djsling
Well-Known Member
What are the differences between an non'cap and a cap engine, specifically on a 66. I know the intake is a different casting number but that's about it
273 Commando with C.A.P.
- Thread starter djsling
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Other than a couple calibration things, the CAP air cleaners have a hose to a valve cover cap for ventilation. If you look at the tune up specs, the CAP specs are pretty anemic. Timing is close to zero.
Cuda Al
Well-Known Member
This is the CAP system on a 67.
The green unit is a vacuum control valve.
On my 67 there was a vacuum supply going to the intake port (the other line is the vacuum gauge, it is there hiding under the bracket).
The distributor advance line is split with this valve, one side to the distributor, the other to the carburetor.
I cheated, my advance goes directly between the distributor and carburetor. The valve just has a line looping around the coil back to itself.
Alan
The green unit is a vacuum control valve.
On my 67 there was a vacuum supply going to the intake port (the other line is the vacuum gauge, it is there hiding under the bracket).
The distributor advance line is split with this valve, one side to the distributor, the other to the carburetor.
I cheated, my advance goes directly between the distributor and carburetor. The valve just has a line looping around the coil back to itself.
Alan
Cuda Al
Well-Known Member
The CAP cars would have also had the hose between the breather cap and the air cleaner housing.
Alan
Alan
Drawing outside air into the crankcase came to an end with CAP. Now crankcase air is drawn from the air cleaner. I think '67 was the first year for the valve. It's purpose was to retard the timing during deceleration.
This is close to the factory explanation.
Automotive History: Chrysler’s CAP, The First Effective Exhaust Emission Control (With ’63 Dodge and Dart Road Tests)
CAP was a number of things.
To the green gizmo takes manifold vacume and ported vacume. When manifold vacume is high as in deceleration the ported vacume stays high for a second or two. Then returns to full ported. On acceleration it has no effect on vacume advance.
If you want to keep the green gizmo but not use it just tighten the screw to tighten the spring. When it is tighten enough the gizmo is deactivated, never enough manifold vacume to overcome the spring pressure.
Cap booklet
16 new items by Dana Nance
Automotive History: Chrysler’s CAP, The First Effective Exhaust Emission Control (With ’63 Dodge and Dart Road Tests)
CAP was a number of things.
- The timing curve is very different than on non CAP cars. Initial is 5ATDC but comes on faster.
- The green gismo delays the timing return to initial for a second or so on deceleration.
- Air cleaner has a port on it to go to the breather (4bbl unsilenced air cleaner with CAP also has one)
- The carborator is jetted differently and the idle mixture screws are contained and can not be turned more than a small amount and if you try to remove them (without some "special" adjustment) you will break them
- Cooling system is heavier duty not quite HD or AC but more than standard cooling.
To the green gizmo takes manifold vacume and ported vacume. When manifold vacume is high as in deceleration the ported vacume stays high for a second or two. Then returns to full ported. On acceleration it has no effect on vacume advance.
If you want to keep the green gizmo but not use it just tighten the screw to tighten the spring. When it is tighten enough the gizmo is deactivated, never enough manifold vacume to overcome the spring pressure.
Cap booklet
16 new items by Dana Nance
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Los Angeles assembled cars started with CAP in 1964 on 1965 A-bodies. Dart for sure!
Did they start with the PCV in 64? I should have been more specific.
Cuda Al
Well-Known Member
Cuda Al
Well-Known Member
What else,
Different Distributor,
Different Carburetor
Alan
Different Distributor,
Different Carburetor
Alan
The dist and carb cores are the same CAP vs non CAP just the tune is diferent so different parts number.
You can even get a CAP Prestolite dual point dist.
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