Ford Muscle Cars Tech Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
596 Posts
Discussion Starter · #1 ·
I'm investigating a cam swap when I put on my new AFR 165's this winter. I'm being told from my dad that he
believe's that the current cam has a .516 lift. We can't find all the spec's as engine was put together in the early 90's.
I'm looking at the 282S cam from Comp which shows it
has a .528 lift, AFR specs on the 165's are .550 lift max.
I'm wondering if my current cam is .516 lift is there much if any power advantage in going w/ the 282s @.528 lift.
I know that other factors like lobe sep, duration all play a role unfornuately i just don't know those spec's on my current cam. the 282s shows a 236 duration and 110 ls...
Also my current set up w/stock heads seems to give out
at 5300-5400 rpm, I don't know if that is b/c of the cam or if the stock heads(valve springs) just aren't up for higer rpm's as some folks have told me....any thoughts would be great, i'm still trying learn about cams so be gentle.....
 

·
Registered
Joined
·
502 Posts
i would expect a cam with 236 dur at .050 & over .500 lift to go higher than 5400 rpm, depending on heads, etc. i would vote for springs as most likely problem.
 

·
Registered
Joined
·
1,892 Posts
.550" max lift is what the springs are rated for. Not the limit of the head itself.

Remember to take into consideration the lash required for a solid cam. The measurements they advertise deal with the lobe with a 1.6 rocker and not with what the valve will see once the lash is taken into account.

I like my little solid cam and feel from the comparisons I've seen and what I've heard people who I trust say that a solid will make more power than a comparable hydraulic. Without knowing what's in there now it'd be hard to say if a cam change would be a big deal. I do know that there seems to be a lot of people that really like the 282s cam.
 

·
Registered
Joined
·
1,506 Posts
I would suggest just buying the cam you want and replace whatever you have in there. That way you know for SURE what your cam specs are.
 

·
Registered
Joined
·
170 Posts
You really need to change the valve springs whatever you do. I bet that with that cams and stock head with stock springs, you are WAY beyond what those stock springs are rated for.

If you get the AFR 165s you can't go wrong.
 

·
Registered
Joined
·
1,506 Posts
On 2006-11-15 12:05, truedog wrote:
You really need to change the valve springs whatever you do. I bet that with that cams and stock head with stock springs, you are WAY beyond what those stock springs are rated for.

If you get the AFR 165s you can't go wrong.
He plans on putting AFR165's on it, which should have springs good enough to handle the 282S cam.
 

·
Registered
Joined
·
1,487 Posts
That is a genius idea! LOL

I like running my 282S with .018 lash for net lift at the valve of .510. I have heard that AFR makes a nice head with poor valve springs. Use the Comp 972 springs or Comp 26986 beehives. I had 972s and reved my 331 to 6800 or so. I went with probe shaft mount 1.7 rockers for my rebuild and I am also switching to the 26986 beehives to handle the extra lift and 'cause they are supposed to be a nice upgrade from traditional springs..
 

·
Registered
Joined
·
596 Posts
Discussion Starter · #9 ·
On 2006-11-15 14:29, truedog wrote:
That's my point, but UNTIL he changes either the springs or heads, that cam will never work right.
Just clarfiy, I have the AFR 165's now and they are complete w/ springs on them, If i do put the 282s in it are the normal afr springs ok to go with that came w/ the new heads?
 

·
Registered
Joined
·
1,892 Posts
I thought the valve spring issue was on the older AFR's and that the problem had been addressed? Just give a call to comp and see what they say about the springs you have and that cam.

<font size=-1>[ This Message was edited by: 289nate on 11/16/06 6:15am ]</font>
 

·
Registered
Joined
·
1,892 Posts
On 2006-11-15 14:28, blkfrd wrote:
That is a genius idea! LOL
Sounds like this 289 will be similar to a 306 you wanted to build a while back.
 

·
Registered
Joined
·
1,487 Posts
On 2006-11-15 14:42, ga289stocker wrote:
Just clarfiy, I have the AFR 165's now and they are complete w/ springs on them, If i do put the 282s in it are the normal afr springs ok to go with that came w/ the new heads?
Ya never know 'till you find out what the heck they are and AFR should be able to tell you the seat pressure and rate of the springs. For a 282S, about 125 lbs seat pressure and 280-290 lbs open pressure @ .510 lift will do (about 300 lbs/in spring rate). If the springs are some stout roller cam springs then you'll put undue strain on the valve train and cam and eat up HP from the energy needed to open the valves.
 

·
Registered
Joined
·
1,287 Posts
On 2006-11-15 11:59, 82GT wrote:
I would suggest just buying the cam you want and replace whatever you have in there. That way you know for SURE what your cam specs are.
I agree here.

Make sure the new cam fits with the AFR heads springs...or make sure you upgrade the springs when you buy the new cam, whichever head you use.

If you don't know the cam that's in there, we can't give any suggestions based on simple lift numbers =). Lift alone has far far less impact on a motors performance than any of the other measurements you mentioned, unless you're talking going from .500 to .600, and even then it's far less an impact than 10dgr duration.

Hope this helps!

Cris
 

·
Registered
Joined
·
5,028 Posts
I run the 282s cam in my 393w with no issues to my 6400 redline. I use the premium spring specified for the cam and 1.7 ratio rockers which bumps the lift up to .560". Lash set to .018.

I'm sure your 289 would love it!
 

·
Registered
Joined
·
4,003 Posts
Use a dial indicator on a magnetic mount to measure the lift at the valve with your current cam. That is easy. If you set a degree wheel on the crank you can measure the duration at .050" lift too.
Paul
 

·
Registered
Joined
·
596 Posts
Discussion Starter · #16 ·
Thanks for the comments and input..I priced the 282s kit w/ lifters for right at $199 from jegs and summit, I assume it would be a good idea to replace the timing set as well? I think they have double rollers for about $50 bucks as well.
 

·
Registered
Joined
·
16 Posts
Its always good idea to put in a new timing set when changing the cam and valvetrain. I have 165 AFR's on my 1968 306 and a custom Crower grind (solid, 236/240 @.050 and .501 lift, 108 centerline). When I put the engine all together with the assembled AFR heads it wouldn't rev past 5400 rpm (cam is good for 2300-6500) and my valve lash kept coming loose. I put in stiffer springs from Crower (130#/300#) and the engine buzzed right up to 7200 before I realized it. The AFR springs were floating so I had to replace them with the heads on the engine. I would have preferred to have done it off the car if I had known in advance what going to happen. Its cheap insureance to replace the springs before the head goes on the engine. Just my .02 cents.
 

·
Registered
Joined
·
596 Posts
Discussion Starter · #18 ·
On 2006-11-16 16:51, RDay wrote:
Its always good idea to put in a new timing set when changing the cam and valvetrain. I have 165 AFR's on my 1968 306 and a custom Crower grind (solid, 236/240 @.050 and .501 lift, 108 centerline). When I put the engine all together with the assembled AFR heads it wouldn't rev past 5400 rpm (cam is good for 2300-6500) and my valve lash kept coming loose. I put in stiffer springs from Crower (130#/300#) and the engine buzzed right up to 7200 before I realized it. The AFR springs were floating so I had to replace them with the heads on the engine. I would have preferred to have done it off the car if I had known in advance what going to happen. Its cheap insureance to replace the springs before the head goes on the engine. Just my .02 cents.
Wow, thanks interesting, how long ago did you do the heads? I had read that the older AFR's did have some valve spring issues at hight rpm's but I just bought mine in August. Spec's say they are 120 lbs on seat.....
 
1 - 18 of 18 Posts
Top