getting dyno tuned tomorrow!
05-03-2010, 06:58 PM
#21
3rd Gear Member
Join Date: Jan 2009
Location: Florida
Posts: 570
Yeah, if they all do it, there really are no other options. Just is asinine that major machine shops are delivering products that far off from specs. Especially when every .001" matters with these motors. Good thing timing/crank gears have the ability to correct their half-assed work.
From what I understand the master lobes are 5" in diameter and if you are off a thousandths there lining up to the keyway it moves it a degree or so.
The factory cams are better but not much.
Worse cams I have seen was a set of Comps that were 8 degrees advanced one side and 6 or 7 degrees retarded the other. Its not just the modulars that have this issue its all aftermarket cams.
The OEM heads vary about 1-2 degrees, and the TFS head I just tested was 10 degrees retarded compared to an OEM. I have some more TFS heads coming in that are all going to get thrown on the bench. I can't fix 10 degrees with a crank gear alone.........
05-03-2010, 07:04 PM
#22
3rd Gear Member
Join Date: Jan 2009
Location: Florida
Posts: 570
MHS still matches all the cam gears but also has to test the cams too, its on their website. I have tested all of them and nobody is better than the other when it comes to the degree test. I use Bullet because they will make whatever lobe spec my crazy mind can dream up. They have 4 different lifts now for just 225 duration because of me, Comp won't do that unless you are buying a bunch up front. Plus with Bullet you get to use the mod guru Mark Chacon, he has a bunch of mod records under his belt now from his cam designs.
05-03-2010, 07:24 PM
#23
5th Gear Member
Join Date: Sep 2006
Location: CA
Posts: 4,039
MHS still matches all the cam gears but also has to test the cams too, its on their website. I have tested all of them and nobody is better than the other when it comes to the degree test. I use Bullet because they will make whatever lobe spec my crazy mind can dream up. They have 4 different lifts now for just 225 duration because of me, Comp won't do that unless you are buying a bunch up front. Plus with Bullet you get to use the mod guru Mark Chacon, he has a bunch of mod records under his belt now from his cam designs.
Makes a lot of sense now. I just don't get why they don't just cut the keyway after and deliver more accurate cams. Maybe there is some reason that cutting the keyway first is required in the process?
05-03-2010, 08:11 PM
#24
3rd Gear Member
Join Date: Jan 2009
Location: Florida
Posts: 570
The keyway is cut by the manufacturer of the cam blank, of which there is one supplier for all mod stuff. They have to have a keyway to index the cam grinder to, its getting the keyway lined up perfectly to the master that is the issue from my admittedly limited understanding. Here is an article showing some pictures of how cams are ground:
Cam manufacturing article
05-03-2010, 08:35 PM
#25
5th Gear Member
Join Date: Sep 2006
Location: CA
Posts: 4,039
The keyway is cut by the manufacturer of the cam blank, of which there is one supplier for all mod stuff. They have to have a keyway to index the cam grinder to, its getting the keyway lined up perfectly to the master that is the issue from my admittedly limited understanding. Here is an article showing some pictures of how cams are ground:
Cam manufacturing article
Cam manufacturing article
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