Setting timing with a vacuum gauge?

[cudaken]

 I index the oil pump gear the way Ron told me I think and Cooter said the rotor should be point to #1 hole.

Well it is not, first try it was pointing toward # 7, then I flipped it 180 degrees and it is now pointing towards # 2. Witch happens to be about where 1 was before I started working on her. I am fine with that.

But what has got me wondering is I am 99% sure #1 was at TDC, it blew my finger out of the spark plug hole. Damper is at 0 on the timing chain cover. No cam lopes could be seem when I got it on TDC. So I should be at TDC, right?  

I am now wondering the damper timing ring has slipped. I do know how to check. But after letting her sleep for 8 years, I just want to get her running for now.

So after I get her running, just time her till I have the highest vacuum then I am done?  

And if by chances the timing ring did not slip, is timing by vacuum better than with a timing light?  

I don't know much about the engine it self. It was a just get me by with engine that was sort of fresh 383 out of a 71 Road Runner till I got a nasty 440. Like a fool I installed MP 509 cam, has a Torker intake, Hooker Comp Headers, 750 Holley and Accel Mechanical Advances Distributor.

Thanks in advances for the coming reply's.

HO, by the way. Accel told me the dwell and point gap specks.  

Cuda Ken  

[ws23rt]

Try pulling the oil drive shaft up and rotate a bit till the dist. drive tang is pointed to where the rotor will point near no.1 (with no. 1 at tdc comp)
I think you are only off one tooth on the gear.

[firefighter3931]

With a 509 in a 383 it's going to want a lot of base timing. I wouldn't be suprised if it needed at least 25* at idle (or more) 

I like using the vacuum guage to tell me what the motor wants....then i can shorten the mechanical advance to achieve the desired total advance.

Ken, it will still be worthwhile to check the indexing on your balancer and install some timing tape.....that'll make tuning easier. 


Ron

[cudaken]

With a 509 in a 383 it's going to want a lot of base timing. I wouldn't be surprised if it needed at least 25* at idle (or more) 

I like using the vacuum gauge to tell me what the motor wants....then i can shorten the mechanical advance to achieve the desired total advance.

Ken, it will still be worthwhile to check the indexing on your balancer and install some timing tape.....that'll make tuning easier. 


Ron

Ron, wanting the base at 25 degrees explains something that had perplexed me for years! Years ago when I ran a Midas Shop I left the Road Runner at work on my day off for our head mechanic to tune her. She had a bad stumble off idle and I had to play with the throttle a little to get her going. When I picked her up, stumble was gone, but the wires where a mess? I asked him what he did and all I could get out of him was "I sat the timing". He did not talk much.

Use the PCV line off the back of the Holley 750 correct?

Ken and thank you for your time Ron! 

[ottawamerc]

I tried the vacuum and timing and I was over 30* and still seeing a increase in the vacuum so I just dropped it back to 18* and hoped for the best

Scott

[cudaken]

I tried the vacuum and timing and I was over 30* and still seeing a increase in the vacuum so I just dropped it back to 18* and hoped for the best

Scott

Scott, with the MP 509 Cam I be lucky to see 15 pounds! 

Ken

[flyinlow]

  So after I get her running, just time her till I have the highest vacuum then I am done? 

 

Probable not. Your engine might idle with 40-50* and  high vacuum, but under load it won't work and you would want a supply of spare starters.

You will be shooting for timing of around 36* BTDC at or above 2500 rpm. So you ask , my engine likes 36* BTDC at idle, why not just lock my centrifugal advance and be done with it? If you engine is not detonating and you can restart the engine 10-15 minutes after a fully warm shut down you can do this.

As an example I have a 440 that idles at 24* BTDC. I have one that could only take 14* with a conventional starter. After installing a mini starter I could run 20*  Both engines idle timing are limited by the starters ability to restart when warm.  You have to adjust the amount of centrifugal advance the distributor produces every time you change the base timing to keep the total around 36*

These suggested numbers are for automatic transmission cars.