Another Engine Rebuild Thread - 80 3.0L

[wastintime]

yeah, that's pretty hot for highway driving... granted mine's a 964, but it never gets to 140 on the highway.

I know we'd had the concern about your oil lines before the rebuild, did you guys do anything with those during the rebuild? Hopefully it's just a guage issue, wouldn't be unheard of by any means.

[Gunter]

Heat source for bending the tip:
Just run the engine.
If you use Propane, keep a broad flame and not too much in one spot.

[mca]

Originally Posted by wastintime

yeah, that's pretty hot for highway driving... granted mine's a 964, but it never gets to 140 on the highway.

I know we'd had the concern about your oil lines before the rebuild, did you guys do anything with those during the rebuild? Hopefully it's just a guage issue, wouldn't be unheard of by any means.

Oil lines are the finned Elephant Racing lines. I also have an external cooler in the front wheel well.

[mca]

Originally Posted by Gunter

Heat source for bending the tip:
Just run the engine.
If you use Propane, keep a broad flame and not too much in one spot.

Great! So the muffler straps will offer all of the support I need to bend the muffler?

Do I need to be worried about cracking the SSIs?

[timc]

Originally Posted by mca

Great! So the muffler straps will offer all of the support I need to bend the muffler?

Do I need to be worried about cracking the SSIs?

You "should" have no problem if you have the two muffler straps secure around the muffler and the rear engine muffler support. But proceed carefully and slowly.

Regarding your oil temps, if you will look closely at the edge of the gauge, near the bezel about midway up, you will see a small white hash mark, that is where the factory calibrated the gauge at 212. The gauge is not linear.

[Gunter]

Originally Posted by mca

Great! So the muffler straps will offer all of the support I need to bend the muffler?

Do I need to be worried about cracking the SSIs?

You're NOT bending the muffler, you're just bending the tip on the muffler.
Aside from the straps, build up some support by placing 6x6, 4x4, 2x2 pieces of wood under the muffler towards the tip-end before pressing down on the tip.
The pipe extension you're using has to be a tight fit inside the tip.
If you go too small, you'll distort the tip.

[mca]

I forgot to mention that the alternator issue is solved. Both alternators checked out ok. Looks like it was as simple as my belt being too loose. This was a little odd b/c I changed from 2 shims in / 4 out to 1 shim in / 5 out. Seems a little tight now though.

I also went ahead and had the bearings replaced in my spare alternator. Brushes were ok so those were not replaced.

Regarding the heat ... I am going to test my gauge this evening with it out of the car. If it tests OK then I am thinking that the high temps could be caused by the following:

1) dizzy not advancing all of the way - only seems to get hot at highway speeds

2) external t-stat not opening FULLY - it opens b/c the oil lines are burning hot

3) excessive heat around exhaust since heat exchangers are not connected - need help with this theory b/c i have never had exchangers on the car. I read a post by Grady Clay and he said:

"First, you are correct; heat exchangers should always have
cooling air going through them. Only if replaced with headers
(no heat exchanger) can you block off the air supply from the
fan shroud.

Disconnecting the supply air from the heat exchanger causes
the exhaust to run too hot. This can start a fire. It also raises
the temperature of the catalytic converter possibly leading to
failure.

Disconnecting the outlet of the heat exchanger allows too
much air to pass and reduces the engine cooling.

Using headers _requires_ the air from the fan shroud to
be blocked off."


My interntal t-stat is ok and my temp sender is ok.

Any other ideas?

[wastintime]

Craig, you have the blockoff, I installed it on your original motor. I highly doubt it's number 3, but I'm glad I was right about the fan belt being loose and it wasn't anything more severe. ooohhhhh, just read elombards post below... I forgot you left the heat exchangers on... yeah, that's a good point.

Wait to see how the gauge tests out... I suppose there could be something with the vacuum advance on the dist., but who knows.

[Elombard]

hmmm just to be clear you have both ends of the heat exchangers closed right? If you are not using them the cooling air from the fan wont go through the cylinder fins and will just blow out the open hole.

[timc]

How hot are you actually running?

[mca]

Originally Posted by Elombard

hmmm just to be clear you have both ends of the heat exchangers closed right? If you are not using them the cooling air from the fan wont go through the cylinder fins and will just blow out the open hole.

No, I don't have them blocked! Both ends are open on both sides.

I have never had heat on my car and I haven't investigated the back-date setup yet.

Wayne's book says to leave the heater disconnected for the first 1000 miles in order to prevent smoke / smell from entering the cabin. But I don't know exactly what would be blocked or disconnected since I am not familiar with the setup.

Please advise!

[mca]

Originally Posted by timc

How hot are you actually running?

Tim,

I was seeing 230 on the highway after about 20 mins (probably about 90 - 100 degrees on the pavement). It isn't terribly scorching hot ... but much too hot for a rebuilt engine, new exhaust, elephant finned oil lines, and an external fender mounted oil cooler.


Thanks,
Craig

[Gunter]

You want maximum air going over the cylinders.
With or without the extra heater blower on top, the HE have to be connected to provide a heat sink and get air through the cylinders.

Pictures with extra heater blower removed and SSI's connected, right side:



Left side:



Some people just use a block-off plate on the right and only blow air through the HE on the left side.
Regardless on what you do, air has to go over the cylinders and the HE's cannot be left open on the intake side.

Of course, when you had the fan belt slip and the Alt. light came on, it also meant less cooling effect.
Get max air over the cylinders and your heat problems may just disappear.

[Gunter]

Originally Posted by mca

No, I don't have them blocked! Both ends are open on both sides.

Please advise!

Well, that may be your problem!
Can you take a picture and let us see the area left and right of the fan were the ducts are normally connected?

[mca]

The temps were up with the fan belt tightened. So the fan was doing its job.

With the back-date setup, I won't be using the blower motor?

I have my old heater blower, hoses, and the plate for the left side. Until I find everything I need for the back-date, should I run the hose like you have it on the left and then cap the other ends of the HEs?

[Gunter]

If you don't want any heat inside the cabin, just leave the ends of the HE's open or connect them to the flapper boxes and keep the valves closed.

I would not just block the ends of the HE's because you want air flowing thru to dissipate heat from the exhaust side of the cylinders.

With SSI's, the extra heater blower is really not needed especially if you don't want heat in the cabin but the intake ends of the HE's cannot be left open.

The very name Heat Exchanger tells the story.
Heat can only be dissipated if there is air flow.
Connect the HE's up correctly on both sides so they can serve their intended purpose of exchanging heat.

[Elombard]

Gunter I dont know if it will matter if you have out put side of the SSIs blocked as long as the intake end is blocked (where your pics show), no air will get through their anyway will it? I guess as the hot air expands it will leave out a little.

MCA look how the air comes from the fan and goes over the cylinders. All the holes need to be closed up (on the top) until you get the back date installed.

This is very confusing better take some pictures so we can see what you have.

[mca]

Originally Posted by Elombard

Gunter I dont know if it will matter if you have out put side of the SSIs blocked as long as the intake end is blocked (where your pics show), no air will get through their anyway will it? I guess as the hot air expands it will leave out a little.

MCA look how the air comes from the fan and goes over the cylinders. All the holes need to be closed up (on the top) until you get the back date installed.

This is very confusing better take some pictures so we can see what you have.

Currently I have both sides blocked off - installed left side block off plate after pulling all of my heating hoses a couple of years ago.

Doesn't that mean that I am forcing the maximum amount of air over the top of the cylinders but NOT cooling the exhaust side by sending air through the HEs?

Here is pic of the engine. See prior pics for views of underside.



If there is any chance that this is cause high temps, please let me know what I can do to ensure air flow over the cylinders and through exchangers.

[timc]

I've run some of my early 911's this way, with the heat blocked off to get max air to the cylinders at various times with no noticeable increase in engine temps, but then these were 2.2 litre engines and not a 3.0 like yours. It does create more heat on the exhaust, but I really have never measured it "before and after" to determine exactly how much. Since this is a street car, I would, at some point in the near future add the two air ducts to each side of the engine to get air over your exhaust as it was designed. I really cannot say with any "fact" to back it up, that this is your problem.

How hot are you actually running? You have the gauge with the lower white mark, and upper red mark, then the two white marks in between correct? Where does the needle run?

[mca]

Originally Posted by timc

Yes, I've run some of my early 911's this way, with the heat blocked off to get max air to the cylinders at various times with no noticeable increase in engine temps. Does create a bit more heat on the exhaust, but I really have never measured it "before and after" to determine exactly how much. I really do not think this is your oil temp problem. How hot are you actually running? You have the gauge with the lower white mark, and upper red mark, then the two white marks in between correct? Where does the needle run?

248F is the top white mark (120C).

194F is the bottom white mark (90C).

On the highway I was running at 230. Basically the gauge needle's width away from touching the top white mark.

Regular driving from downtown Charleston to Mt. Pleasant got me to 9 o'clock on the gauge.

The interesting thing is that my SSIs quickly developed a purple hue. Yet these same SSIs were used for 6 months by the guy who sold them to me.

Also, my bumper was incredibly hot to the touch. Could not even keep my hand on it. This COULD have to do with the muffler touching it though. Not sure.