"Jumping" the distributor a tooth
07-26-2014, 12:14 PM
#21
Melting Slicks
I think it's more accurate to say the rotor should be pointing to the R.S., inboard valve cover bolt unless you are talking HEI.
Many engines with aftermarket camshafts are known to not have the distributor gear teeth indexed properly and this throws the distributor out of proper orientation by a "half tooth". That's why the advice to rotate the gear 180*, wherever it may be currently.
Many engines with aftermarket camshafts are known to not have the distributor gear teeth indexed properly and this throws the distributor out of proper orientation by a "half tooth". That's why the advice to rotate the gear 180*, wherever it may be currently.
07-26-2014, 12:19 PM
#22
Instructor
Thread Starter
You turn the dist counter- clockwise to advance it, clock-wise to retard it.
If you are hitting the coil, you are turning the dist the wrong way to advance it, you should be hitting the intake if you cannot get enough advance.
You need to pull your dist.
Take cap of dist, and rotate the engine via the crank snout bolt until the timing mark is lined up with the timing tab at 12 degrees (note, the crank rotates twice for every one revolution of the distributor). The rotor firing tab should be pointing towards the front of the car when the timing tab and balancer marks line up.
Now pull your dist out.
Now on the bench, install the cap (no need to lock down) and with a black marker, mark on the dist base where the number 1 cap tower plug terminal is located. This. Will be a reference mark for where the rotor tab should be pointing.
Next, look at the dist drive gear. There is a dimple on the gear casting above the gear, it should be in line with the rotor firing tab. If it is not, you need to knock the roll pin out of the gear, remove (don't loose the shims) and rotate it 180 degrees, then reinstall the roll pin.
Next, reinstall the dist in the engine. You want the dist to be installed so the rotor tab is aligned with the mark you made on the dist base. A long flat blade screw driver works,nut eye balling it will work as you can fine tune later. The vacuum advance can should be in the middle of the travel range between the coil bracket and the intake.
Since we set the balancer mark to the 12* mark on the timing tab (6 notches BTDC) your base timing should be very close. Also, as long as the vacuum can is not real close to hitting either the coil or the intake, you now have room to make adjustments to fine tune your timing.
Notes.
The number 1 cap tower is the first terminal to the left of the points window.
Each notch on the timing tab is 2*
You may need to use a long flat blade screw driver to orientate the dist oil pump drive shaft.
Using this method, I am seldom off by more then 1 or 2 degrees and the engine will fire off immediately.
Mark
If you are hitting the coil, you are turning the dist the wrong way to advance it, you should be hitting the intake if you cannot get enough advance.
You need to pull your dist.
Take cap of dist, and rotate the engine via the crank snout bolt until the timing mark is lined up with the timing tab at 12 degrees (note, the crank rotates twice for every one revolution of the distributor). The rotor firing tab should be pointing towards the front of the car when the timing tab and balancer marks line up.
Now pull your dist out.
Now on the bench, install the cap (no need to lock down) and with a black marker, mark on the dist base where the number 1 cap tower plug terminal is located. This. Will be a reference mark for where the rotor tab should be pointing.
Next, look at the dist drive gear. There is a dimple on the gear casting above the gear, it should be in line with the rotor firing tab. If it is not, you need to knock the roll pin out of the gear, remove (don't loose the shims) and rotate it 180 degrees, then reinstall the roll pin.
Next, reinstall the dist in the engine. You want the dist to be installed so the rotor tab is aligned with the mark you made on the dist base. A long flat blade screw driver works,nut eye balling it will work as you can fine tune later. The vacuum advance can should be in the middle of the travel range between the coil bracket and the intake.
Since we set the balancer mark to the 12* mark on the timing tab (6 notches BTDC) your base timing should be very close. Also, as long as the vacuum can is not real close to hitting either the coil or the intake, you now have room to make adjustments to fine tune your timing.
Notes.
The number 1 cap tower is the first terminal to the left of the points window.
Each notch on the timing tab is 2*
You may need to use a long flat blade screw driver to orientate the dist oil pump drive shaft.
Using this method, I am seldom off by more then 1 or 2 degrees and the engine will fire off immediately.
Mark
07-26-2014, 12:53 PM
#23
I think it's more accurate to say the rotor should be pointing to the R.S., inboard valve cover bolt unless you are talking HEI.
Many engines with aftermarket camshafts are known to not have the distributor gear teeth indexed properly and this throws the distributor out of proper orientation by a "half tooth". That's why the advice to rotate the gear 180*, wherever it may be currently.
Many engines with aftermarket camshafts are known to not have the distributor gear teeth indexed properly and this throws the distributor out of proper orientation by a "half tooth". That's why the advice to rotate the gear 180*, wherever it may be currently.
07-26-2014, 01:01 PM
#24
http://forums.corvetteforum.com/c1-a...alignment.html
Robert, look at this old post. Scroll down to JohnZ's post and there is a photo of the dist. drive gear and the small dimple.
Robert, look at this old post. Scroll down to JohnZ's post and there is a photo of the dist. drive gear and the small dimple.
Last edited by ghostrider20; 07-26-2014 at 02:05 PM.
07-26-2014, 02:26 PM
#25
Instructor
Thread Starter
You turn the dist counter- clockwise to advance it, clock-wise to retard it.
If you are hitting the coil, you are turning the dist the wrong way to advance it, you should be hitting the intake if you cannot get enough advance.
You need to pull your dist.
Take cap of dist, and rotate the engine via the crank snout bolt until the timing mark is lined up with the timing tab at 12 degrees (note, the crank rotates twice for every one revolution of the distributor). The rotor firing tab should be pointing towards the front of the car when the timing tab and balancer marks line up.
Now pull your dist out.
Now on the bench, install the cap (no need to lock down) and with a black marker, mark on the dist base where the number 1 cap tower plug terminal is located. This. Will be a reference mark for where the rotor tab should be pointing.
Next, look at the dist drive gear. There is a dimple on the gear casting above the gear, it should be in line with the rotor firing tab. If it is not, you need to knock the roll pin out of the gear, remove (don't loose the shims) and rotate it 180 degrees, then reinstall the roll pin.
Next, reinstall the dist in the engine. You want the dist to be installed so the rotor tab is aligned with the mark you made on the dist base. A long flat blade screw driver works,nut eye balling it will work as you can fine tune later. The vacuum advance can should be in the middle of the travel range between the coil bracket and the intake.
Since we set the balancer mark to the 12* mark on the timing tab (6 notches BTDC) your base timing should be very close. Also, as long as the vacuum can is not real close to hitting either the coil or the intake, you now have room to make adjustments to fine tune your timing.
Notes.
The number 1 cap tower is the first terminal to the left of the points window.
Each notch on the timing tab is 2*
You may need to use a long flat blade screw driver to orientate the dist oil pump drive shaft.
Using this method, I am seldom off by more then 1 or 2 degrees and the engine will fire off immediately.
Mark
If you are hitting the coil, you are turning the dist the wrong way to advance it, you should be hitting the intake if you cannot get enough advance.
You need to pull your dist.
Take cap of dist, and rotate the engine via the crank snout bolt until the timing mark is lined up with the timing tab at 12 degrees (note, the crank rotates twice for every one revolution of the distributor). The rotor firing tab should be pointing towards the front of the car when the timing tab and balancer marks line up.
Now pull your dist out.
Now on the bench, install the cap (no need to lock down) and with a black marker, mark on the dist base where the number 1 cap tower plug terminal is located. This. Will be a reference mark for where the rotor tab should be pointing.
Next, look at the dist drive gear. There is a dimple on the gear casting above the gear, it should be in line with the rotor firing tab. If it is not, you need to knock the roll pin out of the gear, remove (don't loose the shims) and rotate it 180 degrees, then reinstall the roll pin.
Next, reinstall the dist in the engine. You want the dist to be installed so the rotor tab is aligned with the mark you made on the dist base. A long flat blade screw driver works,nut eye balling it will work as you can fine tune later. The vacuum advance can should be in the middle of the travel range between the coil bracket and the intake.
Since we set the balancer mark to the 12* mark on the timing tab (6 notches BTDC) your base timing should be very close. Also, as long as the vacuum can is not real close to hitting either the coil or the intake, you now have room to make adjustments to fine tune your timing.
Notes.
The number 1 cap tower is the first terminal to the left of the points window.
Each notch on the timing tab is 2*
You may need to use a long flat blade screw driver to orientate the dist oil pump drive shaft.
Using this method, I am seldom off by more then 1 or 2 degrees and the engine will fire off immediately.
Mark
07-26-2014, 02:34 PM
#26
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
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07-26-2014, 02:35 PM
#27
OK. Do you have a strap wrench? If so that may work. If not, bump the starter (coil wire off) until you get it close. Then you can tweak it into location. With the sparklugs out the engine will turn over by grabbing the fan belts. If you don't want to pull the plugs, then just go slow and let the compression bleed down.
You can also put the car in gear and push the car back and forth to move the engine a tad.
Mark
You can also put the car in gear and push the car back and forth to move the engine a tad.
Mark
07-26-2014, 03:13 PM
#28
Instructor
Thread Starter
07-26-2014, 03:14 PM
#29
Instructor
Thread Starter
There's no threaded hole. But I did get it lined up at 0* before I pulled the distributor.
07-26-2014, 03:37 PM
#30
Safety Car
If that aftermarket gear is nodular iron, then drive out the roll pin, rotate it 180*, and try to time the engine again using Mark's excellent instructions.
PS: Either your engine is a bastard 327/365, or the crankshaft was replaced at some point in the past.
Last edited by 65tripleblack; 07-26-2014 at 03:41 PM.
07-26-2014, 03:43 PM
#31
Ideally, you should have parked the balancer line on the 12* (6th line) on the BTDC mark on the timing tab. This is where you want to "end" up at.
Now, if you install the dist, the vacuum can will have to near touching the coil bracket, so you can move it counterclockwise (towards the intake runner) to get the 12* of advance. If you center the vacuum can in the travel zone, with the balancer lined up at zero, you will not have enough travel left to get your required advance.
Move the balancer counterclockwise until the balancer line is lined up with the 6th mark above the zero line on the timing tab.
Then install the distributor as I lined out in my previous post.
If you have no indexing dimple, then you have a 50/50 shot of this working. I would try it as is.
Remember, with the oil pump drive shaft the dist will only seat in a certain location, so you may need to use the long flat blade screw driver and move the pump drive shaft so the slots line up.
Your goal is to have the dist seat completely, with the vacuum can centered in the travel range, and the rotor firing tab lined up with your mark you made on the dist housing base, with the balancer line, lined up on the 6th mark above zero on the timing tab.
Don't get frustrated, your almost there
07-26-2014, 05:17 PM
#32
Instructor
Thread Starter
HATS OFF! I followed Mark's directions scrupulously, and despite no dimple on the shaft, I rotated the drive gear 180*, replaced the distributor per instructions, and voila' - started instantly, and ran great!
A hearty thank you for remote supervision and clear directions. You guys are the greatest!
:thumbsup:Rob
07-27-2014, 09:41 PM
#35
Instructor
Thread Starter
If there's no threaded hole in the crank nose and balancer bolt and washer, then what does that tell you?
07-28-2014, 01:09 PM
#36
Either the engine was not born as a 365 SHP motor, or the crankshaft was replaced with a std (non nitrided) crank. All 327 cranks were forged cranks, but the SHP motor cranks were "nitrided", which is a chemical hardening process. The SHP cranks have 2680 marked on them, and the front (snout) was drilled and tapped for the torsional damper (balancer) retaining bolt. The balancer is an interference fit, but for some reason, they decided to use a retaining bolt on the SHP models.
You can have your crank drilled and tapped for the retaining bolt the next time the crank is out
07-28-2014, 10:05 PM
#38
Callies is a company that will do custom cranks, that are not cheap China junk. There off the shelf cranks start at $900.00 and I have no idea what a custom crank would cost.
Looked it up for you
http://www.callies.com/crankshafts/u...l-block-chevy/
- Mark
Last edited by ghostrider20; 07-28-2014 at 10:12 PM.
07-29-2014, 09:03 AM
#39
Instructor
Thread Starter
Thanks, Mark!
Wow, $3000 for a crank, and who knows what other surprises I'll find when the engine is torn down. The good news is that it IS available, so at some point I'll be able to get it right.
Wow, $3000 for a crank, and who knows what other surprises I'll find when the engine is torn down. The good news is that it IS available, so at some point I'll be able to get it right.
07-29-2014, 09:23 AM
#40
Team Owner
Member Since: Mar 2003
Location: Greenville, Indiana
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Don't waste your money. The standard duty crank will work fine in your engine and run forever. Just drill/tap the nose of the crank to hold the balancer on. I'm told you can do it in the car.