Strictly torque
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65ShelbyClone
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mckutzy
Well-known member
Hehehe... a twin charging system.... cool....
karl
Well-known member
Turbo and super chargers are cool and all, but yall every try a 8hp Giant Vac walk behind leaf blower? Instant proven torque my dudes.
Anyway a GX160 head might be what you are looking for. Or a gear ratio change.
Anyway a GX160 head might be what you are looking for. Or a gear ratio change.
yepp..
increase compression (GX160 head, thinner gasket etc..)
retard ignition timing ever so slightly (yes retard is correct)
that way you shift the torque curve to lower rpms
(as opposed to advanced timing which does -you guessed it- shifts the peak torque towards higher rpms )
I'd say ever so slightly.. which means two maybe 4 degrees should be all you need.
yes lower gear ratios improve wheel torque like nothing else;
with one exception:
A torque converter! (if you have a cent clutch, replace it with a series 30 [or clone])
almost 2.7 times the torque without anything else (some losses... but still a huge improvement)
and as a bonus the engine is still untouched for even higher torque gains
'sid
increase compression (GX160 head, thinner gasket etc..)
retard ignition timing ever so slightly (yes retard is correct)
that way you shift the torque curve to lower rpms
(as opposed to advanced timing which does -you guessed it- shifts the peak torque towards higher rpms )
I'd say ever so slightly.. which means two maybe 4 degrees should be all you need.
yes lower gear ratios improve wheel torque like nothing else;
with one exception:
A torque converter! (if you have a cent clutch, replace it with a series 30 [or clone])
almost 2.7 times the torque without anything else (some losses... but still a huge improvement)
and as a bonus the engine is still untouched for even higher torque gains
'sid
65ShelbyClone
Active member
I think this thread was posted with a snowblower application in mind...
bob58o
SuckSqueezeBangBlow
NR torque grind camshaft?
280-0211: THE ULTIMATE TORQUE CAM. Special grind for Marine and Winch Boarding applications. Extreme torque. Designed for 2000 to 5500 RPM, 11 to 1 or Lower compression ratio required, HD Springs required
Might want 26lb springs with that cam which might need reinforced rockers. How far down the rabbit hole you willing to go?
Added: People have said they've often used 26lb springs with stock, stamped rocker arms without issue. If really using on a governed snow blower, then 22lb might be all you need. Email Russell at NR and ask about your application.
Approx .280 lift and 220 duration (at .050). This is a nice cam that works well on both stock and modified motors. This cam produces lots of low end torque. One of the best all around cams we offer. Honda blocks may need to be clearanced to install. 26 lb springs required. Bored or Aftermarket carb needed.
280-0211: THE ULTIMATE TORQUE CAM. Special grind for Marine and Winch Boarding applications. Extreme torque. Designed for 2000 to 5500 RPM, 11 to 1 or Lower compression ratio required, HD Springs required
Might want 26lb springs with that cam which might need reinforced rockers. How far down the rabbit hole you willing to go?
Added: People have said they've often used 26lb springs with stock, stamped rocker arms without issue. If really using on a governed snow blower, then 22lb might be all you need. Email Russell at NR and ask about your application.
Approx .280 lift and 220 duration (at .050). This is a nice cam that works well on both stock and modified motors. This cam produces lots of low end torque. One of the best all around cams we offer. Honda blocks may need to be clearanced to install. 26 lb springs required. Bored or Aftermarket carb needed.
by means of direct drive?
otherwise.. my clutch point's still valid..
as soon as the augers need more torque the tavkit can multiply by 2.7.
And a lower spinning auger has more torque (less throwing distanve maybe) than a faster one
exact same rules apply up to a point of course
'sid
KartFab
Active member
cam, compression, methanol
CAM: see bob58o
COMPRESSION: try not to go over 10.5:1 and you can still use premium pump gas, you can increase compression by:
METHANOL: if you go higher in the compression range, methanol gives you a nice boost in torque especially in the low and mid-range areas.
CAM: see bob58o
COMPRESSION: try not to go over 10.5:1 and you can still use premium pump gas, you can increase compression by:
- thinner head gasket
- switch from dish piston to flat top
- boring to larger diameter bore
- file to fit rings (e.g. purchase a top ring that is +.010" oversize and file to .006" gap)
- milling head
- autolite spark plug
METHANOL: if you go higher in the compression range, methanol gives you a nice boost in torque especially in the low and mid-range areas.
65ShelbyClone
Active member
I think methanol is going to be really hard to start in cold weather. The flash point is only ~53F°.
Then just get the bigger engine or better still, sell what you have and get a snowblower that does what you need.
This topic comes up periodically in various forms when someone wants to modify a mud motor, paraglider engine, a generator(of all things), etc. The major problem is that all of these applications run the engine at high load for long periods of time. Utility engines are purposely detuned and derated so they can do that for 1000 hours or more. Car and bike engines can happily make 300-400% more HP/L because they only do it intermittently. In many cases they are rarely at all commanded to make full power.
A few inexpensive things you could try that may not be too taxing on the GX200 would be a GX390 carburetor conversion and a free-flowing exhaust/muffler. Keep the governor.
Then just get the bigger engine or better still, sell what you have and get a snowblower that does what you need.
This topic comes up periodically in various forms when someone wants to modify a mud motor, paraglider engine, a generator(of all things), etc. The major problem is that all of these applications run the engine at high load for long periods of time. Utility engines are purposely detuned and derated so they can do that for 1000 hours or more. Car and bike engines can happily make 300-400% more HP/L because they only do it intermittently. In many cases they are rarely at all commanded to make full power.
A few inexpensive things you could try that may not be too taxing on the GX200 would be a GX390 carburetor conversion and a free-flowing exhaust/muffler. Keep the governor.
65ShelbyClone
Active member
I know it may not have been "good" news, but the folks with modified mud boats blow the engines up pretty frequently. If your GX200 scattered, then the equipment value goes to near zero and you lose all the investment.
Just to illustrate my point further, back in the mid-1980s Ford UK designed the RS200 Group B rally car. It was a tiny AWD land missile with a Cosworth BDT turbo engine. The top-spec version's engine was only expected to last eight hours.
A further extreme from the same time period was the '86 BMW F1 engine used in various chassis. It was a 1.5L four that made in excess of 1400hp for qualifying. It only lasted a couple laps. Hopefully.
Just to illustrate my point further, back in the mid-1980s Ford UK designed the RS200 Group B rally car. It was a tiny AWD land missile with a Cosworth BDT turbo engine. The top-spec version's engine was only expected to last eight hours.
A further extreme from the same time period was the '86 BMW F1 engine used in various chassis. It was a 1.5L four that made in excess of 1400hp for qualifying. It only lasted a couple laps. Hopefully.
bob58o
SuckSqueezeBangBlow
Without thinking too hard about it.... A Bored stock carb seems easier than a gx390 carb if keeping the governor. The throttle lever moves in opposite directions on the gx200 vs the gx390. So not sure I know how to make that work.
Aside from that, people often make the claim that a larger carb hurts low end torque.
65ShelbyClone
Active member
You're right; a bored stocker would be cheaper and easier. I forget about them because IMO they're a waste of money and potential for any application that doesn't require a stock-appearing or fitting carb....and very few do. This is one of the few.
Regarding carb size and what qualifies as "too large," one way to evaluate that is to hook up a vacuum gauge(with a snubber since we're talking low cylinder count) and see what the manifold vacuum is at max power. -1.0inHg is about the most you'd want to see in a mild to moderate performance application. Full race can shoot for 0.5 or less.
There again, utility engines are detuned with undersized carbs in order to limit power and improve fuel-air mixing for economy and emissions.
A stock 0.615" (15.6mm) bore Predator carb only has 192mm² of CSA while a hemi intake port has about 480, the intake seat about 415, and the valve curtain area 485 at 0.225" lift. The valve bowl/pocket is probably smaller than 415, but I haven't molded one yet. Even so, 415mm² is equivalent to a 23mm round-bore carb.
Regarding carb size and what qualifies as "too large," one way to evaluate that is to hook up a vacuum gauge(with a snubber since we're talking low cylinder count) and see what the manifold vacuum is at max power. -1.0inHg is about the most you'd want to see in a mild to moderate performance application. Full race can shoot for 0.5 or less.
There again, utility engines are detuned with undersized carbs in order to limit power and improve fuel-air mixing for economy and emissions.
A stock 0.615" (15.6mm) bore Predator carb only has 192mm² of CSA while a hemi intake port has about 480, the intake seat about 415, and the valve curtain area 485 at 0.225" lift. The valve bowl/pocket is probably smaller than 415, but I haven't molded one yet. Even so, 415mm² is equivalent to a 23mm round-bore carb.
txluke
Active member
If you had a splined crankshaft a 6:1 gear reduction box like this would work. This is off a gx120 that was on a quarter midget race kart.
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