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Username Post: SBC 350 locating TDCC and aligning rotor correctly other misc issues        (Topic#331459)
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-21-15 09:41 AM - Post#2596864    

Greetings -

I have a 350 swap that is plagued with problems. I was not present for the original installation nor do I have access to the "maker" all I can tell you is what I've experienced since buying the car off Craigslist. THE MOTOR IS SETUP AS A CARBUERATED CONFIGURATION - NO EGR and NO EMISSIONS, original vehicle wiring harness bypassed.

November 2015 - Car would start and idle ok, sort of high rpms in park (1200) and when put into drive (600) and would occasionally stall. Initial off the line performance was horrible, backfiring through carb and cutting out - I'd have to feather the throttle to about third gear and then it ran fine at highway cruising speed. Was getting 20 miles per gallon all indications was that I was running lean but the plugs are super carbon fouled.

I replaced the fuel pump and inspected all fuel lines and have verified that proper fuel is being supplied to the carb.

Next I used a piston stop tool to locate TDC and I observed the following:

The TDC mark was at high noon, appropriate for this JHA suffix engine (Gen 1 1995 truck TBI engine) HOWEVER the timing cover had the timing tag at the 10 degree offset position with that tube for the timing probe (old cover) so I verified visually that the person who swapped the engine advanced the harmonic dampner to the timing tag position and synced the distributor rotor to the #1 cylinder. In effect I would say the timing was off.

December 2015 - I ordered a new harmonic balancer, it arrived and is a duplicate of the one on the motor (high noon TDC position) I went to Oreilly Auto Parts and bought one for a 1980 K5 Blaser that had the timing mark in a different location (was attempting to match the timing tag) got it home and upon further inspection the line was to the left of high noon based on the key way (weird). So I installed the duplicate new harmonic balancer and did the following:

Put a piston stop tool in # 1 and ensured I was on the compression stoke I turned the engine clockwise made a mark, counter clockwise made a mark, split difference for true TDC and then turned engine clockwise to contact piston stop.

I cut off the timing tag on the cover and installed an aftermarket and placed the 0 degree on the leading mark (NOT middle TDC mark). IS THAT CORRECT?

Next I took the distributor out and synced to #1 with new tag and mark made on balancer.

New plugs gapped at .035 and all new spark plug wires.

Motor did not start right up, continual cranking and finally it started but idles very hard and erratic.

I will put a timing light on it tonight and report back but the only way to sustain idle is to turned the distributor clockwise until the vacumm advanced hits the firewall/dipstick area.

Also the engine is very stubborn to crank (bogged down).

Did I set TDCC correctly or was I supposed to move the middle mark to the leading mark and then align from there?

Misc issues:

November 2015 - the ignition functions for 1 or two cranks and then everything goes stone cold dead, had to jumpstart to run but if it dies it is dead. I took the battery to Autozone it tests fine. December 2015 - I cleaned off the positive and negative battery cables and reinstalled, car cranks after 1 to 2 tries but stubborn to crank (may be related to above work). checked battery voltage after idling car for 20 minutes and it is 13.25 volts so alternator appears to be charging.

November 2015 - no leaks from cooling system

December 2015 - leaking from behind flywheel puller (front of water pump) - this is a weird location for a leak I've never had one develop a leak from not driving the car.




 




LUVmachine 
Frequent Contributor
Posts: 1453

Age: 36
Loc: Redding Ca
Reg: 10-02-14
12-21-15 07:17 PM - Post#2596974    
    In response to Bennybone

Can you give us a little more info on what vehicle this is in? Sounds like you have a whole bunch of issues. Start with the basics make sure all the wiring is in order. Check for good clean connections especially at the grounding locations. Make sure plug wires are properly connected and in the correct firing order. The coolant leak sounds like it could possibly be leaking from the weep hole indicating your pump is on the way out.

What kind of ignition does this thing have? Sounds like it could use some help. It also sounds like you could have a vacuum leak. Check all vac lines for cracks or not connected at all.



71 Chevelle BBC powered
71 C-10 454 with weiand 177 (SOLD)
72 406 sbc powered Chevy LUV sleeper (SOLD)
2010 GMC Sierra crew cab 4X4
http://s626.photobucket.com/user/GJohnson81/libra r...


 
gchemist 
Senior Chevytalk Moderator
Posts: 24365
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
12-22-15 05:58 AM - Post#2597013    
    In response to LUVmachine

Wow!
I would start over on timing. Read this: http://www.73-87.com/7387garage/drivetrain /disremo...
Pull the left valve cover so you can see both #1 valves closed.

Can you post an engine bay picture? What type of carb is bolted on? Is fuel proved by an electrical or mechanical pump?

'95 Jimmy SLT (Bought @131,814)
'83 Silverardo XST - ZZ4 powered
'96 GMC Jimmy LS Ret. @236651 miles


 
FleetsideLarry 
Member
Posts: 620
FleetsideLarry
Age: 73
Loc: Shellman Bluff, Coastal G...
Reg: 01-08-03
12-22-15 06:46 AM - Post#2597015    
    In response to Bennybone

  • Bennybone Said:
...Put a piston stop tool in # 1 and ensured I was on the compression stoke I turned the engine clockwise made a mark, counter clockwise made a mark, split difference for true TDC and then turned engine clockwise to contact piston stop.

I cut off the timing tag on the cover and installed an aftermarket and placed the 0 degree on the leading mark (NOT middle TDC mark). IS THAT CORRECT?





the 0 degree mark on the tab should align with the true TDC mark on the balancer. having used a piston stop, that would be the middle mark you made


Larry


Edited by FleetsideLarry on 12-22-15 06:48 AM. Reason for edit: No reason given.

 
55chevy383 
Silver Supporting Member
Posts: 1447
55chevy383
Age: 50
Loc: Noble, Ok.
Reg: 12-08-05
12-22-15 07:27 AM - Post#2597022    
    In response to FleetsideLarry

Hard starting now, sounds like the timing is off and way too advanced. Start over with the timing. As mentioned pull the valve cover and verify TDC on the compression stroke, then check the rotor to see where it's pointing at.

Phil

11.22 @ 117 N/A.
Phil's '55


 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-22-15 01:11 PM - Post#2597069    
    In response to FleetsideLarry

  • FleetsideLarry Said:


the 0 degree mark on the tab should align with the true TDC mark on the balancer. having used a piston stop, that would be the middle mark you made





While I can understand that this would be optimal, the motor does not have the factory timing tag in place at true TDC.

What I am of the understanding is that I can create my own convenient timing tab by finding TDC and marking elsewhere on the harmonic balancer and lining up to '0' on a new tab.

What is confusing (mis-leading) is to think that any other mark on the balancer at the time the piston is at true TDC will work for the practice of timing the engine. Why the need to rotate clockwise (mark) then counter-clockwise (mark) then divide if a simple mark at '0' on the initial piston stop will do?

OR

Am I suppose to back up X amount of degrees from the initial stop point and use that for the new '0' mark ?

Either way I am not wanting to time from high noon on this vehicle which is where "true" TDC is static.

Thanks all for the input - I am working on the car later today and I will put up more info on the car etc later.

BB



 
acardon 
Ultra Senior Member
Posts: 11020
acardon
Loc: DFW TEXAS
Reg: 03-25-05
12-22-15 02:34 PM - Post#2597083    
    In response to Bennybone

  • Quote:
What is confusing (mis-leading) is to think that any other mark on the balancer at the time the piston is at true TDC will work for the practice of timing the engine. Why the need to rotate clockwise (mark) then counter-clockwise (mark) then divide if a simple mark at '0' on the initial piston stop will do?




O.K. the piston stop does not stop the piston at TDC. It stops it at some unknown degrees before TDC, depending on the depth and location of the spark plug hole, the amount of dome of the piston, deck height, and maybe some other variables I forgot. By rotating the engine till it hits the stop, marking it, then rotating it backwards to the stop, marking it, then halfway between the marks is exact TDC.

Don
66 Corvair (driving)
57 2dr HT (driving)
56 2dr HT (waiting to be restored)


 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-22-15 03:10 PM - Post#2597093    
    In response to acardon

  • acardon Said:
  • Quote:
What is confusing (mis-leading) is to think that any other mark on the balancer at the time the piston is at true TDC will work for the practice of timing the engine. Why the need to rotate clockwise (mark) then counter-clockwise (mark) then divide if a simple mark at '0' on the initial piston stop will do?




O.K. the piston stop does not stop the piston at TDC. It stops it at some unknown degrees before TDC, depending on the depth and location of the spark plug hole, the amount of dome of the piston, deck height, and maybe some other variables I forgot. By rotating the engine till it hits the stop, marking it, then rotating it backwards to the stop, marking it, then halfway between the marks is exact TDC.



I'll simplify my question:

TDC happens at one exact moment in time which is represented by a single degree on the balancer.

The factory determined that they would measure timing at high noon with a tag on the timing cover.

All things equals, isn't every other degree mark on the balancer a true representation of TDC?

For example if I install timing tags at 3/6/9 o'clock positions AND mark the balancer in 3 different colors to corelate then I'd be able to measure timing correctly at any given location?

So black line on balancer at high noon (TDC) would be the same as 3 o'clock red line or 6 o'clock blue or 9 o'clock yellow.

Right?




 
65_Impala 
Very Senior Member
Posts: 4031

Reg: 12-29-02
12-22-15 05:22 PM - Post#2597119    
    In response to Bennybone

By your description you didn't use the stop correctly.

You first put the timing mark tab onto the engine.

Then you rotate each direction and make a mark at your tab.

Finally, you make a permanent mark half way between. This is the new TDC mark that matches with the tab.


In this part, either you didn't explain it right or you did it wrong.


  • Bennybone Said:
Put a piston stop tool in # 1 and ensured I was on the compression stoke I turned the engine clockwise made a mark, counter clockwise made a mark, split difference for true TDC and then turned engine clockwise to contact piston stop.

I cut off the timing tag on the cover and installed an aftermarket and placed the 0 degree on the leading mark (NOT middle TDC mark). IS THAT CORRECT?




This is saying you installed the new timing tab lined up to the new TDC mark while the engine was against the piston stop, which is wrong.






 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-22-15 10:30 PM - Post#2597163    
    In response to 65_Impala

I suppose I've answered my own question:

Keeping in mind that the piston stop halts movement at an exact point (two different directions) it really comes down to where you are indexing the balancer to the motor.

For example I verified tonight that you get two marks off the timing tabs '0' with a TDC in the middle. The TDC was 8 degrees right of high noon.

I then advanced the distance of the index point by the distance between TDC and the original front (clockwise) mark and identified a new marking point on the motor lower and to the right of the timing tab.

Spun it CCW and guess what, now the "true TDC" is on the '0' of the timing tab.

I've been banging my head against the wall for a week thinking about it and went for it tonight and the motor is now timed at 12 degree BTDC and running without backfires and cutting out.

Up next will be to tune the carb and idle, in sure I have a few vacumn leaks so working towards optimum performance.

Was unable to spin the wheels at a dead stop off the line so I know it isn't running optimally, yet.



Edited by Bennybone on 12-22-15 10:33 PM. Reason for edit: No reason given.

 
acardon 
Ultra Senior Member
Posts: 11020
acardon
Loc: DFW TEXAS
Reg: 03-25-05
12-23-15 08:00 AM - Post#2597214    
    In response to Bennybone

  • Quote:
The TDC was 8 degrees right of high noon.

I then advanced the distance of the index point by the distance between TDC and the original front (clockwise) mark and identified a new marking point on the motor lower and to the right of the timing tab.

Spun it CCW and guess what, now the "true TDC" is on the '0' of the timing tab.




That stil doesn't sound right??? If the TDC mark is 8 degrees right of high noon, put the tab 8 degrees to the right. It's that simple.


Don
66 Corvair (driving)
57 2dr HT (driving)
56 2dr HT (waiting to be restored)


 
grumpyvette 
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17178
grumpyvette
Age: 70
Loc: FLORIDA USA
Reg: 03-16-01
12-23-15 08:38 AM - Post#2597226    
    In response to acardon

http://garage.grumpysperformance.com/index.php?thr...

http://garage.grumpysperformance.com/index.php?thr...

http://garage.grumpysperformance.com/index.php?thr...

IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!


 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-23-15 01:24 PM - Post#2597282    
    In response to grumpyvette

Well , strange issue overnight .

After verifying initial timing at 12 degrees BTDC and locking in the distributor and driving 55 miles and not experiencing a single hiccup, all styles of driving tested, today the car is back to its old ways (backfiring and bogging down off the line).

Crazy that it would do this 14 hours after being fine...

I'll look for vacuum leaks and possible carburetor issues next since timing and fuel supply have been verified.



 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-23-15 02:36 PM - Post#2597297    
    In response to Bennybone

Correction timing is Advanced 12 degrees to ATDC (towards drivers side).

Thanks for the links grumpy



 
65_Impala 
Very Senior Member
Posts: 4031

Reg: 12-29-02
12-23-15 05:14 PM - Post#2597316    
    In response to acardon

  • acardon Said:
  • Quote:
The TDC was 8 degrees right of high noon.

I then advanced the distance of the index point by the distance between TDC and the original front (clockwise) mark and identified a new marking point on the motor lower and to the right of the timing tab.

Spun it CCW and guess what, now the "true TDC" is on the '0' of the timing tab.




That stil doesn't sound right??? If the TDC mark is 8 degrees right of high noon, put the tab 8 degrees to the right. It's that simple.





Don't feel bad, I can't even follow what is being attempted here. After using a piston stop, TDC happens when the middle mark is aligned with the pointer. This is turning 3 simple steps into the most convoluted process possible.



 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-23-15 09:07 PM - Post#2597340    
    In response to 65_Impala

  • 65_Impala Said:
  • acardon Said:
  • Quote:
The TDC was 8 degrees right of high noon.

I then advanced the distance of the index point by the distance between TDC and the original front (clockwise) mark and identified a new marking point on the motor lower and to the right of the timing tab.

Spun it CCW and guess what, now the "true TDC" is on the '0' of the timing tab.




That stil doesn't sound right??? If the TDC mark is 8 degrees right of high noon, put the tab 8 degrees to the right. It's that simple.





Don't feel bad, I can't even follow what is being attempted here. After using a piston stop, TDC happens when the middle mark is aligned with the pointer. This is turning 3 simple steps into the most convoluted process possible.



I'll admit there is a tad of over analysis on this , with the car performing poorly again I will now consider putting the tag at high noon.

Which aftermarket tag are yall using for this, I don't want to replace the timing chain cover I.e. Remove the balancer again.

Thx




 
raycow 
Honored Member
Posts: 27573
raycow
Loc: San Francisco, CA
Reg: 11-26-02
12-23-15 09:59 PM - Post#2597345    
    In response to Bennybone

  • Bennybone Said:
I'll admit there is a tad of over analysis on this , with the car performing poorly again I will now consider putting the tag at high noon.

Which aftermarket tag are yall using for this, I don't want to replace the timing chain cover I.e. Remove the balancer again.


Sorry, but it still sounds as if you are trying to make this job more difficult than it needs to be. It doesn't make one bit of difference what kind of tab you use or where it is located on the cover, as long as you can see the tab when you want to set the timing. Just use the tab which is already on the cover and you should be fine.

Now lets go through the procedure one more time.

1. Install the piston stop in cylinder #1.
2. Turn the crank by hand until it stops.
3. Put a mark on the balancer exactly in line with "0" on the tab
4. Turn the crank in the opposite direction until it stops again.
5. Put another mark on the balancer exactly in line with "0" on the tab.
6. Remove the piston stop.
7. Use a tape measure to find the point exactly midway between the two marks.
8. Put a third mark on the balancer at the midway point. THIS is the mark you will use for setting the timing. When it is lined up with "0" on the tab, #1 will be at TDC.

Any questions?

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-24-15 11:39 AM - Post#2597436    
    In response to raycow

  • raycow Said:
  • Bennybone Said:
I'll admit there is a tad of over analysis on this , with the car performing poorly again I will now consider putting the tag at high noon.

Which aftermarket tag are yall using for this, I don't want to replace the timing chain cover I.e. Remove the balancer again.


Sorry, but it still sounds as if you are trying to make this job more difficult than it needs to be. It doesn't make one bit of difference what kind of tab you use or where it is located on the cover, as long as you can see the tab when you want to set the timing. Just use the tab which is already on the cover and you should be fine.

Now lets go through the procedure one more time.

1. Install the piston stop in cylinder #1.
2. Turn the crank by hand until it stops.
3. Put a mark on the balancer exactly in line with "0" on the tab
4. Turn the crank in the opposite direction until it stops again.
5. Put another mark on the balancer exactly in line with "0" on the tab.
6. Remove the piston stop.
7. Use a tape measure to find the point exactly midway between the two marks.
8. Put a third mark on the balancer at the midway point. THIS is the mark you will use for setting the timing. When it is lined up with "0" on the tab, #1 will be at TDC.

Any questions?

Ray



Hi Ray -

#8 - at last check the middle TDC mark was at high noon and my tag is at 1:30.

The previous owner made the mistake of advancing the middle mark to the '0' on the tab AND installing the dizzy at #1.

If I understand you correctly I will ensure that the dizzy is set to #1 when the middle mark is at high noon (front mark where it originally hit piston stop).

Then when I start the engine I'll use the timing light and distributor to move the middle mark to 6-8 degrees BEFORE or AFTER ?

Right?




 
acardon 
Ultra Senior Member
Posts: 11020
acardon
Loc: DFW TEXAS
Reg: 03-25-05
12-24-15 03:05 PM - Post#2597480    
    In response to Bennybone

  • Quote:
If I understand you correctly I will ensure that the dizzy is set to #1 when the middle mark is at high noon (front mark where it originally hit piston stop).




Forget the past. Disregard all other marks on the balancer. Follow Rays directions and then reinset the dizzy.

Don
66 Corvair (driving)
57 2dr HT (driving)
56 2dr HT (waiting to be restored)


 
Bel Air kiwi 
"3rd Year" Silver Supporting Member
Posts: 4260
Bel Air kiwi
Loc: New Zealand
Reg: 04-24-14
12-24-15 07:44 PM - Post#2597528    
    In response to acardon

Hi Bennybone. What Ray has told you is the correct method for finding TDC mechanically. Its the only reliable way to do this as at TDC the piston dwells and rocks slightly as it passes true TDC and so it is more accurate to measure away from TDC and average it.

If you imagine a simple bow and arrow. Where the blocked timing marks are either side of TDC is where the string ties onto the bow. If you hold the arrow in the middle it bisects the curve of the frame and gives you a TDC mark.

Of course none of this is of any use to you if the outside ring of the harmonic damper with the factory graduation/s has failed and slipped or slips when you rev it.

The timing doesn't change but the marks move!
To see if this is happening get some Twink (Whiteout) and put as single line from the balancer bolt out to the outside rim like a spoke in a wheel. Run it for a while and if there is any alignment change you know there is an issue with the balancer. Production bonded balancers often fail like this in HP usage and are routinely banned in competition because of this known weakness in hard conditions

Cheers Kiwi

48 3100 RHD, 51 Deluxe 4DR RHD, 51 Bel Air parts car, 52 Bel Air P-Glide LHD. Others 23T, 32 Tudor, 58 Edsel pacer 4DR HDT, 79 F250 351C RHD. 69,70,82 Capri. No mobile, no TV, and no Jap cars.

And when it was laid to waste, they called it peace.


 
65_Impala 
Very Senior Member
Posts: 4031

Reg: 12-29-02
12-24-15 09:29 PM - Post#2597539    
    In response to Bennybone

  • Bennybone Said:
If I understand you correctly I will ensure that the dizzy is set to #1 when the middle mark is at high noon (front mark where it originally hit piston stop).

Then when I start the engine I'll use the timing light and distributor to move the middle mark to 6-8 degrees BEFORE or AFTER ?

Right?




Not likely. The marks you made when the piston contacted the piston stop are useless once you put the mark between them. They are ONLY temporary to use during the procedure.

Watch this video.

https://www.youtube.com/watch?v=xg6eAWWvrPA

Erase the old marks and try again.

- Put the pointer you want to use onto the engine.
- Rotate each direction until the piston is against the stop and then mark the balancer at the 0* mark on the pointer.
- Put a permanent mark on the balancer 1/2 way between the 2 marks from above.
- Use the new timing mark to put the engine at TDC for installing the distributor.
- Use the new timing mark for setting the timing.

Do it again and do the above only. Using the other marks or installing the pointer after or any other crap like that is just screwing it up.






 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-24-15 11:33 PM - Post#2597558    
    In response to 65_Impala

Ok I get it -

What prevented me from understanding is that I was looking for a solution to a problem and wanting this to be the fix.

The first time I did this I had the piston stop screwed all the way in which gives a very wide difference between the two marks and resulted in a TDC mark at a different location versus when I tried again with the piston stop screwed in halfway.

The only outstanding question I have is:

1) the harmonic balancers come marked 0 degrees to 60 degrees after TDC while the timing tags have more degrees on the before TDC side. For initial timing will I be looking for my balancer mark to zero at 12 degrees BTDC on the tag which is really 12 degrees ATDC on the balancer? I don't have a timing light with advance degree capability so I'm asking to ensure I understand what optimal initial will look like.

2) has anybody had coughing/spitting through the carb and horrible off the line performance due to using an Edelbrock 1406 performer carb? Some research last night indicates these carbs were tuned for economy (lean) settings moreso than other carbs.

Thx



 
FleetsideLarry 
Member
Posts: 620
FleetsideLarry
Age: 73
Loc: Shellman Bluff, Coastal G...
Reg: 01-08-03
12-25-15 08:20 AM - Post#2597592    
    In response to Bennybone

The balancer degree marks are in fact BEFORE TDC. remember the balancer is rotating clockwise towards the stationary tab zero point

BUT. Unless the original TDC mark happened to match your new mark, the balancer degree markings are no longer valid.

You need to use the tab degree marks with the balancer's new TDC mark

Larry


Edited by FleetsideLarry on 12-25-15 08:33 AM. Reason for edit: No reason given.

 
oldeerslayer 
Forum Newbie
Posts: 2

Reg: 08-09-15
12-29-15 11:46 AM - Post#2598458    
    In response to FleetsideLarry

Couple of thoughts.
Does the distributor have a vacuum advance unit? If so, are you plugging the line to it when setting the timing at idle? Is the vacuum advance connected to a ported or manifold source?
When you say #1 are you talking about the front cylinder on the drivers side? I have seen similar cases where a guy thought right front was number 1. (1 follows 2 in the firing order)
Is it possible that the cam is installed incorrectly?




Edited by oldeerslayer on 12-29-15 11:59 AM. Reason for edit: No reason given.

 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-29-15 12:13 PM - Post#2598462    
    In response to oldeerslayer

  • oldeerslayer Said:
Couple of thoughts.
Does the distributor have a vacuum advance unit? If so, are you plugging the line to it when setting the timing at idle? Is the vacuum advance connected to a ported or manifold source?
When you say #1 are you talking about the front cylinder on the drivers side? I have seen similar cases where a guy thought right front was number 1. (1 follows 2 in the firing order)
Is it possible that the cam is installed incorrectly?




The distributor has a vacuum advance, the manual states to place it on the left ported outlet on the front of the carb however it is on the right side. When I switched them the car idled poorly so I put it back on the right ported vacuum outlet.

I will throw a video up tonight or tomorrow of the timing and operation.

While it may be possible that the cam is not installed correctly I would think the carburetor is next in line for a look....



 
Oregonite 
Forum Newbie
Posts: 24

Age: 63
Loc: Sweet Home Or.
Reg: 08-05-12
12-29-15 01:04 PM - Post#2598471    
    In response to Bennybone

Whoever rebuilt the engine used a newer balancer. Don't go by the timing tab that is currently installed O degrees is most likely is @ 12:00 You will need a 12:00 timing tab.http://www.hotrodders.com/forum/chevy-timing-ta b-id-see-photo-178514.html



Edited by Oregonite on 12-29-15 01:16 PM. Reason for edit: No reason given.

 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
12-29-15 08:30 PM - Post#2598575    
    In response to Oregonite

So in the end I suppose I am right back where I started except that I have an improved awareness for finding TDC and timing the motor.

I suppose the guy did have the timing close and that my initial post is full of errors.

Thanks to a good number of members here you continued to advise until I came to the realization that I should just follow the program

With that said here is a video I threw together of how I marked TDC using a tab in an area that I can see clearly.

The car still isn't running that good, I suppose I'll work over the carburetor system next before getting into the heavy stuff...

Thanks again -

VIDEO of what I did



 
Bennybone 
Forum Newbie
Posts: 22

Reg: 12-21-15
01-13-16 09:29 AM - Post#2601777    
    In response to Bennybone

January 2016 -

Installed new intake manifold gaskets, a remanufactuered M4ME Quardrajet, new spark plugs (.045) new spark plug wires, new Summit Racing HEI distributor, reconfigured the throttle return spring.

The car no longer backfires through the carb nor does it die at throttle tip in.

I'm still searching for low end torque and snappy throttle response - the engine is running a bit sluggish - I had one day where it was very nice but the following 3 days were disappointing.

I put a vacuum gauge on the car yesterday

Vacuum Readings from Monte Carlo

Short summary of the video is at 8 degrees BTDC and with 12 inches of vacuum on a full manifold port when I connect the distributor I get 30 degrees of timing AT IDLE.

I sure wish I new what cam this car has in it and whether that is why I am at 12 inches of vacuum.

BB



 
IgnitionMan 
Valued Contributor
Posts: 3368

Reg: 04-15-05
01-13-16 10:33 AM - Post#2601793    
    In response to Bennybone

Not enough initial timing, too much vacuum advance timing. Build the vacuum advance stop, let the pin travel .112 inch, 10 crankshaft degrees, set initial to 12/14 degrees. This would give 22/24 degrees IDLE timing.

Set mechanical degrees to get 22 degrees, would give w/12 initial, 34 total, w/14, 36 total.

Spring mechanical to start 100/150 rpm's over out of gear idle speed, stop curve 2,600/2/800 rpm's.

Vacuum would be low if intake closing degrees were excessive, as in BIG cam.



 
0utlaw 
Very Senior Member
Posts: 2789
0utlaw
Loc: US East Coast
Reg: 09-10-02
01-13-16 01:12 PM - Post#2601814    
    In response to Bennybone

If all else fails,try this.....
My 355 in the 70 C10 has a relatively big cam in it. (why anyone puts these in for street is beyond me because it sacrifices low end torque, gas mileage, ease of tuning, etc, but it is the way I got it) It does sound very cool. I have my HEI timing set right at the end of the timing tab (approx 15 btc)..vac disconnected. ( my distributor has medium springs in it and an adjustable vacuum can) I backed off on the can a until it had a very light flutter at idle.
I use manifold vacuum which when plugged in, the engine speeds up at idle. I set my idle to the highest point on a vacuum gauge. And reset the curb idle to where it idles good in gear (hot).
The timing seems excessive, but it is super responsive and starts in one turn hot or cold. Sometimes you gotta forget what the timing is or supposed to be and adjust it out on the road. A reminder, a perfect working choke is also necessary to make driving enjoyable.

Also, if you have headers, you can locate a dead spark plug by spraying water on the header tubes engine warm. The dead cylinder header will stay wet. Kind of a nice tip to remember. Saves you pulling all the plugs out.
OUTLAW



 




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