Stock Cam questions (KZ1000)

A few question about the stock cams for my bike(1977 KZ1000A:

1.) Are these cams the same as the Z1 cams? If so stock specs are(according to the MegaCycle catalog):

Intake 237 @ .040" .327" lift
Exhaust 229 @ .040" .296" lift

Is this correct or are the KZ1000 cams different?

2.) If they are different, does anyone know the actual lift and duration @ .040"?

3.) If they are the same, has anyone ever ran a intake cam on the exhaust side? Like this:

Intake 237 @ .040" .327" lift
Exhaust 237 @ .040" .327" lift

I know I would lose my tach drive, but I am switching to an electronic tach anyway.

4.)If you have done this, how did it run?

5.)Anyone got a stock intake cam they are tired of tripping over?

I would think it would pick up a few horsepower. Obviosly not as much as some aftermarket drop-in cams, but I don't have the money for a new set and they are not common on ebay from what I've seen.

I know someone who has been racing these bikes for a while will know the answer! Thanks.

You may gain a tiny bit at the top end but you would loose some at lo end and mid range. I would be surprised if you gain 3MPH at the top end by doing this. You will get a lot more if you just clean up your ports, intake and exhaust.

i always go for the big stuff when i'm doing cam swaps so i'never have even measured a set of stockers but if there is that much difference it should work a bit better at least as far as loseing the tach drive no big deal i haven't run one of those for years. and otakar is right you would gain a lot more by spending some quality time on the ports and valve pockets the valve pockets being the biggest gain on the intake side.

what must be realized here in practical terms is that; the .008" of lift gained is equivalent to a standard piece of printer paper folded over once. That is the amount of extra lift you will gain. That is not even worth the postage to ship a cam. Just by removing all of the sand cast roughness, you can easily gain 5-7% in flow. That now is significant. If you really spend some time on the ports, say about an hour on each you can gain 10-15% extra flow. This is all using stock cams. Check out this link for more info. www.flowbenchtech.com/porting/CRH/kz-data.htm

otakar wrote:

what must be realized here in practical terms is that; the .008" of lift gained is equivalent to a standard piece of printer paper folded over once. That is the amount of extra lift you will gain. That is not even worth the postage to ship a cam. Just by removing all of the sand cast roughness, you can easily gain 5-7% in flow. That now is significant. If you really spend some time on the ports, say about an hour on each you can gain 10-15% extra flow. This is all using stock cams. Check out this link for more info. www.flowbenchtech.com/porting/CRH/kz-data.htm

The lift difference is .031", not .008". 8 is the difference in degrees duration @ .040".

Seemed like a worthwhile change that would pick me up 1 or 2 hp for a few bucks.

The lift difference between the stock intake and WC 118 drop in cams is .038", for comparison. Granted that's on both cams with 10 degrees more duration.

But you're right, it may not even be worth messing with. Just rolling it around in my head.

The heads will definitely be ported in the future, I know the value of a good cleanup on a set of heads. Not arguing that fact in the least. I just don't want to pull the heads apart again now the the season just starting.

They were already gone through right before I got the bike and have the first oversize intake valves installed (stock where bent). +1mm I think.

tachrev wrote:

otakar wrote:

what must be realized here in practical terms is that; the .008" of lift gained is equivalent to a standard piece of printer paper folded over once. That is the amount of extra lift you will gain. That is not even worth the postage to ship a cam. Just by removing all of the sand cast roughness, you can easily gain 5-7% in flow. That now is significant. If you really spend some time on the ports, say about an hour on each you can gain 10-15% extra flow. This is all using stock cams. Check out this link for more info. www.flowbenchtech.com/porting/CRH/kz-data.htm

The lift difference is .031", not .008". 8 is the difference in degrees duration @ .040".

Seemed like a worthwhile change that would pick me up 1 or 2 hp for a few bucks.

The lift difference between the stock intake and WC 118 drop in cams is .038", for comparison. Granted that's on both cams with 10 degrees more duration.

But you're right, it may not even be worth messing with. Just rolling it around in my head.

The heads will definitely be ported in the future, I know the value of a good cleanup on a set of heads. Not arguing that fact in the least. I just don't want to pull the heads apart again now the the season just starting.

They were already gone through right before I got the bike and have the first oversize intake valves installed (stock where bent). +1mm I think.

It's reall not worth messing with.

Thanks for the answers everyone. Guess I'll just leave it be for now then.

What needs to be done to the bowls and where? I am thinking of pulling the head and cleaning up the ports some, matching the intake manifolds for a little improvement as I have never done this so don't want to mess it up. Will mess with a junk head to get the feel for it first. Never understood where and/or what to do to the bowl area.