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esde Samba Member
Joined: October 20, 2007 Posts: 5969 Location: central rust belt
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Posted: Fri Jul 05, 2013 8:23 pm Post subject: Differences in these cams performance |
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I am nearly finished collecting parts for an 84X 90.5 2160, it will be going into my 62 ragtop. It is a weekend street car that will see some track time, and some 2 hour drives to shows. The heads are Mofoco 050's (37 X 42) with dual 45 Dellortos, 9.5 to 1 is the compression I am thinking. I have seat time driving the FK8 and 86B, both are great driving. The FK8 seemed to have more engine noise, but they were different engines in different cars so I guess it could have been any number of things. The FK8 is listed as .534 lift and 298* duration, and the 86B is slightly more with .574 and 300*. Talking with Steve Long about lifter compatibility he mentioned his XR302 cam, which is less duration 260* and .52 lift. Nice guy by the way, very informative about cam and lifter selection. I did buy a set of his reground and parkerized lifters. Anyway, my question is, how would these cams differ from each other, in the engine that I'm building? I've read about the webcams being easier on the valve train, something about the lobe profile? But maybe that's just talk? I know nothing about the XR302 cam, but it came up in our discussion. Any thoughts are welcomed, SD |
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fastfil Samba Member
Joined: November 25, 2006 Posts: 356 Location: Sunshine Coast, AUS
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Posted: Fri Jul 05, 2013 9:35 pm Post subject: |
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I'm thinking the xr302 260° measurement would be at .050". And sorry, I have no experience with any of these cams, but I did choose a web cam for my current build. The 86b sounds like a good idea if the 050s can make use of the lift. _________________ "...swingaxle...transaxle...same diff." |
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Dan Ruddock Samba Member
Joined: October 25, 2012 Posts: 3594 Location: Sarasota, in my adopted state of Florida
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Posted: Sat Jul 06, 2013 8:45 am Post subject: |
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It is important to compare cams with the same checking procedure. Measuring at .050 is the most standardized and useful. The FK8 is 258 and the 86b is 260 @ .050. The cam lift is about the same for both cams at .385 and .382 for the Engle. Even the tools used can change the ##'s you get. I am partial to the web stuff and would go with the 86b for it's quietness, durability and quality. How the two will drive will be very close. Dan |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Sat Jul 06, 2013 11:05 am Post subject: |
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It would be nice if that .050 was a std, but still a lot dont have that figure to compare, it's nice to be able to see good compareable figures..even at the beach.
I too liked the fk8 when I ran it. |
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bugguy1967 Samba Member
Joined: January 16, 2008 Posts: 4341 Location: Los Angeles, CA 90016
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Posted: Sat Jul 06, 2013 12:43 pm Post subject: |
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The numbers are too close. There will be no noticeable difference. I'd buy a Web just for quality's sake. _________________ "A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine" |
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esde Samba Member
Joined: October 20, 2007 Posts: 5969 Location: central rust belt
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Posted: Sat Jul 06, 2013 3:55 pm Post subject: |
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bugguy1967 wrote: |
The numbers are too close. There will be no noticeable difference. I'd buy a Web just for quality's sake. |
That's been my thinking, but after lots of reading and asking, it seems that some prefer one or the other, I'm curious why. Is there any discernible difference? Maybe it's quality or brand loyalty,but maybe it's something else? I have an 86B, that I bought when I saw a good deal, but I haven't been committed to it yet. Guess I'm nervous and want to make certain I'm making the right choice. |
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Dan Ruddock Samba Member
Joined: October 25, 2012 Posts: 3594 Location: Sarasota, in my adopted state of Florida
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Posted: Sat Jul 06, 2013 4:44 pm Post subject: |
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esde wrote: |
bugguy1967 wrote: |
The numbers are too close. There will be no noticeable difference. I'd buy a Web just for quality's sake. |
That's been my thinking, but after lots of reading and asking, it seems that some prefer one or the other, I'm curious why. Is there any discernible difference? Maybe it's quality or brand loyalty,but maybe it's something else? I have an 86B, that I bought when I saw a good deal, but I haven't been committed to it yet. Guess I'm nervous and want to make certain I'm making the right choice. |
I like the clearance ramp design which gently lifts the valve off it's seat and gently lowers the valve back onto the seat which is why it has the rep as a quiet cam and is easy on the valve train. Dan |
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CUBA Samba Member
Joined: December 06, 2005 Posts: 454
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Posted: Sat Jul 06, 2013 9:03 pm Post subject: |
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FK8!
Just do it.
It's Glenn Approved. |
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croSSeduP Samba Member
Joined: June 13, 2004 Posts: 1106 Location: Western Washington State
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Posted: Sat Jul 06, 2013 9:23 pm Post subject: |
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Like someone else said, these cams are so close to each other you would notice no difference in their drivability. I've used an 86b, fk8, in the same size motor you are building. I really liked the 86b. I now have a 2275 that has the Steve Long XR302 cam in it. I can't comment on it yet because all I've done is break it in. But, like I said, these cams performance in the same engine combo would be identical in the driver's seat. The only place any difference might be observed is on a dyno. _________________ Please check my '67 sedan project progress!
http://www.thesamba.com/vw/forum/viewtopic.php?t=502253&highlight= |
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Pat D Samba Member
Joined: March 10, 2004 Posts: 414
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Posted: Sun Jul 07, 2013 7:22 am Post subject: |
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You can have two grinds with the same .050 duration numbers but they can be very different grinds. Ask for the cam's .100,.150,.200,.250 and .300 duration numbers. Compare these numbers between the two cams. This will give you exact information when comparing different cam grinds. The cam with the higher duration in the mid and upper lifts has a more aggressive ramp. This will usually give you more power but it is also harder on parts and requires more valve spring to control. _________________ Pat, Im too fast slow me downs! |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Sun Jul 07, 2013 3:39 pm Post subject: |
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yup , it would be nice if those figures were on the card or catalogs. |
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