underhood heat

[superfragl]

That sound decent for an engine with non-stock cam.

 

[Glenwood]

It pings at wot at 25* initial. I'll have to pull the dist to see what the mech is on it
It is sluggish at 14-17* and seems to hate the vac adv when connected to carb manifold port. It adds about 8-10* at 18" vac.

 

[superfragl]

Yep, check the maximum mech. advance and limit to 34-36. Vacuum advance should be plugged into proper port on the carb - not direct manifold vacuum, but metered vacuum that provides vacuum only when the throttle opens (this is where it makes the difference to have the throttle closed enough so there is no vacuum at that port while idling - you can check with vacuum gauge).
I know there have been many discussions about this, but at least for me it worked much better this way. If I plugged vacuum advance to direct manifold vacuum and set the initial timing to where I wanted it to be the - the timing would be more erratic/fluctuating since vacuum at idle was not very steady.

 

[Glenwood]

I decided to take the BR out of the cct and the volts to the coil bumped up to 10.4v and the temperature of the coil climbed to 230F. I wonder what its limits are. The prim coil bumps up to 2ohms when hot meanting the current reaches over 5A. Didn't seem to smooth the ramp up anymore though.

 

[threewood]

Flamethrower II and III coils are to be run without ballast resistor. The Ignitor II and III are paired with these coils so I don't know what affect they would have on a MP ignition. Just don't use them with points lol.

 

[miller]

Turning the mixture screws 1/4 either way has no effect on vacuum so I'm not sure how to get it right. More reading ahead!

I gotta be careful! Might learn something. Never have tried setting mixture, using vacuum...might look into it, for grins.
It's pretty common on carbs, not to get a mixture response, in a 1/4 turn. Not if it's in range already. Also takes a few moments, for the mixture setting to 'catch up' with the motor. That's why they say do it slowly. But, I'll toss in, mixture cannot be adjusted, if the idle speed is high enough, that the carb is out of the 'idle circuit'. Position of the throttle plates control that, on any carb. Guessing anything over 750-800 RPMs, is too high.

12 volt batteries full charge is 14+ volts. Sounds like your getting there. Wiring getting hot...not so good. (Might peek at your fuse block, too.)

Think you've got your VR acting right, now?
Another story, but my alternator is 80 amp, though I also added in parallel wiring, to help with the normal loads.

 

[threewood]

I gotta be careful! Might learn something. Never have tried setting mixture, using vacuum...might look into it, for grins.
It's pretty common on carbs, not to get a mixture response, in a 1/4 turn. Not if it's in range already. Also takes a few moments, for the mixture setting to 'catch up' with the motor. That's why they say do it slowly. But, I'll toss in, mixture cannot be adjusted, if the idle speed is high enough, that the carb is out of the 'idle circuit'. Position of the throttle plates control that, on any carb. Guessing anything over 750-800 RPMs, is too high.

12 volt batteries full charge is 14+ volts. Sounds like your getting there. Wiring getting hot...not so good. (Might peek at your fuse block, too.)

Think you've got your VR acting right, now?
Another story, but my alternator is 80 amp, though I also added in parallel wiring, to help with the normal loads.

I always set the mixture with a tach. And you are correct about the idle circuit although I'm not certain about the max rpms to be in it. My 440 idles at 900ish depending on gas and is responsive to adjustments so it should be in the circuit (800cfm AVS)

 

[Glenwood]

Edelbrock manual:
The Edelbrock Performer Series carburetor has conventional Idle Mixture Screws (IMS) that provide a leaner A/F when turned clockwise and richer A/F when turned counter clockwise.The idle air flow is controlled by a conventional screw that opens the Primary Throttles. The following procedure should be used to set the idle mixture and speeds.
1. Fully warm engine and ensure choke is fully open.
2. Air cleaner in place.
3. Set desired speed with the air screw.
4. Adjust the IMS on ONE side to get the maximum possible RPM. Do not go rich beyond the maximum speed point.
5. If the above changed the idle speed more than 40 RPM, then readjust the speed.
6. Adjust the side OPPOSITE of that in Step 4 to get maximum RPM.
7. Reset the speed.
8. Carefully trim each IMS to again get the maximum idle RPM.
9. Go leaner just enough to get a 20 RPM drop in speed.
10. Reset the speed to the desired RPM.
11. This is a Lean-Best Idle Set. Setting richer than this will notimprove idle quality or performance, but could tend to foul plugs.

Problem is my tach is not a fine enough resolution to see a 40rpm change. Do some timing lights also have a digital tach? My timing light is a simple strobe but is strobing too fast now for some reason.

 

[miller]

My timing light is a simple strobe but is strobing too fast now for some reason.

Hmmm...yes, my timing light, is a simple one (kinda old, too), but works great. Strobing too fast? Should only hit off #1 plug wire. Don't think your getting cross-fire, do you? No, don't see that, unless something is happening under the cap.

I wouldn't worry too much on the 40RPM bit/bs, Glen. Tachs are not marked that close. Only need to look at which way the RPMs are going. Too rich, or too lean, it will fall, with a short range peaked out. There are too many differences, motor to motor, cam, intake, carb, ignition, all come into play, where your motor tells you what 'it' wants, to run good.

I don't claim to know it all. But, carb basics, tell you the throttle plates movement, from idle speed, goes from idle circuit to primary circuit, once a certain port in the barrels are un-blocked, by the plates.
That being said, should be a high RPM range, when that happens...for any carb.

I can't even tell if this would apply, but on the carbs used on radial engines, setting mixture, was right when RPMs momentarily rise, when shutting down.

Just want to watch for movement on the tach, at idle speed, and go from there.

 

[Glenwood]

I decided to pull the dist and check the mech advance. It is 13 (×2) so 26*. For now would it make sense to set initial lower at say 10-12 and manifold vac at around 6-8* if possible?

Also the reluctor gap was very tight and is probably contributing to the timing light and running issues. I'll set it on the bench this time and check each tooth.

 

[miller]

Is there a manual for it? Sorry, not much help...some of the other guys, that work with those, can give better ideas, than me. Only worked a couple, long time age.

 

[threewood]

Something every gearhead should own...

 

[Dennis H]

Does this still have to do with underhood heat? I blame the dome light.

 

[Glenwood]

I know this has ventured into ignition and fuel but i think these are contributing factors to the excessive heat under the hood. The engine is not overheating but the rad is keeping up with it for now. The 500F+ manifold heat doesn't help either. Hopefully a shroud will redirect some of it below as suggested.

 

[Glenwood]

a few pics from my bulkhead connector. the engine harness was new!

 

[Glenwood]

my mock up shroud. Didn't really help that day though.

 

[Glenwood]

Took the distributor apart. The gap was tighter than .006. Easier to do in a vice.

Getting the vac advance disconnected is fun!

looks like 26* mech.

 

[Glenwood]

Setting the gap with full vac advance.

Something wrong here...too much play! I must have popped the mech advance plate off of the weights while assembling. Had to take it apart again. Helps to put the clip on before the reluctor.

 

[threewood]

Took the distributor apart. The gap was tighter than .006. Easier to do in a vice.

View attachment 523966 View attachment 523967 View attachment 523969

Getting the vac advance disconnected is fun!

View attachment 523974

View attachment 523976

looks like 26* mech.

View attachment 523977

You said you needed a welding project lol. Weld those slots up for 16° mechanical. That will put you in the sweet spot between 32 and 36 depending on initial.

 

[threewood]