Tuning Up Your Old StoveBolt - Timing and Compression

[Deve]

I have had to second guess myself on putting a second version of the same document to Head these topics. It just makes twice as much work for me, and then things are not as neat. So, there are a few documents that will help you learn about the relationship between Tuning and Timing and how to achieve the very best performance for your GM Inline 6.

Check out these documents in particular, but don't limit yourself, there are plenty of complimentary How-To's that will help you better understand your engine.

For Timing and preparation for a proper tuning job, check this one out... http://devestechnet.com/Home/EngineTiming
For adjusting your Valves in preparation for a proper tuning job, check this one out... http://devestechnet.com/Home/ValveAdjust
For tuning and for testing your compression... http://devestechnet.com/Home/TuneUpGuide

I am always happy to hear comments and ways to improve these documents. Thanks!

[mcgillis]

Deve, in this photo of your engine http://devestechnet.com/Images/Proje...Filter39lg.jpg
the distributor does not seem to be positioned as described in http://devestechnet.com/Figures/enginetiming.pdf
My 1967 Motors Auto Repair Manual confirms what your engine timing pdf says, #1 should be farthest from the block and the clips parallel with the block.
Thanks for sharing this great site!
Dennis

[Deve]

Yes. And I agree it should be the way Motors says. Since that picture was taken, I have fixed that issue. I have had that distributor out so many times! Right now, I am perfecting the HEI project so I have one stock dizzy and one HEI one. The fun never ends!

[Neverdone]

Deve , in mcgillis's post above he mentions http://devestechnet.com/Figures/enginetiming.pdf. .... In FIG 2-3 there is blue writing under each one ...what does it say ? I enlarge the type and still can not make it out...

Also it says """" and re-connect the plug wires going 'round clockwise beginning with #5, then #3, then 6, 2, 4 and you’re done.""""
Starting from where ? the number 1 plug ? Do you have a diagram as to where the numbered wires are on the distributor cap ?
Dan

[Deve]

Figure 2 small type says... To begin the distributor installation, index the rotor to approximately the 8 o'clock position. The distributor cap spring clamps should be approximately parallel to the engine block and the advance mechanism's vacuum port should be pointing forward also parallel to the engine block.

Figure 3 says... As the distributor is lowered the shaft will turn CCW towards the desired 6 O'Clock position. If the distributor assembly does not seat completely simply rotate the crankshaft a small amount in both directions to help align the oil pump drives. Return the crankshaft to the TDC and check the distributor rotor for the proper 6 o'clock position.

The HEI Movie on Youtube tells you visually how to do all that. And also the Project 1959 document has that in it as well. #1 on the cap should be between 5 and 6 o'clock. Then clockwise from 1, its 5-3-6-2-4. Did that help? I need to fix that document. Its on my long list. Thanks for saying something though.. I needed to get out my magnifier to read it and now its HERE!

[Neverdone]

Deve
I have a printout of “Installing the distributor and static timing the Chevrolet inline 6 “” for the last 3 weeks trying to figure out exactly what it says …
My engine is in the truck and running but hard starting..

My first question is if the flywheel ball and the pointer align is it now on TDC and no need to go further and I can go to the next step of installing the distributor ?
Dan

[Deve]

Yes. That will work. The BB is 3 degrees before top dead center, but TDC is that U|C marking on the flywheel. Using the BB is fine and how I do it. My 235 starts right up and runs great. To be precise, use TDC and of course that is also debatable since the REAL way to tell where TDC is, is to rotate the engine while looking at the valve action. My suggestion if you are trying to also learn stuff along the way like me is to adjust your valves first using this:

http://devestechnet.com/Home/ValveAdjust < go to near the bottom to Jeff's explanation. He's good at explaining stuff.

Once that is done, there is no doubt where TDC is and you can rotate the engine until #1 or #6 valve train is rocking, then look at your pointer and confirm that the BB is at the pointer or the U|C is. Since your rocking action isn't perfect, if you see the U|C or the BB, then that confirms your engine is ready for the distributor to be installed so that in the end, its pointing to #1.

I have recently redone that article you printed out so the words are clearer. This one:http://devestechnet.com/Home/EngineTiming

If it's not any more clear now, just give me a call. Number is in your PM.

[Neverdone]

Where in relation of the BB is the U | C mark ? Right or left of it and how close

My motor turns slow [ still 6 volt ] I have already done the usual ...battery charged ..contacts clean ... rebuilt starter ...heavy cables ..etc.

I have never started from scratch with the timing
Dan

[Deve]

It's about an inch to the right. You can't hurt anything in trying as long as you don't break anything. Once you understand what is happening as far as the relationship to the valves and the pistons, then how the distributor drives off the cam when it is in a specific location, you will feel great about it. Its a great feeling understanding that relationship. The piston of #1 and #6 are all the way up at the same time. Jeff tells the story better than I could. You are better off turning the engine by hand during all this. If you remove the spark plugs, it will turn with the fan EASY.

[Neverdone]

Deve ,
I do not want to sound dense but I feel I have not yet received a definite answer ........ If the pointer is on the center line of O | U........ I can install the distributor without the fear of being 180 degrees off ?

When this is over I am going to rewrite these procedures so that someone with no mechanical knowledge can understand it ... yes an IDIOTS guide .
Dan

[Deve]

I wish someone would write that. Its badly needed. The answer is no. Two things have to occur. The U|C or BB is TDC for pistons 1 and 6. So, to tell if 1 is in firing position you have to look at the valve action. If number 6's valves are moving (rocking) then you are in #1 firing position. If #1's valves are moving, then it is 360 degrees out. (the whole system fires around a total of 720 degrees or two rotations). Long story short, check the valves are moving on #6. When they are, rotate it an inch or so back to the U|C and put your distributor in with the rotor installed and pointing away from the engine at between 5 and 6 o'clock. I use the BB instead of U|C because as the engine starts moving, it loses about 3 degrees and it seems to run better there. I think that is why they went to the trouble to embed the BB in the first place. (that is my opinion).

[Neverdone]

Now THATS understandable .......
Dan

[Neverdone]

Now that explains it very well .....
Dan

[Deve]

What you are seeing at devestechnet.com is the evolution of the writing process. First, Nathan and Jeff wrote the very valuable articles you see there, then based on that, I wrote this one http://devestechnet.com/Home/Project...ialvalveadjust

But really, what we need is someone to really start from the very beginning and explain every detail of the timing/tuning process. I envision it would be outlined like this:
1) Removing the Valve Cover (including replacement gasket part numbers)
2) Adjusting both solid lifter and hydraulic lifter valves. Initial Static Adjust and also Hot Adjust) (explaining the marks on the flywheel, how to make them easier to see, etc)
3) Checking the Compression of each Cylinder. If they are not within 5% of each other, then how to do a Leak-Down test and how to determine if it's valves or rings causing it.)
4) How to install the Distributor for optimal tuning. (This is here because the person already knows about valve rocking, etc so it's easier now)
5) Static (engine off) tuning. (Adjustment of points, plugs, rotor, etc in relationship to the flywheel TDC)

Note: Everything above is with Engine OFF.

6) Initial startup. Using a dynamic timing light to get things adjusted dead on. (Alternative using a Vac Gauge and Roadside "by Ear" adjustments.)
7) Carb Adjustments, care of fuel system etc.

Everything is here on the site but in too many various places, I agree. One good, long detailed document with a few short movies even showing a few key issues wouldn't hurt anything.

[Neverdone]

Why do the points HAVE to be adjusted to BEFORE distributor is installed ?
Dan

[Deve]

Where are you seeing that Dan?

[Neverdone]

I can see where it would be easier to do the points with distributor out.... BUT On http://devestechnet.com/Figures/enginetiming.pdf on page 1, section 2 , last paragraph ...section c