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  #1  
Old 06-16-2005, 05:47 PM
Rods67Cuda Rods67Cuda is offline
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Default timing

I have never changed the timing on the car since i got it, but it's a 67 barracuda with a 400 (about 8.7:1, MP .509 cam)
the timing is set at 30* initial, and advances to 55*, in at 3000

would 12* initial and 38* total be better? the car starts quickly and smoothly, and runs GREAT.....just seems like too much timing.....
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Old 06-16-2005, 07:18 PM
benno318 benno318 is offline
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it obviously likes (needs) lots of timing due to the low compression and large-ish cam. if it is not detonating or pinging and is running fine i personally wouldnt change it. see what the other guys opinions are but thats what i think.
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Old 06-16-2005, 07:52 PM
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ehostler ehostler is offline
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I would recommend that you confirm that the balancer hasn't slipped. Line up the balancer at 0 and then pull out the number one spark plug. It should be at TDC. I'm going to guees that it is not at TDC and that the balancer has slipped.
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Old 06-16-2005, 08:09 PM
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ehostler ehostler is offline
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Also, I have a hard time with that big a cam with that low of static compression. I would think that the engine would run like crap (if at all) with that combination.
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Old 06-16-2005, 10:18 PM
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SSHAKERR SSHAKERR is offline
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Question

Quote:
Originally Posted by ehostler
Also, I have a hard time with that big a cam with that low of static compression. I would think that the engine would run like crap (if at all) with that combination.
I had a low compression 72 340 that had a big cam (292 .505 or .509) it did run like crap. A friend recomended an offset crank key. Car shred tires bigtime after a that simple change. Ran real strong. It was a long time ago and I didnt fully understand it then or now.
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Old 06-16-2005, 11:10 PM
mgreen2994 mgreen2994 is offline
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Default timing

rods 67 your just about where you need to be lol people just dont understand when you have lower compressure it raises your timing we race a 318 on a 3/8 mile dirt track i built a low compressure motor about 8.4 and run a 485 lift spilt cam you couldnt blow it up if you wanted too but it well run with thoses chevys and fords all night lol i set the inital at 26 and the total is 54 degress if you had like 10.5 or 11 compression the your timing would be about 10 or 12 degress and your total around 34 or 36
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Old 06-16-2005, 11:19 PM
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Are you checking that with the vacuum on or off?

If on, to which port?

Just curious.
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  #8  
Old 06-17-2005, 07:33 AM
Rods67Cuda Rods67Cuda is offline
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Quote:
Originally Posted by ehostler
I would recommend that you confirm that the balancer hasn't slipped. Line up the balancer at 0 and then pull out the number one spark plug. It should be at TDC. I'm going to guees that it is not at TDC and that the balancer has slipped.
I checked that when the engine was out and the heads were off....perfectly centered on 0 at TDC (dial indicator)

also...i don't have vacuum advance, so that's no issue....
i think i will drop the initial down a little, because i do have a minor heat problem idling in traffic.....
i had a dual electric fan setup on it with a shroud i built myself, and it ran 180-190 for about 30 minutes in the garage at idle....then on the road, over a 5 mile trip, it rose to about 230 (got it home by then and let it idle to cool down)....made some 2" holes in the shroud and the cruising temp came down to 210.....i went back to the flex fan that allows 180-190 cruising and 220-230 idling in traffic....i think if i back the timing off 10*, then it will stop running hot altogether
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Old 06-17-2005, 07:37 AM
Rods67Cuda Rods67Cuda is offline
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Quote:
Originally Posted by ehostler
Also, I have a hard time with that big a cam with that low of static compression. I would think that the engine would run like crap (if at all) with that combination.
it actually runs GREAT.....i haven't gotten it to the track yet, but on the street, SHEW....car's got some sac
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Old 06-17-2005, 01:01 PM
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Quote:
Originally Posted by Rods67Cuda
it actually runs GREAT.....i haven't gotten it to the track yet, but on the street, SHEW....car's got some sac
With a light car like yours it still can run decent with low compression as long as you have decent gears and a 4spd. or high stall. It just don't have alot of torque but when your car is only 3300 lb you don't need an abundance of torque. Put it in a 69 Charger with a stock auto and 2.76 or 3.23 gears and it would be a whole different story.

Retarding the timing should help your over heating problem at least some. Sure can't hurt. It may not even hamper performance. LOL
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Old 06-17-2005, 02:05 PM
Rods67Cuda Rods67Cuda is offline
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yeah...it's got a 3000 stall, 3.91s and 26" tall tires

it weighed in at 3100# with a full tank of gas last i weighed it, but i have probably dropped 50-75 pounds since then, so it's about 3200 with me in it and the tank full
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Old 06-18-2005, 06:08 AM
benno318 benno318 is offline
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just observe what happens by retarding, (to lower the temp,) ive always found engines running retarted run hotter than when advancing the timing...i bet youll end up with it right where you had it originally, due to the performance loss you will no doubt suffer by pulling timing out of it....let us know
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Old 06-18-2005, 09:40 AM
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ehostler ehostler is offline
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In this situation, I would adjust idle timing with a vacuum gauge.

Connect the gauge up to full time vacuum. Adjust timing to get max vacuum, then bring the idle speed back to where it was and then adjust the idle jets for max vacuum. You may need to do this a couple of times.
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  #14  
Old 06-18-2005, 11:20 AM
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racintracy racintracy is offline
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Quote:
Originally Posted by ehostler
In this situation, I would adjust idle timing with a vacuum gauge.

Connect the gauge up to full time vacuum. Adjust timing to get max vacuum, then bring the idle speed back to where it was and then adjust the idle jets for max vacuum. You may need to do this a couple of times.
Good suggestion. With your big cam and low compression there is no real guideline to go by for setting the timing but you'll get it very close this way. But I bet you end up pretty close to where you are now.

I have also seen what Benno318 refered too as far as some engines running cooler with the timing advanced and hotter with it retarded. But there are limits to this. Over advancing one to the point of spark knock occuring will cause higher temps. also. Seems like they run the best and coolest when timed just right.
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