Identify an Aftermarket Cam
February 8th, 2022, 02:11 PM
#1
Registered User
Thread Starter
Join Date: Jan 2022
Location: Las Vegas Nevada
Posts: 79
Identify an Aftermarket Cam
Hi
I installed a cam in my 455 in approx 1988 and can't remember any details about it other than it's fir 2500 to 6500 rpm.
I popped the freeze out plugs in the back of the cam, hoping for some part numbers.
There is only one number stamped... 280
it has a handwritten 16 also.
Anyone have a clue from these numbers?
thanks
I installed a cam in my 455 in approx 1988 and can't remember any details about it other than it's fir 2500 to 6500 rpm.
I popped the freeze out plugs in the back of the cam, hoping for some part numbers.
There is only one number stamped... 280
it has a handwritten 16 also.
Anyone have a clue from these numbers?
thanks
February 9th, 2022, 01:10 AM
#3
Registered User
Thread Starter
Join Date: Jan 2022
Location: Las Vegas Nevada
Posts: 79
Yes, that's probably it.
Since the cam is stamped 280 I will trust that more than my failing memory.
I think if it's the rpm range I thought. 2,500 to 6,500, that would be a 292 cam.
Since I retarded the cam timing 4 degrees, msybe i my mind i thought the rpm range advance 400 so the 2000-6000 became 2400-6400 which became 2500-6500 rounding up. Idk. It's been over 30 years and lots of beers.
I am thinking I should change the cam timing though. Go from the current 4 degrees retarded to zero degrees, aka straight up.
One lesson to learn is keep records of whats happening.
Thanks man
OldOldsLover
Since the cam is stamped 280 I will trust that more than my failing memory.
I think if it's the rpm range I thought. 2,500 to 6,500, that would be a 292 cam.
Since I retarded the cam timing 4 degrees, msybe i my mind i thought the rpm range advance 400 so the 2000-6000 became 2400-6400 which became 2500-6500 rounding up. Idk. It's been over 30 years and lots of beers.
I am thinking I should change the cam timing though. Go from the current 4 degrees retarded to zero degrees, aka straight up.
One lesson to learn is keep records of whats happening.
Thanks man
OldOldsLover
Last edited by OldOldsLover; February 9th, 2022 at 01:31 AM.
February 9th, 2022, 05:24 AM
#5
Registered User
Join Date: Nov 2008
Location: Central Fl
Posts: 7,830
Ok one more time.
The rpm range for any given cam is based on the entire engine family it fits. So, for Olds it’s typically everything from a 330-455. What that means is it’ll favor the higher rpm range in the smaller engines, and a lower range in larger engines.
And depending on the grind and overall build specs, advancing or retarding the cam 4* may or may not have any real effect.
The rpm range for any given cam is based on the entire engine family it fits. So, for Olds it’s typically everything from a 330-455. What that means is it’ll favor the higher rpm range in the smaller engines, and a lower range in larger engines.
And depending on the grind and overall build specs, advancing or retarding the cam 4* may or may not have any real effect.
Last edited by cutlassefi; February 9th, 2022 at 05:26 AM.
February 13th, 2022, 01:06 PM
#7
Registered User
Thread Starter
Join Date: Jan 2022
Location: Las Vegas Nevada
Posts: 79
Ok one more time.
The rpm range for any given cam is based on the entire engine family it fits. So, for Olds it’s typically everything from a 330-455. What that means is it’ll favor the higher rpm range in the smaller engines, and a lower range in larger engines.
And depending on the grind and overall build specs, advancing or retarding the cam 4* may or may not have any real effect.
The rpm range for any given cam is based on the entire engine family it fits. So, for Olds it’s typically everything from a 330-455. What that means is it’ll favor the higher rpm range in the smaller engines, and a lower range in larger engines.
And depending on the grind and overall build specs, advancing or retarding the cam 4* may or may not have any real effect.
Please help to understand more of what you are saying
I understand that the cams are made for a whole line of different displacements.
are you saying that the cam that says it has a rpm range of 2,000 to 6,000 is like an average of all displacements or mainly for the small bock?
My main question is are you saying the i a 455 big block, the rpm range will Not be 2k-6k? But it will be lower? And if so, what is a more accurate range?
my maim concern is I have an edelbrock torker that's supposed to be 2,500 to 6,500 rpm range.
If I have a cam that's not close to that then it a mismatch and performance will suffer.
When i had the engine rebuild years ago they said the compression is about 9.3 to 1 but I think they just made it up. Talking with others and describing the pistons with E heads I might be at 10:1.
I'll be running 4.10 posi with tires just under 26"(for now at least)
it a 4 speed with a wide ratio muncie.
My main concern is trying to ensure the cam and intake range are close to matching.
I'm not going to take the cam timing which is 4 degrees retarded an setting it to zero advance. I don't think I would notice any difference.
the engine (3:23-1 gears) now runs very strong in the 2500 an up rpm range, and it spins up fast.
thanks for additional info on cam characteristics
OldOldsLover
February 13th, 2022, 03:26 PM
#8
Registered User
Join Date: Jan 2010
Location: central Indiana
Posts: 5,261
Engine within the same FAMILY often have different displacements, but some internal components will interchange. Let’s use Olds as an example, a cam from a 455 will fit a 350. A mild performance cam for a 455 will be a lot “bigger” in the 350 due to the smaller displacement.
Let’s say you have a 350 modified with a cam that has a noticeable idle. That same cam will idle much smoother in a 455, the added 105 displacement will really tame the cam. Because the cam is milder, the power band will also be lower. The 350 might make peak power at 5800 rpm with the performance can, that same came in the 455 might make peak power at 4500.
Let’s say you have a 350 modified with a cam that has a noticeable idle. That same cam will idle much smoother in a 455, the added 105 displacement will really tame the cam. Because the cam is milder, the power band will also be lower. The 350 might make peak power at 5800 rpm with the performance can, that same came in the 455 might make peak power at 4500.
February 13th, 2022, 03:48 PM
#9
Registered User
Join Date: Jan 2020
Location: Sarasota Florida
Posts: 2,094
Ok one more time.
The rpm range for any given cam is based on the entire engine family it fits. So, for Olds it’s typically everything from a 330-455. What that means is it’ll favor the higher rpm range in the smaller engines, and a lower range in larger engines.
And depending on the grind and overall build specs, advancing or retarding the cam 4* may or may not have any real effect.
The rpm range for any given cam is based on the entire engine family it fits. So, for Olds it’s typically everything from a 330-455. What that means is it’ll favor the higher rpm range in the smaller engines, and a lower range in larger engines.
And depending on the grind and overall build specs, advancing or retarding the cam 4* may or may not have any real effect.
February 13th, 2022, 04:40 PM
#10
Registered User
Join Date: Feb 2020
Location: VT
Posts: 60
I rebuilt a 455 a few years ago and pulled an old cam out of it that had a 280 stamped into it. I think on the cam chain end. The guy I bought the motor from had it rebuilt many years before and he still had the comp cams spec sheet for it. It was that 280H the other guy said yours likely is. I threw it out only a month or two ago. Wish I still had it to post a pic. I'm told it's a good cam for a jet boat. Thats where my motor came from.
Thread
Thread Starter
Forum
Replies
Last Post
