Polaris ATV Forum banner
1 - 20 of 28 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 ·
So I have a Hawkeye 300 and I’ll be getting an AMR300 and a few other things and I’m looking to run 10lbs of boost. I have the carburetor figured out and I’ll be using a carb from a riding mower as may people on YouTube have been (thunderhead289,robot cantina). I’d like to know yalls opinions on what a stock engine can hold and what the weak points are and what kind of boost it should hold before bending the connecting rod. I’ll be tapping the engine block for head studs from a Cummins 12valve if I end up stretching the stock bolts, and I believe im going to drive the blower by an attachment that bolts to the cam gear and Will have a sprocket on the outside of the cylinder head. What fuel do you think I’ll have to run? 91 93 or methonal
 

·
Premium Member
2008 800 ho efi, 2019 850 SP premium
Joined
·
14,063 Posts
So I have a Hawkeye 300 and I’ll be getting an AMR300 and a few other things and I’m looking to run 10lbs of boost. I have the carburetor figured out and I’ll be using a carb from a riding mower as may people on YouTube have been (thunderhead289,robot cantina). I’d like to know yalls opinions on what a stock engine can hold and what the weak points are and what kind of boost it should hold before bending the connecting rod. I’ll be tapping the engine block for head studs from a Cummins 12valve if I end up stretching the stock bolts, and I believe im going to drive the blower by an attachment that bolts to the cam gear and Will have a sprocket on the outside of the cylinder head. What fuel do you think I’ll have to run? 91 93 or methonal
Font Line Window Pattern Automotive exterior
to the forum
Ball Automotive lighting Vehicle registration plate Font Gas

From the Official Forum Greeter, be careful of the other imposters.
 

·
Administrator
Joined
·
18,962 Posts
Instagram? You are speaking baby language - I don't instagram, fakebook, twister, lurkedin, rumbler or use any other 'so called social media' app. Upload videos to VIMEO and post links on the forum. Otherwise just post pics of your project.
 

·
Premium Member
2015 Sportsman XP 1000 LE Touring
Joined
·
395 Posts
Sounds interesting 🤔
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #8 ·
Instagram? You are speaking baby language - I don't instagram, fakebook, twister, lurkedin, rumbler or use any other 'so called social media' app. Upload videos to VIMEO and post links on the forum. Otherwise just post pics of your project.
I’ll post pics on the forum too but the only other things I’ll post too is youtube Instagram and telegram
 

·
Premium Member
2015 Sportsman XP 1000 LE Touring
Joined
·
395 Posts
I like YouTube links...
 

·
Premium Member
04 Sportsman 700, 04 Scrambler 500, 04 trail touring 550 sled
Joined
·
1,548 Posts
Why a 300? Why not something like a scrambler 500 that’s got a stout engine, dohc, a little lighter than say a sportsman, and awd? Maybe even an 800 which is even bigger cc and awd? You won’t get very far with 10lbs and 9.2:1 compression without forged rods, correctly gapped rings, and a lower comp flat top forged piston. You also won’t be gaining much in hp with that small of cc, no cam changes, no flow increases (head, exhaust) and no intercooler. Even with all that, it would also be very cool to see a supercharged four wheeler and I’m interested to see how it goes.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #11 ·
Why a 300? Why not something like a scrambler 500 that’s got a stout engine, dohc, a little lighter than say a sportsman, and awd? Maybe even an 800 which is even bigger cc and awd? You won’t get very far with 10lbs and 9.2:1 compression without forged rods, correctly gapped rings, and a lower comp flat top forged piston. You also won’t be gaining much in hp with that small of cc, no cam changes, no flow increases (head, exhaust) and no intercooler. Even with all that, it would also be very cool to see a supercharged four wheeler and I’m interested to see how it goes.
Very good points! The reason I’m using a 300 is it was a good deal. I know without porting and cam it will have a problem flowing however I can’t find a better cam or a forged rod, In the future I’ll have a custom rod made. I would use an intercooler however I’m doing a draw through carb and that wouldn’t work. If I had EFI I would do a turbo. Thanks for the imput!
 

·
Premium Member
04 Sportsman 700, 04 Scrambler 500, 04 trail touring 550 sled
Joined
·
1,548 Posts
Good point. If it blows, it’s just a 300 that you got a good deal on. Good luck.
 

·
Premium Member
04 Sportsman 700, 04 Scrambler 500, 04 trail touring 550 sled
Joined
·
1,548 Posts
Nope.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #17 ·
So far I got a blower, oil cooler, remote oil mount, cooling fan, boost gauge, front diff and axles, front driveshaft, 4wd transmission case, the gears and shafts for the transmission, the 4wd switch, a bunch of little fittings and odd parts. The induction setup will use two lawn mower carbs as they are simple, small, and butterfly. Each carb is 30mm. The drive pulley from the cam gear seems like it will work out... won’t have much more info on that untill I begin making the drive shaft and pulley coming out of the head. 👍
 

·
Premium Member
04 Sportsman 700, 04 Scrambler 500, 04 trail touring 550 sled
Joined
·
1,548 Posts
Very cool. Keep us updated.
 
  • Like
Reactions: Joint Performance

·
Premium Member
2015 Sportsman XP 1000 LE Touring
Joined
·
395 Posts
1 - 20 of 28 Posts
Top