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Topic Review (Newest First)
12-25-2010 11:38 PM
mud.man.rj
points

andythedrummer did make a good point on the vacumn gauge though, you can set it with a light but is the right cover or balancer on it or as I have seen often the balancer slips on the rubber ring and is out by the mark. so if you want to set any old style without computor timing use the full vacumn port with the vacumn advance hose off the distrib and advance timing to highest vacumn it will go before it runs rough usually 18 to 20 depending on cam, then back off timing about 2.5 ponds on gauge and the timing is pretty much as close as you can get it with and cam out there. Works great I have checked it with the light after with dampeners I new were good(new) and it always works, it's a good alternate method especially without cam specs or year of motor, doesn't even mater what comp ratio. Good luck.
12-25-2010 10:21 PM
kc8oye idle speed is going to depend entirely on your cam. if it's MILD like you say it is. .then I would say 850 in park is probably about right. 1000 is too high.

you want around 700-800rpm IN GEAR. and then the in park idle will go where ever it wants to.

here's a short video of my gauges idling.. and I shift from park into reverse to show the park/gear difference.. and I have a VERY mild smallblock right now (300hp if I'm lucky)

http://www.youtube.com/watch?v=fTPR0EOqaNc
12-25-2010 08:02 PM
StockR Thanks everybody for your help! She runs pretty good at 36 degrees @3000 RPM.

One more simple question... what would be the ideal RPM rate at idle? in drive and in park?

Remember, it's a mild SB 350 with 3 speed Automatic. I have it set on 850 in park. is that good enough or can i go more? say.... 1000 RPM?
12-20-2010 10:05 AM
cobalt327
Quote:
Originally Posted by StockR
I do have a timing tab on the timing chain cover, so when the timing mark on the balancer matches up to the "0" mark on the tab does that mean it's at TDC??
Maybe, maybe not.

The following is from another post I made on this:

Quote:
There are several different dampers. Both the diameter, thickness and the placement of the line on the outer ring of the damper can differ. So you need to know what you have, to know what tab to use.

The three most common locations for the timing mark on the damper:

The pre-'69 damper has the TDC line on the outer ring at the 2:30 o’clock position- or 2º before- (i.e. to the LEFT of the keyway, looking at the front of the engine) the keyway centerline. The keyway is seen in the ID of the damper.

The damper used from '69 to mid-80's has the TDC line at the 2 o’clock position- or 10º before the keyway. You'll find that aftermarket dampers are the 10º type, as are the bolt-on tabs sold in the aftermarket, unless they're adjustable.

A third timing mark was used from about 1978 to about 1991-'92. It is at the 12 o’clock position- or 40º before the keyway. This damper uses a timing cover that has the tab welded on at about the 12 o'clock position.
Above, Custom10 provided a link to make a timing tape. In addition, if you're unsure, or just want to check the accuracy of the tab/mark for TDC, DETERMINE TDC to see for sure.

I believe that replacing the points distributor w/an HEI unit will be the way to go, for sure. It gives a hotter spark and is generally a very reliable unit.

The total advance (vacuum advance disconnected and the hose plugged) should be around 36°, all in as soon as the engine will allow w/o pinging- shoot for about 2500-3000 RPM.

The initial timing can be around 12°-14°. This won't usually cause hard starting when the engine's hot.

I'd use the HEI's vacuum advance connected to manifold (full time) vacuum, limited (if necessary) to about 10°-12°, by physically limiting the vacuum advance can's travel w/a VACUUM ADVANCE LIMITER PLATE- Crane #99619-1, INSTRUCTIONS for 99619-1 . A limiter for either the points type or HEI distributor can be made as well.
12-20-2010 06:40 AM
345 desoto To set the timing on my engine for initial fire up, I bring the timing mark on the damper up to the pointer, turn the ignition on, then slowley turn the distributor back and forth slightly. Wen the points spark, that's close enough to fire it up and finish with the light...
12-19-2010 07:31 PM
StockR
Quote:
Originally Posted by SDLuck
What timing cover and balancer do you have? They are different for different years abd miss matching them is a common problem.Did you mak sure tdc is correct?

I do have a timing tab on the timing chain cover, so when the timing mark on the balancer matches up to the "0" mark on the tab does that mean it's at TDC??

And for the timing cover and balancer, I'm not sure about those...
12-18-2010 03:04 PM
SDLuck What timing cover and balancer do you have? They are different for different years abd miss matching them is a common problem.Did you mak sure tdc is correct?
12-18-2010 07:50 AM
Frisco
Quote:
Originally Posted by StockR
Yeah, you guys were right... it's points. I don't know what I was thinking.

Anyways, Frisco, The block is from a 1980 Chevy truck I believe. So with the specs you listed for the original stock 69 block do those also pertain to the 1980 block as well?
Yes, the factory specs would still apply. Check my post #7 above. Setting the timing somewhat higher (within a reasonable amount) than the factory specs for a stock small block Chevy engine will help overall performance.
12-17-2010 04:34 PM
StockR Yeah, you guys were right... it's points. I don't know what I was thinking.

Anyways, Frisco, The block is from a 1980 Chevy truck I believe. So with the specs you listed for the original stock 69 block do those also pertain to the 1980 block as well? I can look for the casting numbers if you want?
12-17-2010 01:25 AM
kc8oye those are not HEI wires. those are definately points-style. not to say it doesnt have a pertronix or some such in it..
12-16-2010 05:01 PM
Custom10 Good eye T
12-16-2010 04:57 PM
1ownerT Are you sure it is an HEI?
It sure looks like there is a coil wire in addition to the plug wires, HEI will have the coil in the cap.
12-16-2010 04:51 PM
Custom10 The digital device you have allows what some may consider a simplified way to calculate the 3 different aspects of setting up your timing. The up down arrows on the gun are there to allow you to zero the timing tab marker in relation to the damper 0 mark when setting/checking for base, mechanical adv and vacuum advance values.

These are the three amigo's of engine timing in your case.

Essentially there is no difference in what the gun display is telling you that you could not figure out with a simple inductive light without a dial back pot other than you don't need a timing tape that reads up to 60 deg BTDC with a dial back or in this case your digital dial back unit.

Before you go to far it is a real good idea to check that your timing tab/marker aligns with the balancer/damper tab at TDC, as bubba stated I also would highly recommend that you do this first and foremost:

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

Did i mention I love El Camino's?
12-16-2010 02:43 PM
StockR
Hei

Thanks guys for the help, I forgot to add that the distributor is a HEI (non-points) distributor.

So the timing gun that I have is an Actron Digital CP7529.

There are several options...

1. Measuring Engine RPM

2. Setting Initial Timing

3. Checking & Measuring Centrifugal Advance

4. Measuring Vacuum Advance.

So what is the purpose and difference for those`?

Appreciate the help, guys.
12-15-2010 08:40 AM
Frisco I just checked my manual. The point gap is .019 and the dwell is 28-32 degrees. Spark plug gap is .035. The original factory specs for the timing varies with the engine used. Stock 1969 Chevy El Camino with the 350 runs from 4 degrees BTDC to 8 degrees BTDC. This was slightly lower for California cars with the smog pumps.

My experience was that running 10-12 degrees BTDC gave the best overall performance for the stock 1969 350 cu in Chevy smallblock with a four barrel carb and a 4 speed trans.
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