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Idle speed for 64 365?

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Old 04-12-2017, 07:43 PM   #1
gsholz
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Default Idle speed for 64 365?

After going through the rest of the car (new fluids, shocks, new N11 exhaust, lubed the steering, new tires, checked and flushed brakes) it is time to take a look at the engine. She runs pretty well and pulls well above 4000 rpm but I suspect the timing, carb and valves were not touched the last 10 years.

My question is about correct idle speed for this engine. The chart I have shows 475 rpm for idle speed for the 63 and 64 V8s. Seems awfully low for this engine. My car came set to about 550 rpm when warm. It never died but it is not smooth either.



Shows idle speed as 475 rpm

What are you guys using for idle on the 365hp engine?
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Old 04-12-2017, 07:47 PM   #2
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I pay no attention to factory idle specs. Set it anywhere you want as long as it does not run-on when you shut it off.
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Old 04-12-2017, 07:51 PM   #3
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I taught a lot of you people how to drive a manual trans car with big engine cars/low gears with the idle turned up. It is hard to kill it on take off. Once they get over their nerviousness of take of and shifting gears it is easy for them to drive a 4 banger with a 5 speed.
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Old 04-12-2017, 07:51 PM   #4
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I believe the factory spec is 700RPM at warm idle for your solid lifter 365.
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Old 04-12-2017, 08:04 PM   #5
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And I believe if you don't idle a 30-30 cam at at least 850 rpm, you're whistlin' Dixie.

They won't idle much below that and behave themselves especially if you use those ridiculously tight valve settings some recommend.

Last edited by MikeM; 04-12-2017 at 08:06 PM.
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Old 04-12-2017, 10:11 PM   #6
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It was running at 550 but rough. Much better at 700 rpm though.

Regarding valve lash, I'm reading that for solid lifter 365 hp camshaft one cannot adjust the valves at TDC since the valves are still on the ramps. Why can't I just account for the ramp at TDC and set the valves at 0.024 instead of 0.026?
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Old 04-13-2017, 06:10 AM   #7
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Quote:
Originally Posted by gsholz View Post
It was running at 550 but rough. Much better at 700 rpm though.

Regarding valve lash, I'm reading that for solid lifter 365 hp camshaft one cannot adjust the valves at TDC since the valves are still on the ramps. Why can't I just account for the ramp at TDC and set the valves at 0.024 instead of 0.026?
My lil ole 250 hp 63 won't idle at the factory setting either. I don't even try and don't worry about it.
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Old 04-13-2017, 07:18 AM   #8
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Quote:
Originally Posted by gsholz View Post
It was running at 550 but rough. Much better at 700 rpm though.

Regarding valve lash, I'm reading that for solid lifter 365 hp camshaft one cannot adjust the valves at TDC since the valves are still on the ramps. Why can't I just account for the ramp at TDC and set the valves at 0.024 instead of 0.026?
The Chevrolet Service manual says to set the valve clearance at 30-30. That's what I'd go with with whatever method you choose to use to set them.
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Old 04-13-2017, 08:27 AM   #9
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I agree with MikeM. If you set the valve lash at .024", your engine will not idle or run properly. Go with the correct .030" for all valves.
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Old 04-13-2017, 10:27 AM   #10
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Last edited by 65tripleblack; 04-13-2017 at 10:28 AM.
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Old 04-13-2017, 11:12 AM   #11
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I should have read the manual....The shop manual supplement for 1964 does show the correct idle speed for the 365hp engine is 800 rpm.

The manual also shows the valve lash to be 0.030" set hot on a running engine. Oil deflectors are recommended. Sounds simple but possibly messy. Does anyone have any firsthand experience setting valve lash on a running engine?
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Old 04-13-2017, 11:33 AM   #12
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Quote:
Originally Posted by gsholz View Post
I should have read the manual....The shop manual supplement for 1964 does show the correct idle speed for the 365hp engine is 800 rpm.

The manual also shows the valve lash to be 0.030" set hot on a running engine. Oil deflectors are recommended. Sounds simple but possibly messy. Does anyone have any firsthand experience setting valve lash on a running engine?
Get the engine hot then remove all 8 plugs when its safe to do so. Disconnect neg battery cable or open cutoff switch. Get a 1/2" drive socket on the balancer center bolt which is I believe 5/8" and use it to turn the engine (if you have a remote starter switch that makes it much easier, otherwise a long screwdriver to momentarily short the "R" and "BAT" terminals works). Sometimes you can turn the engine using the belts, but not always possible. You can also put it in gear and rock or push.

GOOGLE "EO-IC valve lash adjustment" if you don't already know how. Engine should be warm-hot. Use the hot setting.

Your choice:

If you want the engine's lifters to "sing", the idle vacuum to be about 1 in-hg lower, the idle to be "lumpier", the engine to make less torque below about 4500 RPM, "come-on-the-cam" much more dramatically, and make more horsepower, then set them @ .023 -.023, warm/hot.

If you want the engine to sound like a diesel with that nice, clattering sound, make more idle vacuum with a smoother idle, make more low-midrange torque, and make less horsepower, then set them @ .030- .030 warm,hot.

There is a back-story to why GM changed the lash for the 346 cam from .025-.025 to .030-.030. I'll leave that for another day.

Last edited by 65tripleblack; 04-13-2017 at 11:41 AM.
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Old 04-13-2017, 11:44 AM   #13
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Quote:
Originally Posted by gsholz View Post

Oil deflectors are recommended. Sounds simple but possibly messy. Does anyone have any firsthand experience setting valve lash on a running engine?
Some engines squirt oil out of the rockers and over on the exhaust manifold. Some don't. Almost all will allow oil to overun the back end of the head before it all goes in the drain hole. You can lay a rag on the manifold to stop that. Do one side at a time to minimize the chance of a mess.

I do them one cylinder at a time, cold, engine off at 30-30. Do the exhaust when the intake is full open. Do the intake when the exhaust starts to open. Works for me.
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Old 04-13-2017, 12:13 PM   #14
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Check out the attached pdf of the Hinckley-Williams cold lash method.

Due to the extreme overlap of the 30-30 cam, it's tough to get acceptable idle quality at anything less than 900, especially if you use the recommend .023" cold lash.

The GM drawing specifies .025" lash, which is derived by multiplying the "design" rocker ratio of 1.5 times the maximum height of the constant velocity clearance ramp above the base circle, which is .017".

The .023" recommendation is derived by multiplying .017 by the true, measured rocker ratio, which is 1.37:1 at low lift. At maximum lift the rocker ratio achieves 1.44:1.

Based on several 30-30 cam engines I've tuned, best idle mixture is achieved at about 1.5 turns out from the seat, but it could be a little more with the cold lash set at .023".

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Last edited by SWCDuke; 04-13-2017 at 12:16 PM.
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Old 04-13-2017, 05:07 PM   #15
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Quote:
Originally Posted by gsholz View Post
I should have read the manual....The shop manual supplement for 1964 does show the correct idle speed for the 365hp engine is 800 rpm.

The manual also shows the valve lash to be 0.030" set hot on a running engine. Oil deflectors are recommended. Sounds simple but possibly messy. Does anyone have any firsthand experience setting valve lash on a running engine?
One last thing here. The engineers that designed the valve train said to set clearance at .025/.025 during design and development.

When it came time for the rubber to hit the road, the group that deals in customer satisfaction/complaints and pays for warranty work changed the spec to .030/.030 in the service manual.

You are more than welcome to make your own choice.

Last edited by MikeM; 04-13-2017 at 05:12 PM.
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Old 04-13-2017, 05:53 PM   #16
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Quote:
Originally Posted by gsholz View Post
I should have read the manual....The shop manual supplement for 1964 does show the correct idle speed for the 365hp engine is 800 rpm.

The manual also shows the valve lash to be 0.030" set hot on a running engine. Oil deflectors are recommended. Sounds simple but possibly messy. Does anyone have any firsthand experience setting valve lash on a running engine?
I've adjusted hydraulic lifters on a running engine, but I don't understand how you could adjust solid lifters on a running engine. (Doing it by ear?)

Oil deflectors are useful, but as MikeM says, you can still get overflow at the back of the head. I've seen people cut the top off an old steel valve cover and put that in place to prevent that. Seems extreme, but if you do a lot of valve adjustments it would be useful.

Last edited by Duck916; 04-13-2017 at 05:55 PM.
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Old 04-13-2017, 07:46 PM   #17
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I have the same question. I searched Youtube but I cannot find anyone adjusting solid lifters on a running engine. Do you try to push the feeler gauge while it is running? I don't think it would cause the valve train to bind but can't be good for the gauge.

I think I'll use the EOIC method as soon as I figure out how to attach the remote starter switch to the solenoid from above. I'd really like to leave the plugs in. I just changed them and the wires and my hands are still healing from all the ignition sheet metal cuts. A couple of the plugs I could only get to from below. I'll pull the coil wire just to be safe.

Thanks for all the help
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Old 04-13-2017, 08:41 PM   #18
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A flat rate mechanic would go hungry if he set every solid lifter engine with it not running. That used to be the way everyone did it unless it was a new engine build.
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Old 04-13-2017, 09:32 PM   #19
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Oil deflectors work and yes you can adjust the solids on a running engine. You get a feel for it pretty quickly.
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Old 04-13-2017, 10:34 PM   #20
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It's easy to learn. It's the burning oil fumes that is a problem! And yes, you will eventually wear the gage.
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