Tried using a timing gun on my 318 RR tonight. What do you think of the numbers I got? Anything telling or changes you’d make?

[tonyp25]

So after reading a bunch of posts here I wanted to try my hand with a digital timing light (also has tachometer built in). The engine is running pretty smoothly but wanted to see what you all thought. Would love any input.

At idle (after it’s warmed up) my RPMs were roughly 730 and drops about 100 when put into drive. The timing was at 15 degrees. At around 2500rpm the timing is at 34-36 degrees. This is all with vacuum advance disconnected.

If it helps it’s a 318, automatic, 4bbl Carter, 340 edlebrock manifold and Comp Cam. Running non-ethanol gas. I found the Cam receipt but the numbers don’t mean much to me (if anyone could give me more info, I’ve attached a picture of it). Not sure if it matters but it also has headers and flowmaster mufflers.

 

[4mulas]

Timing looks good

not sure what’ more info’ you’re looking for. It’s all on the cam card. It’s a little baby cam suitable for a 318 that is probably designed to make good torque.

 

[WileE]

I'll reserve any comment until I see pics of your car !

 

[tonyp25]

Timing looks good

not sure what’ more info’ you’re looking for. It’s all on the cam card. It’s a little baby cam suitable for a 318 that is probably designed to make good torque.

Thanks! I’m new to aftermarket cams so I guess I was just wondering if the numbers on the receipt greatly impacted the way it should be tuned/timed from a stock setup.

 

[moparedtn]

I'm betting it runs just fine - and needs to be left alone.

 

[440Coronet500]

Seems just about right with that setup. How does it start/run? 440'

 

[toolmanmike]

So after reading a bunch of posts here I wanted to try my hand with a digital timing light (also has tachometer built in). The engine is running pretty smoothly but wanted to see what you all thought. Would love any input.

At idle (after it’s warmed up) my RPMs were roughly 730 and drops about 100 when put into drive. The timing was at 15 degrees. At around 2500rpm the timing is at 34-36 degrees. This is all with vacuum advance disconnected.

If it helps it’s a 318, automatic, 4bbl Carter, 340 edlebrock manifold and Comp Cam. Running non-ethanol gas. I found the Cam receipt but the numbers don’t mean much to me (if anyone could give me more info, I’ve attached a picture of it). Not sure if it matters but it also has headers and flowmaster mufflers.

View attachment 1493612

Run it

 

[YY1]

.440 lift is .040 more than the factory .400 lift "318 cam".

That's a sizeable increase as the closer you get to .500 lift the more problems you start running into, like milling the valve guides.

My guess is the duration is a relative increase as well (don't have stock spec in front of me).

That's a "single pattern" cam, meaning the intake and exhaust are the same.
Cams like that work best with increased exhaust flow, commonly done with headers and duals, but also with installing larger exhaust valves.

 

[Outsider]

So 34-36 degrees is maxed out w/o vac adv? If it doesn't ping, might be good. General observation though, it might be a little quick advance rate for a street car w/HW gears, but the main thing is if doesn't ping.

 

[snakeoil24]

Good!

 

[Ron H]

Only thing I'd include is the rpm's at hot idle (730) and (630) in gear? Have a mildly built poly, slightly hotter cam than it appears you may have. Hot idle around 500, in gear 400. Much more gets the ride rolling quick with a hard thrust when putting it in gear.

 

[DeltaV]

Looks good to me.

I am curious if your timing mark wanders around at idle. I've found worn timing sets looking for this. Your car might have nylon (plastic) teeth on the cam sprocket.

Also, I'll slightly blip the throttle by hand and watch the timing mark after releasing the throttle. If it wanders or skips around after returning to idle speed, then I would take a look at the chain and gears. The factory service manual provides pass/fail measurement for the timing chain/gears. That being said, I would replace both gears and chain with a double-roller set if I saw the plastic toothed cam gear.

 

[hemidon1]

Time your engine to 36 degrees total with the vaccumn advance HOOKED UP---not disconnected..cam is very mild--idle speed at 850 in park or nuetral--630 in gear for automatic --manual can be idled down to 750 if it likes it

 

[hemidon1]

Delta V gave you good advice

 

[Cranky]

Also depends on your compression. Most teens don't have much and pretty much no quench either. I give my engines the timing they like and have had a couple that liked more....a lot more. And I like a cam card that tells me what's happening at .050 instead of .006 . The .006 figure makes the cam 'look' bigger than it actually is and there's not much happening at .006 lift. Basically, you have a cam that's barely a step up from stock. Do a compression test with all the plugs out and the throttle wide open. That will tell you some more info.

 

[RemCharger]

Time your engine to 36 degrees total with the vaccumn advance HOOKED UP---not disconnected..cam is very mild--idle speed at 850 in park or nuetral--630 in gear for automatic --manual can be idled down to 750 if it likes it

???
If you're going to time it with the vacuum hooked up then just do it by ear.

 

[tonyp25]

Thanks for all the information everyone! Really appreciate everyone explaining the cam numbers to me. The timing light seems pretty steady at idle and doesn’t skip around (it might be moving a fraction up and down but that could also just be my eyes).

When I start it cold it seems to idle at 500 but then warms right up into the 750 range. No pinging that I can hear.

This is probably a question for a different thread or because I’m new to driving carbuerated cars. But I’ll pump the gas pedal a couple times and it starts right up from a cold start. After I drive it for awhile (30 min) and shut it off. If I try to start it right up again within about 10min I can only get it to start if I hold the gas pedal down. If I pump it a few times or don’t prime it at all it won’t start. Maybe a dirty/clogged carb or filter?

 

[Cranky]

Thanks for all the information everyone! Really appreciate everyone explaining the cam numbers to me. The timing light seems pretty steady at idle and doesn’t skip around (it might be moving a fraction up and down but that could also just be my eyes).

When I start it cold it seems to idle at 500 but then warms right up into the 750 range. No pinging that I can hear.

This is probably a question for a different thread or because I’m new to driving carbuerated cars. But I’ll pump the gas pedal a couple times and it starts right up from a cold start. After I drive it for awhile (30 min) and shut it off. If I try to start it right up again within about 10min I can only get it to start if I hold the gas pedal down. If I pump it a few times or don’t prime it at all it won’t start. Maybe a dirty/clogged carb or filter?w

With the engine off after it's been off for a few minutes, look down the throat of the carb and pump the throttle one time and observe the squirter and see what it looks like. A weak squirt will point to that problem....

 

[Outsider]

A hot start problem where you have to hold the pedal down to get it to start? Possible worn float needle and seats and gas running into the motor after shut off during heat soak.

 

[Ron H]

If your engine idles at a lower rpm cold, this is reverse of what should be happening. Linkage adjustment should set the idle higher when cold. Step on the pedal once or twice to set the choke (if it's adjusted correctly). Choke/throttle plate should be closed or near closed to allow cold start up and it opens when warming up. The setting may be off and can impact warm starting. One thing to check when it won't start is the position of the plate, have a partner or you, close it more when trying to start it to see if it triggers a start up. A warm/hot motor shouldn't need much, if any pedal pumping to start it if it's in tune.
Hard starting can be an engine timing thing aside from needed carb adj's/cleaning.