I'm not saying the 268h is too big and can't be made to work, it's just a mismatch with your intake setup. Is this the root of all your problems? I don't think so but it may be a contributing factor. When things are out of whack, causing the car to run in a way that is not ideal, it makes it more difficult to find the real problems.
This is true. I just ordered a new intake, but it won't be here until next week. I'm going to the shop right now to take a look at it myself and to talk to the guy who was working on it. Any carb suggestions for an edelbrock intake?
65 C code with original Phoenician yellow paint
The carb/cam combo is just until I get a new carb. I understand what you're saying about my "experts". But can you tell me why Comp Cams "stock replacement" style cam is apparently too big? The springs can handle it and there is enough clearance for the valves. The reason I'm posting on here is because I don't have complete faith in my engine or carb guys. That's why I would like to know if anyone else has any ideas of what could be happening because out of the five or six guys that have had their hands on this engine, none of us can figure it out.
Which "stock replacement" cam? They seem to have taken even a few liberties
with their copy of the factory 289 hipo cam.
I see no reason why the cam in and of itself is the problem. It's a mismatch for the intake and carb but that shouldn't cause all the problems he is experiencing. The car is not going to perform great with his combo but it should be able to be made to idle and cruise around without overheating or stumbling.
My carburetor guy said it's running too lean and it dies when you put it into gear. There is also a possible vacuum leak. I have the original autolite 2100 carb. (2bbl)
Well, I think we've found the problem. Not only is your original 2100 a bit undersized for the job, I find it hard to believe that your "carb guy" is spending the time to swap out jets in a 2100 trying to make it work. I'd park it until your new manifold and carburetor shows up.
Any off the shelf 500-600 should work. Guys on here will say 500 for a 289, or if they are being exceptionally cute they will suggest 465. Cost and time wise your best bet is probably a used Edelbrock 500 or 600. If you have the time to locate one in useable shape, or can have it rebuilt, a good choice is the Autolite 4100.
Overheating: Usually caused by either insufficient coolant flow or improper coolant flow routing. Since you have had the radiator cleaned, and it's a 3 row radiator that's probably not the issue. If you are sure the head gaskets are on right we need to move on. Air locks are a very real issue and can be very difficult with a 289 unless you know the trick, which is to loosen the heater hose clamp on the hose that goes into the intake manifold to let any air escape. When you get a trickle of coolant, there is no more air in the system. (do this on a cold engine)
Another thing that I have seen is a faulty head gasket letting compression leak into the radiator. The engine seems to get hot in a hurry and blows the coolant out of the system.
Camshaft: The 268H Comp Cams cam is a great cam but it really likes a 4V carb. The 2100 Autolite can be made to work but the internal passages, accelerator pump and main jets and off idle circuit need to be correct. It takes a good carb guy to straighten one out. The 2100 is also very limited in air flow so another carb would work a lot better.
Timing: These engines like a total ignition timing of usually 34 to 36 degrees before top dead center at 2000 to 2400 RPM. It would be a really good idea to have a competent engine builder check that the TDC mark on the balancer is really true TDC when it's lined up with the pointer on the timing cover. The outer ring on the balancer is rubber mounted, if it slips, which I have seen them do, it will retard the timing. A competent distributor shop can adjust the advance curve in the distributor to arrive at the proper timing. The same shop can also check the vacuum advance unit. (Briefly, the distributor has around 14 degrees centrifugal advance internally, which equates to 28 degrees at the crankshaft, setting the initial timing at 8 degrees gives 36 degrees total. The rate that this internal advance comes in is adjustable. Bringing it in a little sooner than stock is desirable)
One thing you can do before spending any money is to measure the diameter of the balancer and figure out how much distance is 36 degrees. (simple math) mark the balancer with a piece of masking tape, spin the engine up with a timing light connected and see where the timing marks lines up.
Chasing this problem can be exasperating, everyone has an opinion, what I have listed here are things I have seen in the past.
1965 AC Cobra CSX2580
1967 410HP 427 Fairlane
Thanks for that response. The cooling system has been bled the way you said. I think it's just running hot because it is a new engine and is still breaking in. I think I'm just going to go with a new carb that can put more gas/air into the engine. The timing is dead on right now. We are checking the vacuum advance to make sure the curve is right. I'll let you all know what happens.
65 C code with original Phoenician yellow paint
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