Trading cams; re-installation help

[81xsproject]

I am planning on doing the 80' for 70's cam swap today and am wanting some advise. should I just remove the sprocket bolts and slip the 70's cams right into place? Doing a visual comparison of new cams againsy current cams in position, they look pretty close, but I want to be sure. I don't see any other indicator marks, special links in the chain, or anything else for that matter (I think it's at TDC). On that subject though, my timing plate only has a couple marks near the T. Is TDC the single mark, or the the double mark bridged at the top?

[81xsproject]

Nevermind, I found the TDC holes in the cams and figured it out on my own. Typical, huh.

[pggg]

Hey 81, I found that when running 78 cams in an 80 motor, there's a noticible drop in power below about 5000 revs. Top gear roll-ons at, say, 3000 - 4000 revs, feel a bit sluggish compared to the 80 cams' immediate response in that range. Swapping 78 cams for 80 cams in a 78 motor also improves the 78 motors' low to midrange. I've always reckoned the 80 cams are an improvement over 78 cams for all-round road use.

[Dan Hodges]

Rolling On

Originally posted by pggg
Hey 81, I found that when running 78 cams in an 80 motor, there's a noticible drop in power below about 5000 revs. Top gear roll-ons at, say, 3000 - 4000 revs, feel a bit sluggish compared to the 80 cams' immediate response in that range. Swapping 78 cams for 80 cams in a 78 motor also improves the 78 motors' low to midrange. I've always reckoned the 80 cams are an improvement over 78 cams for all-round road use.

When you are rolling down Interstate 55 in Missouri at 80 mph and the trucks are passing you,you need all the power you can get and hope you got enough.This is not to mention the hotted up Harleys that sometimes want to race and one cannot deny them the a-- whoupin they ask for.When I'm at 3000 rpm and want to take off,I simply change gears.You are correct though in the fact that the late cam's are stronger down low,but it all depend's on what you want.

[GNEPIG]

.. i think i'm going to try it the other way. what the hell, if i dont like it i will change them back. i will try the later cams in the early motor and see what happens. i dont think it will make it as slow as a harley but it might not be the fastest bike on the top end anymore. i dont spend as much time WFO as i used to[i'm gettin tired of going to jail]. and i really dont like the price of gas
.. i'm looking forward to posting some dyno results, ride impression and the wheelie factor[i still like the wheelies]

[pggg]

Yeah just for thrills a 78 motor feels racier. My tricked 80 motor with 78 cams used to spin the back tyre in 4th gear on a damp road way too easily. Wouldn't mind slapping some 78 cams back in one day.

[andreashweiss]

If anyone wants to try this I still have a set of 81 cams in the misc pile. Used of course. $25.00 for both includes shipping in continental USA.andreas

[lparker]

78 with 79 motor tour alot on it would the late cams be worth doing in top gear on hwy. if im over 5000 rpm im not woried about power its the hwy patrol i care about

[GNEPIG]

.. i have tried the later model cams in my early motor and all i could feel was less power. this set up might be good for gas mileage or to make your ol ladies bike easier for her to ride [less scary] but it is not for me. i will be changing back to the old cams at first light tomorrow.
check out the before and after dyno results in Procampers dyno test thread

[John]

GNEPIG

Where are you getting your new V/C gaskets? Or are you using the same one over?

[GNEPIG]

.. we had an account with K&L Supply were i work. K&L desided that we [or i] was not buying enough stuff from them and that they didnt want to do business with us anymore[me, i was the only one buying stuff from them]. i stocked up on some gaskets when i first started working there, i have a few more left.
i am trying the PAM trick on this one, we'll see how that worked tomorrow
if you need one let me know. i also have a small stock of cam-end plugs also
or if you have a line on were to get more at a good price let me know
..Gene