Help me out before I start her up for the first time!
09-22-2016, 01:03 AM
#1
Help me out before I start her up for the first time!
Hey all,
I haven't been on here in forever (since I first got my corvette project going awhile back). This site has helped turn me from somebody who didn't know a lick about cars into a guy who can atleast hold a conversation with somebody now
. So I have a few questions for you all......
I got my 1981 corvette awhile back, it was completely stock that I know of. Decided to trash the old exhaust and opted for true duals. Next I got a new set of heads, new cam and new intake and deleted most of the smog stuff (don't need it in my state for a car >25 years old) and stripped 7 or so trashy old paint jobs off the car. I did all of this work myself, slowly over the last year or so while I finished medical school. I'm finally to the point where I'm getting ready to start this car up for the first time since I started working on it. Again, the car has not been started at ALL since I finished the top end. Everything is torqued to specs, everything is lubed correctly and I have a good break-in oil ready to go so I can break in my cam shaft appropriately. I just installed my distributor today and the engine is currently in TDC for cylinder 1. I plan on priming the engine up on Saturday as well.
My question has to do with timing, which I am still pretty poor at understanding. I want to make sure the car is as properly timed as it can be before starting the engine with the new camshaft and trying to run it at 2000 RPM or so for fears of crappy timing ruining the camshaft break in process. From what I understand, if the engine is set at TDC for cylinder 1 and the distributor is installed, I have the "initial timing" set. Is this correct? If so, is this sufficient to try and break in the camshaft for 20 minutes? If not, should I go ahead and get a timing light to adjust the distributor while the car initially runs to improve timing?
I just want to make sure that the timing isn't something that is going to ruin my break in process and screw up everything I've worked on over the last year. Any input on setting the timing correctly for the break in process would REALLY be appreciated. Thank you all!
I haven't been on here in forever (since I first got my corvette project going awhile back). This site has helped turn me from somebody who didn't know a lick about cars into a guy who can atleast hold a conversation with somebody now
. So I have a few questions for you all......I got my 1981 corvette awhile back, it was completely stock that I know of. Decided to trash the old exhaust and opted for true duals. Next I got a new set of heads, new cam and new intake and deleted most of the smog stuff (don't need it in my state for a car >25 years old) and stripped 7 or so trashy old paint jobs off the car. I did all of this work myself, slowly over the last year or so while I finished medical school. I'm finally to the point where I'm getting ready to start this car up for the first time since I started working on it. Again, the car has not been started at ALL since I finished the top end. Everything is torqued to specs, everything is lubed correctly and I have a good break-in oil ready to go so I can break in my cam shaft appropriately. I just installed my distributor today and the engine is currently in TDC for cylinder 1. I plan on priming the engine up on Saturday as well.
My question has to do with timing, which I am still pretty poor at understanding. I want to make sure the car is as properly timed as it can be before starting the engine with the new camshaft and trying to run it at 2000 RPM or so for fears of crappy timing ruining the camshaft break in process. From what I understand, if the engine is set at TDC for cylinder 1 and the distributor is installed, I have the "initial timing" set. Is this correct? If so, is this sufficient to try and break in the camshaft for 20 minutes? If not, should I go ahead and get a timing light to adjust the distributor while the car initially runs to improve timing?
I just want to make sure that the timing isn't something that is going to ruin my break in process and screw up everything I've worked on over the last year. Any input on setting the timing correctly for the break in process would REALLY be appreciated. Thank you all!
09-22-2016, 01:09 AM
#2
Heel & Toe
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Can't help with your question but I think you might be me from the future... I just picked up an '81 project car and I'm halfway through 3rd year of med school. Good luck getting things sorted and post some pics of all your hard work!
09-22-2016, 04:57 AM
#3
Melting Slicks
I would get a timing light, start it up and then adjust the timing. Have everything at hand so you can get it done reasonably quickly ( don't panic!) then do the break in. I am almost ready to fire up my rebuild, but it's a 86 TPI engine that is going into my 78. My problem will be if it doesn't fire up, could it be the computer or something the engine. But that is part of the challenge/fun of doing stuff like this. Good luck
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Osteoclast (09-22-2016)
09-22-2016, 08:58 AM
#5
Had a 1976 L-82, 4-sp
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Royal Canadian Navy
Now that you are at tdc and 0* on the balancer, rotate the engine by hand so the timing mark at the balancer is aligned at the 10* btdc mark. Then go back to your dist'r and re-align the rotor to #1 plug. This will get you in the ball park on flashup.
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Osteoclast (09-22-2016)
09-22-2016, 09:12 AM
#6
Drifting
With the damper set between 6* and 10*, hook up timing light and turn key to on position. Slowly rotate distributor body; when light flashes tighten down distributor. Easy $$.
A common mistake is setting TDC. When the timing set marks are at 6 and 12 o'clock, the distributor is 180* out. It will kick and misfire...
Good luck and have fun with it!
A common mistake is setting TDC. When the timing set marks are at 6 and 12 o'clock, the distributor is 180* out. It will kick and misfire...
Good luck and have fun with it!
09-22-2016, 01:28 PM
#7
Team Owner
The engine has a four-stroke cycle [intake charge stroke down, compression stroke up, firing/power stroke down, exhaust stroke up]. That means that it rotates TWICE for each complete firing cycle. Each piston has to have a "compression" stroke and an "exhaust" stroke. So just putting the engine rotation at #1 TDC does NOT necessarily mean that you are correct in your setting.
Remove the #1 spark plug and rotate the engine. As the piston approaches TDC you will either feel very little air coming from the spark plug hole (exhaust cycle) or you will feel a steady pulse of air coming from it (compression cycle). For the engine to be rotated properly, set it on the 'compression' stroke.
You could also detect to correct firing point via the distributor, as it only rotates once for the TWO rotations of the engine. (no confusion there) The ignition points will just 'break' connection on cylinder #1 at the point of plug firing.
Hopefully, some of this will assist you in getting the engine timed correctly (or close enough) so that it will start.
Remove the #1 spark plug and rotate the engine. As the piston approaches TDC you will either feel very little air coming from the spark plug hole (exhaust cycle) or you will feel a steady pulse of air coming from it (compression cycle). For the engine to be rotated properly, set it on the 'compression' stroke.
You could also detect to correct firing point via the distributor, as it only rotates once for the TWO rotations of the engine. (no confusion there) The ignition points will just 'break' connection on cylinder #1 at the point of plug firing.
Hopefully, some of this will assist you in getting the engine timed correctly (or close enough) so that it will start.
Last edited by 7T1vette; 09-22-2016 at 01:32 PM.
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Osteoclast (09-22-2016)
09-22-2016, 07:30 PM
#8
The engine has a four-stroke cycle [intake charge stroke down, compression stroke up, firing/power stroke down, exhaust stroke up]. That means that it rotates TWICE for each complete firing cycle. Each piston has to have a "compression" stroke and an "exhaust" stroke. So just putting the engine rotation at #1 TDC does NOT necessarily mean that you are correct in your setting.
Remove the #1 spark plug and rotate the engine. As the piston approaches TDC you will either feel very little air coming from the spark plug hole (exhaust cycle) or you will feel a steady pulse of air coming from it (compression cycle). For the engine to be rotated properly, set it on the 'compression' stroke.
You could also detect to correct firing point via the distributor, as it only rotates once for the TWO rotations of the engine. (no confusion there) The ignition points will just 'break' connection on cylinder #1 at the point of plug firing.
Hopefully, some of this will assist you in getting the engine timed correctly (or close enough) so that it will start.
Remove the #1 spark plug and rotate the engine. As the piston approaches TDC you will either feel very little air coming from the spark plug hole (exhaust cycle) or you will feel a steady pulse of air coming from it (compression cycle). For the engine to be rotated properly, set it on the 'compression' stroke.
You could also detect to correct firing point via the distributor, as it only rotates once for the TWO rotations of the engine. (no confusion there) The ignition points will just 'break' connection on cylinder #1 at the point of plug firing.
Hopefully, some of this will assist you in getting the engine timed correctly (or close enough) so that it will start.
Yeah the engine is on TDC for the compression stroke for cylinder one. I watched the valves on the first cylinder when I did it so I'm pretty sure its on compression!
I will certainly have somebody with a fire extinguisher around when this gets going as well! I had a few other questions regarding the old intake manifold ports.....this car had so many wires unplugged and cut when I bought it that I have no idea what wires remain and what is vital as the car was at least running when I got it. I labeled ALMOST everything as I disconnected it from the car but a few things were just plain not connected to anything. so.....
RED ARROW - Pretty sure its a vacuum port. I have the port with 3 connectors above as you can see. However, I have NO idea what wires actually install into it. Anybody have a picture of a stock set up that I can see? I honestly can't remember if ANYTHING was attached to this and frankly wouldn't be surprised if there wasn't as I was very diligent when labeling
GREEN ARROW - you can't really see it but there is a cut black hose nub right here that its over a nut with a small hole in it. Looks like a vent of some sort but it goes right into the intake so I'm not sure. 100% this is how the car was when I took the intake off. My question is if I need to install this onto the new intake or if I can just block it off with a nut.
PURPLE ARROW - Broken sensor that was not connected to anything either when I took the intake off. Pretty sure I found the connector but I have no idea what actually is. Can somebody educate me please?
You guys are great help. Thanks again
Edit- IGNORE the red arrow. I did some digging and found exactly what goes here and it is now installed correctly in the intake manifold. However, still not sure as to the green and purple arrow.
Last edited by Osteoclast; 09-22-2016 at 07:57 PM.
09-22-2016, 07:54 PM
#9
Melting Slicks
Member Since: Jul 2010
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red is the vacuum port your "T" can go in there, headlights , brake booster, run off it . someone who knows distributors better will tell you where to connect your timing advance from your dizzy
green is in the manifold water(coolant ) cross over, its for your cabin heater, the other hose would go to your water pump , the small hole in it would be to restrict the amount of hot water flow ,not a factory fitting or its been modified by the previous owner, maybe the car was getting too hot inside the cab. (its not just rusted closed is it ?)
purple is part of emissions control switch, it would have two small vac hoses running to it and when the coolant got hot it would switch open or closed and help save the environment.
not really needed for running in just make sure it doesn't leak
hope it helps
green is in the manifold water(coolant ) cross over, its for your cabin heater, the other hose would go to your water pump , the small hole in it would be to restrict the amount of hot water flow ,not a factory fitting or its been modified by the previous owner, maybe the car was getting too hot inside the cab. (its not just rusted closed is it ?)
purple is part of emissions control switch, it would have two small vac hoses running to it and when the coolant got hot it would switch open or closed and help save the environment.
not really needed for running in just make sure it doesn't leakhope it helps
Last edited by bazza77; 09-22-2016 at 08:03 PM.
09-22-2016, 08:13 PM
#10
Melting Slicks
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Just be careful if you decide to try and take out the purple or green fittings, the vacuum one came out ok because its in a dry environment but the other two STEEL ones lived in (hopefully nice coolant ) but maybe in crappy water and they could be rusted and its very easy to strip the manifold alloy threads
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Osteoclast (09-22-2016)
09-22-2016, 08:20 PM
#11
red is the vacuum port your "T" can go in there, headlights , brake booster, run off it . someone who knows distributors better will tell you where to connect your timing advance from your dizzy
green is in the manifold water(coolant ) cross over, its for your cabin heater, the other hose would go to your water pump , the small hole in it would be to restrict the amount of hot water flow ,not a factory fitting or its been modified by the previous owner, maybe the car was getting too hot inside the cab. (its not just rusted closed is it ?)
purple is part of emissions control switch, it would have two small vac hoses running to it and when the coolant got hot it would switch open or closed and help save the environment. not really needed for running in just make sure it doesn't leak
hope it helps
green is in the manifold water(coolant ) cross over, its for your cabin heater, the other hose would go to your water pump , the small hole in it would be to restrict the amount of hot water flow ,not a factory fitting or its been modified by the previous owner, maybe the car was getting too hot inside the cab. (its not just rusted closed is it ?)
purple is part of emissions control switch, it would have two small vac hoses running to it and when the coolant got hot it would switch open or closed and help save the environment.
not really needed for running in just make sure it doesn't leakhope it helps
So the nut with the green arrow isn't rusted closed. I can see the small hole through it. Would it be safe to just cap this off? I have no idea what the old owner did to it or why hahaha.
09-22-2016, 08:36 PM
#12
Melting Slicks
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the purple switch is a heat activated switch already so yes putting a modern one in there will work the same way.
plugging off the green plug is deleting your heater. it wont hurt anything but you have to plug off the other one at the pump as well. if you cant do that you could just run a hose from/to each other . its a bypass, it will look crazy but you wont have to worry about hooking up a heater core which might be leaking (for your running in time ).
plugging off the green plug is deleting your heater. it wont hurt anything but you have to plug off the other one at the pump as well. if you cant do that you could just run a hose from/to each other . its a bypass, it will look crazy but you wont have to worry about hooking up a heater core which might be leaking (for your running in time ).
09-22-2016, 09:04 PM
#14
you will be fine, just triple check everything before you turn that key.
09-26-2016, 05:33 PM
#16
Safety Car
"prime" your car before starting it...
When you refer to priming your engine, are you talking about removing the distributor and using a oil pump priming tool and an electric drill to get the oil circulated RIGHT before you try to crank it over?
Some people think of priming as filling the carb with gas before starting it. My motorcycle has a "prime" position where it lets the gas flow to my carbs before starting. My 1964 BSA has prime button on its carb.
Be sure to prime the oil system before that glorious moment, install the distributor, connect the timing light and go for it.
That is a really important moment and you should video it, I wish I had made a movie of my startup, three guys, two fire extinguishers and elevated heartbeats....
Some people think of priming as filling the carb with gas before starting it. My motorcycle has a "prime" position where it lets the gas flow to my carbs before starting. My 1964 BSA has prime button on its carb.
Be sure to prime the oil system before that glorious moment, install the distributor, connect the timing light and go for it.
That is a really important moment and you should video it, I wish I had made a movie of my startup, three guys, two fire extinguishers and elevated heartbeats....
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Osteoclast (09-26-2016)
09-26-2016, 10:44 PM
#17
When you refer to priming your engine, are you talking about removing the distributor and using a oil pump priming tool and an electric drill to get the oil circulated RIGHT before you try to crank it over?
Some people think of priming as filling the carb with gas before starting it. My motorcycle has a "prime" position where it lets the gas flow to my carbs before starting. My 1964 BSA has prime button on its carb.
Be sure to prime the oil system before that glorious moment, install the distributor, connect the timing light and go for it.
That is a really important moment and you should video it, I wish I had made a movie of my startup, three guys, two fire extinguishers and elevated heartbeats....
Some people think of priming as filling the carb with gas before starting it. My motorcycle has a "prime" position where it lets the gas flow to my carbs before starting. My 1964 BSA has prime button on its carb.
Be sure to prime the oil system before that glorious moment, install the distributor, connect the timing light and go for it.
That is a really important moment and you should video it, I wish I had made a movie of my startup, three guys, two fire extinguishers and elevated heartbeats....
So, a bunch to fill you all in on. As of today, I installed an oil pump priming tool and made sure I circulated oil over the engine before I cranked it. I had oil coming up from the rocker arm bolts, dripping down over the springs by the end. I also spun the engine over to about 6* before TDC on cylinder 1 before start up (right before I got to 6* I installed the fuel pump and got some fuel into the carb by hand cranking the engine to 6*). I installed the distributor and turned the key to the "on" position as recommended above and got the "flash" from my timing light while adjusting the distributor over the 1st firing position. I triple checked all of my connections, had a buddy with the timing light ready (with fire extinguisher) and another who would adjust the timing while I started the car (also with a fire extinguisher hahaha).
So...I got in to start it and..........crank crank crank. Nothing. It wouldn't start. It cranked fine without any catastrophic sounds/fire/smoke/disaster but would not successfully fire up. So I'm stuck. I'm not sure what the problem is. I'm going over the basics of ignition...spark/fuel/air. I know I'm getting spark at TDC on cylinder 1 so that shouldn't be the issue and my spark plugs/wires are on correctly. Air shouldn't be the issue either. I don't have the air filter on but it should be pulling air fine. I'm stuck with fuel as the problem. I did put brand new gas in the tank before running it. I also know that I'm getting fuel through the pump as I got some out while I cranked the engine before connecting the pump to the carburetor. The only thing I can think of is the fuel filter. I forgot to change it before connecting it to the carb and I know for a fact that it is old/dirty/destroyed for the most part. I went out and bought another one and will install it tomorrow. I'm hoping this MAY be the problem and feel dumb for not fixing it first.
However, is there anything else you guys could think of that I should check before I try to crank this thing over again? I'm at a loss other than this filter. I don't want to keep cranking the engine over without successfully starting it as I don't want to remove any more lubrication than necessary from the camshaft.
09-26-2016, 10:50 PM
#18
Both actually!
So, a bunch to fill you all in on. As of today, I installed an oil pump priming tool and made sure I circulated oil over the engine before I cranked it. I had oil coming up from the rocker arm bolts, dripping down over the springs by the end. I also spun the engine over to about 6* before TDC on cylinder 1 before start up (right before I got to 6* I installed the fuel pump and got some fuel into the carb by hand cranking the engine to 6*). I installed the distributor and turned the key to the "on" position as recommended above and got the "flash" from my timing light while adjusting the distributor over the 1st firing position. I triple checked all of my connections, had a buddy with the timing light ready (with fire extinguisher) and another who would adjust the timing while I started the car (also with a fire extinguisher hahaha).
So...I got in to start it and..........crank crank crank. Nothing. It wouldn't start. It cranked fine without any catastrophic sounds/fire/smoke/disaster but would not successfully fire up. So I'm stuck. I'm not sure what the problem is. I'm going over the basics of ignition...spark/fuel/air. I know I'm getting spark at TDC on cylinder 1 so that shouldn't be the issue and my spark plugs/wires are on correctly. Air shouldn't be the issue either. I don't have the air filter on but it should be pulling air fine. I'm stuck with fuel as the problem. I did put brand new gas in the tank before running it. I also know that I'm getting fuel through the pump as I got some out while I cranked the engine before connecting the pump to the carburetor. The only thing I can think of is the fuel filter. I forgot to change it before connecting it to the carb and I know for a fact that it is old/dirty/destroyed for the most part. I went out and bought another one and will install it tomorrow. I'm hoping this MAY be the problem and feel dumb for not fixing it first.
However, is there anything else you guys could think of that I should check before I try to crank this thing over again? I'm at a loss other than this filter. I don't want to keep cranking the engine over without successfully starting it as I don't want to remove any more lubrication than necessary from the camshaft.
So, a bunch to fill you all in on. As of today, I installed an oil pump priming tool and made sure I circulated oil over the engine before I cranked it. I had oil coming up from the rocker arm bolts, dripping down over the springs by the end. I also spun the engine over to about 6* before TDC on cylinder 1 before start up (right before I got to 6* I installed the fuel pump and got some fuel into the carb by hand cranking the engine to 6*). I installed the distributor and turned the key to the "on" position as recommended above and got the "flash" from my timing light while adjusting the distributor over the 1st firing position. I triple checked all of my connections, had a buddy with the timing light ready (with fire extinguisher) and another who would adjust the timing while I started the car (also with a fire extinguisher hahaha).
So...I got in to start it and..........crank crank crank. Nothing. It wouldn't start. It cranked fine without any catastrophic sounds/fire/smoke/disaster but would not successfully fire up. So I'm stuck. I'm not sure what the problem is. I'm going over the basics of ignition...spark/fuel/air. I know I'm getting spark at TDC on cylinder 1 so that shouldn't be the issue and my spark plugs/wires are on correctly. Air shouldn't be the issue either. I don't have the air filter on but it should be pulling air fine. I'm stuck with fuel as the problem. I did put brand new gas in the tank before running it. I also know that I'm getting fuel through the pump as I got some out while I cranked the engine before connecting the pump to the carburetor. The only thing I can think of is the fuel filter. I forgot to change it before connecting it to the carb and I know for a fact that it is old/dirty/destroyed for the most part. I went out and bought another one and will install it tomorrow. I'm hoping this MAY be the problem and feel dumb for not fixing it first.
However, is there anything else you guys could think of that I should check before I try to crank this thing over again? I'm at a loss other than this filter. I don't want to keep cranking the engine over without successfully starting it as I don't want to remove any more lubrication than necessary from the camshaft.
09-27-2016, 09:24 AM
#20
Yeah I never got it to fire or cough. I did get a small misfire after I sprayed a little starter fluid into the carb but that was it.