melonized gear

[Gaz64]

What springs do you have in there?

What is your idle speed?

What camshaft specs? Must be mild if you are expecting 10 at idle.

And what advance bushing do you have in there?

Gary

[hauss]

No actual specs on cam I am 3rd owner and unable to get build sheet. Idle 950 rpm with lots of rumble big cam. Dropped it down to 10* because anything higher would cause pinging using 92 octane. going to purchase new weight and spring kit from Summit can"t remember what bushings but the springs are silver.

[Gaz64]

You need the advance bushing and spring kit, and go for a curve that has less total. I use an 18 in most, and a custom 14 in some.

Gary

[blykins]

Originally Posted by patrickt

Having read pretty much everything blykins has written over the last 20 years on this forum, and the FE forums, I can tell you that his engine advice is quite pragmatic. Theoretical engine discussions are fun, but if I had a mind to buy an engine building shop, I'd put him in charge of the engineer/build side of it.

You couldn't afford me.

[hauss]

Installed new weights, pads, bushings and springs. using the geen stop,heavy silver and light blue springs. car idles 950 rpm at 10*. full timing 35* at 3000 rpm. motor returns back to 10* at idle. Test drove and motor runs great.running 20* cooler,than before.

[Gaz64]

Now to prove if 35 is correct for power.
Don't worry about idle timing, pull it down to 32, and retest.
You really need a dyno run to get the best timing curve.
And why do you want 10 at idle?
I would be running 15 at idle.
Gary

[hauss]

15* at idle would give me 40* total I live in california and the gas here is 91 rated octane I have experienced pinging before with too much initial timing so that is why it is set where it is.

[patrickt]

If anyone is interested, my mill performs best at 35 degrees all in. To get there, I use the silver bushing and spring combo to achieve the following curve, which is just right for me. This is an MSD distributor with no vacuum advance. One advantage of an initial setting of ten degrees is that it makes cranking a bit easier, which helps the starter motor, flywheel teeth, and what not.

[hauss]

Originally Posted by patrickt

If anyone is interested, my mill performs best at 35 degrees all in. To get there, I use the silver bushing and spring combo to achieve the following curve, which is just right for me. This is an MSD distributor with no vacuum advance. One advantage of an initial setting of ten degrees is that it makes cranking a bit easier, which helps the starter motor, flywheel teeth, and what not.

When was the last time you checked your timing. Car running rev to 3000 rpm then watch it go back to set point?

[Gaz64]

It is very easy to have 10 while cranking, 15 at idle, 32 - 35 at 2800 rpm or so.

But you need to take advantage of an adjustable vacuum/mech advance distributor.

Gary

[patrickt]

Originally Posted by hauss

When was the last time you checked your timing. Car running rev to 3000 rpm then watch it go back to set point?

Well that's a darn good question. Probably not in the last five years.

[hauss]

Originally Posted by Gaz64

It is very easy to have 10 while cranking, 15 at idle, 32 - 35 at 2800 rpm or so.

But you need to take advantage of an adjustable vacuum/mech advance distributor.

Gary

What are you saying change bushing ?

[patrickt]

Originally Posted by hauss

What are you saying change bushing ?

If everybody would post a graph of their timing curve, it would be easier to compare. Note that I idle at around 700 to 750 RPM. That's when I'm at 10 degrees. I'm up to 15 degrees at about 1300 RPM and all in around 2800 RPM. If the next guy is idling at 1100 RPM and says he has 15 degrees at idle, then he's really not a lot different than I am down low. Of course, the all in timing is the most important thing for overall power and performance, but the curve will affect how your around town slowwww driving is more than you think.

[Gaz64]

Originally Posted by hauss

Installed new weights, pads, bushings and springs. using the geen stop,heavy silver and light blue springs. car idles 950 rpm at 10*. full timing 35* at 3000 rpm. motor returns back to 10* at idle. Test drove and motor runs great.running 20* cooler,than before.

This sounds like a happy result, and improvement over the original curve.

The seat dyno is a good start, now off to a real dyno to plot timing versus rpm/torque output.

Gary

[hauss]

Ok, I took you advise at cranked up total timing to 39*.Now my idle is 16*. AS shown with timing light. Went for a drive .Better low and high power response. I put the car in fifth and tried the make the car ping and no pinging! Car is running at 195* Very happy with the results thanks for the advise on timing my car Gaz64. Just listening to it run will put a big grin on your face.

[blykins]

Now change the bushing and get the total timing back down. You can put the black bushing in for 18° advance.

I like to see initial at around 16-18° and total timing at around 34-36° with most SBF heads.

[Gaz64]

Originally Posted by hauss

What are you saying change bushing ?

Originally Posted by blykins

Now change the bushing and get the total timing back down. You can put the black bushing in for 18° advance.

I like to see initial at around 16-18° and total timing at around 34-36° with most SBF heads.

Yes, change the bush to black, the other bushings have never had any use to me.

I am surprised your engine can take 39, pull it back.

Gary

[hauss]

Ok will do thanks guys going to get some rain so will take some time before testing but I will be sure to let you know the results . By the way 92 octane Chevron, victor jr heads ,scorpion 1.6 rollers and unknown cam specs.

[hauss]

No rain! Installed the black bushing set 36* and 16* at idle . low power seemed a little down. Went back and changed to the blue bushing, set total to 36* and idle to 14* retested low power good, top end good, car even idles better. Final settings heavy spring, light blue spring ,blue bushing and 36* total timing ,with 950 idle. No overheating and runs strong all the way to 6500 rpm. Thanks to all who helped out .

[RET_COP]

FWIW I always keep the same springs on each side I believe it keep one spring from pulling uneven on the shaft. I never thought that that slight roundness in the curve with uneven springs really mattered. I also use a custom bushing. 10* works for my combination. I use the vacuum advance also. I don't use the light springs as the advance coming in too soon interferes with my idle. My car idles at 1200. I have my reasons for that.