Timing Question

[straightlinespeed]

Hey guys, I have a question timing a 360.

I looked in a manual and online and it says that a 360 should be at 5* BTDC or 2.5* BTDC if a California car. My car does not run at those specs. It runs rough at about 20*BTDC and runs very smooth at 32-34*BTDC.

So what the heck does that 5* mean? Like I said my engine will not even start. I just want to get the car started and running correctly so I can drive it and get it to the dyno place and have it all fine tuned.

Also where are you guys running your timing at? If it matters Im running a XE268 cam.

 

[Bad Sport]

I run the HE268 in my teen and I have it at 18* initial.

 

[69MOPE]

Stock 360 balancers are known for spinning on the rubber. Check that first.

 

[straightlinespeed]

Stock 360 balancers are known for spinning on the rubber. Check that first.

Its a brand new balancer and we did look at it but it didnt appear to be spinning.

My brothers 273, (granted its a race engine) is timed at 38*

We were both confused on what that 5* meant. Like I said though it does run but its rough at 20*

 

[Bad Sport]

Its a brand new balancer and we did look at it but it didnt appear to be spinning.

My brothers 273, (granted its a race engine) is timed at 38*

We were both confused on what that 5* meant. Like I said though it does run but its rough at 20*

When you say 38* or 20* are you talking initial, or total.

If you have yours set at 20* total, go back and bump up the initial to 16* - 18* and see what it runs like.

I believe that 5* is a setting for emission crap!

 

[Johnny Dart]

Hey guys, I have a question timing a 360.

I looked in a manual and online and it says that a 360 should be at 5* BTDC or 2.5* BTDC if a California car. My car does not run at those specs. It runs rough at about 20*BTDC and runs very smooth at 32-34*BTDC.

So what the heck does that 5* mean? Like I said my engine will not even start. I just want to get the car started and running correctly so I can drive it and get it to the dyno place and have it all fine tuned.

Also where are you guys running your timing at? If it matters Im running a XE268 cam.

You need to do some reading up on timing. Sounds like you are mixing up your "initial" timing with your "total" timing.

The 5* BTDC is the initial timing. (Set at idle).

The 32*-34* is total timing. (What your timing maxes out at).
Your total timing (depending on distributor) would be checked anywhere from
2000rpm-4000rpm. That is your total timing. To much total and your car will start pinging,and your starter will kick back when trying to start. To much total is not good.

Mild small blocks generally run well at 12in-34tot as a starting point.

When you start getting into more radical camshafts/engines,generally your initial
timing will need to go up.

The XE268 isn't a very radical camshaft. I run the same camshaft in my 360.
My timing is set around 12-14 initial (set at idle)and 34-36 all in.

My advice to you would be to set your initial timing at 12 BTDC (set at idle) as a starting point,and go from there.

 

[straightlinespeed]

When you say 38* or 20* are you talking initial, or total.

If you have yours set at 20* total, go back and bump up the initial to 16* - 18* and see what it runs like.

I believe that 5* is a setting for emission crap!

Hmm now Im not sure..

If I understand correctly initial timing is unhooked advanced. Total timing is with the advanced hooked up? Correct?

 

[straightlinespeed]

You need to do some reading up on timing. Sounds like you are mixing up your "initial" timing with your "total" timing.

The 5* BTDC is the initial timing. (Set at idle).

The 32*-34* is total timing. (What your timing maxes out at).
Your total timing (depending on distributor) would be checked anywhere from
2000rpm-4000rpm. That is your total timing. To much total and your car will start pinging,and your starter will kick back when trying to start. To much total is not good.

Mild small blocks generally run well at 12in-34tot as a starting point.

When you start getting into more radical camshafts/engines,generally your initial
timing will need to go up.

The XE268 isn't a very radical camshaft. I run the same camshaft in my 360.
My timing is set around 12-14 initial (set at idle)and 34-36 all in.

My advice to you would be to set your initial timing at 12 BTDC (set at idle) as a starting point,and go from there.

Thanks for the response, I just read another article and now I understand the timing as far as the initial and advanced.

We were trying the 5* initial at idle and it would die instantly. I think it was around the 15* mark initial where it would run but very very rough. 20* was rough but it stayed running.

The 32-34* mark with the advanced hooked up where it ran smooth makes sense to me now.

Thank you for the starting points, that helps a lot! I will give this another shot. We were both just confused with that 5* we kept running into online and in books.

 

[Bad Sport]

Ok, please forgive me but what do you mean the initial? I thought you started the car and used the light and just rotated the distributor until it runs smoothly. Which I thought was the total timing. Ok maybe I need schooled on timing.

Initial is with the vacuum advance unhooked and plugged. Rotate the distributor until you get in the neighborhood of 16*, that's where I would start. Total timing is initial plus mechanical.

Let's say for instance you set initial at 16* and your distributor is set at 18*, you would have total of 34*. Getting it all in early would require lighter springs in the dizzy.

A stock dizzy is going to yield more than the 18* mechanical, I have the slots brazed and filed to lock it at 18* in my distributor.

 

[Johnny Dart]

Hmm now Im not sure..

If I understand correctly initial timing is unhooked advanced. Total timing is with the advanced hooked up? Correct?

Initial timing...Checking the timing at idle.

Total timing...Checking the timing around 2000rpm-4000rpm.

Set initial/total with vacuum advance disconnected,and all ports on carb plugged.

 

[Bad Sport]

I believe abodyjoe posted this sometime ago, it's a good read.

 

[Saetun]

I run the XE268 in my 318. The teener likes the initial set at 20* and total at 34*, all in by 2500 RPM. I pull 14"Hg vacuum & with that set up the 318 is wide awake. Took some tweaking to get to what my setup liked, but I started with 16* & kept adjusting until I saw diminishing returns. I used the 4secondsflat disc to limit mechanical timing, which made it a snap.