Your donations help keep this valuable resource free and growing. Thank you.
|
AMC 69/70 Cam Specs |
Post Reply |
Author | |
badaboom
AMC Apprentice Joined: Apr/07/2010 Location: CO, USA Status: Offline Points: 142 |
Post Options
Thanks(0)
Posted: Apr/12/2015 at 8:33pm |
I was wondering if someone would be nice enough to provide some factory cam specifications(lift - etc.) for the 1969 AMC 390 and the 1970 390 4 barrel carburetor motors.
Also anything for the performance package group 19 cams 69/70 and or component's. (or current production equivalents) any reference links appreciated Thanks |
|
Sonic Silver
Supporter of TheAMCForum Joined: Nov/23/2011 Location: East Tennessee Status: Offline Points: 7949 |
Post Options
Thanks(0)
|
Measured at .050 lift:
1969-Early 1970 196 degrees 111 lobe centers .425 lift Late 1970 207-208 degrees 114 lobe centers .457 lift Group 19 224 duration 114 lobe center .477 lift Edit: Sept 26 1969 is the cutoff engine build date between early and late 1970 cams. Edited by Sonic Silver - Apr/12/2015 at 9:21pm |
|
badaboom
AMC Apprentice Joined: Apr/07/2010 Location: CO, USA Status: Offline Points: 142 |
Post Options
Thanks(0)
|
Thanks what is a good current production comparable cam like the Group 19 camshaft specs?
|
|
Sonic Silver
Supporter of TheAMCForum Joined: Nov/23/2011 Location: East Tennessee Status: Offline Points: 7949 |
Post Options
Thanks(0)
|
Howards Camshaft has one that is similar , as does Sig Erson. In Erson's 2013 catalog, it is called a "Street Fighter Hydraulic" part number E710018. Their website is pbm-erson.com, but I don't find the cam listed there. You may have to call them. Howard's Camshafts also has that cam. It is pretty much just the old 350/350 or L82 Chevy grind. Good for higher compression engines, due to late closing intake timing. You can easily find cams that are more modern, and make more mid-range torque.
|
|
badaboom
AMC Apprentice Joined: Apr/07/2010 Location: CO, USA Status: Offline Points: 142 |
Post Options
Thanks(0)
|
kinda checking the comp cam Magnum 10-203-4 270H seems pretty close a tad larger
Duration @ .050" Lift: Int: .224 Exh: 224 Lobe separation: 110 Valve lift INT: 0.48 and Exh: 0.48 Edited by badaboom - Apr/13/2015 at 12:06am |
|
Sonic Silver
Supporter of TheAMCForum Joined: Nov/23/2011 Location: East Tennessee Status: Offline Points: 7949 |
Post Options
Thanks(0)
|
IO: 6 BTDC IC: 38 ABDC EO: 46 BBDC EC:-(2) ATDC The 110 lobe center advances the intake numbers 4 degrees compared to the 114 lca, and retards the exhaust numbers 4 degrees compared to the 114. The same cam lobes on a 114 lca with a 4 degree advance would be: IO: 2 BTDC IC: 42 ABDC EO: 50 BBDC EC:-(6)ATDC I don't think that the Group 19 had a 4 degree advance as ground so figures would be: IO:-(2) BTDC IC: 46 ABDC EO: 46 BBDC EC:-(2) ATDC Notice on the bottom 2 cams that the overlap is the same at-(4) degrees. Add the IO and EC numbers to get the degrees that both valves are open. The first cam on a 110 lca has +4 degrees overlap. The 110 lca has 8 degrees more overlap, and an intake closing that is 8 degrees sooner than the last cam. The first cam will fall off the power band quicker and have more mid range torque than the last cam, due to the earlier intake valve closing. It will also idle rougher due to the increased overlap. |
|
Post Reply | |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |