I just got my 327 running......runs good but......... usual used carb ****. 735 CFM dual inlet vac secondary LIST4280 - stumble under acceleration & fouls out plugs (too big) 600 CFM double pumper LIST4776(4150)- idles and starts great, falls on its face with anything over half pedal under load 650 CFM single inlet vac secondaries LIST9834 (4160) - leaks gas like crazy from crossover tube (o ring maybe) would it be better to rebuild one of the above, or buy a new one ($$$) if so which one, i would think the VAC secondary would be best. engine is a 65 327 with 1.94 1.50 newer heads (1977) and a crane cam .470 lift & 221 duration it is advertised as a 282 cam. I dont want it to be fast, just run good. any advise is greatly appreciated
Well, you said it. If a new Edelbrock is out of the question, I'd go with the 650. I think a vac. sec. 600 would be better, maybe swap locally with someone for a better sized carb?
I would just Kit the 650 That is all the 327 would need But check va***e when you get kit in carb and setup your power valve properly Or this could give problems also Still cheaper than new carb which would still need power valve thing Keep simple Good luck Ray
I am overall pleased with how well the engine runs. It had been sitting for several years. I discovered a stuck valve and flat cam right before putting it in the truck. It did some nice burnouts with the 735 carb on it, just loaded up fast with fuel. thanks for the respnses
650 with vacuum secondaries will be fine. I had a 327 with a 4 speed in a 55' Chevy. Ran a 780 vacuum secondary Holley with great results. Engine had a Sig Erson Hi-flow 1 cam.
Hate to be a **** but your symptoms could very well be an ignition problem. All of those carbs could make a 327 run like a champ, pick the one that looks the most virgin, rebuild it 100% stock, if that doesn't get it, jet accordingly two sizes at a time, + or- , till it works. Setting up carbs for a clean idle, crisp response, and good hp numbers is a challenge. If you are a newbie to the carb work world and have a few bucks to spare you may be miles ahead to buy a new carb. I am a Holley guy myself but the aftermarket is full of excellent carbs. It can't hurt to try a buddy's known good carb too. Maybe it is your ignition.
Sawracer is correct any of those carbs should work fine,ck all tune up and try different timing, after making sure everything else is ok, See if you can borrow a friends good carb and test it on your car.
I ordered a kit for the 650 today. I have never rebuilt a carb before, so time will tell. Looking forward to trying something new. I forgot to mention it has an HEI distributor.
Take pictures of the dis***embly with your digi camera, to help with the re***embly. You may be glad you did
anyone around with a good working carb you can borrow it try, how about someone with a good running engine to try one of your carbs on?
I pulled the 650 off of a running car (rebuilt 306). It idled and sounded good, just flopped under a load like it does on 327.
May have something going on with the ignition like sawracer said. Make sure both advances in the distributer work, and if you have electronic ignition you are gatting 12 volts and not 9 through a resistor. It sounds like the 735 may have a power valve blown out. The 4776 is my favorite carb in a light car with a 3.50 or taller gear. The 600 va***me secondary would likly work best on your car. Good luck!! Jeff
You might check the pump cams and make sure they are getting a good stroke. The pump squirters like to plug up too. Jeff
Check that the vacuum advance port you are using is the one below the throttle plate. The upper one will screw up the advance on a Chevy.
Does this hei have a vacuum advance on it? No vacuum advance means it is computer controled timing so it has only advance is in the module .Is the hei wired to the old wiring, if so the hei is not getting 12v.What is the timing set at,it should be approx 12 to 14 degrees btdc,spark plugs .040 to .055 and may need advance kit installed.
The distributor has a vacuum advance, it is hooked up directly off ignition switch (run position). I can check voltage with meter. what is lowest voltage the HEI can create spark@ ?
While you are checking advances check the centrifigal advance under the cap. Just pull the cap and the rotor should turn and snap back with spring pressure. That or hook a timing light up, disconnect the va***me advance, and watch the timing as you run the rpms up. You should see the timing advance. Jeff They will creat sparke at nine volts. You just want to make sure there is battery voltage at the distributer with the key on. If you still have the 9 volts required for points you need to run a new wire. Jeff
Dyce is right,I have seen used Hei with the Mech advance frozen,also seen rotors that when tighen down would bind mech advance.
I rebuilt the 650 VAC SEC carb yesterday. It runs better than it did with any other combo before. I am surprised how much the smalladjustments can make to a carb. Idle air bleeds, float levels etc. I think I have it pretty close now. Only problem I am trying to work out now is, it has more power under half/partial throttle than it does when you floor it. I am going to raise the float level on the secondary to see what that does. Any other suggestions. I also will check the advance on the HEI as well. I had to put it up early because the alternator is trying to lock up on it. thanks all for the help
Did you put the check ball back in the secondary va***me chamber? It keeps the secondary from opening to fast.
I didn't see a check valve. I actually changed the vac diaphragm ***. from the 750 and put on the 650. The rubber diaphragm was torn on the 650 (kit didn't include). I didn't open the one I put on. I am going to order a new diaphragm tomorrow. I looked at the diagram for the 4160, and see the check ball in the exploded view. I did'nt see one when I dis***embled my carb. Does it just drop into the VAC inlet ? Thanks
If you split the diaphragm chamber apart the ball will be in a releif cut into the base, just follow the va***me port. When you get the new diaphragm be carfull. They are tricky, the screws like to tear the rubber up. The way I do it is this, I put the diaphragm into the lower chamber, I clamp the diaphragm rod into a vice to support the rod and the base just sits on top of the vice, then i lower the lid with the spring onto the base and the diaphragm. It works for me. If the ball is there and you are still having trouble you may have to get a secondary spring kit. If it acts like the secondary is kicking in to soon. That's what it sounds like but it's real hard to tell from the computer... Jeff
So I should be able to see the ball just by taking the lid off? I will look again tomorrow and see if the check ball is there. It looked like the screws had torn this one up. Thanks Jeff
You pull the lid and the ball will be in the extra hole where the vacuum comes in. Your diaphragm may still seal if it didn't tear to bad. Put it together, push the rod in against the spring, and stick your finger over the vacuum (dang i've been spelling vacuum wrong ) port and it should hold. If not it's leaking. Good luck!! Jeff
Replaced the diaphragm today. It runs even better now. I am going to replace the plugs and do a liitle more adjusting. You can floor it now and it does not stumble. I also replaced the fuel filter on it. It was new when I started the engine a few weeks ago, but I was worried that it had picked up some trash. I put a see thru on this time, and I can see a little trash already. thank you all for the help
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