Question cams

1

12valvetater

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Nov 4, 2009
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I currently have east coasts street/towing cam. I didn't know the right question to ask when I bought it and I haven't been able to get the specs from them. I'm confused on the differences between your cam and what I have. Mine is a regrind, I know you don't like regrinds. Mine also doesn't have a bolt on gear. When do you need a bolt on gear? I'm still really new to the game but with my engine going down the other week I'll have lots of time to maybe redo what I've done any do it right this time.
 
Regrinds in and of themselves are ok. No problem there. The problem lies in the fact that there are numerous options on lobe shape and lift. With all of the options it is easy to get into the softer part of the cam when reshaping it. THis is a bad thing, and will lead to premature cam failure.

I only sell new cast billets, so that I can keep the bse circle and the cam as a whole as large as possible. This allows us to keep the surface of the cam as hard as possible which reduces wear. As far as how we differ functionally, as stated above, there are numerous shapes and sizes of cam lobes. While most agree that more aggressive ramps, more duraion and higher lift are all needed, There is a great deal of difference in how different companies cams look. It all comes down to engine theory and experience each cam grinder has.

Billets allow us to go as wild as possible and still keep a good shape, where regrinding paints you into a lower performance corner. As far as profile shape, I like a little bit more lift and more agressive ramp rates than others. This dictates more spring pressure but yields great results in terms of driveability and performance. In my opinion, biased though it is, we have some very nice cams that are some of the more efficient cams on the market while still giving plenty of power increases. We also have some nasty grinds that give up a bit of efficiency to make the most power if that is what you are looking for. Let us know what your goals are and we will do our best to get the cam to help you get there.

Thanks for the interest in our cams,

Zach Hamilton
 
If I can get the specs of the cam I have can you explain them to me? I only understand enough to get myself in trouble and I'd like to change that. Also you've said that 60lb springs have the same pressure on a high lift cam as stock springs. If this is true what is the point of them? I'd like to try to keep the pressure on the nose of the lobe as low as possible but at the same time I don't want t float the valves. I turn 4k maybe a few times a year most of my driving is towing and DD with a heavy foot.
 
12valvetater said:
If I can get the specs of the cam I have can you explain them to me? I only understand enough to get myself in trouble and I'd like to change that. Also you've said that 60lb springs have the same pressure on a high lift cam as stock springs. If this is true what is the point of them? I'd like to try to keep the pressure on the nose of the lobe as low as possible but at the same time I don't want t float the valves. I turn 4k maybe a few times a year most of my driving is towing and DD with a heavy foot.
Click to expand...

What is the point of 60lbers? That is something I have been asking myself for years. For mild performance engines producing less than 40lbs of boost and going less than 3800rpm they will work fine. I know people that run them higher and have not had failures. I have also seen people with 4k kits pull the locks through the retainers and drop valves into the engine. In my opinion the cracked retainers comes from valve float, where the valve slams on the seat. When this happens harmonics travel to the retainers and keepers. The retainers are very heavy and britttle while the keepers or locks are very small and pull through the retainers at this point. Some companies address this with lighter Titanium retainers. This helps the RPM ratins of the valvetrain due to less mass but it does nothing to address the lower seat pressure and the low over the nose pressure the 60lbers have. To fix this we went with a retainer with half the mass of Ti retainers a beehive spring to cancel harmonics and reduce mass further. In fact our spring package reduces almost 50grams of mass on the valve. We then added a more progressive spring rate that works well with the rpm level and boost most of the cummins run. I will post up a spring pressure chart later if I can dig it up. It features factory , 60#(actually 147lbs on the seat, and our HD165#.

Ask around, you will find instances of broken retainers with 4k kits. Don't just take my word for it. I have seen lots of people do it on factory retainers without issue, but every so often it will bite somebody.

Zach
 
lift Stock 60lb HD165
1.940 88 150 150
1.900 98 156 165
1.800 125 170 200
1.700 150 187 240
1.600 182 210 285
1.500 210 225 327
1.400 245 245 365

With our springs and retainers installed height is actually 1.900" as opposed to 1.940" with the factory stuff.

Zach
 
Cumminsfever said:
Last I heard, the 12 valve E C D cam was a 194/194 108 or 110 lobe seperation.
Talk to LReiff he can get the specs from Lamar for you if you can't get them.
Click to expand...

While all cams have varying ramp rates and and I can't say 100% that this cam is no good, a smaller intake with a higher duration exhaust would make the truck a lot snappier. Cams that use a single duration lobe for intake and exhaust usually aren't the best idea and leave a lot of power on the table. THat being said, there are exceptions. To really see what the cam is, you would need to map it out in the engine with a lift vs. crank angle chart.


zach
 
I'll map it out once I start tearing the engine back apart. The biggest thing is I put the cam in when I did my rebuild and I changed so much stuff at one time that I don't if it made any difference. With my stock injectors and a 215 pump I could easily bury my pyro in no time. Something that has me worried is I've pulled 4k a few times on stock retainers and keepers with 60lb springs. I have a slight feeling that I may have broke a piece off one of my valves. I know I blew the tip off #4 injector and I don't know if it was a cause or effect of my compression loss. There I a good bit of soot in the plenum. Is this from the cam or floating valves? I have so many questions I just don't know how to ask them all.
 
With that big of an intake and that small of an exhaust, yes that could be part of the problem. Reversion, damaged valves and too restrictive turbine housing could all cause what you are describing as far as the carbon buildup. If you really want to see how your seats are at higher pressure cut out a t-3 flange that you can bolt to your exhaust manifold. Drill and tap it for 1/8"NPT and put a regulator on it. start low and then get up to the full 120lbs. of shop air. This will help you find issues with the head, springs, or seats.

Zach
 
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