200ci Degree the cam?
- Thread starter Dustyford
- Start date
This applies only to 200ci
Not to derail the discussion from the points that have been raised but @pmuller9 but regarding PCV, the 1968 200 definitely had a PCV from the factory and it is important to evacuate the pressure to prevent blowing the seals.
I'm not sure whether you have a performance cam or mild cam installed but the one I am running is said to be a mid-range street cam and I have no problems running a PCV. If you have 18" of vacuum at idle and 18" of vacuum at cruise, you can certainly run a PCV. Your engine is designed to have a breather cap at one end of the valve cover and a PCV at the other. The PCV line should go from the valve cover to the intake log below the carburetor or to a fitting on the spacer below the carburetor.
I have a rough 14” at idle and 18” at cruise with new mild cam. PCV makes it unable to idle unless I raise it up to 850+ rpm. I have a ‘65 200 with ‘68 carb and distributor
Dustyford, did you do the test while driving on the road?
No sir. Static in neutral. I haven’t done any tests while driving except rpm. I don’t have a vacuum hose that long.
Again, Get an AFR meter installed.
If you want to keep the cars appearance stock, you can remove the AFR meter after the carb is tuned properly. The only thing that will not appear stock is the O2 bung welded on the exhaust down tube along with the plug. The O2 bung can be put in a non-conspicuous place.
You have to get it on the road under full throttle on a full load for a good length of time to get an accurate reading.No sir. Static in neutral. I haven’t done any tests while driving except rpm. I don’t have a vacuum hose that long.
Try doing the test in 3rd or 4th gear close to 3,000 rpm for approximately 5 to 10 seconds.
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It’s a ‘65 200 with ‘68 carb and distributor. The draft tube came with the engine from the factory. I changed to PCV after 15 people told me it would be better
@Dustyford after all is said and done and you running. If you don’t use the road draft tube, I’d be a buyer.
I think @vssman would like to buy your unused draft tube.
This is probably for later but if the engine is happy at 850 RPM then let it run at that speed. Mine runs from 600 - 900 RPM depending on the temperature and whether I have the halogen headlamps on. Crankcase ventilation is well worth sorting out.
By the way, I keep forgetting this recommendation but I struggled getting my tune sorted out until I came to an understanding of how much time it takes to get this iron lug up to operating temperature. Make sure that your engine is fully up to temperature when you attempt to make changes to the tune. For mine, in the winter, that might be 5 or 10 minutes of warm up and another 10 minutes of driving; so up to 20 minutes before it's settled into operating temperature. After I came to terms with that little detail, I was able to get my idle jets sorted out and my air/fuel mixture and idle speed dialled in.
Also, Yes, I understand that the throttle linkage gets hot. AS a matter of fact, I worry that it is just another way to introduce unwanted heat into the carburetor. I'm adding a heat shield for mine it will bolt onto the exhaust manifold (header) studs and extend across the exhaust, almost to the shock tower. It will be 3ft x 6in if I recall the measurements and just a piece of light gauge sheet metal.
Oh!
No, that stays with the original car parts.I am introducing ported vacuum at idle if I run it over 550
Dustyford,
Your last post made me think of something so I just went through the entire thread again and there is something that has not been discussed.
The carburetor idle circuit:
Is it working properly? This is where an AFR meter will make life much simpler.
I’m wondering if the idle circuit is not able to be richened up enough so the engine is able to idle properly.
I’m also wondering if the engine is only able to operate out of the carburetor’s idle circuit and is transitioning to the main circuit.
Please do some tests:
With the engine operating near recommended idle, turn out the idle mixture screw and see if the RPM’s and vacuum changes. Make sure to count the amount of turns so you’re able to put it back. If there is no or very little change when turning the idle mixture screw out then there is most likely a carburetor idle circuit issue.
Then do another test on turning the idle mixture screw in and see if the RPM’s and vacuum changes. The engine should stall out at some point when turning the idle mixture screw in.
Your last post made me think of something so I just went through the entire thread again and there is something that has not been discussed.
The carburetor idle circuit:
Is it working properly? This is where an AFR meter will make life much simpler.
I’m wondering if the idle circuit is not able to be richened up enough so the engine is able to idle properly.
I’m also wondering if the engine is only able to operate out of the carburetor’s idle circuit and is transitioning to the main circuit.
Please do some tests:
With the engine operating near recommended idle, turn out the idle mixture screw and see if the RPM’s and vacuum changes. Make sure to count the amount of turns so you’re able to put it back. If there is no or very little change when turning the idle mixture screw out then there is most likely a carburetor idle circuit issue.
Then do another test on turning the idle mixture screw in and see if the RPM’s and vacuum changes. The engine should stall out at some point when turning the idle mixture screw in.
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