Distributor Question

[The flying turd]

I am getting close to firing up my re-camed GMC, hopefully tomorrow or Sunday.

When setting the initial timing upon startup, my thought would be to rotate the dist. about 1/2 way between. I do have a mark where the old timing was set with a flat cam and a chain with lots of stretch.

So is the 1/2 way mark where one would start? I obviously want to get this running as smooth as possible at or above 2500 rpm asap per the cam instructions

Will the radiator hold enough coolant to keep things cool while Im breaking the cam in? Was told to run for approx. half hour..

Any thoughts or advice is greatly appreciated.

Dave~

 

[Jims86]

I am getting close to firing up my re-camed GMC, hopefully tomorrow or Sunday.

When setting the initial timing upon startup, my thought would be to rotate the dist. about 1/2 way between. I do have a mark where the old timing was set with a flat cam and a chain with lots of stretch.

So is the 1/2 way mark where one would start? I obviously want to get this running as smooth as possible at or above 2500 rpm asap per the cam instructions

Will the radiator hold enough coolant to keep things cool while Im breaking the cam in? Was told to run for approx. half hour..

Any thoughts or advice is greatly appreciated.

Dave~

You need to set the timing at least 4* BTDC. ar you sure the dist was installed correctly? Cooling system is sufficient for break in, just make sure you have a 195 thermistat, and the right coolant mixture. double check Vac lines too.

 

[The flying turd]

Hi Jim,
I have not installed the distributor yet, that will be the one of the last to do, planning on priming the oil pump then install. As I recall, my 78' is 8* BTDC.. Not 100% sure but will be when the time comes. If I understand you correctly, I'll be aiming my timing gun, twisting the dist into the right setting as it runs. I guess the engine will be telling me what it needs on initial fire up. Yep on the 195 thermostat and vac lines.

 

[Jims86]

Hi Jim,
I have not installed the distributor yet, that will be the one of the last to do, planning on priming the oil pump then install. As I recall, my 78' is 8* BTDC.. Not 100% sure but will be when the time comes. If I understand you correctly, I'll be aiming my timing gun, twisting the dist into the right setting as it runs. I guess the engine will be telling me what it needs on initial fire up. Yep on the 195 thermostat and vac lines.

You can do that, or you can confirm TdC on #1 by having your finger blown out of the #1 spark plug hole, and with the #1 terminal position marked on the distributor, and the timing mark at 8 or 4...which ever you choose to run, install the dist with the rotor pointing at #1, and that should get you pretty close for an immediate start up for break in.

 

[The flying turd]

You can do that, or you can confirm TdC on #1 by having your finger blown out of the #1 spark plug hole, and with the #1 terminal position marked on the distributor, and the timing mark at 8 or 4...which ever you choose to run, install the dist with the rotor pointing at #1, and that should get you pretty close for an immediate start up for break in.

Ahhh!
I just learned something here. Thanks Jim, thats exactly what I will do. I'll send out a post when its all done.

 

[The flying turd]

I am still learning how to post stuff, But I like your idea Jim. Thats what I will do.

Dave

 

[Jims86]

I am still learning how to post stuff, But I like your idea Jim. Thats what I will do.

Dave

Any time Dave, happy to help.
What cam and carb are you using?

 

[The flying turd]

Its a Edelbrock performer plus with matching intake. I also had a local guy rebuild the Q-jet to match the cam/intake and headers.

These forums are awesome, I also have a 60' Studebaker which i can get answers just like here.. you cannot put a $$ value on all the advice and knowledge.

Tell me a bit on your rig..

 

[Jims86]

Its a Edelbrock performer plus with matching intake. I also had a local guy rebuild the Q-jet to match the cam/intake and headers.

These forums are awesome, I also have a 60' Studebaker which i can get answers just like here.. you cannot put a $$ value on all the advice and knowledge.

Tell me a bit on your rig..

Mine is an ongoing project....I like to tinker with fuel injection, but my Burb was factory equipped with a computer controlled feed back QJet, and computer controlled ignition.
I did convert it to Tuned Port injection, but after about 10 years of trying to tune it, and toasting 2 exspensive Catalytic converters, I decided to step down to a Factory 87-92 TBI induction system. And thats where it is now.
Being un employednhas put the kybash on alot of it for the last 2 years, but with some side jobs, after all the priorities are taken care of, she gets treats every now and then.

 

[bucket]

You can do that, or you can confirm TdC on #1 by having your finger blown out of the #1 spark plug hole, and with the #1 terminal position marked on the distributor, and the timing mark at 8 or 4...which ever you choose to run, install the dist with the rotor pointing at #1, and that should get you pretty close for an immediate start up for break in.

That's how I do it too, I aim for 8*. That way if it ends up being off a few degrees, it will still run well either way. I hate cam break-ins too, talk about nerve-racking on a motor that everything is changed from what it was before.

 

[The flying turd]

Mine is an ongoing project....I like to tinker with fuel injection, but my Burb was factory equipped with a computer controlled feed back QJet, and computer controlled ignition.
I did convert it to Tuned Port injection, but after about 10 years of trying to tune it, and toasting 2 exspensive Catalytic converters, I decided to step down to a Factory 87-92 TBI induction system. And thats where it is now.
Being un employednhas put the kybash on alot of it for the last 2 years, but with some side jobs, after all the priorities are taken care of, she gets treats every now and then.

I understand the budget thing for sure..
I don't know a lot about GM's TBI systems, I know they are a much better way to go over a Q-jet..
Talk to you soon Jim.

 

[The flying turd]

I will aim for 8* as well.
Your right, its very nerve racking. I should turn the key over tomorrow, fingers crossed.

Dave

 

[Jims86]

I will aim for 8* as well.
Your right, its very nerve racking. I should turn the key over tomorrow, fingers crossed.

Dave

Timing was usually set at 4 from the factory on alot of small block trucks, so that or 8 should put well within a good operating range.
Qjets are the best carb out there. Some people are getting 23 mpg out of them with some very fine tuning.
EFI is fairly simple, its just like a different language.
I have self taught myself about all fuel systems, even turbin. But I like EFI the most.
Before you fire it up, dump some fuel into the vent of the carb, and down the primaries, then it should fire with very little effort. Triple check your firing order also.

 

[HotRodPC]

I won many beers and even some good money when I used to build motors. After deadstick timing the motor, (what's called when stabbing a dizzy), and pre filled the carb bowl of fuel so when I hit the accelerator pump I was getting a shot of fuel, I'd bet a start up first try on less than 3 full motor revolutions.
Always double checked firing order, had lifters soaked overnight in oil, if hydraulic lifters, valves adjusted just 1 turn past zero lash, mechanicals at 1/4 turn past zero, motor oil primed with a drill motor to the oil pump shaft before stabbing the dizzy. I don't recall that I even lost either. Back then motor oil had plenty of the good stuff in it, so I only did about 2000 rpm for the first 15 minutes. Then I'd bring it down to about 800rpm and start adjusting the hydaulic valves, to no clatter then half turn. Book calls for full turn if running hydraulic lifters, and doing a motor running valve adjustment, but 1/2 turn works fine and puts less strain on the cam lobes, and if it's not quite enough, the hydraulic lifters will compensate, so I never got crazy tight on hydraulic lifters and never had a problem with cam lobes going flat, or floating vavles unless the rpm or the cam and springs was exceeded.. The motor I ran most of the time didn't float valves until 7500 rpm, although I didn't try that very often either. Can't imagine why

 

[The flying turd]

Timing was usually set at 4 from the factory on alot of small block trucks, so that or 8 should put well within a good operating range.
Qjets are the best carb out there. Some people are getting 23 mpg out of them with some very fine tuning.
EFI is fairly simple, its just like a different language.
I have self taught myself about all fuel systems, even turbin. But I like EFI the most.
Before you fire it up, dump some fuel into the vent of the carb, and down the primaries, then it should fire with very little effort. Triple check your firing order also.

I agree, the Q-jet is a great carb. That's why I had it rebuilt vs a new something else.

If I ever buy a GM EFI system, I know who to ask questions too.
Yep on the fuel priming, for sure.
When I torqued the balancer bolt, I moved the engine off of TDC, ****! I hate rotating with all my cam lube where it needs to be.. Oh well, I have no choice. I'll drop you a line later today with the results.