196 cc engine mods

[leesiel]

i'll be keeping an eye out for you posting a vid of the f-275 in action.
i have the 275 cam (its actually .276 lift & i have the non F series) but i want to see yours in action before i decide to send mine back. the powerband, due to the high duration and LSA, wont kick in until higher rpms but when it does it should be stronger than the stock cam.
.

My current setup pulls real good down low thru middle range but slowly eases up in the upper rpms so I'm quite excited to try a different cam. Hopefully I don't lose my low end to much and gain some strong uppers if not I'm willing to try a cam in between stock and the f-275 which is why I wanna keep stock valve train if possible.

 

[cavfire]

I have a Dyno CS cam with a .265 lift and 225in/236ex duration and it benefited noticeably with a bigger carb even though it's advertised that it can be used with a stock carb. I would imagine the F275 cam could use a bigger carb too.

 

[leesiel]

How do you like it ? How noticeable was the improvement? Also what size carb / jet combo did you settle on?

 

[cavfire]

It pulled harder and has better top end now. Carb is a GX270 carb with a ARC carb adapter which I think is in the neighborhood of .660" on the venturi with .020" pilot and .040" main. For simplicity's sake, and cheaper overall, NR racing has .650" and .670" ruixing carbs for $40-$50. No need for the adapter so the carb will set level and you can maintain your current filter adapter if you already have one.

 

[leesiel]

Thank you.
I'm looking at carbs this weekend and will probably order this week.

 

[leesiel]

Parts came in today! Yaaaaayyyy! So this is what 8400 rpm looks like.
Still have not decided on a carb yet ; think I'm gonna go .650 or .670 blueprinted. Opinions anyone?

 

[Poboy kartman]

Parts came in today! Yaaaaayyyy! So this is what 8400 rpm looks like.
Still have not decided on a carb yet ; think I'm gonna go .650 or .670 blueprinted. Opinions anyone?

They look slightly different when they go from 8400 to zero! Just messing with ya. Seriously, though....that's when a billet flywheel is good idea...that's a lot of rpms.

Oh...and yeah....just looking at a 275 cam...they say a bigger carb is required....

(That's not for you Leesiel...but another post.)

 

[leesiel]

They look slightly different when they go from 8400 to zero! Just messing with ya. Seriously, though....that's when a billet flywheel is good idea...that's a lot rpms

(That's not for you Leesiel...but another post.)

After carb my next purchase is the flywheel, I May go pvl and lap the flywheel to set my timing; I need tread on my dive tire (tyre?) So that may come first.
My current tires (tyre?) With bearings aren't ready for 55mph so I need to upgrade them also.

 

[leesiel]

Buying carbs tomorrow really need some suggestions.
Running stock compression ( may get thinner head gasket if it is helpful ) as said above I'm looking at bored and blueprinted .650 or .670 , if I "go it alone " I'm going with the .650. Willing to go .625 If it would work with cam for some low to mid range but seems to me .650 would would be best. No???????
What would be a good head gasket if I go thinner?
---------- Post added at 04:42 PM ---------- Previous post was at 04:26 PM ----------
These are the carb s I'm looking at
http://www.nrracing.com/mobile/Product.aspx?ProductCode=16100-Z0V-BORED-650
http://www.nrracing.com/mobile/Product.aspx?ProductCode=16100-65CLN-BORED-650
http://www.nrracing.com/mobile/Product.aspx?ProductCode=16100-65CLN-BORED-670 or
http://www.nrracing.com/mobile/Product.aspx?ProductCode=CARB-BP625

 

[bob58o]

Just going off the descriptions....

Cam is 8200-8400 max
.670 carb is for 7500+ RPM (says in description for one of the .650)

Too small and you wont reach max rpm.
Too big and you loose low end.

How fast will your tires and gearing get you at 8000?

 

[leesiel]

Just going off the descriptions....

Cam is 8200-8400 max
.670 carb is for 7500+ RPM (says in description for one of the .650)

Which is why I'm not sure which to go with... May not like how my cam and engine come together and may " downgrade " The cam as I may need more low-end torque for my off road adventures and the f 275 will be kept for speed....but we shall see


52 mph @ 8000 rpm 11"tires 5:1 gear ratio
55 mph @8400. .....................................
Upgrading tires soon to either 13 or 15 " tires very soon! ( most likely 13")
62 mph @8000. 13 " tires 5:1
65 mph @8400. .....................................

71 mph @ 8000. 15 " tires 5:1
75 mph @ 8400. .........................
All hypothetically
Back to carbs

 

[bob58o]

Which is why I'm not sure which to go with... May not like how my cam and engine come together and may " downgrade " The cam as I may need more low-end torque for my off road adventures and the f 275 will be kept for speed....but we shall see


52 mph @ 8000 rpm 11"tires 5:1 gear ratio
55 mph @8400. .....................................
Upgrading tires soon to either 13 or 15 " tires very soon! ( most likely 13")
62 mph @8000. 13 " tires 5:1
65 mph @8400. .....................................

71 mph @ 8000. 15 " tires 5:1
75 mph @ 8400. .........................
All hypothetically
Back to carbs

This relates to carbs....
With that gearing, you might not reach 8000?
Do you got enough flat flat straight away to get to 52mph with that engine?

Maybe the bigger carb with little tires?
Or the smaller one if you go bigger tires?

Does this even make sense?

Ideally you match gearing, tire size, cam, and carb to produce power at a certain RPM / MPH.

 

[leesiel]

This relates to carbs....
With that gearing, you might not reach 8000?
Do you got enough flat flat straight away to get to 52mph with that engine?

Maybe the bigger carb with little tires?
Or the smaller one if you go bigger tires?

Does this even make sense?

Ideally you match gearing, tire size, cam, and carb to produce power at a certain RPM / MPH.

With my un-cammed motor I could get to top speed of 37-40 mph in about 200 yds,a good bit faster than a 212 ( nodded )&420 predator ( no mods ) both with a tc ,so imo I think space is not a problem (I live in the country ),
55 is plenty fast so no matter what tires I get I'm not really concerned with going any faster I'll gear higher if speed becomes a problem.

 

[Poboy kartman]

With my un-cammed motor I could get to top speed of 37-40 mph in about 200 yds,a good bit faster than a 212 ( nodded )&420 predator ( no mods ) both with a tc ,so imo I think space is not a problem (I live in the country ),
55 is plenty fast so no matter what tires I get I'm not really concerned with going any faster I'll gear higher if speed becomes a problem.

I call BS!!!! a 4 stroke engine CAN'T run without a cam!

 

[leesiel]

Touche......I was lying . it has a cam ,albeit, not a good one; I was lying about the 212 also...it isn't nodded.

 

[bob58o]

What I was getting at is if you keep that cam, and go with bigger tires... You may want 6:1 instead of 5:1

should get you to 8k and over 55mph.

 

[FreeRunner15]

Which is why I'm not sure which to go with... May not like how my cam and engine come together and may " downgrade " The cam as I may need more low-end torque for my off road adventures and the f 275 will be kept for speed....but we shall see

You went with the f-275?
oh man.. i sent the .275(non f series) i ordered back because i heard the powerband didnt hit until about 4k rpm. and the f series will have an even wider duration than that.

Well at least it will sound nice and modded at idle. and built for top-end rpm.

 

[leesiel]

Did you not notice that the cam is somewhat adjustable ? Don't know anything about adjusting cam timing but you can bet a smog pump turbocharger that I will learn about it if I'm not happy with cam characteristics I will ask questions.

---------- Post added at 01:03 PM ---------- Previous post was at 12:43 PM ----------

What I was getting at is if you keep that cam, and go with bigger tires... You may want 6:1 instead of 5:1

should get you to 8k and over 55mph.

I have considered changing gear ratios to something higher possibly greater than 6:1. With so many rpms to play with, gear ratios give me a lot of choices as far as where and what I want my power along with cam timing, and carb tuning.

46 mph @ 6:1 @ 8200 rpm
42 mph @ 6.5:1 @8400 rpm

 

[leesiel]

http://m.dhgate.com/product/the-mot.../142440984.html#mymlpd-1-9|null:01:1288141682

Something doesn't seem right!

 

[FreeRunner15]

http://m.dhgate.com/product/the-mot.../142440984.html#mymlpd-1-9|null:01:1288141682

Something doesn't seem right!

a 60watt Electric "turbo" charger.

i don't know how much energy that is cause it isn't in volts or if it is enough to even do anything. someone does.

Just wanted to point out that it is 60watts. and i want to ask a question on behalf of both of us since you seem to want to know as well.......... How many watts/volts would be needed to boost?