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-   -   Seems like I have to keep advancing my timing (https://67-72chevytrucks.com/vboard/showthread.php?t=714478)

chrismoore701 08-14-2016 09:59 PM

Re: Seems like I have to keep advancing my timing
 
So here is the latest. I brought the motor over to tdc. Cranked it over wth started until it blew my buddy's finger off number 1. Then cranked by hand to get to zero. Tab on rotor was pointing between no 1 and no 8. That would make sense since I have it at 32 degrees. I pulled the distributer. It seems like the springs are real light and one of the weights move a little free. Not a lot but it moves. Any thoughts. Engine builder was supposed to come over today and got tied up

chrismoore701 08-15-2016 08:58 PM

Re: Seems like I have to keep advancing my timing
 
Builder thinks it may be my fuel pressure. It is about 9 psi. He thinks I have to advance the timing to burn the extra fuel. Thoughts?

rich weyand 08-15-2016 10:22 PM

Re: Seems like I have to keep advancing my timing
 
I don't think that's it. A rich mixture should burn faster, so it should require less advance.

That said, your fuel pressure is too high, and could be compounding your troubles.

You need to put in a fuel pressure regulator.

chrismoore701 08-15-2016 10:42 PM

Re: Seems like I have to keep advancing my timing
 
Regulator coming tomorrow

Mr.Chevy4x4 08-16-2016 07:33 AM

Re: Seems like I have to keep advancing my timing
 
When you say you pulled the distributor, did you actually pull it out, or just pull the cap? If it was mine I'd want to see the gear. I've had one get chewed up in a matter of a couple hundred miles, and caused other damage.

Mike

chrismoore701 08-16-2016 09:33 AM

Re: Seems like I have to keep advancing my timing
 
I pulled the whole distributer for that very reason. All looks good

geezer#99 08-16-2016 10:44 AM

Re: Seems like I have to keep advancing my timing
 
Quote:

Originally Posted by chrismoore701 (Post 7684763)
I pulled the whole distributer for that very reason. All looks good

What do you have for a hold down clamp on the distributor?
You got a pic of it?

chrismoore701 08-16-2016 12:50 PM

Re: Seems like I have to keep advancing my timing
 
Standard wishbone looking clamp. The distributer was tight. Tried to twist it. It was originally timed at 12. So not like I am putting it back to 12. It was timed as follows
12. Ran great for 400 miles
14. Ran great for anoth 400
16 would not run
22 ran but could not drive
26 ran but could not drive
32 ran and drove. Confirmed this is not right and have been tearing into it

geezer#99 08-16-2016 12:54 PM

Re: Seems like I have to keep advancing my timing
 
Have you confirmed tdc #1 is accurate with your timing tab/balancer mark?

http://www.crankshaftcoalition.com/w...op_dead_center

chrismoore701 08-18-2016 11:04 AM

Re: Seems like I have to keep advancing my timing
 
I did confirm tdc on timing mark. Builder came over and said he is going to replace the fuel pressure gauge says it is junk. Rebuilding the carb just to be sure. And he thinks the weights on top of the distributer is the biggest issue he is going to replace the weights and stuff on top of distibuter. Keep your fingers crossed

Chris

Tiger Joe 08-18-2016 11:17 AM

Re: Seems like I have to keep advancing my timing
 
I'm a little confused by your timing figures, you started at 12 and are now at 32. is that base timing? so you have constantly be upping the base timing, plus you still have all of the additional advance?

so you are at 32 degrees to start, plus all the timing your distributor is putting in, which im guessing is like 18-20? that would be an awful lot of timing on a sbc.

I have had good success forgetting base timing and just setting total timing. id aim for 34-36 on a sbc

geezer#99 08-18-2016 11:39 AM

Re: Seems like I have to keep advancing my timing
 
Quote:

Originally Posted by chrismoore701 (Post 7686978)
I did confirm tdc on timing mark. Builder came over and said he is going to replace the fuel pressure gauge says it is junk. Rebuilding the carb just to be sure. And he thinks the weights on top of the distributer is the biggest issue he is going to replace the weights and stuff on top of distibuter. Keep your fingers crossed

Chris

What tool did you use to confirm tdc #1?

chrismoore701 08-18-2016 01:37 PM

Re: Seems like I have to keep advancing my timing
 
Quote:

Originally Posted by Tiger Joe (Post 7686991)
I'm a little confused by your timing figures, you started at 12 and are now at 32. is that base timing? so you have constantly be upping the base timing, plus you still have all of the additional advance?

so you are at 32 degrees to start, plus all the timing your distributor is putting in, which im guessing is like 18-20? that would be an awful lot of timing on a sbc.

I have had good success forgetting base timing and just setting total timing. id aim for 34-36 on a sbc

Yes that is correct. 32 degees base timing. Just to keep it running

chrismoore701 08-18-2016 01:38 PM

Re: Seems like I have to keep advancing my timing
 
I stuck a pick in the cylinder to feel the piston. Was not exact. But it was close

geezer#99 08-18-2016 02:05 PM

Re: Seems like I have to keep advancing my timing
 
Quote:

Originally Posted by chrismoore701 (Post 7687120)
I stuck a pick in the cylinder to feel the piston. Was not exact. But it was close

Did you know there's almost 20 degrees of crank rotation when the piston is at tdc.
You want to figure out your timing problem you need to be precise on your timingtab/balancer mark.
Otherwise you're just banging your head on the wall!

Only a piston stop will work.

chrismoore701 08-18-2016 02:16 PM

Re: Seems like I have to keep advancing my timing
 
thought about that, will check that when the builder comes back

Tiger Joe 08-18-2016 03:19 PM

Re: Seems like I have to keep advancing my timing
 
if you need 32 base just to run, something is seriously wrong. if that is an accurate measurement, that's almost to the point of having too much timing to start.

how much timing is your distributor adding and when are you all in by? I don't remember off the top of my head what a stock hei adds, might be 18?

I would be curious what your timing is at say 3,000 rpm right now the way things are set

chrismoore701 08-18-2016 04:28 PM

Re: Seems like I have to keep advancing my timing
 
All I know is, it ran great at 12 now at 32. see what heppens

Tiger Joe 08-18-2016 07:54 PM

Re: Seems like I have to keep advancing my timing
 
does it "start hard"? As in does it sound like it struggles to turn over, or does it sound almost like a stock motor?

If it truly had 32 initial I would have a hard time believing it even started, and if it did it would have to start hard.

Are you disconnecting the vacuum advance to measure initial timing?

chrismoore701 08-21-2016 07:19 AM

Re: Seems like I have to keep advancing my timing
 
Ok folks here is what's up. I got the carb and distributer back. Looks like I am still pushing 8-9 psi at the fuel pump with. New gauge. Replaced the weights bushings and springs on the top of the distributer. You can tell the springs are tighter. I just need to see if the slings were actually replaced because he said he didn't want to. But you can tell a difference. Rebuilt the carb. Fired her up and after adjusting the distributer one tooth he had initial at 12 degrees. Adjusted to 16 and running good. Took for. Short drive. Putting her in. Show today about 45 min away. Will see what happens today and if this issue ever happens again.

Jaysonb 08-21-2016 12:51 PM

Re: Seems like I have to keep advancing my timing
 
Good luck!

chrismoore701 08-21-2016 07:21 PM

Re: Seems like I have to keep advancing my timing
 
Put about 80 miles on her today and she is running great. Hopefully things will stay this way.

rich weyand 08-21-2016 08:32 PM

Re: Seems like I have to keep advancing my timing
 
Excellent! Thanks for letting us know.


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