Overheating and heat risen valve
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
Overheating and heat risen valve
Guys, I'm experiencing overheating and looking at this valve I see (at idle) is partially open. Could the valve cause overheating if it doesn't open fully? I'm thinking of locking it full open... I really hope the overheating is caused by it...
Pro
Joined: Feb 2012
Posts: 577
Likes: 6
At this point you are guessing and that is typically a very bad thing to do when diagnosing a cooling problem. The cooling is relatively simple but a lot of things affect it and it needs to be looked at as a whole and have a few areas checked before a culprit can be named. First, yes, make sure that valve is working as it should. Start by telling us about the car's cooling system. Is it stock or have you done anything to it? Have you checked the fluid level in the radiator? Do you still have the air dam under the nose? Have you checked for debris in and around the radiator or between it and the condenser? Have you checked the fan clutch to see if it's engaging and moving enough air through the radiator? Factory shroud still in place? When was the last time the engine was timed properly? Are you running the factory T-stat and has it been changed or removed? So many questions to explore.
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
The car is all stock. The problem is that the overheating problems started when I replaced the stock bad point distributor with a pertronix module. Before the car worked very badly, bad acceleration and some pistons not firing because of the bad points. Pertronix module solved that BUT overheating started... and I discovered that valve not completely open. In the next days I want to check if opening it could solve the problems. From what I know it it is closed the exhaust returns back to the motor for quicker heating so that makes sense to me if the valve is partially open...
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
The car is all stock. The problem is that the overheating problems started when I replaced the stock bad point distributor with a pertronix module. Before the car worked very badly, bad acceleration and some pistons not firing because of the bad points. Pertronix module solved that BUT overheating started... and I discovered that valve not completely open. In the next days I want to check if opening it could solve the problems. From what I know it it is closed the exhaust returns back to the motor for quicker heating so that makes sense to me if the valve is partially open...
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
Before temps were around 190, now it goes to 210 and when I started to see vapor from the right side of the car, from the open tube of the vapor canister of the radiator I stopped it and returned back to home. Hopefully I was near....
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Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
I suggest you get the timing figured/straightened out FIRST - that could simply be the issue if it isn't right.
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Incorrect timing can cause the engine to run "lean" which can cause over-heating. Start by wiring the heat riser open... that only takes a few seconds. Then move on to the more complicated items.
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
Putting the dial back to 0, I see the timing mark 2 degree clockwise from the 0 of the timing tab which is fixed. IMHO it means I'm 2 degrees after TDC. Am I correct?
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
The reason it may seem to run OK at cruise is the mechanical and vacuum advance are coming in (if the engine is otherwise set-up correctly). If you haven't done so, get the distributor on full manifold vacuum.
Thread Starter
Racer
Joined: Apr 2011
Posts: 471
Likes: 3
Yesterday I tried to adjust timing but after loosing the screw that holds the distributor a bit, I tried to move the distributor cap counter-clockwise (in order to anticipate) but I realized I can't go further the position I have now because the distributor cap hits the ignition coil and it doesn't allow me to rotate more.... ????
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
Yesterday I tried to adjust timing but after loosing the screw that holds the distributor a bit, I tried to move the distributor cap counter-clockwise (in order to anticipate) but I realized I can't go further the position I have now because the distributor cap hits the ignition coil and it doesn't allow me to rotate more.... ????
Pro
Joined: Feb 2012
Posts: 577
Likes: 6
Considering the way the distributors is installed and possible interferences between the firewall, the tach cable, the vacuum advance can and any other obstacles, can the distibutor be turned clockwise roughly 35 degrees? And I do mean clockwise. If so, then you might be able to move all the plug wires counter-clockwise one tower on the distributor cap, given enough slop in the wires. Assuming the distributor is still sitting at 2 degrees retarded, you're timing is off about 12 degrees. By moving the plug wires on the cap, you'll change the no. 1 wire position by 45 degrees. Once you've moved the wires, rotating the distributor 33 degrees clockwise should get you to 10 degrees advance.
Creative thinking but over complicating it. The OP simply needs to start over and do it right. Iron Dog, bump the starter with the #1 plug removed and using your finger to feel for air being pumped out of #1, set it to TDC on the compression stroke. Pull the cap and see where it's pointing. I'd bet not on #1.
Disconnect everything and pull up and re drop the distributor so it's pointing to #1 with the engine on TDC on the compression stroke. Once that's done, re time. Get it right and test drive and let us know if you still have an overheating problem.