280h comp cam
Thread Starter
Heel & Toe
Joined: Nov 2019
Posts: 19
Likes: 0
From: South Carolina
280h comp cam
anyone else running this cam? what heads do y’all run? what is initial timing idle speed in park/neutral and in gear? what rear end gears and what is the horsepower torque at the flywheel with this setup
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Yes, I ran that 280 a few years back. It was the Magnum series, 480 lift I believe. You better read the requirements on that duration at Comps web site. It likes high compression, higher torque converter and low gears. Without those three, it will be a dog.
It had decent torque down low but I also have 4:11s. Then I up graded to better heads, bigger cam, more compression.
Your timing will vary from others but around 14-16 at idle should work. And never set your timing in gear. Way to dangerous and not wise.
H.P. data is impossible to figure on yours.
It had decent torque down low but I also have 4:11s. Then I up graded to better heads, bigger cam, more compression.
Your timing will vary from others but around 14-16 at idle should work. And never set your timing in gear. Way to dangerous and not wise.
H.P. data is impossible to figure on yours.
Drifting
Joined: Jun 2005
Posts: 1,950
Likes: 498
From: Chino Hills CA
280 is a lot of cam for a street car. A C3 with the stock 3.31 gears and a mildly modified small block I think would be happiest in the rang of 225 to 235. I run 230's in all my three sbc's,
Thread Starter
Heel & Toe
Joined: Nov 2019
Posts: 19
Likes: 0
From: South Carolina
yeah i installed a 350 4 bolt main into my 68 a year ago. it was bored 30 over i got the 280 cam installed it then got my engine builder to order some aluminum heads he says were good he built the heads with heavy duty springs 2.02 1.60 valves not sure of the compression but you can feel a strong burst of wind from 6 feet behind the car from exhaust 2500 stall and 3.73 rear gears and 14 initial timing 650 cam holley double pumper thing has got some power not had it dynoed so not sure what it is making but sounds great i would like to idle it at 650 in park and 550 in gear but it seems sluggish there so i’m having to settle for 750 in park and 650 (the lope is more rough not viable in the lower idle) in gear seems to take off a little better barely touch the gas and it spins the tires where the lower idle takes a second to get the throttle response there id just like to know if maybe i’m being robbed of power if there is something i can do to get all the performance i can out of it
Last edited by Chandler Cox; Dec 29, 2019 at 10:47 PM.
Instructor
Joined: Oct 2016
Posts: 150
Likes: 25
From: Acton MA
I just put my L-82 back together with a set of 64cc alum heads, 280H, and a set of 1.6 rockers. CR is around 10:1 and I'm just finished cam break in and setting timing. Don't be surprised if it will take closer to 18-20 for initial timing. My 78 is a 4spd with the factory 3.70 rear.
Thread Starter
Heel & Toe
Joined: Nov 2019
Posts: 19
Likes: 0
From: South Carolina
I just put my L-82 back together with a set of 64cc alum heads, 280H, and a set of 1.6 rockers. CR is around 10:1 and I'm just finished cam break in and setting timing. Don't be surprised if it will take closer to 18-20 for initial timing. My 78 is a 4spd with the factory 3.70 rear.
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
You guys need to set your total advance timing (not including vacuum) for 35 or 36 degrees and don't be so concerned with initial timing. As long as the engine starts easily, initial is fine. Total timing (without vacuum advance) determines how your car performs at full throttle. If you don't have that right you're leaving a lot of power on the table.
