I just switched to gas with new engine combo , so not sure if related as i didnt have this problem on alky. I spin engine over fine first start of the day with the ignition on, no issues. After making a run and coasting to the ticket booth with the engine off, when i crank engine back up with ignition switch back , the motor wont spin over unless i switch ignition off, then back on once engine's spinning over. ignition timing is set to 34 degrees with no retards set in the Grid. This is on 16volt with a brand new 139 tooth starter. SR20's on x16 fuel. Thoughts?

This message has been edited. Last edited by: Mike Frizie,

Sounds like you need to retard the timing while
cranking...........34° is a lot while cranking a hot engine. Pull 20° while cranking

quote:

Originally posted by DRB Motorsports:
I just switched to gas with new engine combo , so not sure if related as i didnt have this problem on alky. I spin engine over fine first start of the day with the ignition on, no issues. After making a run and coasting to the ticket both with the engine off, when i crank engine back up with ignition switch back , the motor wont spin over unless i switch ignition off, then back on once engine's spinning over. ignition timing is set to 34 degrees with no retards set in the Grid. This is on 16volt with a brand new 139 tooth starter. SR20's on x16 fuel. Thoughts?

That's par for the course gasoline. Hit the ignition after you spin the engine, or work on the cooling system so you don't have to shut it off.

I put a billet 153 tooth flexplate on a BBC in a Camaro for the first time, last time too most likely. I'm not impressed.

It's not horrible, but it ain't great either, acts like yours.

quote:

Originally posted by "The Bender":
Sounds like you need to retard the timing while
cranking...........34° is a lot while cranking a hot engine. Pull 20° while cranking

That's my thought. First time of the day it's probably not primed nor inclined to fire. So it spins pretty easy.

quote:

Originally posted by DRB Motorsports:
I just switched to gas with new engine combo , so not sure if related as i didnt have this problem on alky. I spin engine over fine first start of the day with the ignition on, no issues. After making a run and coasting to the ticket booth with the engine off, when i crank engine back up with ignition switch back , the motor wont spin over unless i switch ignition off, then back on once engine's spinning over. ignition timing is set to 34 degrees with no retards set in the Grid. This is on 16volt with a brand new 139 tooth starter. SR20's on x16 fuel. Thoughts?

Michael, 16 volts here with a House of Payne Ultimate Big Dawg 139 starter. We run 35 degrees timing with the grid and no start retard. We always spin the engine first then hit the ignition switch to start.

First check the basics and make sure you have a good ground. Assuming all is good, I have seen carbs that restart easy and some that fight you! Start retread is usually needed but I have seen different values work for similar engines, mine likes 8 degrees. If you try this make sure you have phased the rotor correctly or a large degree retard could cause a jump to the wrong cylinder! Also I don't see why you wouldn't hit the start button first and then the ignition all the time,,,, your starter will be happier for it!!

Michael have you checked/set the timing in the car with your ignition box? Mine was 5 degrees more than as delievered/from PARs dyno.

quote:

Originally posted by 1320racer:
Michael have you checked/set the timing in the car with your ignition box? Mine was 5 degrees more than as delievered/from PARs dyno.

I'm assuming you have a grid also? Mine was also 5 degrees advanced from the dyno. But the condition is still present after correcting the timing to the car's ignition . And only once engine has made a run .

quote:

Originally posted by TOP38:
First check the basics and make sure you have a good ground. Assuming all is good, I have seen carbs that restart easy and some that fight you! Start retread is usually needed but I have seen different values work for similar engines, mine likes 8 degrees. If you try this make sure you have phased the rotor correctly or a large degree retard could cause a jump to the wrong cylinder! Also I don't see why you wouldn't hit the start button first and then the ignition all the time,,,, your starter will be happier for it!!

Like i said, cranks perfectly fine doing it that way, just didn’t know if it was a characteristic of the fuel and high compression.

quote:

Originally posted by DRB Motorsports:

quote:

Originally posted by TOP38:
First check the basics and make sure you have a good ground. Assuming all is good, I have seen carbs that restart easy and some that fight you! Start retread is usually needed but I have seen different values work for similar engines, mine likes 8 degrees. If you try this make sure you have phased the rotor correctly or a large degree retard could cause a jump to the wrong cylinder! Also I don't see why you wouldn't hit the start button first and then the ignition all the time,,,, your starter will be happier for it!!

Like i said, cranks perfectly fine doing it that way, just didn’t know if it was a characteristic of the fuel and high compression.

I would say yes. We almost never start the dragster motor with ignition on before hitting the starter switch, gas or alky.

No start retard or you run the risk of what Al said.....cross fire in the cap due to rotor phase being off

I did use it for a while with a Terminator but found no retard and ignition on during cranking worked best....35-36 degrees of timing..

If it's hot crack the throttle and maybe try a pump or two on the gas pedal before cranking

Cold it started very easily with an occasional minor sneeze back but usually not

HOP 139 Big Dawg starters and 12 volts....

I always coasted after a run to keep heat down and started many times...Gas carb..

I am just throwing this out there. I believe the grid has some sort of a run timer to help from stuck throttle etc. If you have that set it may be shutting it down?

quote:

Originally posted by Curly1:
I am just throwing this out there. I believe the grid has some sort of a run timer to help from stuck throttle etc. If you have that set it may be shutting it down?

That's clearly not his problem but safety reminders are a good thing, and I believe the grid has the same safety function and the Digital 7 box, you set a time after T brake release or loss of a 12v signal and an rpm limit, I use 2000 rpm's 7.5 seconds,,, but never thought to change it on 1/8 tracks!! Another safety reminder I see over and over that is overlooked, the transbrake lock out after release, I believe every delay box has a lockout feature that allows you to set a time where the T brake will not reactivate after release, I have seen too many racers accidently hit the t brake button in first gear on a run, usually doesn't turn out so well.

quote:

Originally posted by Curly1:
I am just throwing this out there. I believe the grid has some sort of a run timer to help from stuck throttle etc. If you have that set it may be shutting it down?

just won turn motor over if the ignition switch is flipped on prior to cranking it. spin her over then hitting the ignition , fires right up.

Ramp in the timing, instead of setting it at 34 degrees at 0 rpm, set it for 26 at 0 rpm and 34 degrees at 750 rpm.


joe

I always spin it before hitting the ignition switch. I've torn up a few flexplates trying to start it with the ignition on first

Just me but I don't see the problem. Spinning and then flipping the ignition seems to work so no problem. My POS low compression small block will crank hard if I turn the ignition on and start it hot with locked timing. It will act up sometimes hot if I touch the throttle even with spinning and then turning ignition on. The rich mixture makes it harder to start hot.

I don’t know how racing carbs work, but if using an electric fuel pump, have you tried turning off the pump 15 -30 seconds prior to turning the engine off hot?

Agree, what Joe posted about programming ramping cranking retard if trying this method.

quote:

Originally posted by markemark:
I don’t know how racing carbs work, but if using an electric fuel pump, have you tried turning off the pump 15 -30 seconds prior to turning the engine off hot?

Agree, what Joe posted about programming ramping cranking retard if trying this method.

my engine has mech belt drive apd pump. and for clarification, it wont cant/wont crank the engine at all. have to have ignition off, then it spins. all connections check ok. battery is 16volt agm and has been in service since 2017.maybe since i'm running 16volt with 139 tooth stuff, its still strong enough to get engine spinning with ignition off. new battery going in this week. if condition still present will add retard in.

Fatten up all 4 idle mix screws 1/8 to 1/4 turn.