It’s a little frustrating that nothing in the CVF Racing site mentions this set is underdrive. Maybe I should have inferred it from “racing.”
Finding a larger 8-rib double crank may be a task, but hopefully there’s a smaller diameter 8-rib alternator pulley available.
I question the 3500 rpm. If you are using an older tach / dwell meter and it’s set for 4 cylinder it doubles the RPM. At 3500 rpm dropping it in drive is going to be exciting. Unless you have a very high stall speed converter I don’t see you sitting at a light in drive. It’s an easy mistake to make if you aren’t really familiar with what 3500 rpm is with a 5 liter v8.
1750 rpm does line up with an under drive pulley
That’s a tiny crank pulley and a standard alt pulley. Try a small alternator pulley and maybe you can keep the rest of your set up. Looks like you have good money in it. Like these.
To get an alternator pulley to match your crank and get 3:1 ratio, the alternator pulley should be 1-3/4in. At 1.811, the pulley that EliminatorClone posted looks close, it will give you 2.9:1 ratio (much better than 1.9:1). I love the looks of the billet v-belt pulleys, but I stayed with factory since the billets only come in underdrive and no matter how the math worked, I couldn’t get the right ratio without sacrificing the alternator.
This is good point, It would also explain the conditions that happened when the idle was adjusted down.
It sounds like your issue is with the pulley but double check that RPM so you can get it set right after swapping to a better pulley ratio.
Ordered the smaller pulley. Hopefully I have enough adjustment in my tensioner that I won’t have to get a smaller belt.
I was checking things with the tach again last night, and it decided to switch itself over to volts and stay there, so now I can’t get it to read anything except volts off the coil. I’m going to find a new timing light that has a tach built in, so I can get this sorted once the new pulley arrives.
I guess I’m also going to have to reset the tension on my AOD shift cable as this will likely change the shift points.
I have that same meter. Since you are on the LOW RPM setting, you need to read the top red scale x 100. So in the picture you are running 1125 RPM. Better than 3500, but still too fast for idle and will cause dieseling at shut off.
Maybe electric fans are efficient if the factory matches them to a engine and radiator size but they suck when bubba does it - like has been the case here. It’s a total disaster and efficacy is not in any of the questions. This guy needs to put his car back stock and leave the figuring to engineers.
This is as good as the instructions. Not sure if I can find them I built it in the early '70s.
As Calicat said above 1125 rpm is high but the pulley change will bring you down to below 800 rpm which should be workable.
I built my Heathkit ID29 too. I’m impressed that the plastic case on yours is still intact. Mine disintegrated a few years ago. You know you are getting old when you outlive plastic.
I picked up a 44mm 8-rib alternator from Amazon for $29. It got my crank to alternator pulley ratio to 3:1 and what a difference it made!
When you have electrical power, the car idles much better than when it’s struggling to run off the battery. I set the idle speed to 900 rpm, which drops to about 600 rpm when in gear and on the brake. The car is no longer pulling against the brake and was running at 180 with no issues. The 14volts no longer dips down to 12volts when the fans and AC are on. It’s finally running like it should.
I wish I could say, “that’s that,” but I took the car to pick my son up from school after the swap, and while it continued to run fine, I started hearing a little grindy-whine sound. The new pulley had loosened on the shaft.
I took it apart again and found the lock washer had flattened out.
I used an impact driver to get the nut loose and then to put it back on because there’s no way to hold the internals of the alternator still. Delco alternators have a hex slot in the end of the shaft, so you can use a pass through socket on the nut and then an allen wrench in the end of the shaft to keep it all from turning, but I’m not quite sure what do here aside from get a new lock washer and use loctite when I put the nut back on.
Any tips for alternator nut tightening?
Get another belt and clamp the belt around the pulley where it will hold tight - perhaps figure a way to hold it in a vice like that or other clamping tool. Then use the impact to tighten it.
I would measure the internal diameter of those pulleys to compare. Being a cheap amazon part its more then likely a cheaply made overseas part and may not be in spec. could also be junk hardware. try replacing the nut and lock washer. I would not use locktite
That’s good news, I’m glad to hear that changing the pulley size made an improvement with the drivability. I agree with the other comments; I wouldn’t use Loctite and it could be cheap amazon part. Be sure to torque the pulley down good and maybe look at Summit Racing for a replacement. Summit Racing sells a Powermaster brand pulley that is 1.90 in outer diameter.
Last update on the issue. I got a higher quality lock washer and added a spacer over it as well to ensure the nut wouldn’t hit any possibly buggered threads on the alternator. Put it back together with just a dab of red loctite, and all is good.
Car is running fantastic. I drove it the hour commute into work this morning and it had no trouble idling in gridlock and staying right at 180 degrees. It’s only a humid 80 degrees in Houston right now, so we’ll see how it does when the temp hits 95 and the ambient temperature on the walled freeway lanes is 110+.
Now I have to figure out why my AC isn’t blowing cold …
Glad to hear it’s working!
