1974 Distributor is Knocking
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Noonie,
I am not sure how that will help me. As I said I pulled the valve covers and both #1 valves are closed at my #1 TDC.
I did set TDC at about 8* BTDC (suggested 6-12) on the tab according to Lars' paper for the rotor tip set to #1. I have read elsewhere that perhaps I should set at 0* and do timing later. I really do not know.
I am not sure how that will help me. As I said I pulled the valve covers and both #1 valves are closed at my #1 TDC.
I did set TDC at about 8* BTDC (suggested 6-12) on the tab according to Lars' paper for the rotor tip set to #1. I have read elsewhere that perhaps I should set at 0* and do timing later. I really do not know.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If nothing elso it's just an easy way to confirm without removing anything but the no 1 sparkplug.
Also to check for spark, just use spare good spark plug and any plug wire, lay the plug on the exhaust manifold to ground the case and crank, no reason to remove any plugd from the engine. Just a little less work.
Also to check for spark, just use spare good spark plug and any plug wire, lay the plug on the exhaust manifold to ground the case and crank, no reason to remove any plugd from the engine. Just a little less work.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
If nothing elso it's just an easy way to confirm without removing anything but the no 1 sparkplug.
Also to check for spark, just use spare good spark plug and any plug wire, lay the plug on the exhaust manifold to ground the case and crank, no reason to remove any plugd from the engine. Just a little less work.
Also to check for spark, just use spare good spark plug and any plug wire, lay the plug on the exhaust manifold to ground the case and crank, no reason to remove any plugd from the engine. Just a little less work.
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Brett Foote
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
To go through a complete cycle the crank rotates 2 times.
Intake , compression , power , exhaust
The intake will open and close 2 times and so will the exhaust.
With both valves closed on #1 and the timing mark on "O" look at the other valves on the drivers bank. #3 intake and #5 exhaust should be open, if they are not open, you need to rotate the crank around again to the timing mark. #3 I and #5 E should be open - Now you are ready to drop your dist in on #1
Intake , compression , power , exhaust
The intake will open and close 2 times and so will the exhaust.
With both valves closed on #1 and the timing mark on "O" look at the other valves on the drivers bank. #3 intake and #5 exhaust should be open, if they are not open, you need to rotate the crank around again to the timing mark. #3 I and #5 E should be open - Now you are ready to drop your dist in on #1
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
To go through a complete cycle the crank rotates 2 times.
Intake , compression , power , exhaust
The intake will open and close 2 times and so will the exhaust.
With both valves closed on #1 and the timing mark on "O" look at the other valves on the drivers bank. #3 intake and #5 exhaust should be open, if they are not open, you need to rotate the crank around again to the timing mark. #3 I and #5 E should be open - Now you are ready to drop your dist in on #1
Intake , compression , power , exhaust
The intake will open and close 2 times and so will the exhaust.
With both valves closed on #1 and the timing mark on "O" look at the other valves on the drivers bank. #3 intake and #5 exhaust should be open, if they are not open, you need to rotate the crank around again to the timing mark. #3 I and #5 E should be open - Now you are ready to drop your dist in on #1
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
Paul, if you are positive that you found TDC on #1 on the compression stroke and not the exhaust stroke and when you dropped the distributor the rotor was pointing to the #1 firing position than the distributor should be in correctly so lets look at other ideas.
I don't know how the Breakerless SE wires in so excuse me for asking this but did you need to change any other wiring such as the ballast resistor? I know on Pertronics units the ballast resistor gets bypassed. Did you change that with the Breakerless and than not switch it back when you went back to points?
With all the fooling with the distributor removing the Breakerless SE and reinstalling points and condensor could you have a broken wire or connection on the black ground wire from the breaker plate that goes to the coil? Breaking the connection is common and without that ground working it won't fire.
Did you double check all the ignition wires for proper indexing on the distributor cap?
Even if timing is off by a fair amount still it should still start as long as you have spark, fuel and air as I know you know so start at the basics and check all those first. It's gotta be something simple. Even if you dropped in the distributor a tooth off it should still start.
just throwing some ideas out to see what may stick....
I don't know how the Breakerless SE wires in so excuse me for asking this but did you need to change any other wiring such as the ballast resistor? I know on Pertronics units the ballast resistor gets bypassed. Did you change that with the Breakerless and than not switch it back when you went back to points?
With all the fooling with the distributor removing the Breakerless SE and reinstalling points and condensor could you have a broken wire or connection on the black ground wire from the breaker plate that goes to the coil? Breaking the connection is common and without that ground working it won't fire.
Did you double check all the ignition wires for proper indexing on the distributor cap?
Even if timing is off by a fair amount still it should still start as long as you have spark, fuel and air as I know you know so start at the basics and check all those first. It's gotta be something simple. Even if you dropped in the distributor a tooth off it should still start.
just throwing some ideas out to see what may stick....
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Intake opens at the end of the exhaust stroke, closes at the beginning of compression. Exhaust open at the end of power, closes at beginning of intake.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
The plug would be firing with the piston at TDC but the wrong TDC.
I've been sick all day so I guess I could be wrong but I don't think so.
#1 and #6 are companion cylinders-correct ?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Paul, if you are positive that you found TDC on #1 on the compression stroke and not the exhaust stroke and when you dropped the distributor the rotor was pointing to the #1 firing position than the distributor should be in correctly so lets look at other ideas.
I don't know how the Breakerless SE wires in so excuse me for asking this but did you need to change any other wiring such as the ballast resistor? I know on Pertronics units the ballast resistor gets bypassed. Did you change that with the Breakerless and than not switch it back when you went back to points?
With all the fooling with the distributor removing the Breakerless SE and reinstalling points and condensor could you have a broken wire or connection on the black ground wire from the breaker plate that goes to the coil? Breaking the connection is common and without that ground working it won't fire.
Did you double check all the ignition wires for proper indexing on the distributor cap?
Even if timing is off by a fair amount still it should still start as long as you have spark, fuel and air as I know you know so start at the basics and check all those first. It's gotta be something simple. Even if you dropped in the distributor a tooth off it should still start.
just throwing some ideas out to see what may stick....
I don't know how the Breakerless SE wires in so excuse me for asking this but did you need to change any other wiring such as the ballast resistor? I know on Pertronics units the ballast resistor gets bypassed. Did you change that with the Breakerless and than not switch it back when you went back to points?
With all the fooling with the distributor removing the Breakerless SE and reinstalling points and condensor could you have a broken wire or connection on the black ground wire from the breaker plate that goes to the coil? Breaking the connection is common and without that ground working it won't fire.
Did you double check all the ignition wires for proper indexing on the distributor cap?
Even if timing is off by a fair amount still it should still start as long as you have spark, fuel and air as I know you know so start at the basics and check all those first. It's gotta be something simple. Even if you dropped in the distributor a tooth off it should still start.
just throwing some ideas out to see what may stick....
The breaker plate and ground wire are brand new. The Breakerless SE uses a stock coil but if need be I have a new one. On the 1974 there is no ballast resistor; it is a wire. You are thinking back to C2s and believe me I appreciate that having been there. I am ... lost... for the first time in over 25 years of driving C2s and C3s.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I'm a little cloudy right now , I took some Tylenol PM about an hour ago.
Sorry to mislead Paul. :o
Drifting
Joined: Jul 2002
Posts: 1,944
Likes: 20
From: The only Corvettes in Highett Victoria
It's only on the other side of the equator that the valves open twice each on two cycles of the crankshaft, it's to do with the corealis effect or somethin'
Or maybe I've had one G&T too many
Regards from Down Under
aussiejohn
