Timing question

Evening. So I'm new to the timing portion of my Lark. I'm trying to do a "power tune" Currently I'm at 34* on my advance timing light at 2,800 RPM's. I have a completely gone through distributor done by Ken on here. On his card he said the distributor is set up to have all but 2* in by 3k. I have a 9.5 converted built by Jim to be in the 2,800-3,000 stall range.

My question is what RPM's are best to have my timing in by? Do I want it in earlier or closer to 3k to match the converter? Trying to get the most out of her as she feels like there's more left out there. Let me know if you guys need any other info.

Thanks,

Kyle

 

Everything depends on everything else. First off, based on what you've posted, we don't know when the ignition timing is "all in" right now.

Light cars, and cars with "drag-race" gears/high-stall converters can get by with a quick advance curve. Heavy cars, or with highway gearing/low-stall converters need a slower curve.

Typical "street performance" would suggest timing all-in by 3000--3300. But you should be asking the guy who curved your distributor. He's going to be the expert, 'cause he knows what he intended for that distributor when he built it.

 

I suppose it’s the “by” that’s getting me. To me that doesn’t mean 3k it can mean an area around 3k but not over. According to the card it’s 20* by 3k, 22* by 4k, with an initial of 12*-14*, & 10* of vacuum advance.

I can certainly get in touch with Ken to see what the best RPM’s to have it in by for my distributor.

Does the converter have any effect on timing?

Kyle

 

Not directly, when you set timing where you want it, that's where it stays.
BUT, a looser than stock convertor will allow the engine to tolerate more timing sooner than a stock tight convertor.
Reason being is the engine is not seeing/experiencing the same load as the tight stock convertor would impose on the engine.
At highway cruise, say at 3200 rpm if you have vacuum advance, you could run 40 plus degrees of total timing with no issue because the engine is not experiencing a load, but at WOT with the engine under load, that 40 plus degrees would rattle the engine to death, so at WOT IF you are running vacuum advance, the vacuum goes away to near zero, the vacuum advance goes back to zero, so your left with just your mechanical advance of say 32 to 36 degrees.
When you return to your light throttle cruise rpm of 3200 rpm, vacuum is restored, and the vacuum advance goes back into action advancing to timing to 40 plus degrees.
So timing the engine will tolerate is load, rpm and octane based.

 

I’ve read on here that you want it all in as soon as possible so the 3k seems late to me. I’ll get in touch with Ken to see what the best is for my distributor.

I’m just going by seat of the pants feel here. I also could be a few degrees over what the engine may like as well. It’s very easy to adjust just need away to get data from my changes.

Kyle

 

Good point. I have an inkling I might could back it off a few degrees. Seemed to run a bit better at 34* to me anyway. I can easily adjust between the few degrees.

I've got a call into Ken to find out the best RPM for my distributor.

Kyle

 

I like “ all in” by 2200. Get a Crane distributor adjustable kit and recurve it yourself and experiment to see what works for your setup. My 462 loves 33 total and all in at 2000-2200 , with a 2500 converter and there’s no hesitation and hammers thru each gear to 5200 without missing a lick!

Each engine is different, compression, cams, carbs, distributor ect......

 

Why don't you simple check it at 2000, 2500, 3000, 3500, 4000 and find out exactly where it's all in at rather than someone saying it should be. Should be and is/are be are sometimes not the same thing. It only takes a few seconds to find d out exactly what's going on

 

Update:

So I tinkered around today & don't have any mind blowing results. I'm at 34* at 2,500. Putting my initial at like 17* checked initial at idle with vacuum advance hooked up, advance with vacuum disconnected from canister. Don't get me wrong she feels strong, but from a standing stop it will not roast the tires. Now she hooks good & pulls strong, from a rolling start I can sometimes get some tire spin.

I understand that hooking up is a great thing. I just thought that with this amount of HP & torque at my foot I'd have trouble getting traction. Just seems slowish to me.

Kyle

 

It’s a mildly built 455. Just finished the 350-455 swap.

Kyle

 

It does not. Yes. A 9.5 built by JW. If I remember right he says the stall is near 3k.

Hooked to a TH350 with 3.42 gears with Tru-Trac. I feel like something is just a bit off.

Kyle

 

TA 284-88 cam. 800 CFM Quadrajet gone through by Ken 1231876 heads with Stage 1 valves, some port & bowl work done to the heads, stock manifolds, & 2-1/2” “H” pipe exhaust.

Yes. Looked at that today. As they pressed the pedals I looked through the air flaps to see if the secondary blades were opening & they opened all the way under easy throttle manipulation.

I feel like I’m close, but just missing that little something.

Kyle

 

I would think that the shop that built the motor did that. Should be 4* advanced if I remember correctly. Claimed they got the motor to 10.1 compression.

Not sure on static compression. The one thing I don’t have is a vacuum gauge. On engine dyno did 370hp & 470 torque before I had heads worked on.