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Discussion Starter · #1 ·
I Just thought I'd check under the cover of a 1750 engine I'm getting ready to sell and found what appears to be non-standard cams for that model. The only mark on them is a stamped "520", as shown in the pic. I compared it with a stock 1750 cam measuring from the back of the lobe to the tip. It measured 1.420" (just over 36mm) as compared to 1.448" (just under 37mm) on the stock cam. I guess that would mean less lift than stock? I should point out that my shadetree mechanics have consisted primarily of "make it run" endevors more than "make it perform" so my knowledge of cam profiles is pretty scant (okay, non-existant). I'm mostly hoping someone will recognize this cam and tell me if it's worth the trouble of swapping out for when I get a chance to read all those past cam threads. At this point, all of my cars are for street, not track, use. Thanks.
 

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Hi Bill:
Not necessarily less lift with your mystery cam. If the base circle has been ground on a standard cam then you will have more lift and duration. Does your motor have thicker shims when set up with this cam?
Ed
 

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Richard Jemison
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Lift

Since the cam does appear to be a reground camwithout a lot of duration, you can determine lift fairly accurately by measuring the base circle (side of lobe at cam to the otherside). Stock base circle is 27.5mm (1.080) them subtract from the measurement of the lobe from the base circle to tip of lobe nose.
A picture of the full cam & one of the lobe`s full profile would help.
From the C&C engraving of the "520" it indicates that it isn`t an old cam. What builder did the head or do you know?
 

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Discussion Starter · #4 ·
Thanks Ed & Richard,

I'll pull the cams from the head later today and get a better picture and measurements. The engine is one that I pulled from a non-running (no intake manifold) rusty 69 Berlina a while back so I don't know much about it. The head has not been ported, don't know about the valve size. I may still have some of the maintainence paperwork that came with that car so I'll dig around. Maybe I'll find the receipt. I'll keep you posted.
 

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Discussion Starter · #5 ·
Richard,

If I understood you correctly on the method of measuring the base circle, mystery cam measures 1.038". Subtracted from my original lobe measurement of 1.420 gives .382" lift. Compared to the stock '69 1750 cam which I measured at 1.448" - 1.086" = .362 lift. My measurements seem a little off from what my old Shankle catalog lists so my accuracy with a dial caliper may be questionable. In any case, this cam does have a little more lift but as you can tell from the pictures, has a very similar profile. Could this just be a copy of the venerable 10548? Yes Richard, I know it's old technology but it might be just the ticket for one of my street engines. Mystery cam is on the left, on the top in the horizontal shot. Thanks for any observations.

Ed,

You were right about the base circle. I'm learning as I go!
 

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Richard Jemison
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New Cam Pics

Still hard to tell, but with overall lift at 9.6mm I would guess that it is probably a repaired cam. I does not appear to have any significant duration.
But the only way to know is to have it profiled.
Rj
 

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Bill, I think IAP and Centerline sell Euro cam copies. Maybe call them to see how they're marked?

-Jason
 
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