FE Power Forums

FE Power Forums => FE Technical Forum => Topic started by: fryedaddy on February 28, 2019, 10:40:10 PM

Title: best idle setting
Post by: fryedaddy on February 28, 2019, 10:40:10 PM
i have a 428 with a .244 at .050 flat tappet cam, bbm heads,11 to 1 comp, c6 with 3600-3800 stall.it hits a good lick at 850-900 rpm but has only 30 psi oil pressure hot at 850 rpm.if i bump it up to 1000-1100 rpm at idle it has 50 psi oil pressure and still sounds aggressive at 1100.with the stall either works ok.where would some of you guys set the idle.
Title: Re: best idle setting
Post by: machoneman on February 28, 2019, 11:06:35 PM
And what's wrong with 30 psi at idle? Nothing.....
Title: Re: best idle setting
Post by: Stangman on February 28, 2019, 11:19:58 PM
I agree I idle between 850-900 in gear hot about 24 psi
Title: Re: best idle setting
Post by: fryedaddy on February 28, 2019, 11:33:19 PM
it might be closer to 25 after a good drive. i was talking about in park or neutral not in gear. but by the responses it looks like i asked a dumb question.sorry
Title: Re: best idle setting
Post by: cjshaker on March 01, 2019, 12:03:33 AM
It's not a dumb question, so no need to apologize. I'd tend to set it as low as the engine feels comfortable with while in gear. Not sure how much rpm drop you get when you put it in gear (guessing not much with that stall), but as long as I could see 20 lbs of pressure or better, and the engine didn't feel sluggish, I'd feel fine with it at 850-900 in park. Especially since the pressure comes up right away. To me, hearing an engine that idles high just sounds like it's masking an idle tuning problem, provided it doesn't have some big monster cam in it.
Title: Re: best idle setting
Post by: fryedaddy on March 01, 2019, 12:12:43 AM
thanks.it sounds like popping corn at 850-900 in park.it dont drop hardly any when i put it in gear.i guess i should leave it alone.i didnt know if it would live longer and happier if i raised the idle.
Title: Re: best idle setting
Post by: RustyCrankshaft on March 01, 2019, 04:30:27 AM
25 or 30 psi at idle is plenty of oil even for a flat tappet. It won't live any longer idling higher I don't think, just whatever makes the engine happy.

Not that I'd recommend it intentionally, but the 460 in my 73 F350 dump truck might have 5 psi at idle and doesn't make much more than 30psi anywhere above that and it's been that way for years. No idea what clearances or oil pump it was built with, but since it's been like that for so long I suspect someone set it up pretty loose.

I don't think it's ideal and tend to like to try and set the clearances (and by default oil pressures) for the application, but the old rule of 10psi/1000rpm I've found will keep something from killing itself.

Title: Re: best idle setting
Post by: Falcon67 on March 01, 2019, 12:17:36 PM
As above - no problem with hot oil pressure around 30 at idle.  No problem either with 55~60 at 7000. 
Title: Re: best idle setting
Post by: Stangman on March 01, 2019, 02:16:41 PM
I agree with Doug there are no dumb questions.
Title: Re: best idle setting
Post by: plovett on March 01, 2019, 06:27:40 PM
I think it is better to err on the high side when it come to idle speed.  A little too high will cause no problems.  A little too low could.  Not likely, but it could.


I have a fairly big cam in my 428.  I set the idle so it is about 900 rpm stone cold. When it is completely hot on a hot day the idle is 1200-1300 when in park or neutral.  Who cares?  I think it is better for the engine to run at a little higher rpm.

JMO,

paulie
Title: Re: best idle setting
Post by: fryedaddy on March 01, 2019, 06:49:50 PM
I think it is better to err on the high side when it come to idle speed.  A little too high will cause no problems.  A little too low could.  Not likely, but it could.


I have a fairly big cam in my 428.  I set the idle so it is about 900 rpm stone cold. When it is completely hot on a hot day the idle is 1200-1300 when in park or neutral.  Who cares?  I think it is better for the engine to run at a little higher rpm.

JMO,

paulie
WOW  just the opposite answer.that is why i asked the question in the first place.i know my oil pressure almost doubles from 850-1100.i understand 25 might be enough,but why not 50.thats why i asked.
Title: Re: best idle setting
Post by: plovett on March 01, 2019, 09:05:54 PM
Well, I also don't think 30 psi oil pressure at idle is bad.  I have an "aggressive" solid flat tappet cam and the higher idle speed (more than the oil pressure) keeps it alive.

JMO,

paulie
Title: Re: best idle setting
Post by: fryedaddy on March 01, 2019, 09:51:29 PM
Well, I also don't think 30 psi oil pressure at idle is bad.  I have an "aggressive" solid flat tappet cam and the higher idle speed (more than the oil pressure) keeps it alive.

JMO,

paulie
what size solid cam are you running if you dont mind me asking.im thinking about going solid.
Title: Re: best idle setting
Post by: plovett on March 01, 2019, 10:00:01 PM
Well, I also don't think 30 psi oil pressure at idle is bad.  I have an "aggressive" solid flat tappet cam and the higher idle speed (more than the oil pressure) keeps it alive.

JMO,

paulie
what size solid cam are you running if you dont mind me asking.im thinking about going solid.

It's 252/260 @ 0.050".  The advertised duration is 279/287 so it has pretty fast ramps.  My spring pressure is about 405 lbs open.  I could be wrong, but I think a higher idle speed helps keep it from wiping out.  I think the oil volume reaching the cam and lifters is more important than the pressure at the gauge.  I think so?
Title: Re: best idle setting
Post by: fryedaddy on March 01, 2019, 10:40:36 PM
im going to get Brent to match me up with a solid flat tappet cam. anything bigger than my .244 hyd from what i have read on here,i would be better off to go solid if i want to go bigger + run more Rs
Title: Re: best idle setting
Post by: My427stang on March 02, 2019, 09:32:43 AM
Late to the game, but for cam life, I'd be less worried about idle oil pressure, you have plenty.  IF you wanted to change the idle it would be to increase the splash oiling on the cam from the crank, the real volume of lube the lobes and lifters use.

Raising the idle will throw more, that being said, don't lose sleep, my 489, solid cam with dumbells and no oil to the lifters idled at 1050 from 2006-2009, but once I went EFI, I dropped it to 850 and it has no more pressure than you and it's been 9 years and lots of in traffic miles.

I think you are fine.  I also think you'd like a solid flat, it'll generally hang in longer up top, depends how you run it.
Title: Re: best idle setting
Post by: fryedaddy on March 02, 2019, 01:05:54 PM
i have owned about 9 or 10 fe cars and trucks over the last 40 years,but i have never had a solid cam in any of them.i have hs rockers and a couple sets of factory adjustables,and i dont mind setting them now and then