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posted by lemon:

I think the beastie boys answered this one quite succinctly in their song "eggman"

"Which came first, the chicken or the egg/I egged the chicken and then I ate its leg".

Perry 951

That was one of the most entertaining posts in a while. Thanks Skip!

Longtime76

As one who does not understand with great detail the car in which I travel, I am wondering what exactly the problem is described by the Skip's forboding third story. Is this the malicious #2 rod bearing problem? What must be done to the car when this problem arises?

Skip

Sorry, I took liberty that all had heard that story before. Yes, the dreaded #2 rod bearing. And if I didn't realize it before, Porsche oil dran plugs are magnetized... so you get to see the bits and pieces that do the harm. A sobering vision, I assure you. You have 3 options at this point: 1. trash the block and start over. 2. tear it apart and hope it only needs an oversize piston set and that the crank is useable after careful study and polishing. 3. park the car and start volunteering to work the timing van for all run groups... just so you can be *near* the excitement.

I now have an 89 2.7 liter engine in my 86 944na. Comparatively, it runs like a partially heated cat, as opposed to a luke-warm kitten.

Oh, and I found my heater clip on the floorboard last week... isn't that nice!

Skip

rplencne

Even though this thread was probably never meant to be a technical exchange (thanks for the interlude Skip), I guess I need a little clarification on the 3 options you have when the #2 rod bearing goes. I don't see how option number 2 might require an oversized piston set, but only a polishing of the crank. I would think that if there was enough bearing material flying around to scratch the cylinder walls (causing the need for an overbore/oversized piston set), that the crank would be hurt enough to require more than just polishing ... that is ... needing to have the crank turned and using non-std bearings. I've lost rod bearings before (not in a 944) and only hurt the crank. Unless Sip meant to say oversized bearings instead of oversized pistons ...

Either way, great thread to wind down a Friday with

-Bob P.

Skip

No problem and good point, Bob. And, you are correct that both could be damaged to the point of no return. In my wording I leave room for interpretation; "...and hope it only needs...". It's generally accepted that the rod-bearing repair can be anything from a new rod bearing, to a new engine. If taking your car to a shop, they might recommend a new short or long block, rather than chancing the amount of labor and parts needed to repair yours. This is a gamble, and one that I took... mostly because my prior engine had over 150k miles... and the bearing let go at high RPM's, continued to be driven, and the shrapnel content in the oil was quite high. The cost of 1st oversize pistons, honing of the block, and a new crank was roughly 2.5 times higher than the cost of a 40k mile 89 2.7 liter engine with shipping from Florida (came out of an automatic to boot). Now, I have a used block with no guarantees... whereas someone might want to know exactly what's going back in there. In steps the machine and engine building shops we hear about here so often. They will strip the motor of all its bits and have some quality time with it. Only at that time will you know the amount of damage you have suffered. From hearing the countless stories from both the owners and the shops who are versed with this... a certainly majority can be established. I offer that in my own experience I have heard of more 944/951 rebuilds going the way of first oversize pistons, polished crank, and 1st undersize bearings (crank gets smaller). As with Perry's latest adventures, he is also having the crank reworked for optimum reliability and effectiveness. A typical set of new pistons will run $1500-2000... maybe you only need one... great. The crank work itself is in likely in excess of $500... if you need a new or good used one, you're looking at another $1500-2000. This just illustrates the cost so you realize that the engine builder will be able to estimate the repair bill from the first few hours of analysis... at this time you would have the choice of continuing with a rebuild, or turning back in defeat. Some don't care what it costs... they just want a great engine... for this, I'm sure the list engine builders are more than happy to make them happy For mortals with credit limits, we choose the path of least marital resistance. I will also apprehensively point out that the Porsche internal bits and pieces are made to different standards than *most* vehicles. This may be the reason the cranks are usually okay with a polish and spit shine. The gap between the cylinder walls and the pistons is a high velocity friction area. If particulate from a disintegrating rod bearing gets trapped in there for any amount of time, the walls are scarred. It is up to the engine builder to determine the allowable wear. bored yet? Another point to make is the age of the motor in which this may happen (since it seems to happen predominantly in high-mileage cars). The cylinder walls may have been damaged well before the incident, which makes them a while-you're-there fix, rather than actually affected by the immediate debris. In my case, I was afforded the opportunity to upgrade to the 2.7 motor, so I did. So far so good… no strange noises… and I tend to drive it like I stole it from the biggest baddest ugliest stinkiest ogre the world has ever known… Shrek!

Skip (yadda, yadda, yadda)

Lemon Yellow 87 n/a

Schnider, I think you are right, if Adam was your typical guy, the piston literally came first.