Stage 3 212cc clone speed.

[kart_goes_brrr]

Hi, quick question, is it even possible for a stage 3 212cc clone to get over 100kmh with the right gearing? Thx

 

[bob58o]

I’m sure it’s possible to modify a clone engine to get to 62 mph on some sort of vehicle. Not sure what stage 3 means. I don’t buy “stage X” kits.

8000 RPM, 13” tires, 5:1 gearing, a light vehicle, a light driver, a decent clutch, and an engine set up to give you the power you need above 7500 RPM.

But if you set up for 62 mph, you’ll burn through clutches fast. The set up I showed won’t even lock up the clutch until going about 15 mph. Until you are going 15 mph, the clutch is slipping and burning.

The right head, carb, camshaft, compression ratio, and timing …. Might could get you there. Might require a performance head? Milled, port work, valves?

I was going to suggest and ISKY Bkack Mamba Camshaft, but it looks like smallenginecams.com doesn’t have any cams in stock. Not sure if Tim’s still making them.

STORE

Small Engine Cams is the leader in custom racing cams for minibikes, karts, jr dragsters, lawnmowers, and small boats.

smallenginecams.com

 

[kart_goes_brrr]

Oh wow, that is one of the most detailed replies I've seen on this website, thank you dude, also is it ok if the gearing is 2:1 (axle sprocket/clutch), are there any differences? Is it even better? Once again thanks for the help.

 

[kart_goes_brrr]

Another thing, is it ok to use the stock cam or do I have to modify it of some sort? P.S I'm not from the U.S just so yk.

 

[kart_goes_brrr]

Stage 3 means the same as stage 2 but like changing the cam, piston head (70mm), billet rod (3.308), mikuni carb vm22, 10k rpm flywheel (the basic one not slipstream), stock crankshaft, 22lbs springs, performance spark plug, governor removal ofc, and that's it I guess.

 

[bob58o]

Oh wow, that is one of the most detailed replies I've seen on this website, thank you dude, also is it ok if the gearing is 2:1 (axle sprocket/clutch), are there any differences? Is it even better? Once again thanks for the help.

Gear ratio will depend on tire size. 62 mph in a kart using a 200cc snow thrower engine isn’t easy. 2 : 1 gear ratio smells like burnt clutch from my house.

The camshaft is the brains of the engine. A stock camshaft isn’t gunna get you 100km / h.

What size diameter tires do have?

With 13” tires, you need about 5 : 1 gear ratio. You need a camshaft designed to make power at 8000+ RPM. You need to valve springs specified for the cam. You need a cylinder head (compression ratio, port work, valve size, valve spring pockets) that work for the cam. Below you can see that these cams like high compression ratio. You’d want a head sized to give the desired ratio. These cans ask for dual springs. Can the head’s spring pockets fit them? Or do the pockets need to be cut larger? …. Pick the camshaft first, then build around it.

I’ll post an cam listed NR Racing cam for example…

274 (F200) Series: Radical Cam Grind for F200 Series and Super Box Stock

Approximately .274 lift and 260 duration. Square lobe design to maximize valve opening time. While meant to use with larger carbs, it actually works very well with smaller carbs by holding open the valve as long as possible with reduced lift to maximize velocity. Honda blocks may need clearance to install. Dual springs recommended (37lb will work, but will limit RPM to 7500).

Cam Options:

Camshaft 274-0607: 8500rpm. 12-to-1 or higher compression ratio required. Big track cam. Warning: may cause traction problems. Use with 1.3 billet steel rockers for maximum power.
Camshaft 274-1007: 9000+RPM. 12-to-1 or higher compression ratio required. Recommended for serious competition. Use for large ovals or where traction is a problem. Dual springs required.

*Note: Honda blocks may require clearance to clear camshaft lobes.

 

[Sparkwizard]

An old saying:
Speed costs money. How fast do you want to go?

 

[bob58o]

Racing Cams and Parts | High-Quality Precision Camshaft for 196cc Clone & 212cc Hemi | Aggressive Ramp | Modified Class | F-275-CL | DynoCams

Precision camshaft with aggressive ramps for 196cc Clone and 212cc Hemi engines. Requires upgraded springs, billet rod, and flywheel. Ideal for maximum valve duration. Welded lobes for durability. Max RPM 8200-8400. | F-275-CL

www.dynocams.com

 

[bob58o]

TBH, a kart that has a lot of TQ is more fun and drivable than one that goes 62mph. Unless you have the space (or track) to drive it at 60 mph for long periods. You give up a lot of things that make a kart fun. When you build a race car, it doesn’t idle well, hard to start, can’t do stop and go driving, can drive it as slow speeds, can’t climb hills, needs high stall clutch…

 

[kart_goes_brrr]

Alr so here's the info:
-clutch : 16 teeth (centrifugal)
-axle sprocket: 32 teeth
-tires: 10" racing tires (wet)
-cam (that I bought) : stock 168f steel.
So honestly, I'm not really trying to reach those speeds, but I was just wondering if can go more than 100kmh with what I have. Budget is tight too, max 1k, in which rn I spent like uhh, 960 overall? I forgot. Anyways thanks again everyone, you are literal life savers on this website.

 

[kart_goes_brrr]

So with 22lbs valve springs and stock cam how much rpms am I gonna get?

 

[Sparkwizard]

With a stock connecting rod and flywheel, I would not exceed 4500, maybe 5000 for a few seconds.
Some of them blow up at about that speed.

I would drive it with a stock engine until I collected all of the parts, tools and knowledge to build the engine properly.

 

[kart_goes_brrr]

Stage 3 means the same as stage 2 but like changing the cam, piston head (70mm), billet rod (3.308), mikuni carb vm22, 10k rpm flywheel (the basic one not slipstream), stock crankshaft, 22lbs springs, performance spark plug, governor removal ofc, and that's it I guess.

I did all of these mods, any idea what could be the stats? Stock cam just so yk.

 

[bob58o]

With 10” tires, 22 lb springs, stock camshaft, …
It might turn what? 6000 RPM? Just guessing. Maybe 6500 RPM?

6250 RPM, 10” Tires, 2:1 ratio…
93 miles per hour….
2 : 1 ratio doesn’t work.
Clutch slips and burns you until 30 mph.

You’ll need a clutch with less than 16T. Because rear tires are 10”, you need a rear sprocket that is about 8.5” or smaller.
something like a 48T on the rear and 10-12T on the clutch.

let’s assume 48T and 10T…
10” tires
6250 RPM…
39 mph …
<- 40 mph top speed is much more reasonable and make for a more drivable machine. Doesn’t burn through clutches as quickly. Accelerates better. Starts better. Idles better.

 

[bob58o]

What are your intentions with the kart? Race? Back yard? Streets? Open highway? Sand Dunes? …. I’m assuming it is a racing kart cause the 10” tires. Show some photos.

was this the 20mm shaft engine? Or am I confusing two people?

what pitch is the rear sprocket? #35? #420?

 

[panchothedog]

With the gear ratio you are describing, 2: to 1:, you'll be lucky if the kart even moves. That is way too tall of gearing. You need to get down to 4 to 1, or lower.
With a stock cam and 22 lb. valve springs your engine will struggle to get much more than about 5600 rpm. Maybe 60 to 65 kmh. bob58o has given you some very detailed and expert information. From the responses you are giving, it appears that you need to study performance engine building a little more. I'm going to guess that your engine is making 9 to 10 horsepower. To achieve
100 km you are going to need to double that number.

 

[Master Hack]

Scenario B:
lets assume you were able to buy a stage 9 kit and made 40hp.
On your test run you start accelerating past 50, 60, then ya feel vibrations. The vibrations increase, then the 10in chinese tires come apart and you crash and die.
The chinese tires were only rated for 45kph. The speed rated tires were $400 each, so since you're broke from the stage 9 kit, you passed.
And nobody lived happily ever after!

 

[kart_goes_brrr]

What are your intentions with the kart? Race? Back yard? Streets? Open highway? Sand Dunes? …. I’m assuming it is a racing kart cause the 10” tires. Show some photos.

was this the 20mm shaft engine? Or am I confusing two people?

what pitch is the rear sprocket? #35? #420?

Yeah same guy here, honestly it's like a beater kart for fun like streets etc but maybe if I'm lucky I can enter a tournament / competition, i don't really know what pitch means but I think it's the #420 from what I know. I'll do photos in like 10 hours since for me now it's 5 am.

 

[kart_goes_brrr]

Alr so I changed the gearing to 3:1, is it a bit better or still bad?

 

[kart_goes_brrr]

Out of context but I love how a small question turned into an entire massive discussion