Cam lobe question

SirKnightTG

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Today my Hot Rod cams came in from Sutton (as some of you know I was scammed on ebay a while back and received stock cams) and I've been looking at these things and something seems weird to me.

Both cams have the proper XE-XXX part numbers so I know they're what they're supposed to be, but the lobes on one cam looks different than the other. What I mean is the angle between the intake lobes and exhaust lobe.

On one cam, the angle between the lobe centerlines of the intake and exhaust lobes looks smaller (closer together). But the other cam, they are pointing more away from each other so the angle is larger. I have not measured them I'm just "eye balling" it. I looked at the pic of these cams on fordracingparts.com and their picture shows the same thing as I'm observing. So I know I have the right thing, but WTF?

So for cams for a SOHC engine, is this normal? Why in the hell does one cam have lobes with a tighter angle between them than the other? I just cant visualize the overlap on one of the cams like I can the other. I'm confused!

Here's another pic I just found that shows it:


33384220010_large.jpg
 
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marcspaz

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That's how you get the crazy sound... by mis-tuning the engine... LOL

Sorry, had to.

They all look like that because of the phasing, firing order, and the rotation direction. You should be fine. You can always call FRPP to confirm if it helps with the piece of mind.
 

SirKnightTG

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Yeah I'm sure they're ok since they both have the proper part numbers on them and all the pics look just like mine.

I tried to find some similar pics of other cams but I was not successful. The only pic was this lame one of the Thumprs and close inspection shows they just copied one and pasted it twice as the lobes for "both" all point the same which can't happen due to firing order and what-not.
 

SirKnightTG

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Somehow I missed this pic of the Thumprs from comp's site

127010_600.jpg



It's very hard to see, but I can see the same thing going on here. One cam has different angles between the I and E lobes than the other.

This is supposedly SPRs:

127200_600.jpg


It's even harder to tell from that angle, but I think I see the same thing here too.

So yeah this is just how it's supposed to be. I guess having two (or four) cams will make things look different than what I thought from how I normally think of cam things (single cam OHV). :boobies:
 
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