Which cam for my 70?

[Daddio]

Okay you 70 gurus I am putting my atc 70 together and I'm curious what cam you would recommend. It has a 48mm piston for a 71 cl70 which is a high compression piston and the head, intake and carb from a 71 cl70. The head has the 22mm ex. and 25mm in. valves. I will be cleaning up the ports a little.
I got the head stripped down and the cam was well worn as were the valves so it will be getting new. So far I have used all Honda parts and I was wondering if anyone knows which cam would work best for this build.

[Daddio]

Any ideas? :wondering

[Daddio]

I find it hard to believe that with all of the knowledge flowing around out there nobody has any ideas or even opinions about this. :rolleyes: I guess I'm on my own on this one.:w00t:

[big specht]

WEB made some good cams for those engines. I think greg's atv (was gibson's) behind KFC has one of those cam's in his show case he is open to 6:00 during the week and to 2 on the weekends . Hell I would put a bigger carb on it than that cl carb. A good cam and some port clean up and more compression will make a big differance and some electroic(can't spell) ignition will help to.

[Daddio]

WEB made some good cams for those engines. I think greg's atv (was gibson's) behind KFC has one of those cam's in his show case he is open to 6:00 during the week and to 2 on the weekends . Hell I would put a bigger carb on it than that cl carb. A good cam and some port clean up and more compression will make a big differance and some electroic(can't spell) ignition will help to.

Thanks Jason. Now that's what I was talking about. This is my first 4stroke build up project. I was just looking for a few pointers.
I'll have to try to get off work early so I can get over to Greg's on Saturday. I just had the cl stuff sitting around. I noticed that the intake port was much larger than the carb. I will see what I can dig up for a carb. I ordered the valves guides and springs today at work.

[The Goat]

Daddio, search for a post from the member iamschmee, he posted the website for cdi ignition for cheap, a power increase in and of itself.

Most 70 cams aren't high lift, they are huge duration... Seems like it'd be a pain to tune. What compression are you at, I think stock is 7.1 or so.

[Daddio]

Daddio, search for a post from the member iamschmee, he posted the website for cdi ignition for cheap, a power increase in and of itself.

Most 70 cams aren't high lift, they are huge duration... Seems like it'd be a pain to tune. What compression are you at, I think stock is 7.1 or so.

I'm not sure what the cl is. I was thinking it is 9-1. The spec sheet on the atc 70 says it's 7.5-1. With the extra 1mm on the bore it should bump it up a little. I used to have the specs for the 71 cl 70. I do remember that it was rated at 6.5 h.p. vs the 3.6 from the 84 atc 70. I may go with the electronic ignition set-up, we will see. I wonder if a 22mm keihin pd carb would be too big? The intake port on the cl head is 22mm with a 25mm valve. The cl carb is a 16mm.

[big specht]

Here is a web site that has alot of info on building these motors
http://www.jrbranson.com/HondaRacer/mainpage.htm

[Daddio]

Here is a web site that has alot of info on building these motors
http://www.jrbranson.com/HondaRacer/mainpage.htm

Thanks for all of the help. Lots of good info on that site. Maybe I'll try to make it up to race with you guys when I get this thing done. :naughty:

[big specht]

So how is it coming???