Another Engine Rebuild Thread - 80 3.0L

[mgbruno]

Subscribed. Great Thread! Thanks MCA.

Mike

[ShakinJoe]

subscribed

[timc]

Originally Posted by mca

Do you know anyone in Charleston that can bench test an alternator? No one seems to be able to do it b/c of the size and nature of the alternator.

Carolina Auto Electric on Meeting street should be able to test the alt. You can hook up a multimeter to any hot wire in the car while it is running and that should give you the voltage on the alt, I usually pick up the hot wire off of the light switch behind the dash. That is how I determined that my alt was overcharging. Sounds like you have a battery problem, same issue on one of my cars with a 8 month old battery. Exchanged it under warranty.

Just saw this thread last night, good job!!!!

Tim

[mca]

Originally Posted by timc

Carolina Auto Electric on Meeting street should be able to test the alt. You can hook up a multimeter to any hot wire in the car while it is running and that should give you the voltage on the alt, I usually pick up the hot wire off of the light switch behind the dash. That is how I determined that my alt was overcharging. Sounds like you have a battery problem, same issue on one of my cars with a 8 month old battery. Exchanged it under warranty.

Just saw this thread last night, good job!!!!

Tim

Thanks Tim!

I called Allied Alternator today up in North Charleston. The guy knew exactly what I was talking about ... he asked "Is that the alternator with the fan on it?"

He told me that they would try to fashion some sort of pulley and some way to hold the alternator in place. We shall see.

Last night I pulled the trickle charge off of the battery. It is now holding at 12.7 volts.

So, if the battery was only 50% charged when I had it running in the car, would the alternator light come on as a result? I am still cloudy on how the charging system works.

[wastintime]

again... 911 charging system... hard to compare to other cars. I'd never expect to see the same voltage in a 911 as I would in a Honda.

[timc]

Originally Posted by mca

Thanks Tim!

I called Allied Alternator today up in North Charleston. The guy knew exactly what I was talking about ... he asked "Is that the alternator with the fan on it?"

He told me that they would try to fashion some sort of pulley and some way to hold the alternator in place. We shall see.

Last night I pulled the trickle charge off of the battery. It is now holding at 12.7 volts.

So, if the battery was only 50% charged when I had it running in the car, would the alternator light come on as a result? I am still cloudy on how the charging system works.

No, the alt light will not come on due to a weak battery, or I should say, in theory, it should not come on. I have had many weak/defective batteries, and never had an alt light come on as a result, in any of my 911's, or any other car that I've owned. The only time the alt ligght should come on is if it is not supplying enough voltage to operate the elect system and/or provide sufficient charge to the battery. It will stay on after you turn the car off if there is a bad diode in the alt.

[timc]

Originally Posted by wastintime

again... 911 charging system... hard to compare to other cars. I'd never expect to see the same voltage in a 911 as I would in a Honda.

Not true. Same theory in all the cars that I've owned and worked on. Alt's charge at approx 14 volts, and battery's run at approx 12.5. A 911 is no different.

[wastintime]

Hey tim, what's up? Haven't seen you in a while. I disagree though... 911s are singularly hard on charging systems. From the relays required for engine starting to the amounts of electronics draining the battery even when the car is off.

911s are unique in that they generally start with lower voltages than other cars, yet are ultimately incapable of starting at an equivalent voltage that another car might still start at. I've never seen a 911 built prior to '98 that would jump back up to a normal voltage after starting unless that was the day you installed a new battery and alternator.

My point wasn't that a dead battery isn't a dead battery, or that an alternator is really charging even if the battery voltage never goes up, but in virtually every 911 I've ever worked on I've seen a slightly lower voltage than normal while charging, I generally don't worry about it either.

911s are harder on their charging systems than almost any other car you will ever work on, it doesn't mean the system is any different, nor was that my claim, just that you will occaisionally see different values than you would in another car and that isn't necessarily a reason to freak out.

[T77911S]

wastintime,
you must be working on those euro 911's with their strange voltage.
i just started my 77s, cold, and did not touch the gas at all. the start volts dropped to 10.6 and then settled at 14.4. i dont know what else could be more normal or perfect, and i never even got in the car. now the vlolts may drop back down some after the battery recovers from the start, but even hondas do that.

now there have been times i have started it and the alt light was on, but just until i blipped the gas, but it never came back on.

if the charge voltage never goes (above 12v), the alt is not charging, period.

as far as 911's being hard on an electrical system due to relays, when was the last time you counted the relays in a range rover? the bad thing with porsche and electrical systems are those crappy fuses they use and that they get hot.

and what electronics are draining the battery? i have gone a month or more and never had a dead battery.

by the way, i use to work at carolina auto electric, although it has been 15 years, best place in town! the dealers use to send us their cars they could not fix!

[mca]

Originally Posted by T77911S

by the way, i use to work at carolina auto electric, although it has been 15 years, best place in town! the dealers use to send us their cars they could not fix!

I called them today. Gonna run by there tomorrow and see what they can do. When talked to the guy on the phone he didn't seem to know much about the 911alternators. The whole fan / pulley thing.

We shall see!

[mca]

Carolina Auto Electric saved the day. They tested it on the spot and confirmed that it is in great condition.

Now that I know it works, I will install it and see what happens.

I will test the one that is currently in the car. If it is bad, I may as well have it rebuilt since these alternators are getting harder and harder to find.

Thanks T77911S and Tim for the tip on using Carolina Auto Electric.

[911 tweaks]

great news !!
Let us know how this impacts the lights... hopefully they wont glow...
Bob

[mca]

Originally Posted by 911 tweaks

great news !!
Let us know how this impacts the lights... hopefully they wont glow...
Bob

Me too ... I hope this solves the problem.

I can't test it out until the rest of my exhuast system arrives and I get it installed. SSIs are coming in tomorrow, muffler / gaskets / clamps coming early next week, and the time-sert kit coming early next week.

[mca]

I just wanted to say thanks to Gert vanRooyen (Gertvr) for selling me his SSIs.

He really saved my butt b/c new SSIs are on back order until early November. I paid him on Wednesday and received them on Friday. All nicely packed ... even got a full roll of paper towels in the box.

So, thanks Gert!

[wastintime]

Sweet,
I know it's more money you didn't want to "blow" right away, but you're going to love the sound once everything arrives, and at least you're not worried about anything cracking or your valves cooking.

[mca]

Got muffler on this morning. It is a tight fit and I may need to cut part of my bumper as the polished muffer tip is slightly touching the back/inside part of the bumper.

I drove to work and it was a sweet sound and nice ride. Lots of smoke though (from underside of engine). Could be that gasket sealant I used with the muffler and header gaskets. Maybe it is just burning away - supposed to be good up to 700F. Guess the exhaust gets hotter than that? Gert (the guy who sold me the SSIs) suggested using the sealant as extra precaution. Helped keep them in place while installing too.

Anyhow, the car was running pretty hot. Granted it was prolly 90-100F on the highway this morning but still ... shouldn't get that hot with a "new" engine, elephant oil lines, and an external fender cooler (no fan though).

Towards the end of my drive to work the temp was near the upper white mark. I am starting to think that my gauge is off since both temp sensors seem to give the same readings.

What else could it be? External t-stat not opening all of the way?

Ignition timing is correct. If anything I may be running slightly rich but I have not checked yet.

[Gunter]

Re muffler:
Don't let the muffler just hang on the HE-flanges, support it with straps as intended to prevent the flanges from cracking.
Instead of factory straps, I use 6-7 inch SS hose clamps, 2 per side, 4 all together.
I recommend you use the good copper gaskets from PP between the flanges.
The flanges on the muffler should fit square onto the HE-flanges without sealant.
I use large channel-lock pliers to align the pipes for a straight flow before tightening the bolts on the flanges.

Recheck the nuts that hold the HE to the heads after some time, they tend to come loose.

Muffler tip touching the bumper:
After installing holding straps for the muffler, I was able to bend the tip down by using heat, inserting a tight-fitting metal pipe into the tip and pressing down hard.
If that doesn't work, consider having the tip re-welded on the muffler body instead of cutting the bumper.

As for overheating.
Are both lines going to the front cooler getting hot?
Meaning: Is the oil circulating thru the front cooler?

[mca]

Originally Posted by Gunter

Re muffler:
Don't let the muffler just hang on the HE-flanges, support it with straps as intended to prevent the flanges from cracking.
Instead of factory straps, I use 6-7 inch SS hose clamps, 2 per side, 4 all together.
I recommend you use the good copper gaskets from PP between the flanges.
The flanges on the muffler should fit square onto the HE-flanges without sealant.
I use large channel-lock pliers to align the pipes for a straight flow before tightening the bolts on the flanges.

Recheck the nuts that hold the HE to the heads after some time, they tend to come loose.

Muffler tip touching the bumper:
After installing holding straps for the muffler, I was able to bend the tip down by using heat, inserting a tight-fitting metal pipe into the tip and pressing down hard.
If that doesn't work, consider having the tip re-welded on the muffler body instead of cutting the bumper.

As for overheating.
Are both lines going to the front cooler getting hot?
Meaning: Is the oil circulating thru the front cooler?

Ya, I have the straps but didn't have time to install them this morning. The muffler bracket notches will suffice until this weekend. It ain't going anywhere cause it is tight!

Oil lines getting hot. It could be a volume issue though if enough oil is not flowing due to a partially opened t-stat.

Thanks for the tips on the muffler. This is a game of millimeters for sure. What did you use as your heat source prior to bending?

[wastintime]

I wouldn't worry about the smoke. That's pretty normal with new exhaust pieces. You might want to retighten things once it cools down too. I didn't see it in the pics, but you did put the straps on the muffler right?

I'm confused on the temps... was it hot by 100f? the temps you saw on the highway sound right, and without a fan it's not too hard to get a 911 to overheat in traffic, getting close to 270 doesn't sound impossible... running a little rich is always safer though.

[mca]

Originally Posted by wastintime

I wouldn't worry about the smoke. That's pretty normal with new exhaust pieces. You might want to retighten things once it cools down too. I didn't see it in the pics, but you did put the straps on the muffler right?

I'm confused on the temps... was it hot by 100f? the temps you saw on the highway sound right, and without a fan it's not too hard to get a 911 to overheat in traffic, getting close to 270 doesn't sound impossible... running a little rich is always safer though.

It was probably running at 230-240 on the highway. A needle's width from the upper white mark. No traffic either.

Kevin and I are going to swap gauges this weekend to elminate a faulty gauge.

I have straps but didn't have time to put them on this morning. I will do so this weekend.