Comparisons of Engines

KRIEG150 · 4th June 2009, 09:17

i am conceptualizing a 6WD atv using independent suspensions on all six wheels and skid steering system. I have finalized all other tech aspects except one primary thing - the engine

. The points that are kind of bugging me are selection of engines from the two options i have finalized:

1. Pulsar150 (1st gen): I have this engine from my past gokart project
(refer http://www.team-bhp.com/forum/introd...etting-me.html)

the specs:
Power: 11bhp @ 8000rpm (apprx)
Torque: 11Nm @ 7000rpm (apprx)

2. Bajaj Rikshaw 180cc engine: a small engine compared to the torque it generates. Also, it is one of the cheapest engines to maintain and very mechanic-friendly too

the specs:
power: 8bhp @ 5000rpm
torque: 11.5Nm @ 4000rpm

now as a general rule, power = torque X rpm x "some constant"; by that analogy, the P150 appears more powerful than the rik. But then, riks have been known to carry much heavier loads (though a bit sluggishly) whereas the pulsar is fast and quick.

Are the engines equally matched? all that my ATV would need is torque since i want skid-steering in it. Please advise.

alpha1 · 4th June 2009, 11:21

More torque at lower RPM means you can run your gears at low RPM without shifting down.

It also means you can start off with less clutch slip, low revving.

Converse is true for higher torque/RPM at higher RPM. You don't need to upshift, you can zoom by just revving the engine.

It all boils down to your application.

sgiitk · 4th June 2009, 11:54

For an ATV you will need a lot of low end otrque and should not be too worried about the high end power.

Also, your chassis reminds me of the Tatra Trucks of the Army. They apparently have a backbone structure with each apir of wheels allowed to flex independently. You may call it a Caterpillar design, with a backbone allowing individual axles a lot of flexibility.

KRIEG150 · 4th June 2009, 13:17

@sgiitk
Also, your chassis reminds me of the Tatra Trucks of the Army. They apparently have a backbone structure with each apir of wheels allowed to flex independently. You may call it a Caterpillar design, with a backbone allowing individual axles a lot of flexibility.[/quote]

i am fan of all variations of TATRA trucks - they use modified de dion half-axles with a combination of leaf springs and pneumatic dampers. my design however has the basic mcpherson with bell-crank lever and horizontally mounted shocks(primarily to save space)

Shan2nu · 4th June 2009, 20:02

Only looking at an engine wont tell you the complete story, gearing plays a much larger role in transfering torque to the wheels, which explains why the 1st gear in a car has so much more pulling capability than the 5th gear, even thought the torque/power comes from the same engine.

So if you can sort out the gearing, the Pulsar engine would be better or else stick to the other one.

Shan2nu

Technocrat · 4th June 2009, 20:24

Just a small correction P150 classic produced approximately 13 bhp at 8000 rpm

Why dont you try to source a Karizma engine it has more power & torque at relatively lower RPM

Power - 17ps@7000 RPM

Torque - 18.35Nm@6000 RPM

KRIEG150 · 4th June 2009, 20:37

@technocrat
thanks for the information update; i couldnt get the figure fr P150 (1st gen) so felt it might a a couple of horses lesser than the dtsi's

@shantanu
probably, an option that i have is to use the P150 engine and manipulate & increase the sprocket size of the final transmission shaft so that in any given gear, i get a higher torque at the wheels (SIX of them in fact) than the stock P150. it seems, well, a pretty straight forward course from here onwards. Thanks for the support guys!

4th June 2009, 09:17	#1
KRIEG150 Newbie Join Date: May 2009 Location: mumbai Posts: 9 Thanked: 0 Times	Comparisons of Engines i am conceptualizing a 6WD atv using independent suspensions on all six wheels and skid steering system. I have finalized all other tech aspects except one primary thing - the engine . The points that are kind of bugging me are selection of engines from the two options i have finalized: 1. Pulsar150 (1st gen): I have this engine from my past gokart project (refer http://www.team-bhp.com/forum/introd...etting-me.html) the specs: Power: 11bhp @ 8000rpm (apprx) Torque: 11Nm @ 7000rpm (apprx) 2. Bajaj Rikshaw 180cc engine: a small engine compared to the torque it generates. Also, it is one of the cheapest engines to maintain and very mechanic-friendly too the specs: power: 8bhp @ 5000rpm torque: 11.5Nm @ 4000rpm now as a general rule, power = torque X rpm x "some constant"; by that analogy, the P150 appears more powerful than the rik. But then, riks have been known to carry much heavier loads (though a bit sluggishly) whereas the pulsar is fast and quick. Are the engines equally matched? all that my ATV would need is torque since i want skid-steering in it. Please advise.
	() Thanks

4th June 2009, 11:21	#2
alpha1 Senior - BHPian Join Date: Apr 2007 Location: LandOfNoWinters Posts: 2,095 Thanked: 2,605 Times	More torque at lower RPM means you can run your gears at low RPM without shifting down. It also means you can start off with less clutch slip, low revving. Converse is true for higher torque/RPM at higher RPM. You don't need to upshift, you can zoom by just revving the engine. It all boils down to your application.
	() Thanks

4th June 2009, 11:54	#3
sgiitk BANNED Join Date: Dec 2007 Location: Gurugram Posts: 7,969 Thanked: 4,788 Times	For an ATV you will need a lot of low end otrque and should not be too worried about the high end power. Also, your chassis reminds me of the Tatra Trucks of the Army. They apparently have a backbone structure with each apir of wheels allowed to flex independently. You may call it a Caterpillar design, with a backbone allowing individual axles a lot of flexibility.
	() Thanks

4th June 2009, 13:17	#4
KRIEG150 Newbie Join Date: May 2009 Location: mumbai Posts: 9 Thanked: 0 Times	@sgiitk Also, your chassis reminds me of the Tatra Trucks of the Army. They apparently have a backbone structure with each apir of wheels allowed to flex independently. You may call it a Caterpillar design, with a backbone allowing individual axles a lot of flexibility.[/quote] i am fan of all variations of TATRA trucks - they use modified de dion half-axles with a combination of leaf springs and pneumatic dampers. my design however has the basic mcpherson with bell-crank lever and horizontally mounted shocks(primarily to save space)
	() Thanks

4th June 2009, 20:02	#5
Shan2nu Senior - BHPian Join Date: Feb 2004 Location: Hubli - Karnata Posts: 5,533 Thanked: 125 Times View My Garage	Only looking at an engine wont tell you the complete story, gearing plays a much larger role in transfering torque to the wheels, which explains why the 1st gear in a car has so much more pulling capability than the 5th gear, even thought the torque/power comes from the same engine. So if you can sort out the gearing, the Pulsar engine would be better or else stick to the other one. Shan2nu
	() Thanks

4th June 2009, 20:24	#6
Technocrat Senior - BHPian Join Date: Feb 2004 Location: GTA Posts: 14,813 Thanked: 2,700 Times	Just a small correction P150 classic produced approximately 13 bhp at 8000 rpm Why dont you try to source a Karizma engine it has more power & torque at relatively lower RPM Power - 17ps@7000 RPM Torque - 18.35Nm@6000 RPM Last edited by Technocrat : 4th June 2009 at 20:28.
	() Thanks

4th June 2009, 20:37	#7
KRIEG150 Newbie Join Date: May 2009 Location: mumbai Posts: 9 Thanked: 0 Times	@technocrat thanks for the information update; i couldnt get the figure fr P150 (1st gen) so felt it might a a couple of horses lesser than the dtsi's @shantanu probably, an option that i have is to use the P150 engine and manipulate & increase the sprocket size of the final transmission shaft so that in any given gear, i get a higher torque at the wheels (SIX of them in fact) than the stock P150. it seems, well, a pretty straight forward course from here onwards. Thanks for the support guys!
	() Thanks