.265" vs .275" vs .276" cam

[Hondagx160DB]

I am looking to upgrade my cam on my clone. It has a .265" right now from AGK. My carb is a 22mm mikuni and I'm running 26lb springs. These are my options:

.275":This is great cam for classes with a .275" max lift rule. This cam has .275" lift and 238.5* duration @ .050" lift. Cam pulls hard all the way through the power band. Excellent choice when using stock size valves and a good carburetor.

.276":Custom Ground .276" Lift Cam with 246* duration @ .050" lift.
This is our favorite cam with amazing power throughout the power band. Capable of 8000+ rpm.
This precision ground cam is great for increased horsepower and torque. Hard face welding is used on the lobes to reduce wear. Cam performs great in all engine applicatioins.
Instructions included.

What is the major difference in performance between these 2 cams? The .276" is 50 bucks more. Will my carb be fine with either one of these? Thanks in advance!

 

[rmm727]

I'd call Tim @ smallenginecams.com He has a cam called the Black Mamba which I believe is 275 lift and its only $75. I've read good things about it on Bob's 4 Cycle. Worth a look.

 

[Newoldstock]

The difference between the two you quote is one is a regrind and the other is a welded lobe.

The welded lobe has more durration and thats good for higher RPM power.
You will loose a bit of low end though.

What about the rest of the engine?
What head and piston?
If your still running a dish and 22cc head I would scrap that before I went to a bigger cam.
I feel compression is more important at this point.

 

[Hondagx160DB]

The difference between the two you quote is one is a regrind and the other is a welded lobe.

The welded lobe has more durration and thats good for higher RPM power.
You will loose a bit of low end though.

What about the rest of the engine?
What head and piston?
If your still running a dish and 22cc head I would scrap that before I went to a bigger cam.
I feel compression is more important at this point.

I am running a flat top piston right now and just ordered a 14cc head and all new valvetrain parts. While i have it apart, I was contemplating upgrading to one of those cams, but only if it is going to make a significant improvement in power. I am actually running 18lb springs with my .265" (current cam), but i have the 26lb on order. Thanks for all the input guys. This forum is helping me out alot with my build.

 

[saychz316]

a very very general rule of thumb with camshafts: and i mean very general. lol...

when you start getting a longer duration, you will be gaining more top end on the motor, but will be giving some of that gain up in the bottom end.

 

[MB165]

What are you looking for? More top end, more across the board?

 

[Newoldstock]

You have a modest but good cam there thats not hurting your bottom end near as much as its giving you more top.
And thats what you want on a daily driver or something that needs to fan through the entire RPM range while being well behaved.

Some of NR's 252 Cams off the same in a welded lobe or regrind.
Tim Isky is offering what I think are superior regrinds because of this parkerising process ( longer life ).

The G200 springs limit you to .275 lift but they will let you turn to 6000 and maybe more with lighter valves and parts as you have sugested you are going to .

The stainless valves offer a little better flow too.

The carb you have is good and I would not change that for anything larger unless you have some bigger valves and a more agressive cam.

The compression at 14cc will give you the best bang for your buck.
20 dollar clone heads are the single cheapest and best one shot up grade.
I tell people thats good for even a stock governed engine because they have no draw back at all other than more power and better performance all around.

Good luck.

BTW I use the same combination you have with the addition of the tillotson carb.
No complaints, other than I have a little more carb thanI need. Bigger carbs are not much help unless you have the valves to suport them and are prepared to run at high rpm.

 

[Hondagx160DB]

So I have decided to either go with the .275" or just keep my .265" for right now. I'm not totally sure yet. The .275" should give me a little better all around performance and top end correct? If I stay with the .265", will the 26lb spring be okay with that or is it going to wear out the cam a lot quicker? I was just emailed that my 14cc head is back ordered until the week of March 12th so I have some time to make my decision

 

[Newoldstock]

So I have decided to either go with the .275" or just keep my .265" for right now. I'm not totally sure yet. The .275" should give me a little better all around performance and top end correct? If I stay with the .265", will the 26lb spring be okay with that or is it going to wear out the cam a lot quicker? I was just emailed that my 14cc head is back ordered until the week of March 12th so I have some time to make my decision

Drop the order fro the 14cc head.
Look around localy for a 5.5hp clone in a scrap bin at the local motor shop.
could be free if your lucky.

Just stay with the 265 cam and 18 pound springs for now.
Is this the 236 durration intake version?

Build a good head with good valves and components and see if thats all you need. You might be happy with just that.

I don't think the 275 will offer you much but more top end and you will loose something at the bottom.

 

[Hondagx160DB]

Okay sounds good. Can I still run the 26lb springs?

 

[Newoldstock]

Okay sounds good. Can I still run the 26lb springs?

Do you need to?

Are you floating your valves?
If your not turning above 6000 rpm or so I would not bother.
Extra springs with no purpose are just more wear and drag.
The extra drag robs you of a bit of power.

A little bird has messaged me about a new 14cc head from China with 27.5 Intake and 25 exhaust today.

I will not be buying anymore heads for the time being untill these are in my hand to evaluate.
If they seats can be bored further it would be nice, but just that alone is enough to shake things up in the aftermarket.

 

[hal_armour]

New aftermarket head

A little bird has messaged me about a new 14cc head from China with 27.5 Intake and 25 exhaust today.
I will not be buying anymore heads for the time being untill these are in my hand to evaluate.
.

Keep us posted, I am keeping my eye out for a 14 cc head and that sounds like some major work already done !

 

[Newoldstock]

Keep us posted, I am keeping my eye out for a 14 cc head and that sounds like some major work already done !

I might be putting something together again.

Might be getting some 208 standard clone blocks and cranks with the heads.

I was asked last fall about Honda parts and I am still considering.

I have a Chinesew factory lined up to run off some TAV clones.

This would be Canadian only I am afraid because of the high shipping costs.

I have a lot on my plate here.
More than I am willing to do for free anymore.
This takes up a lot of my time ordering things for people and often sitting on inventory after they change their minds.....