement in 2020. Thanks to this forum I replaced head bolts one at a time and made a DIY video