Ruby's Rebuild Redux
#1
Rennlist Member
Thread Starter
Ruby's Rebuild Redux
I figured I'd start a new thread now that this is in progress.
Recap: I built the engine two years ago and spared no expense other than using my original pistons and cylinders which were within spec. I recently got a set of new Mahle 98mm 10.5:1 compression pistons and cylinders which are going in, along with twin plugging. I do not intend to split the case again.
So, the motor came out yesterday, and today I stripped the top of the engine down. I'll start on some exterior cleaning next weekend before stripping the topend down and removing the old "jugs".
Some pics from yesterday and today:
Recap: I built the engine two years ago and spared no expense other than using my original pistons and cylinders which were within spec. I recently got a set of new Mahle 98mm 10.5:1 compression pistons and cylinders which are going in, along with twin plugging. I do not intend to split the case again.
So, the motor came out yesterday, and today I stripped the top of the engine down. I'll start on some exterior cleaning next weekend before stripping the topend down and removing the old "jugs".
Some pics from yesterday and today:
#3
Rennlist Member
Thread Starter
Well, it really comes down to making sure I don't get any contaminants in the case when I open up the internals. She does have a little oil around the breather on top of the case and general grit that accumulates.
#4
Rennlist Member
Thread Starter
OK, surprise #1. Whalebird made a comment on a thread a few weeks ago about how it isn't a bad idea to drop your engine every once in a while. It struck a cord in me, and I've always counseled people that it is easier in the long run to drop an engine to reseal top goodies, etc, than it is to do a partial drop and try to do the work in a compromised environment.
Well, take a look at my MOTOR MOUNT!! If this engine was not out, I probably would not have seen this, and it is only going to get worse. This is what is bolted over your crank pully, and what the engine support bar attaches to. It is what supports the weight of the engine. I've had this engine out twice, and I did have a crack at the ear right above this (non-structural) where the engine tin mounts to. That was welded and painted the first time I took the motor out, probably 6 or 7 years ago. I then rebuilt my engine two years ago, and recoated-no issues at inspection then.
Now, look at the cracks. The metal just looks plain worn out. It is sobering. I know Ruby puts out some decent power, and I do make some use of it, but wow!!!!
Well, take a look at my MOTOR MOUNT!! If this engine was not out, I probably would not have seen this, and it is only going to get worse. This is what is bolted over your crank pully, and what the engine support bar attaches to. It is what supports the weight of the engine. I've had this engine out twice, and I did have a crack at the ear right above this (non-structural) where the engine tin mounts to. That was welded and painted the first time I took the motor out, probably 6 or 7 years ago. I then rebuilt my engine two years ago, and recoated-no issues at inspection then.
Now, look at the cracks. The metal just looks plain worn out. It is sobering. I know Ruby puts out some decent power, and I do make some use of it, but wow!!!!
#5
Rennlist Member
Ed: Fascinating. Maybe 20 years ago I wrote a brief tech article for PCA - LA about this issue. During a period of about a year my shop discovered this problem on about 3, maybe 4, '84 Carrera Targas. It scared us enough that an inspection of the pylon, using flashlight and mirrors, became a routine part of services done after that to all 1984/85 cars. We erred on the side of safety, and replaced (rather than repaired) a number of pylons. The problem seemed to be with manufacturing of a batch of mounts (improper cooling?), but we never determined the cause. I will try to find that article, but I'm not sure that I still have it.
#6
Rennlist Member
Thread Starter
Wow, that is interesting Pete. I've no interest in repairing this piece. My initial thought is that it may indeed be a high-strength steel or heat treated, for it to crack like that.
I believe I've found one off of an '85 to replace it with. There seems to be a different part number for SC's and '84-89. Is that due to the size of the crank pulley and the clearance required?
I believe I've found one off of an '85 to replace it with. There seems to be a different part number for SC's and '84-89. Is that due to the size of the crank pulley and the clearance required?
#7
Race Car
Nobody wants to find problems, but there is satisfaction in KNOWING. This isn't a PPI; your keeping(not "getting") things right and prudent care and feeding of Ruby is fun for you. Finding stuff like this just feels good and is a sign of good things to come.
Cheers Ed.
Cheers Ed.
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#9
Rennlist Member
Wow, that is interesting Pete. I've no interest in repairing this piece. My initial thought is that it may indeed be a high-strength steel or heat treated, for it to crack like that.
I believe I've found one off of an '85 to replace it with. There seems to be a different part number for SC's and '84-89. Is that due to the size of the crank pulley and the clearance required?
I believe I've found one off of an '85 to replace it with. There seems to be a different part number for SC's and '84-89. Is that due to the size of the crank pulley and the clearance required?
#11
Rennlist Member
Thread Starter
No kidding on lucking out in seeing this now. When I have all that extra HP on tap soon, I'd have just ripped this part to shreads!!!
Mario-anytime, my friend!
Mario-anytime, my friend!
#13
Race Car
Howdy Shepp. I was thinking about you...subtle Rush referance in post #190 in the now epic "amber lamps" thread in OT.
Sorry Ed. I promise not to derail your "epic" Ruby Redux thread. I'm keeping an eye on this thread and will be with you every step of the way. Hey, did you decide against the Extrudehone?
Sorry Ed. I promise not to derail your "epic" Ruby Redux thread. I'm keeping an eye on this thread and will be with you every step of the way. Hey, did you decide against the Extrudehone?
#14
Rennlist Member
Greetings to you, too, bird. I couldn't find the "amber lights' thread" but will look further (don't go there much,..just occasions to argue with the theists..
This thread will be a good one,..hope Ed has lotsa' memory sticks..maybe we should offer up a collection (for the pics)? Very excited to see this process begin.
Best to you, Ed, on this process!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!,
Doyle
This thread will be a good one,..hope Ed has lotsa' memory sticks..maybe we should offer up a collection (for the pics)? Very excited to see this process begin.
Best to you, Ed, on this process!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!,
Doyle
#15
Rennlist Member
It seems like nothing more than a bad batch of engine mounts.
My shop saw a large number of broken valve springs in 1978 model 911 SCs, and it was a first for that. I kept some crude notes about them, and it dawned on me that all of the broken springs had occurred to the engines in the first 1,000 consecutive build numbers, by VIN.
The mounts are the same kind of deal, bad heat treating? A stamping problem? I talked with people inside the Porsche system, at the time, and they admitted nothing.
My shop saw a large number of broken valve springs in 1978 model 911 SCs, and it was a first for that. I kept some crude notes about them, and it dawned on me that all of the broken springs had occurred to the engines in the first 1,000 consecutive build numbers, by VIN.
The mounts are the same kind of deal, bad heat treating? A stamping problem? I talked with people inside the Porsche system, at the time, and they admitted nothing.