What camshaft should I use?

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There is a vacuum port connected to the number 6 runner on my 225 that runs the heater controls under the dash. Any chance you could have some kind of a vacuum leak? What's connected to that port on your car? Have you done a vacuum test?
 
Aaron65 said:
There is a vacuum port connected to the number 6 runner on my 225 that runs the heater controls under the dash. Any chance you could have some kind of a vacuum leak? What's connected to that port on your car? Have you done a vacuum test?
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There is no vacuum fitting on the intake manifold. It is not hooked up to anything. Heater is not vacuum operated. I have been working on cars for 12 years and have never heard of a vacuum test.
 
Stimulus money or not.... Harbor Freight is the LAST place I shop for anything.
 
Have you checked the carburetor to assure it is tight on the manifold? I know it sounds stupid, but it's a really common problem on slants for some reason. Remove the air cleaner and grab the carburetor with both hands and "twist it". See if there is any back and forth motion. Take note of where it is. It's not always the two manifold attaching bolts. Sometimes it's the screws that actually hold the carburetor together. They can all work loose over time and cause a vacuum leak making the engine run badly.
 
RustyRatRod said:
Have you checked the carburetor to assure it is tight on the manifold? I know it sounds stupid, but it's a really common problem on slants for some reason. Remove the air cleaner and grab the carburetor with both hands and "twist it". See if there is any back and forth motion. Take note of where it is. It's not always the two manifold attaching bolts. Sometimes it's the screws that actually hold the carburetor together. They can all work loose over time and cause a vacuum leak making the engine run badly.
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I have checked. It’s tight. It’s a Holley 1920 not a BBS so it has a one piece air horn. No screws to get worked loose.
 
John Martin said:
The distributor works fine. I have checked it, the weights are free, the vacuum advance is a new NOS unit, and it has new points, condenser, cap and rotor.

I said above, that the carburetor has been rebuilt, I put a new economizer into the carburetor.
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SCRAP the Holley and go Carter …...
 
Here is a write up I did when I was designing my own cam for my slant six in 2018. I took a few stock cams and ran them through the cam doctor. Hope this helps.

Ok Cam talk time. So as we know I am new to these leaning towers of ok power. I have always wondered why the stock valve setting are what they are 0.010"/0.020" and now I have my answer and a very good reason why you NEVER pick a cam based on advertised duration. So I pulled out a a few 100% stock cams 1968 and 2 1969 cams and they have the exact same specs so we are good on that. Duration at 0.050" 175/184 on a 110 lsa with a lobe lift of 0.217"/0.231" but here is where the funny business comes in. The ramp rates now let look at the intake first, duration at 0.005" 229, 0.010" 217, 0.020" 201, 0.050" 175, 0.100" 141, and 0.200"72. I design cam profiles for a living and these are more in line with modern Hydraulic flat tappet profiles hence the reason for the 0.010" lash. Now the exhaust is 100% like a solid flat tappet should be for that time. Duration 0.005" 326, 0.010" 271, 0.020" 223, 0.050" 184, 0.100" 148, and 0.200" 71. Now this is why the the lash on the exhaust is set at 0.020" because that is when the ramp rate really starts to move fast. The cam that I am doing for my new slant six is going to be a duration at 0.050" 204/208 on a 110lsa with a 0.299" lobe lift. These masters are true solid profiles so the lash will be 0.020" intake and 0.022" exhaust when done. So for me the age old mystery of this lash has been solved.
 
John Martin said:
So you say a wiped lobe on the cam will not cause an issue? I find that a little hard to believe.
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Surely it will. If an exhaust lobe is wiped, that cylinder will still fire, but back up through the intake and disrupt everything. If the intake lobe, the engine will skip, and power will be down and efficiency goes out the window. So yes, mileage will be adversely affected either way. Have you had the valve cover off to inspect for a wiped lobe?
 
RustyRatRod said:
Surely it will. If an exhaust lobe is wiped, that cylinder will still fire, but back up through the intake and disrupt everything. If the intake lobe, the engine will skip, and power will be down and efficiency goes out the window. So yes, mileage will be adversely affected either way. Have you had the valve cover off to inspect for a wiped lobe?
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I suspect it. I saw a few pushrods spinning but I need to double check. I know that no matter what I do to the car it will have a rhythmic “pop-pop” out of the tail pipe, you can hear an audible drop in engine speed that matches the misfire out of the exhaust, and looking at the engine you can see it shaking when running.
 
John Martin said:
I suspect it. I saw a few pushrods spinning but I need to double check. I know that no matter what I do to the car it will have a rhythmic “pop-pop” out of the tail pipe, you can hear an audible drop in engine speed that matches the misfire out of the exhaust, and looking at the engine you can see it shaking when running.
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Here is the dead giveaway if it is an exhaust lobe. Remove the air cleaner. Start the engine. Drop it in drive (I assume auto). Hold the brake firm. Load the engine up against the converter. If you get a rhythmic POP out of the carburetor, you have "something" holding the exhaust valve closed. Whether it's a wiped lobe, bent pushrod, broken rocker......or "whatever".
 
RustyRatRod said:
Here is the dead giveaway if it is an exhaust lobe. Remove the air cleaner. Start the engine. Drop it in drive (I assume auto). Hold the brake firm. Load the engine up against the converter. If you get a rhythmic POP out of the carburetor, you have "something" holding the exhaust valve closed. Whether it's a wiped lobe, bent pushrod, broken rocker......or "whatever".
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Pushrods are good. I took them out and cleaned them, they were all straight. I also cleaned the rocker assembly. A soaking in kerosene and scrubbing got a lot of grime off of them.

Everything was reassembled and torqued to 30 ft.lbs. evenly.
 
John Martin said:
Pushrods are good. I took them out and cleaned them, they were all straight. I also cleaned the rocker assembly. A soaking in kerosene and scrubbing got a lot of grime off of them.

Everything was reassembled and torqued to 30 ft.lbs. evenly.
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I assume you mean the rocker hold down bolts and NOT the rocker adjusters. I am assuming since it is running, you adjusted the valves correctly?
 
RustyRatRod said:
I assume you mean the rocker hold down bolts and NOT the rocker adjusters. I am assuming since it is running, you adjusted the valves correctly?
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Yes the shaft bolts.

The car was allowed to warm up for 10 minutes. I dropped the idle down to about 300-400 and then I popped the valve cover off. Intake was set to .010” and exhaust to .020” while running.
 
John Martin said:
Yes the shaft bolts.

The car was allowed to warm up for 10 minutes. I dropped the idle down to about 300-400 and then I popped the valve cover off. Intake was set to .010” and exhaust to .020” while running.
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I absolutely hate adjusting valves running. I will not do it. It can be dangerous if you're not very careful. I adjust them cold so as not to get burned. They only change "about" .002" when warmed up and that's not going to affect a thing. Sounds like you got it right though. Do you get they rhythmic pop through the carburetor upon a load?
 
RustyRatRod said:
I absolutely hate adjusting valves running. I will not do it. It can be dangerous if you're not very careful. I adjust them cold so as not to get burned. They only change "about" .002" when warmed up and that's not going to affect a thing. Sounds like you got it right though. Do you get they rhythmic pop through the carburetor upon a load?
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I tried to do it while cold and it actually added misfires and it was tapping like a diesel.

The carburetor sounds fine. No popping, but it definitely doesn’t like being loaded up. Even after idling in neutral for a few seconds after it was running much rougher overall.
 
John Martin said:
I tried to do it while cold and it actually added misfires and it was tapping like a diesel.

The carburetor sounds fine. No popping, but it definitely doesn’t like being loaded up. Even after idling in neutral for a few seconds after it was running much rougher overall.
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You can try a compression test. If you have one cylinder that's a "good bit" higher than the rest, that would indicate a closed exhaust valve.
 
RustyRatRod said:
You can try a compression test. If you have one cylinder that's a "good bit" higher than the rest, that would indicate a closed exhaust valve.
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I was told it was good by the guy who did the cylinder head gasket. It was leaking from 5 to 6. It runs smoother than before.
 
John Martin said:
I was told it was good by the guy who did the cylinder head gasket. It was leaking from 5 to 6. It runs smoother than before.
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You need to see the data for yourself. It's all part of the diagnosis. ....and I would WANT accurate diagnosis BEFORE I spent money on a new camshaft, or anything else.
 
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