Slant Six Forum
https://www.slantsix.org/forum/

Starting the tune up tomorrow
https://www.slantsix.org/forum/viewtopic.php?t=22732		 Page 1 of 1
Author:  Jopapa [ Sun Apr 15, 2007 7:04 pm ]
Post subject:  Starting the tune up tomorrow
I've had the answers to these before, but after searing around today I can't find them anymore. I seem to remember the correct valve lash settings to be .01" intake and .02" exhaust, and set with the engine hot, correct?

And with the timing, I can't remember at all what the recommended starting point is. Little help please?

I'm ordering all the literature I need in the next couple days, but since I have Monday and Tuesday off, I wanted to at least get started on tuning up my car.

Also, what's the total coolant capacity with a '75+ engine?
Author:  slantvaliant [ Sun Apr 15, 2007 7:19 pm ]
Post subject: 
Assuming a stock cam, I'd set the intake to 0.010" and exhaust to 0.20", hot and running.
Basic timing, I'd look for 10 degrees BTDC and see how she does.
Your results may vary.
Author:  SlantSixDan [ Sun Apr 15, 2007 7:53 pm ]
Post subject:  Re: Starting the tune up tomorrow
Quote:
I've had the answers to these before, but after searing around today I can't find them anymore. I seem to remember the correct valve lash settings to be .01" intake and .02" exhaust, and set with the engine hot, correct?
Yep, see here.
Quote:
And with the timing, I can't remember at all what the recommended starting point is. Little help please?
On your '75, the factory spec probably calls for 0° (TDC). You may want to try 2½° BTDC and see if it runs well without pinging. That's at curb idle, with the vacuum advance hose disconnected and plugged. Hey, speaking of which, does your vacuum advance hose run directly from the carburetor to the distributor, or does it go from carburetor to a valve on the air cleaner housing, and from there to the distributor?
Quote:
Also, what's the total coolant capacity with a '75+ engine?
Ummmmm...:shock:
Author:  SlantSixDan [ Sun Apr 15, 2007 8:09 pm ]
Post subject: 
Quote:
Basic timing, I'd look for 10 degrees BTDC and see how she does.
H'mmm...given the '74-'75 advance curves I've seen, I think 10°BTDC is going to cause a lot of pinging. It definitely will if the EGR is disabled. But, yeah, see how much you can get away with. I'd be surprised if you can go beyond 5° BTDC (with no EGR) and run on regular gas with no pinging.
Author:  slantvaliant [ Sun Apr 15, 2007 8:43 pm ]
Post subject: 
Quote:
H'mmm...given the '74-'75 advance curves I've seen, I think 10°BTDC is going to cause a lot of pinging.
Hence the " ... and see how she does. " part. :wink:

Our cars are old, they've lived varied lives, and parts have been swapped around over the years. 0, 10, somewhere in there will get you started. Then you can tune for your situation.
Author:  wicked/six [ Sun Apr 15, 2007 11:17 pm ]
Post subject: 
Coolant capacity is 13 quarts for non air conditioning and 14 quarts for Increased cooling(I.E. Air Conditioning)
Author:  Jopapa [ Mon Apr 16, 2007 12:03 am ]
Post subject: 
Quote:
Quote:
Basic timing, I'd look for 10 degrees BTDC and see how she does.
H'mmm...given the '74-'75 advance curves I've seen, I think 10°BTDC is going to cause a lot of pinging. It definitely will if the EGR is disabled. But, yeah, see how much you can get away with. I'd be surprised if you can go beyond 5° BTDC (with no EGR) and run on regular gas with no pinging.
I'm hoping to lose the EGR tomorrow if I can, so I'll go with your recommendation. I just need to take a close look at the system and get my hands on the necessary plugs/caps/whatnot.

Hopefully this basic stuff, plus tracking down and correcting any vacuum leaks will help cold driveability a great deal. I discovered a busted vacuum line (the brake booster line actually) yesterday during lunch and fixed it, and that helped a bit. Hopefully there will be more I can fix that'll add up to a much smoother idling and accelerating engine.

I never could get the knack of setting valve lash with the engine running. No problems holding the feeler gauge or screwdriver, but it just felt like I could never get it set right. Engine off, I'd have no problems. Is there a technique that I'm missing for doing it with the engine running?
Author:  SlantSixDan [ Mon Apr 16, 2007 7:26 am ]
Post subject: 
Quote:
Is there a technique I'm missing
Didjya read the post I linked? ;-)
Author:  Jopapa [ Mon Apr 16, 2007 8:22 am ]
Post subject: 
Quote:
Quote:
Is there a technique I'm missing
Didjya read the post I linked? ;-)
I didn't even catch it when you posted it :roll:

That should help me out though. I just have trouble finding the "just right" setting when the thing's running.
Author:  Sam Powell [ Mon Apr 16, 2007 1:46 pm ]
Post subject: 
The EGR is to cool the combustion chamber, and thus help keep pre-ignition under control. I would keep it.
Sam
Author:  SlantSixDan [ Mon Apr 16, 2007 2:12 pm ]
Post subject: 
Quote:
The EGR is to cool the combustion chamber, and thus help keep pre-ignition under control.
That is indeed theoretically true, and EGR can indeed be part of an effective engine management system, but for the most part that's not how it is on our cars. The EGR systems on slant-6s were "hang on and pray" emission controls designed to effectively strangle dirty-running engines so they'd squeak past unrealistic Federal emission control type approval tests so the cars could legally be first sold. That's when these clunky, primitive EGR systems were new. Now they're old. :shock:
Author:  SlantSixDan [ Mon Apr 16, 2007 2:13 pm ]
Post subject:  Re: Starting the tune up tomorrow
Quote:
Hey, speaking of which, does your vacuum advance hose run directly from the carburetor to the distributor, or does it go from carburetor to a valve on the air cleaner housing, and from there to the distributor?
:?: :?: :?:
Author:  Jopapa [ Mon Apr 16, 2007 6:29 pm ]
Post subject:  Re: Starting the tune up tomorrow
Quote:
Quote:
Hey, speaking of which, does your vacuum advance hose run directly from the carburetor to the distributor, or does it go from carburetor to a valve on the air cleaner housing, and from there to the distributor?
:?: :?: :?:
It goes from the dizzy to the air cleaner to the carb. Any real reason or benefit to running it like that, or should I run it straight to a (now unused) vacuum port on the carb?
Author:  SlantSixDan [ Mon Apr 16, 2007 7:14 pm ]
Post subject: 
Take the valve on the air cleaner out of the line: Run the hose directly from the existing port on the carb directly to the distributor. You will be very pleased at the improvement in acceleration and around-town mileage.
Author:  Jopapa [ Mon Apr 16, 2007 7:17 pm ]
Post subject: 
Quote:
Take the valve on the air cleaner out of the line: Run the hose directly from the existing port on the carb directly to the distributor. You will be very pleased at the improvement in acceleration and around-town mileage.
Sounds good to me. I'll be doing some more work on it tomorrow, so I'll do it then.
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/