Cam and valvetrain longevity....??? low duration high lift...
09-30-2016, 07:33 PM
#801
Registered
Tim, while your lobe's finish looks like crap, it also looks like your lifters got some good hang time as well.
When you page thru master lobe listings, whether from crane cams, comp cams, etc, lobe designs can be engine specific. Granted, they can custom make you about anything you want, but I'm talking about application specific. Some cams are designed for LS engines, some for small blocks, some for fords, some for big blocks, some for big block drag race, big block marine, big block circle track, big block towing, so on and so forth.. I know you run rev limiters, and I know you havent spent much time over 5400-5500rpm. I see no reason the lifters should have been losing contact with the lobe. AFR's hyd roller springs you have, if I recall, come in around 200-500 lb range. If a hyd roller needs more spring than that to be stable and keep the lifter on that cam at 5500rpm, I'd say, that cam is a pile of chit.
Question.
Does anyone know, if these 680 lift cam designs, on such a short lobe, are proven big block chevy cam designs? Being honest, I'd like to know what kind of R&D goes into Bob Maderas cams.
I know everyone gets a Metric bolt, stepped nose, LS firing order camshaft lately from Bob. Supposedly, there was an abundance of leftover 8.1L cores on the market or some crap like that. I also know, Cam motion, is very heavy into the LS engines.
When you page thru master lobe listings, whether from crane cams, comp cams, etc, lobe designs can be engine specific. Granted, they can custom make you about anything you want, but I'm talking about application specific. Some cams are designed for LS engines, some for small blocks, some for fords, some for big blocks, some for big block drag race, big block marine, big block circle track, big block towing, so on and so forth.. I know you run rev limiters, and I know you havent spent much time over 5400-5500rpm. I see no reason the lifters should have been losing contact with the lobe. AFR's hyd roller springs you have, if I recall, come in around 200-500 lb range. If a hyd roller needs more spring than that to be stable and keep the lifter on that cam at 5500rpm, I'd say, that cam is a pile of chit.
Question.
Does anyone know, if these 680 lift cam designs, on such a short lobe, are proven big block chevy cam designs? Being honest, I'd like to know what kind of R&D goes into Bob Maderas cams.
I know everyone gets a Metric bolt, stepped nose, LS firing order camshaft lately from Bob. Supposedly, there was an abundance of leftover 8.1L cores on the market or some crap like that. I also know, Cam motion, is very heavy into the LS engines.
09-30-2016, 07:37 PM
#802
Registered
I'd send some of those pictures to someone who actually grinds cams and deals with various core materials and what not on a daily basis. I do know, that like any heat treated/hardened surface, there is a limit to how much material you could grind away, before hurting the durability of the finish.
09-30-2016, 07:47 PM
#804
Registered
Honestly Tim I truly believe you have a lot of support here and out of probably 95% of the post were your fellow boaters and people who care wanting to help or contribute in some way or another. Bobs done well for many but obviously not all. That pretty obvious but point being gotta move forward. It sucks no doubt but be positive. Negative energy and hatred will make things worse. Can't fix what's already fked up but it's what you do moving forward is what matters. **** happens.... HP is always a risk regardless. The best of the best goes south sometimes. More often than not. You have a lot of people here who care and want to help. Worse things can happen. Your upright and health health is good. I have best of friends and family who are dying of cancer etc. We've all had failures but not the end of the world. If everyone actually stepped up to the plate and come forward with builds that went south we'd probably know much more than we do but often pride fks with you. You have a lot of good sincere people here who have offered in some way or another to help including myself and I don't even know you personally but just wanted to bring something to the table.
09-30-2016, 07:53 PM
#806
Registered
Tim, while your lobe's finish looks like crap, it also looks like your lifters got some good hang time as well.
When you page thru master lobe listings, whether from crane cams, comp cams, etc, lobe designs can be engine specific. Granted, they can custom make you about anything you want, but I'm talking about application specific. Some cams are designed for LS engines, some for small blocks, some for fords, some for big blocks, some for big block drag race, big block marine, big block circle track, big block towing, so on and so forth.. I know you run rev limiters, and I know you havent spent much time over 5400-5500rpm. I see no reason the lifters should have been losing contact with the lobe. AFR's hyd roller springs you have, if I recall, come in around 200-500 lb range. If a hyd roller needs more spring than that to be stable and keep the lifter on that cam at 5500rpm, I'd say, that cam is a pile of chit.
Question.
Does anyone know, if these 680 lift cam designs, on such a short lobe, are proven big block chevy cam designs? Being honest, I'd like to know what kind of R&D goes into Bob Maderas cams.
I know everyone gets a Metric bolt, stepped nose, LS firing order camshaft lately from Bob. Supposedly, there was an abundance of leftover 8.1L cores on the market or some crap like that. I also know, Cam motion, is very heavy into the LS engines.
When you page thru master lobe listings, whether from crane cams, comp cams, etc, lobe designs can be engine specific. Granted, they can custom make you about anything you want, but I'm talking about application specific. Some cams are designed for LS engines, some for small blocks, some for fords, some for big blocks, some for big block drag race, big block marine, big block circle track, big block towing, so on and so forth.. I know you run rev limiters, and I know you havent spent much time over 5400-5500rpm. I see no reason the lifters should have been losing contact with the lobe. AFR's hyd roller springs you have, if I recall, come in around 200-500 lb range. If a hyd roller needs more spring than that to be stable and keep the lifter on that cam at 5500rpm, I'd say, that cam is a pile of chit.
Question.
Does anyone know, if these 680 lift cam designs, on such a short lobe, are proven big block chevy cam designs? Being honest, I'd like to know what kind of R&D goes into Bob Maderas cams.
I know everyone gets a Metric bolt, stepped nose, LS firing order camshaft lately from Bob. Supposedly, there was an abundance of leftover 8.1L cores on the market or some crap like that. I also know, Cam motion, is very heavy into the LS engines.
Last edited by Black Baja; 09-30-2016 at 07:55 PM.
09-30-2016, 08:44 PM
#807
Registered
My local shop has been using comp lately too. Custom cams from them. They have been very happy with the results so far.
09-30-2016, 09:18 PM
#808
Registered
Not sticking up for him but when I've worked with him on combo's he has always asked me what parts I use, especially exhaust. We've reviewed combos for intake restricted engines and exhaust restricted systems. In a recent build, the exhaust was scrapped because the larger cam wouldn't have benefited from the small exhaust.
Maybe the limitations were reviewed, maybe not. I wasn't on the call when it was spec'd. :-)
Maybe the limitations were reviewed, maybe not. I wasn't on the call when it was spec'd. :-)
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