The Ford Barn - View Single Post - Flathead Cams Info needed -what do you have

29AVEE8 · 01-24-2014, 05:32 PM

This is some info from an old Roger Huntington book on the Harman Collins 3/4

Intake opens 19 BTDC, closes 59 ABDC, .320 lift, .011 lash.

Exhaust opens 54 BBDC, closes 14 ATDC, .320 lift .013 lash.

Sooo a little math and it seems to have 258 intake duration with a 110 ICL

248 exhaust duration with a 110 ECL

110 LSA with 33 degrees of overlap.

Caveat: All of the above assumes the H-C 3/4 profile stayed the same throughout

it’s production life and that my calculation methods and math are correct.

01-24-2014, 05:32 PM	#17
29AVEE8 Senior Member Join Date: Dec 2010 Location: Redlands, CA Posts: 148	Re: Flathead Cams Info needed -what do you have This is some info from an old Roger Huntington book on the Harman Collins 3/4 Intake opens 19 BTDC, closes 59 ABDC, .320 lift, .011 lash. Exhaust opens 54 BBDC, closes 14 ATDC, .320 lift .013 lash. Sooo a little math and it seems to have 258 intake duration with a 110 ICL 248 exhaust duration with a 110 ECL 110 LSA with 33 degrees of overlap. Caveat: All of the above assumes the H-C 3/4 profile stayed the same throughout it’s production life and that my calculation methods and math are correct. __________________ Ignorance of the laws of physics does not mean they do not apply to you.