It's official... She started!!!

[SchnellSchweitz]

Yup... fired on the first turn.

I was having troubles for about a week with flooding and backfiring, until I realized I had the distributor reversed 180.

When I got it in correctly, I hit the key and Rrrrrrrrrrrrr!!! White cloud of smoke came rolling out. Not too thick, but obviously not something you want to drive around the neighborhood showing off. Hehe.

(This is an MSD-6A/EFI system.)

Anyway... It seems like the motor is revving pretty high right now. I've only had the motor on for a minute or two.

My tac doesn't seem to work at the moment (blue wire in MSD tach output), but I'd say its revving a little faster than normal at idle.

One note... I am using a 15W40 Royal Purple oil. Would this cause the higher RPM?

Perhaps higher revving is normal for rebuild startups and I just have to break the motor in to get it to idle right?

Thanks for your advice in advance.

Eric J.

[Borsche911]

Read the dedicated section in Waynes book about break in. He recomends runing at 2000rpm for twenty minutes. I do this after every rebuild and whilst it is scary and noisey, it seems to do the trick. Day time hours are reccomended as you will be able to see any (if any) oil or petrol leaks. Set a stop watch cause as wayne say's after 5 minutes you'll swear it has been 20!! Drop the oil and filter and observe the next stage of the break in Procedure. The oil you are using wont cause the higher revs. Is the Timing slightly advanced?
Jim

[SchnellSchweitz]

Sounds good Jim.

I can't say I won't be nervous, but I think you are right. I need to let her run for 20 min.

I'll post a report on my 20 min run.

Thanks

Eric J.

[jpnovak]

Congrats on the start of the new engine. Yes, break in the cams as indicated. use that 20 minutes to check the mixture and timing. Make any adjustments necessary to ensure you are running properly. also check for leaks and other issues. You know you will be ready for a drive when its finished breaking in the cams.

[cmcfaul]

Why do cams need breaking in? There hardened steel?

Chris

73 911 E

[JJ 911SC]

Originally Posted by Borsche911

... He recomends runing at 2000rpm for twenty minutes...

I think a steady 2000 rpm may be critical, so you might need to fix the tac first.

[Walt Fricke]

There are a lot of opinions on how to break in a motor. Best to pick one and use it, and not worry too much if it is the very best. You probably don't want to use mine: put back in race car, load car in trailer, take to track, run the pi**ss out of it right out of the box.

Chris - I have wondered the same thing myself. At one time I thought maybe only one part, either cam lobe or rocker face, was hardened. And the other part was not, but running it in hardened it. But now I wonder if this is so. One often hears of these parts starting to fail because they have worn (or pitted) through the hardening. That could be the worn-in hardening, but as I say, I am quite uncertain about that. Someone here will know. I barely know a Rockwell from a Rockette.

Walt

[SchnellSchweitz]

Ok.... Here's my post break-in report. (3.0L MSD 6A/EFI)

Engine was blowing out lots of blue smoke for most of the 20 minutes and idling at about 3000 rpm (Royal Purple Oil). Sounded like thunder to me, but I now believe this was a normal sound.

Like clockwork, at the 20 minute mark, she settled down and the smoke went away. Almost instantly. Really amazing.

She now runs right at 1900 RPM at idle, but it doesn't sound anything like a purr. More like a quite roar.

New issues:

1) The muffler was extremely hot. Heat was transferring to the engine brace above, making it too hot to touch. Perhaps this was from the oil burn off???

2) My Oil pressure and oil level are pegged at max, but the dip stick is right at the 50% mark when warm. I have the front end oil cooler (13 quarts).

3) My dashboard tach does not function. I currently have the black and violet wire (#12), at the engine compartment fuse panel, spliced into the negative coil terminal. Is this correct??

4) Timing is slightly advanced at idle. I'd say about 1.5" to the left of TDC. I am checking timing with the advance vacuum and retard vacuum hooked up to the dizzy. Will removing them drop the advance?

Below you will see my MS map for the day. It doesn't show gama enrichment for some reason, but that was somewhere in the 75% area.



Thanks for your advice in advance.

Eric J.

[snbush67]

Originally Posted by cmcfaul

Why do cams need breaking in? There hardened steel?

Chris

73 911 E

It is for mating the cam lobe surface to the rocker face. That is why even if you use new cams you should use resurfaced or new rockers. Uneven surfaces on the rocker face could create a pattern where there is less surface to surface contact and form grooves and pitting in the cam surface. An even metal to metal surface dissipates heat and prolongs wear.

Shane

[Walt Fricke]

I wonder if you are picking up your tach signal where you should. The stock CD box had a terminal for that purpose, as (I suspect) the reluctor system which replaced the points ignition does not produce the needed signal.

How does MSD say you should get your tach signal?

[SchnellSchweitz]

Hi Walt,

I get my tach signal from my MSD output. The trouble is... that's also where my EFI gets a spark signal.

I wonder if there is another location to tap a spark signal for the tach? Someone must be doing something creative to overcome this issue.

Anyway... I believe my hot muffler is a richness issue. I will need to deal with that as well.

Thanks for everyone's input.

Eric J.

[Walt Fricke]

Well, my instincts suggest that the coil negative terminal is not the right source of 5V to maybe 12V square waves. Those are what your tach is going to like, I believe. The circuit which makes/breaks the coil current is apt to have severe ringing on it, seems to me. Though I admit that's a guess, and not an overly educated one.

The old points tachs were built to take a higher voltage spiked signal, I think. When Porsche changed to the reluctor instead of the points it also changed the tach. Lower voltage signal, I think. But that's what you have for a tach.

MSD sells a black box which is supposed to clean up the tach signal if needed. I run one in my car (partly because it came with an engine, etc - long story, doesn't weigh much, I have it, etc.)

Their literature, however, ought to indicate a place on their system where you can pull off a tach signal. If their box is needed to clean up that signal, you'd expect they'd say so.

I just switched my track car from Electromotive HPV-1 crankfire and Webers to WinTec3R EFI. I had some tach issues with my LM2, and with my tach. I reinstalled the MSD tach conditioner, and they went away. But the issues may have just been wiring issues - bad connections at some junction boxes and whatnot in a completely non-stock wiring system. Shouldn't have been an issue, but I think they were.

So it pays to check connections/continuity. Simplest fix, too, if it is the issue.

Walt

[SchnellSchweitz]

I think I am going to rip out my current wiring at the rear fuse panel and attach a wiring block and new fuse panel.

I want to eliminate the possibilities of interference. Thanks Walt.

[SchnellSchweitz]

So Walt... I ordered one of these

Tach Signal GMR Pickup - 8918

I think this is what you were talking about? I think you may have hit the nail on the head on this one.

Thank you.

Eric J.

[304065]

There is no reason why you can't try to run the tach off the 1/4" faston connector on the side of the MSD box, the same place you get the spark signal.

However, I think that SC tachs and Carrera tachs both run off a 5V square wave. See here for more details: Tachometer Compatibility Chart

Of course the MSD is a 12V square wave with a 20 or 25% duty cycle. Now, the Bosch CDI triggers on the falling edge of the magnetic pickup signal (for six-pin boxes) whereas the MSD box triggers on the rising edge (points opening) so the duty cycle can throw the RPM reading off.

http://www.megamanual.com/ms2/pickups.htm

The easy thing to do is send it to North Hollywood and tell them you want it calibrated for MSD and drive it off the MSD pin. They can recalibrate it and fix the old movement besides, it's not very expensive.

[Walt Fricke]

What I have is more like the MSD 8920 Magnetic tach adapter. Basically goes in line with the tach signal from the tach output on the MSD box.

However, if an instrument shop can just rework your tach so it will run off the MSD's tach signal output, that might be a better way to go.

The instructions for the 8920 don't get into the good stuff, like what the output is - a square wave, I bet, but at what voltage, etc.

[SchnellSchweitz]

Unfortunately, the tach adapter interferes with the EFI in my situation.

I'm going to give the coil pickup a try and see if it works. If not, I may send the tach to N. Hollywood.

I will report on what I find and again... thanks for everyone's help.

Eric J.

[SchnellSchweitz]

Ok... I got the timing right and the oil gauge figured out, but the oil pressure is still pegged at max @2000 rpm and the right half of the muffler gets too hot in a matter of minutes.

Is it possible I have an oil pressure issue??? The left half of the muffler is fine. If so, what would cause this?

Air adjustment throttle screw is tightened down all the way. I did this because I previously thought I had an air leak. Should I back it out?


This evening's map.



Thanks for your advice... I do appreciate it.

Eric J.

[Walt Fricke]

Eric

I don't think there is enough information squirrled away in these posts to help with some of your questions.

What exhaust system do you have. If you have a 2 in muffler, are you suspecting the right bank is running hotter than the left?

If so, use an infra red thermometer "gun" to take exhaust manifold readings. That will isolate a hot cylinder or cylinders pretty effectively. Or, as happened to me, a cold one, as in a plug wire not plugged once.

Then you can get to pondering why.

For instance, do you have six injectors? I don't know much about testing them, but if there is a side to side or cylinder to cylinder difference in exhaust gas temperatures (extrapolated from manifold temperature readings), you could always swap some injectors and see if the problem moved with them or not.

[SchnellSchweitz]

(Muffler is the stock two in one out)

Interesting stuff Walt. I really would have never thought of these ideas. They really do help lead me to solutions... just by elimination.

I have been reading a few other earlier posts on the hot muffler issue and it seems I am not alone. Sounds like some people just drive their cars until the oil is completely gone and the muffler cools.

I haven't had my car out of the garage yet so this might be the right thing to do? I just know the right side of the muffler currently transfers an unusual amount of heat to the engine tin above. It actually melted a wire I had on the tin. But I can tell the rings haven't fully seated either... as there is still plenty of oil collecting in the muffler.