Most common rebuild mistakes

[Ken911]

yes just got the book but haven't finished it yet just wondering if there was any additional guidance out there..Thanks

[JB]

On removing broken dilivar head studs: I just tore down a SC case that had broken all 6 lower studs on one case half. 4 of the broken studs were several inches long but two were only protruding 1/4" from the spigot surface. The long ones were quite easy as I mig welded a spare head barrel nut to the end of the stud and then used a 10mm allen wrench to remove the stud. For the close ones, I cut a small square of thin sheetmetal and drilled a hole in the center to slip over the broken stud to act as a heat shield. Then I placed a head washer over the broken stud and mig welded it to the stud. Then placed a 10mm barrel nut on the washer and welded it to the washer. The heat from welding loosened the loctite and the broken studs were easily removed without damaging the spigots.

JB

P.S. Does anyone have any experience using materials other than Loctite 574 as a case sealant? For some reason, I hate 574. For the last three motors I have built, I have used a product called Dreibond, available in small tubes through my Porsche dealer at about $18 ea. Works pretty good but am always looking for better ways to do things.

[ChrisBennet]

Originally posted by JB

P.S. Does anyone have any experience using materials other than Loctite 574 as a case sealant? For some reason, I hate 574. For the last three motors I have built, I have used a product called Dreibond, available in small tubes through my Porsche dealer at about $18 ea. Works pretty good but am always looking for better ways to do things.

Based on Henry Schmidt's recommendation, I've switched to Threebond 1104 for the last 3 motors. See this thread: Case Sealing Opinions Wanted
-Chris

[J P Stein]

Originally posted by snowman
The most common mistake is common to everyone. Lack of experience. There is no, and I mean no way to mitigate this problem. Either you pay for a true professional, experienced mechanic or you take some kind of gamble with your rebuild. Even the most professional, meticulous, engineer, with bokoo knowledge cannot outdoo a seasoned mechanic with bokoo experience.

Whats this mean??? Goes back to you get what you pay for. That simple.

Cow flop.

If no one did anything without experience, nothing would ever get done. I'm not about to do brain surgery on my self, but building a 911 motoris not in that league.

The mistake I made was not putting sealant on the #8 bearing OD.....so it leaks. All the machine work was done for under500 bucks. I made parts choices using common sense, not "conventional wisdom"....tho I don't ignore it. It was my first & only 911 engine(thus far).

I've been beating on the engine for 4 years doing AX. It's starting to smoke some at start-up......and the pistons rattle a bit longer during that period so it's time is coming.
Not getting it up to full temp before the first pass is gonna kill it before it's time, but I'll build another.....IT'S JUST AN ENGINE! Total cost was under 4500 and I recouped about 1200 from the previous one.
Put it down to beginners luck if you must, but there it is.

[stevepaa]

Well, I put the engine up into car, and in process of connecting everything I had put the ground strap from the starter to the body on the wrong starter bolt. Will drop and do again.

[JeremyD]

Well you can count me in for camshafts reversed, and distributor 180 degrees and add reference and speed sensor switched...

JB - Ralph used yamabond for his 3.5 build

[rotorhead]

Not tighteneing the rockers shaft bolts enough, only went to the factory torque settings and had several work themselves out of position.

[stevepaa]

Ran starter to build up oil pressure on 964 rebuild. Looked for oil leaks and big puddle under right rear. I had forgotten to tighten the hose clamp on the return tube. This is the one behind the hot air riser and it was facing the wrong way. Yeah, that was fun. Ready to try again.

[rotorhead]

Originally posted by snowman
The most common mistake is common to everyone. Lack of experience. There is no, and I mean no way to mitigate this problem. Either you pay for a true professional, experienced mechanic or you take some kind of gamble with your rebuild. Even the most professional, meticulous, engineer, with bokoo knowledge cannot outdoo a seasoned mechanic with bokoo experience.

Not always the case.... try MM

[kenikh]

Originally posted by rotorhead
Not always the case.... try MM

Boy, that's going against the grain on this site.

EDIT: I just reread the post; it was confusing, but now I get it: you are actually bashing MM. Got it.

[aigel]

Originally posted by snowman
The most common mistake is common to everyone. Lack of experience. There is no, and I mean no way to mitigate this problem. Either you pay for a true professional, experienced mechanic or you take some kind of gamble with your rebuild. Even the most professional, meticulous, engineer, with bokoo knowledge cannot outdoo a seasoned mechanic with bokoo experience.

Whats this mean??? Goes back to you get what you pay for. That simple.

Sorry dude, but I certainly feel that can do as good a job as any trained mechanic. My advantage is that I can take my time. You guys really need to work on your self esteem. Now, I am not saying that a mechanical illiterate should tackle engine rebuilds, but if you have rebuilt a few engines in your career as a hobby mechanic, the flat six is just another engine. This is especially true with all the info from Wayne's book and this site. And if you are still in doubt, go take an engine rebuild class with Woods and Anderson.

George

[911SCfanatic]

Originally posted by aigel
Sorry dude, but I certainly feel that can do as good a job as any trained mechanic. My advantage is that I can take my time. You guys really need to work on your self esteem. Now, I am not saying that a mechanical illiterate should tackle engine rebuilds, but if you have rebuilt a few engines in your career as a hobby mechanic, the flat six is just another engine. This is especially true with all the info from Wayne's book and this site. And if you are still in doubt, go take an engine rebuild class with Woods and Anderson.

George

Word.

Before I tackle my engine rebuild, I'm taking a flight out to Cali with my frequent flyer miles to take the Anderson class. The engine build will take me 6 months. So what? My time at home is free and its a freakin' hobby. This engine isn't powering the space shuttle. People's lives aren't at stake.

[911pcars]

"...but if you have rebuilt a few engines in your career as a hobby mechanic, the flat six is just another engine."

George,
Yes. That's called ........ experience.

Sherwood

[snowman]

It ain't just another engine. Its a specific Porsche engine, each having their own specific personality. If you don't know what that personality is, you could be SOL. Thats where the experience comes in. Just NO other way, except waiting 30 years and hopefully reading ALL of the problems that a particular engine has, and even then All of the problems are NEVER all published, are they?

[911SCfanatic]

Originally posted by snowman
It ain't just another engine. Its a specific Porsche engine, each having their own specific personality. If you don't know what that personality is, you could be SOL. Thats where the experience comes in. Just NO other way, except waiting 30 years and hopefully reading ALL of the problems that a particular engine has, and even then All of the problems are NEVER all published, are they?

I don't get it--are you saying Porsche mechanics don't make mistakes? They have bad days, they go through divorces, their dogs die, blah, blah, blah...and then they get distracted and ***** happens. Dude, I've seen it. Or you talk to the experienced engine builder, but the young guy in the shop is really the one turning the wrench on your engine.

So, engines have their own personality. So what? you painstakingly research that personality. I'm not saying someone that's built 100 engines isn't less likely to make mistakes than someone who's built 3. Sure, that's obvious. But, you seem to be saying unless you've built 100 engines you can't do a successful rebuild of the mysterious, incomprehesible Porsche engine. I'm sure I'm misunderstanding your point, though.

[aigel]

Originally posted by 911pcars
"...but if you have rebuilt a few engines in your career as a hobby mechanic, the flat six is just another engine."

George,
Yes. That's called ........ experience.

Sherwood

I just am tired of people acting like these engines are so special that nobody can work on them, except Dieter and Karlheinz who were trained at the factory and know the engine's PERSONALITY! With reasonable mechancial experience and attention to detail anyone can do as good a job as a pro. Maybe even better, because you have more time.

And no, Sherwood, it does not take experience to find out "if the machine shop machined something incorrectly" It only takes basic measurement tools and a spec book to look things up. And have I mentioned that you have plenty time to do so as a DIYer?

Wayne has done an awesome job supplying excellent DIY books and this site. He has helped get us away from the secret handshake mechanics that want to make everyone believe that these machines are super-complicated technical marvels. If any of you guys still believe in those fairy tales, you should not be here and discourage folks. Instead, how about striking up an entertaining discussion about $150 canuba wax on the detailing discussion board. I'd love to read all about it.



George

[rotorhead]

Originally posted by kenikh
Boy, that's going against the grain on this site.

EDIT: I just reread the post; it was confusing, but now I get it: you are actually bashing MM. Got it.

Actually I was bashing both Snowman and MM. Snowman who has taken engine rebuilding to an artform and MM who puts this art into a sausage machine.

I've read a lot of Snowman's posts and he is usually right in what he says.... Its just the delivery lacks a certain sugar coating

[snowman]

For crying out loud, all I stated was what the most common mistake in rebuilding a Porsche engine, ie lack of experience. THats not in any way a reason not to do it yourself and to do it right the first time, just most likely a fact.

Anyone on this forum or myself for that matter would have never attempted to rebuild any Porsche engine if we thought we didn't have a chance. Its just that if we did rebuild an engine and did make a mistake, almost any mistake, it was due to the lack of experiencen noit a lack fo attention to detail or intelligence. And those with all the experience DO make mistakes, usually due to overconfidence or lack of attention due to familarity. IE we all tend to get complacent or lazy. Especially with highly repetative work.

But still its that experience that gives the pros the edge. And yes the REAL pros do take it to an artform, thats the final step towards perfection.

There are 2 Jack Frosts. One the sweet sugarery one from the east coast and the other the cool frigid one, thats the faster one. Not to sweet, just faster.

[911SCfanatic]

Well said, Jack.

[JeremyD]

I think Jack comes across a little curt or direct at times - but I think the information he gives is valuable and his advice is good.