Ranger's Dec09 motor rebuild thread (lol)

#141

We need more research to help these stupid german engineers solve this head cooling problem. Can Traqmate gather this data?

#142

i’m waiting for the micro-transducers to be installed inside the oil/water passages of the head using thin film deposition techniques. i hear scott is currently building the argon plasma laser and vacuum chamber required for this technique.

one of the issues is that we cannot pack all the processing power to analyze this raw data within the car and still be close to min weight. yet another reason to drop the min weight by 100lbs. one solution is to have wireless real-time telemetry streaming from the car to a trackside telemetry trailer. from there we can tap into a 100,000 node grid compute cluster using a satellite uplink. The analyzed data can then be re-transmitted to the car via satellite signal and fed into the driver’s HUD.

#143

:laugh:

#144

jlevie wrote:

:laugh:

#145

Head will be back tomorrow…Scott can post an “after” picture. Chuck

#146

Scott doesn’t have access to a computer at the moment (how could that be?), so I’m posting the picture of the repair.

Well that didn’t work…

#147

Trying again. On the previous attempt the file was a bit too large. I resized it, but then an Edit of that post didn’t offer the image attach dialog. Dunno what is up with that.

#148

Cool,how much did you have to mill the head?

#149

Just enough to clean up everything… CB

#150

Yep…enough to true, including the .003 sway back in the middle of the head. I just hope the block is not totally out of round. CB

#151

Am back from CT. 16 1/2hrs in the car with wife and 3 kids. Thanks to the book on tape and headset it wasn’t so bad.

Now that I have a real Internet connection I can continue to make an ass out of myself here amongst my buddies. I need to find some .5mm over piston rings and trying to find them on the 2" screen on my cell phone wasn’t cutting it.

My intent to use the phone as a modem for the computer was a big fat failure.

#152

Ranger,

I’m glad you’re back - I need you to distract everyone from my stupid Spec E30 tricks (like installing camber plates on the top of the tower or installing the trans cross-brace backwards…)

Back on topic: I know your head builder saw some oily buildup in the cylinders, but maybe that was just the result of misfires caused by sticky valves?

Did you do a leak down on this motor before you tore it down? If it overheated, I’d be tempted just to re-hone the bores, throw some new rings in it - and call it good. “Loose is fast” when it comes to race engines - so what if she burns a little oil?

Jim

#153

Understood about hone and run. Because the motor was hot enough to crack the head when water was added, I seriously question the roundness of the cylinders. A simple hone job will not make the cylinders round, and new or old rings will not seat on a non round cylinder. We will check the bores next week. CB

#154

I understand the reasons for trying to reuse this head and do it on the cheap. By milling the head, you may inadvertently end up with more compression than is defined by our rules. What is your plan for this?

#155

Gasman wrote:

I don’t know what Ranger plans to do, but milling the head up to 0.012" is an accepted practice as specified in the factory shop manual. The manual also instructs you to use a 0.012" thicker head gasket - ostensibly to maintain factory compression ratio - after decking the head.

#156

Steve D wrote:

[quote]Gasman wrote:

I don’t know what Ranger plans to do, but milling the head up to 0.012" is an accepted practice as specified in the factory shop manual. The manual also instructs you to use a 0.012" thicker head gasket - ostensibly to maintain factory compression ratio - after decking the head.[/quote]
I’d think that the change in compression ratio would be less significant than the change in valve timing.

#157

Jim is correct.

Note…BMW shop manuals have never been available to the public. The best reference we have is the Bentley manual. It specifies a minimum thickness for the head which relates to approximately .022-.025" that is removable while staying within manufacturer tolerances, which is what we want to do. If we need to remove that much, we can. Chuck

Oh, and by the way, after CCing many heads, I have found that milling .025" yields less than 1/3 point in compression.

#158

Gasman wrote:

My plan is to beat you like a dog at every track in the SE. And then taunt you by exclaiming “It must be the compression”.

#159

If by some fluke that should happen, my plan is to say “see, I told you so”. :wink:

#160

Gasman wrote:

Entirely fair.