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Datsun 15/1600 Cam Info÷

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Datsun 1500/1600 CAMSHAFT INFO
Keep in mind these profile numbers are just for comparing the cams to each other; every manufacturer and cam grinder uses different points in the cycle to take the measurements and they can be listed at almost whatever they want them to be with the same cam. Some of this is advertising nonsense; so when looking at cams for any car; make sure you are comparing apples to apples. Even Nissan's published specs are sometimes all over the place.

Historically cam specs were advertising figures; like horsepower that was based on the THEORETICAL amount generated by the explosion in say 8 cylinders and didn't include drag from main bearings etc!; or having to move the crankshaft mass around and around. Engine HP/Torque means nothing unless it is measured with a chassis dynamometer with a street exhaust and street air cleaner system in place.

Such is the situation with cam measurements. I can look at you (but not with a straight face) and tell you a standard grind has 350 degrees of duration. It would be "true"; but at what point in the cycle is this measurement being taken? Probably at the point where the cam has actually been pushed open .001 inch. Not much gas or exhaust moving by with the valve only open one thousandths of an inch! Sure would make for impressive stats specs though.

Some of the more thoughtful cam grinders and engine builders use a figure "at .050 lift" to measure duration; which is what we are doing; and we have used a cam profiler machine to show this on the "stock" cams for comparison. Definitely not as flashy a number bu t more accurate; since adding on the clearance ramp on to duration is usually thought of as a joke to engine builders anyway...

Same with valve lift. Stated figures are THEORETICAL lift; or GROSS lift; or WHITE CLOUDS on BLUE SKY lift. They do not account for loss due to valve lash or anything else.

Better in comparing camshafts is using LOBE LIFT (CAM LIFT); that is what the lobe rise is over the base circle (what is there if all the lobes were removed).

So with the above discussion on bogus specs in place; we have the following information.

130-18, 130-18U. Running a stock new cam on a cam profiling machine; we find that the duration at .05" cam lift is 193.5 degrees. Lobe lift is .237.

130-18R The cam we use as a "stock" replacement cam is a little different. They are cut so the duration is about 214 and the lobe lift is at .255. Still nicely in the stock range; but with a little bit of a shove.

Although there are "metric" and "SAE" cams; it refers only to the threads in the end of the cam for the bolt that holds the gear on; so it is important that you return your bolt WITH your cam core. There is a charge if you don't or if the bolt you send back has bungled up head on it; or bad threads. If the threads in the cam are bad that is not good as a core. Other core info here.

These are just used cams we have not taken to the cam grinder. We do not though sell used cams that have chips out of them or other lobe damage or bearing journal damage visible to a non-cam machinist; other than small scratches that many times can be polished out. Technically speaking you should always use a used cam with its previously run lifters; in the exact positions they were in; but it is rarely possible unless we have recently pulled the engine apart ourselves and saved it specifically for that purpose.

Changing the cam means changing lifters if you want it to live; as does proper break in and lube during break-in. There is little point to using a reground cam with old lifters. They may "look smooth" but are actually cut in a very funny way and they will wreck a reground cam very quickly when they have been run before.

We carry new lifters; and even though they are much more economical then they used to be; people still balk at replacing them when theirs "look OK" (but aren't with a reground cam); so we also carry reground lifters to make your reground cam happy and go even easier on your bank account.


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