Camshaft selection?
#11
Senior Member
RACING JUNKIE
Join Date: Jan 2006
Location: La.
Posts: 2,890
Last year i did some rockwell testing on 3 different cams, one older solid flat tappet Bullit with more than 100 passes on it (still good) it checked 45/47 on the RC scale, i checked a failed hydraulic comp cam newer and it checked 39/41 on the RC scale, i also checked a comp cam solid roller, it checked 58/59 on the RC scale, I also checked solid and hydraulic flat tappet lifter, theu all checked 58 on the RC scale on the bodies. I also checked solid roller lifters on the body and they checked 43 on the RC scale. I have in the shop a certified Rockwell tester where i work.
All the flat tappet cams are failing from most of the mfg'er and they blame it on the lifters, that's just not so, it their HT method and the fact that they used to nitride the cams but now they are cutting cost and won't gurantee anything, they just set back and say O'well. I think the big push is to go hydraulic roller stuff because they make a ton of money on them.
I used to run Compcam roller cams but i no longer do, but stil have a couple laying around,
I personally run Bullit cams and that's what i use on engine builds, they have been good to me and for me.
JMO
Zip.
All the flat tappet cams are failing from most of the mfg'er and they blame it on the lifters, that's just not so, it their HT method and the fact that they used to nitride the cams but now they are cutting cost and won't gurantee anything, they just set back and say O'well. I think the big push is to go hydraulic roller stuff because they make a ton of money on them.
I used to run Compcam roller cams but i no longer do, but stil have a couple laying around,
I personally run Bullit cams and that's what i use on engine builds, they have been good to me and for me.
JMO
Zip.
#12
Senior Member
DYNO OPERATOR
Join Date: Jun 2009
Location: Wi
Posts: 522
Zip, clue me in a little further if you don't mind on the Rockwell testing. Is there standard # that these are compared off? I see 45/47 and 39/41 etc. I don't want to sound as dumb as I am but what does that indicate? Thanks Al
#13
Senior Member
RACING JUNKIE
Join Date: Jan 2006
Location: La.
Posts: 2,890
Originally Posted by ajk
Zip, clue me in a little further if you don't mind on the Rockwell testing. Is there standard # that these are compared off? I see 45/47 and 39/41 etc. I don't want to sound as dumb as I am but what does that indicate? Thanks Al
I had run the older flat tappet cam in my 406" motor with 135 lbs of spring rate. The newer one cam out of my El Camino, with 115 lbs of spring rate with about 3,000 miles on it.
The only compaeison was that todays cams are not heat treated as good as the older cams were, and maybe not even as good of cast iron.
Zip.
#15
Junior Member
SHOW GUEST
Join Date: Jan 2005
Posts: 1
Since you're having a converter built I wouldn't worry about any POS dual plane or anything like that. A 383 in that truck leaving the line at 6 or 6500 would be a must IMO. I'd run mid 250's on the intake and low 260's on the exhaust at .050 on a 107 or 9 LSA. Put a super vic on that dude and rev r up where she'll run.
#16
Junior Member
SHOW GUEST
Join Date: Jun 2012
Posts: 5
Originally Posted by letreat
Since you're having a converter built I wouldn't worry about any POS dual plane or anything like that. A 383 in that truck leaving the line at 6 or 6500 would be a must IMO. I'd run mid 250's on the intake and low 260's on the exhaust at .050 on a 107 or 9 LSA. Put a super vic on that dude and rev r up where she'll run.