The Ford Barn

1937pickup · 05-09-2013, 07:35 AM

Just read Walt's post about an engine with multiple carbs and a L-100 (?) cam. He said he has it idling at 800 rpms. This seems high to me. Is it due to the warm up of the engine? What do others set idle speed at for stock engines? I thought it was around 550-600 rpms.

flatjack9 · 05-09-2013, 08:57 AM

It's because of the cam. The cam has more overlap (intake opens sooner, exhaust closes later) than the stock cam which requires a higher idle speed to get smooth operation.

ford3 · 05-09-2013, 10:17 AM

450 rpm for a stock engine

1937pickup · 05-09-2013, 03:41 PM

Thanks guys for the information.

Al K. · 05-09-2013, 05:39 PM

That caught my eye also. I'm glad you had the guts to ask the question. Al K.

quickchange34 · 05-09-2013, 11:05 PM

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It all depends on what cam profile.

danliveshere · 05-10-2013, 07:22 AM

My old 59a used to idle so slowly you could read the writing on the fan belt!!!

05-09-2013, 07:35 AM	#1
1937pickup Senior Member Join Date: Jul 2012 Posts: 586	Idle speed. Just read Walt's post about an engine with multiple carbs and a L-100 (?) cam. He said he has it idling at 800 rpms. This seems high to me. Is it due to the warm up of the engine? What do others set idle speed at for stock engines? I thought it was around 550-600 rpms.

05-09-2013, 08:57 AM	#2
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,526	Re: Idle speed. It's because of the cam. The cam has more overlap (intake opens sooner, exhaust closes later) than the stock cam which requires a higher idle speed to get smooth operation.

05-09-2013, 10:17 AM	#3
ford3 Senior Member Join Date: Oct 2012 Location: oroville calif. Posts: 1,453	Re: Idle speed. 450 rpm for a stock engine

05-09-2013, 03:41 PM	#4
1937pickup Senior Member Join Date: Jul 2012 Posts: 586	Re: Idle speed. Thanks guys for the information.

05-09-2013, 05:39 PM	#5
Al K. Member Join Date: May 2010 Location: Arlington Hts, IL Posts: 81	Re: Idle speed. That caught my eye also. I'm glad you had the guts to ask the question. Al K.

05-09-2013, 11:05 PM	#6
quickchange34 Senior Member Join Date: May 2010 Location: charlottesville, Va. Posts: 589	Re: Idle speed. Sponsored Links (Register now to hide all advertisements) It all depends on what cam profile.

05-10-2013, 07:22 AM	#7
danliveshere Senior Member Join Date: Jul 2010 Location: Cairns , Australia Posts: 746	Re: Idle speed. My old 59a used to idle so slowly you could read the writing on the fan belt!!!