Chevy 350 idle at 500?

[erikgreen]

What will happen (that's bad) to a chevy 350 that's set to idle at 500 rpm?

I turned my idle down to troll a bit slower (4 mph was my minimum, I'm down to 2.6 now) and it worked, but long term I'm worried how it will affect my engine.

Typically I run 15 minutes on plane to get to where I'm going, then alternate 10 minutes of idling with 3-4 minutes of planing for 2-3 hours to do my thing.

Thanks,
Erik

 

[bigskiohio]

Re: Chevy 350 idle at 500?

did you set it and then adjust your throttle cable.

 

[Bigdave196]

Re: Chevy 350 idle at 500?

Might foul plugs a little easier, but all your really doing is lugging your motor. Only thing I can see is that if you try to "HIT-IT" from an idle you could kill the motor from the fuel overload from the really low idle.

Most 5.7's are reccomended 650-700ish in the idle area. That offers good throttle responce and kinda ensures that you dont stall out just sitting there.

 

[futz]

Re: Chevy 350 idle at 500?

you got it running smooth, warm, in gear at idle? I run 500-550 also at idle as mentioned. What make and year motor?

 

[Rob_NC]

Re: Chevy 350 idle at 500?

...I have to agree you might get a cough,at throttle up,as long as you arent overly rich and burning any oil; maybe change plugs sooner......troll plate ?

 

[Rat Capri]

Re: Chevy 350 idle at 500?

i wouldnt worry about anything as long as your oil pump is up to the task

 

[Howard Sterndrive]

Re: Chevy 350 idle at 500?

no problem. I've set stock industrial 305's to idle at 375 rpm on propane. The slower the better IMO.

 

[erikgreen]

Re: Chevy 350 idle at 500?

I think the oil pump is fine, it was new with the motor when it was rebuilt about 2 summers ago (maybe 100-150 hours on the boat since then).

I thought about a troll plate, but it cuts maneuverability along with speed, which means it's hard to go in a straight line.

The engine idles ok at 500, doesn't stumble, accelerates smoothly after idling.

It's a pre-1986 chevy 350 block with a two piece rear main seal in a 21 foot Sea Ray. Mechanical (non electronic, anyway) ignition, Rochester Qjet carb on the intake manifold from my old 305.

I didn't adjust the throttle cable, just moved the screw on the carb that sets the minimum "stop" for the throttle.

Erik

 

[futz]

Re: Chevy 350 idle at 500?

Good good for you!

 

[erikgreen]

Re: Chevy 350 idle at 500?

I'd love one, but my finances are in ruins ATM due to a summer of diving plus many small boat fixes, and the gas....

Erik

 

[legoman67]

Re: Chevy 350 idle at 500?

if it runs smooth that low and still has the throttle response when you want to get up and go, then leave it be, ours idles sweet at 600. .

 

[Fun Times]

Re: Chevy 350 idle at 500?

Kind of Recently I have noticed Starting somewhere around 06-07 mercruiser has lowerd there idle rpms on MPI engines from a normal 600 rpms down to 540rpms when warm. Now I was told it might have had something to do with emissions And saving fuel but I am not 100% sure of that, I do know the engine manufacturer's had to do other stuff to engines coming into CA to meet CA new emissions laws to get there 3, 4, 5, star rating system with in spec's so that could be it. So now I am curious Has any other boat service tecks out side of CA noticed the lower rpms on newer MPI engines while looking at A scan tool??? And if not then next time you get a chance to check it out while running a engine out with a scan tool could you let us know what you find, Thank's