Recommended total engine timing

[B3422w5]

I have the timing on my motor locked out at 34 degrees.
Am I reading correctly that it’s not optimal doing that?
Most everybody I know has there distributor locked out that I race with

 

[-Boosted-]

So the physics were different back then?

I don’t think so.

There is a reason the factory put a curve in the distributor. And used vacuum advance.

Since you are the head cheerleader for locked out timing, maybe you could explain, with exceptional detail how an engine’s timing requirements are the same when VE changes with load and rpm.

Try using your own words. Pictures of texts from books won’t work. Use your own words.

I can’t wait to be educated.

Thank You in advance.

No pun intended I assume? lol

 

[AJ/FormS]

I have the timing on my motor locked out at 34 degrees.
Am I reading correctly that it’s not optimal doing that?
Most everybody I know has there distributor locked out that I race with

I think by now, the jury is out on that.
The resident guru's are still working it out.
Only you can know for sure, and only with long-term empirical evidence, tempered with same-day trends.
--------------------------------------------------------------
For your perusal;
I bought and installed a dash-mounted dial-back, spark-delay module, that I can adjust in realtime. It ain't dead-nuts accurate, but I can get it within 2 degrees by guessing on the knob clocking.
As a streeter, My 367 hardly knows the difference from 32 to 36 Power-Timing. Only the "data-logger" can see it. I sure can't feel it.
But, the gas tank knows the difference between the correct cruise-timing and 6* short. And midrange torque at Part Throttle is easy to feel, between correct and 4* short.
2* either way, on the street, is a bust
When it comes to Idle-Timing, my engine doesn't much care and runs dandy-fine, anywhere between 5* and 40 the only difference being Idle-rpm, and, a lil in-gear lurchiness with the manual trans, at really low parade rpms..

 

[Newbomb Turk]

I have the timing on my motor locked out at 34 degrees.
Am I reading correctly that it’s not optimal doing that?
Most everybody I know has there distributor locked out that I race with

If you are foot braking it certainly needs a curve.

 

[Newbomb Turk]

I think by now, the jury is out on that. Only you can know for sure, and only with long-term empirical evidence, tempered with same-day trends.

Your nuts. The jury isn’t out on anything.

Every internal combustion engine KNOWN TO MAN wants LESS timing at peak torque and MORE timing at peak power.

So how does a locked or all in by 2500 curve do that?

Explain it in your own words, in detail so we can all learn how physics has changed.

Saying that, there are SOME instances where a timing curve won’t make a difference.

@TT5.9mag has a jet boat. He wouldn’t see any help from a curve.

I apologize to Joe because I forgot his log in but he has the beautiful blue RR with two toilets on it is another example of where a curve won’t show much of an improvement in ET or MPH because he has a trans brake and his converter stall speed is above peak torque.

BUT, that doesn’t mean that a curve would slow either one down.

To actually determine what the curve should look like takes me about an half an hour on the dyno and several more hours (less if it’s not too complicated) to make the distributor have the correct curve.

But to make the claim the jury is still out is complete and utter nonsense.

The physics haven’t changed. Or maybe they have. I’m expecting you will be able to explain that change.

 

[Newbomb Turk]

No pun intended I assume? lol

No pun intended. I’m still waiting for the explanation.

 

[AJ/FormS]

Your nuts. The jury isn’t out on anything.

Every internal combustion engine KNOWN TO MAN wants LESS timing at peak torque and MORE timing at peak power.

So how does a locked or all in by 2500 curve do that?

Explain it in your own words, in detail so we can all learn how physics has changed.

Saying that, there are SOME instances where a timing curve won’t make a difference.

@TT5.9mag has a jet boat. He wouldn’t see any help from a curve.

I apologize to Joe because I forgot his log in but he has the beautiful blue RR with two toilets on it is another example of where a curve won’t show much of an improvement in ET or MPH because he has a trans brake and his converter stall speed is above peak torque.

BUT, that doesn’t mean that a curve would slow either one down.

To actually determine what the curve should look like takes me about an half an hour on the dyno and several more hours (less if it’s not too complicated) to make the distributor have the correct curve.

But to make the claim the jury is still out is complete and utter nonsense.

The physics haven’t changed. Or maybe they have. I’m expecting you will be able to explain that change.

As usual, you misunderstood my post, and took it personal. Boy I'm so glad I'm not like you; life must be so hard always at the ready to fight. Take a pill man. Relax.
Go back and read my post again, slowly. If you don't get it, well, I'm not gonna try to explain it to the master.

 

[Newbomb Turk]

As usual, you misunderstood my post, and took it personal. Boy I'm so glad I'm not like you; life must be so hard always at the ready to fight. Take a pill man. Relax.
Go back and read my post again, slowly. If you don't get it, well, I'm not gonna try to explain it to the master.

I am relaxed. And I read EXACTLY what you wrote.

You said the JURY IS STILL OUT. I’ll say it again. The jury is NOT out.

Unless you want to explain in detail how the jury is out then stop giving out HORRIBLE advice.

I gave two exceptions to when locking out a distributor is acceptable.

Stop acting like a petulant child and explain yourself.

That’s what I did.

 

[mbaird]

If it is a street/strip car I would use a curve.
If it is a pure drag car with a 4000 stall converter then you can run it locked out. But you still have to drive the return road at lower rpms . Locking it could cause detonation in those situations. It really depends on your engine build. Big overlap cams bleed off cylinder pressure at lower rpms.

 

[mbaird]

I think A/J was referring to the argument in this thread when he said the jury is out .

 

[Newbomb Turk]

If it is a street/strip car I would use a curve.
If it is a pure drag car with a 4000 stall converter then you can run it locked out. But you still have to drive the return road at lower rpms . Locking it could cause detonation in those situations. It really depends on your engine build. Big overlap cams bleed off cylinder pressure at lower rpms.

I’ll ask you the same question. What if peak torque is higher than 4000?

What if it is a 4000 converter and he’s foot braking and you have to get to 4000?

It all depends on where peak torque is really.

 

[TT5.9mag]

If it is a street/strip car I would use a curve.
If it is a pure drag car with a 4000 stall converter then you can run it locked out. But you still have to drive the return road at lower rpms . Locking it could cause detonation in those situations. It really depends on your engine build. Big overlap cams bleed off cylinder pressure at lower rpms.

Locking the timing won’t cause detenation issues cruising back on the return road. You need load to cause detonation.

 

[Newbomb Turk]

I think A/J was referring to the argument in this thread when he said the jury is out .

That’s what he wants, but he’s wrong. Again. I have physics on my side.

The OP needs a curve. I see he checked out a long time ago so I don’t really care what he does or not.

But for the people who come along later and read this thread, they need to know there is no dispute that an engine wants less timing at peak torque and more timing at peak power.

And if that is true (it is) then how does locked out timing accomplish that?

You don’t have to answer that. AJ does.

 

[TT5.9mag]

I’ve said it before and I’ll say it again. In any vehicle where the engine accelerates (loaded) through peak torque, you need a curve. Or a better way to say it is, you can benefit from a curve. If your stall speed or shift recovery rpm is above peak torque there is little benefit to a curve because you’re not interested in what the engine is doing at peak torque if you don’t load it there. There is definitely a difference in the timing requirements for peak torque and peak hp.

 

[TT5.9mag]

And if that is true (it is) then how does locked out timing accomplish that?

You’ve proven on your distributor machine that locking the timing is actually worse than you describe. Because you’ll have more timing at peak tq and less at peak hp because of slew rate. The exact opposite of what the engine wants.

 

[B3422w5]

If you are foot braking it certainly needs a curve.

I do foot brake. Was just talking about this to a very good friend of mine who campaigns a NSS car and is very successful with it. Runs low 9’s off the foot but he mostly sets it up for the 9.50 index. He is debuting an NHRA stocker this year( New style Challenger)
He told me on cars like ours( race vert, serious type camshafts, gears, etc) the only way to fly is locked out. Car idles cleaner, timing is all in at the hit( we both leave at 2k off the foot)
He did say some of the NHRA class guys in both stock and super stock put a couple extra degrees in at the hit to help the car’s 60 foot, then pull that back out at an optimal time.
A more street oriented car might like a curve more perhaps I would guess.

 

[TT5.9mag]

I do foot brake. Was just talking about this to a very good friend of mine who campaigns a NSS car and is very successful with it. Runs low 9’s off the foot but he mostly sets it up for the 9.50 index. He is debuting an NHRA stocker this year( New style Challenger)
He told me on cars like ours( race vert, serious type camshafts, gears, etc) the only way to fly is locked out. Car idles cleaner, timing is all in at the hit( we both leave at 2k off the foot)
He did say some of the NHRA class guys in both stock and super stock put a couple extra degrees in at the hit to help the car’s 60 foot, then pull that back out at an optimal time.
A more street oriented car might like a curve more perhaps I would guess.

You leave at 2k off the foot brake but what’s the converter flash to at the hit?

 

[Newbomb Turk]

I do foot brake. Was just talking about this to a very good friend of mine who campaigns a NSS car and is very successful with it. Runs low 9’s off the foot but he mostly sets it up for the 9.50 index. He is debuting an NHRA stocker this year( New style Challenger)
He told me on cars like ours( race vert, serious type camshafts, gears, etc) the only way to fly is locked out. Car idles cleaner, timing is all in at the hit( we both leave at 2k off the foot)
He did say some of the NHRA class guys in both stock and super stock put a couple extra degrees in at the hit to help the car’s 60 foot, then pull that back out at an optimal time.
A more street oriented car might like a curve more perhaps I would guess.

You’d have to ask him if he actually went to a dyno and developed a curve.

Because you can NOT get around the physics of less timing at peak torque.

He might be adding timing because the box is retarding.

I don’t get why they need all that timing to make an engine idle.

 

[B3422w5]

You leave at 2k off the foot brake but what’s the converter flash to at the hit?

4900, it’s a bit shy of where I would like it.

 

[9secRR]

I apologize to Joe because I forgot his log in but he has the beautiful blue RR with two toilets on it is another example of where a curve won’t show much of an improvement in ET or MPH because he has a trans brake and his converter stall speed is above peak torque.

BUT, that doesn’t mean that a curve would slow either one down.

no apologies needed.

6300 converter, leave at 5600 on TB, timing locked out at 37*.

 

[Scampin]

You’d have to ask him if he actually went to a dyno and developed a curve.

Because you can NOT get around the physics of less timing at peak torque.

He might be adding timing because the box is retarding.

I don’t get why they need all that timing to make an engine idle.

Just curious how much et/mph or HP/trq you picked up going from a locked out distributor to one with a curve.

 

[mbaird]

Just curious how much et/mph or HP/trq you picked up going from a locked out distributor to one with a curve.

Do you run it locked out ?
Just curious…. I figured FAST cars would retard timing down low (slow curve ) for traction .

 

[Newbomb Turk]

Just curious how much et/mph or HP/trq you picked up going from a locked out distributor to one with a curve.

On average 20 torque at peak and 20 hp at peak.

 

[Scampin]

Damn that's impressive. What was the combo of you don't mind me asking?

 

[Oldiron440]

Compression ratio and cylinder head efficiency and material is what determines how much total timing is needed more than camshaft, intake, carburetor than all the other things listed.