Hawk engine swap ideas? - Page 2

LesterJames · 10-24-2016, 12:43 PM

This is the best new 450 6-speed engine I've found new. Almost $1000. Wouldn't be a straight bolt in, I don't think. But it would be 3x the horse power. Which might be a bit scary on the Hawk. You would probably need to get new brakes, disks and sprockets at the least to be able to handle it.
http://cqskill.en.alibaba.com/produc...dirt_bike.html

Ariel Red Hunter · 10-24-2016, 12:53 PM

Quote:

Originally Posted by LesterJames

This is the best new 450 6-speed engine I've found new. Almost $1000. Wouldn't be a straight bolt in, I don't think. But it would be 3x the horse power. Which might be a bit scary on the Hawk. You would probably need to get new brakes, disks and sprockets at the least to be able to handle it.
http://cqskill.en.alibaba.com/produc...dirt_bike.html

Interesting. Where are you going to hang the radiator?

jct842 · 10-24-2016, 02:13 PM

How about over the front wheel and around the head light with flexible hoses going back to the frame? That would be one heck of a motor to stick in a craigs listing that had a road title.

there are a lot of older street bikes that motor would fit too.

LesterJames · 10-24-2016, 02:46 PM

Quote:

Originally Posted by Ariel Red Hunter

Interesting. Where are you going to hang the radiator?

Oh ya! And you'd need a radiator. ha. Those are pretty cheep though. Would it fit on the sides of the front part of the frame? Maybe you'd have to loose the side plastics.

Ariel Red Hunter · 10-24-2016, 03:59 PM

Quote:

Originally Posted by LesterJames

Oh ya! And you'd need a radiator. ha. Those are pretty cheep though. Would it fit on the sides of the front part of the frame? Maybe you'd have to loos the side plastics.

Well, the frame geometry was not designed to have that much static weight up high. I don't know how much water those things need, but remember "A pint's a pound the world around" plus the radiator.

BlackBike · 10-25-2016, 12:40 AM

I thought you were thinking of an old 400 air cooled, around $500 online but mabey cheaper junk yard deal at $250 - me dos centavos.

Ahh those junk yard finds...you never know

Ariel Red Hunter · 10-25-2016, 08:42 AM

Quote:

Originally Posted by BlackBike

I thought you were thinking of an old 400 air cooled, around $500 online but mabey cheaper junk yard deal at $250 - me dos centavos.

Ahh those junk yard finds...you never know

I quite agree. A 350-400cc air cooled is much more practical. The Suzuki 350 DR engine would be great, if it is small enough. Over-head cams, though, tend to make the engine too tall. I see no one has shown any love for the BSA B-40, a 350cc push rod air cooled unit construction job. It is a short stroke engine, so should be easier to fit in. Would have to have the wiring re-configured though.

LesterJames · 10-25-2016, 08:49 AM

Quote:

Originally Posted by Ariel Red Hunter

I see no one has shown any love for the BSA B-40, a 350cc push rod air cooled unit construction job.

Ya, I'm cool doing an older engine... but the BSA B-40, may be a little too old, atleast for my tastes. Ha.

A used 350 from like a 90's dirt bike would probably be ideal. I was just trying to see how much it would be to get a new motor on it. Looks like it would be almost as much as the bike. So, yes. Used is the way to go.

BlackBike · 10-25-2016, 10:29 AM

This is why I said , "if the deal is there", otherwise will quickly break the bank and exceed the value.

Weldangrind · 10-25-2016, 11:24 AM

I spotted an '88 Honda Hawk 400 motor on CL yesterday for $100.00. The motor has been in storage since then. It would take some fab work for the mounts and the exhaust, but a 400 twin would be lots of fun.

wilserchinarider · 10-25-2016, 11:54 AM

Quote:

Originally Posted by Weldangrind

but a 400 twin would be lots of fun.

Maybe I'm getting old, I'm afraid it may be too much fun...some of those old twins put out some power!

jimwildman · 10-25-2016, 05:57 PM

I dont think the Hawk has the backbone to handle much more torque.

Normally i would be one to jump at a bigger engine, but this bike already has a noticeable torque twist to it. I suspect the swing arm bushings are the source of the flex.

Ive done it plenty of times and have had motor mounts rip out of the frame tubes on better made units.

I have no idea what is in the steel but welding it is like a firework show with mig, and with tig it dont want to form an alloy with my filler rods.

its a challenge to weld, makes me appreciate the crappy looking welds on the bike. seems they did really well considering what they were working with.

nothing is impossible but there is a point where it becomes less value then the effort taken.

Ariel Red Hunter · 10-25-2016, 06:25 PM

Quote:

Originally Posted by LesterJames

Ya, I'm cool doing an older engine... but the BSA B-40, may be a little too old, atleast for my tastes. Ha.

A used 350 from like a 90's dirt bike would probably be ideal. I was just trying to see how much it would be to get a new motor on it. Looks like it would be almost as much as the bike. So, yes. Used is the way to go.

Too old? BSA = Best Scoot Available. Although Triumph riders used to say, BSA - means Bastard's Stopped Again!

Ariel Red Hunter · 10-25-2016, 06:31 PM

Quote:

Originally Posted by jimwildman

I dont think the Hawk has the backbone to handle much more torque.

Normally i would be one to jump at a bigger engine, but this bike already has a noticeable torque twist to it. I suspect the swing arm bushings are the source of the flex.

Ive done it plenty of times and have had motor mounts rip out of the frame tubes on better made units.

I have no idea what is in the steel but welding it is like a firework show with mig, and with tig it dont want to form an alloy with my filler rods.

its a challenge to weld, makes me appreciate the crappy looking welds on the bike. seems they did really well considering what they were working with.

nothing is impossible but there is a point where it becomes less value then the effort taken.

Yes I agree with you. As I've said before-it is what it is. However the lousy swing arm bushings problem is easy to fix. A little machine work on the swing arm, and you can put in roller bearings back there. I said the B-40 because it is short in height, is a pushrod motor and has a short stroke.

BlackBike · 10-26-2016, 12:11 AM

I welded up the dorsal frame seam to make room for valve cover removal with a flux core point and shoot welder upside down. Can you blow it out , yes. Is the tube thin, yes. Can you weld it, absolutely, low and slow

10-24-2016, 12:43 PM	#16
LesterJames Join Date: Sep 2016 Location: Acworth, GA Posts: 21	450 Engine This is the best new 450 6-speed engine I've found new. Almost $1000. Wouldn't be a straight bolt in, I don't think. But it would be 3x the horse power. Which might be a bit scary on the Hawk. You would probably need to get new brakes, disks and sprockets at the least to be able to handle it. http://cqskill.en.alibaba.com/produc...dirt_bike.html Last edited by LesterJames; 10-24-2016 at 12:44 PM. Reason: Update
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10-25-2016, 12:40 AM	#21
BlackBike Join Date: Feb 2016 Location: George West, Texas Posts: 4,097	I thought you were thinking of an old 400 air cooled, around $500 online but mabey cheaper junk yard deal at $250 - me dos centavos. Ahh those junk yard finds...you never know __________________ ***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
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10-25-2016, 10:29 AM	#24
BlackBike Join Date: Feb 2016 Location: George West, Texas Posts: 4,097	This is why I said , "if the deal is there", otherwise will quickly break the bank and exceed the value. __________________ ***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
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10-25-2016, 11:24 AM	#25
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I spotted an '88 Honda Hawk 400 motor on CL yesterday for $100.00. The motor has been in storage since then. It would take some fab work for the mounts and the exhaust, but a 400 twin would be lots of fun. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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10-26-2016, 12:11 AM	#30
BlackBike Join Date: Feb 2016 Location: George West, Texas Posts: 4,097	I welded up the dorsal frame seam to make room for valve cover removal with a flux core point and shoot welder upside down. Can you blow it out , yes. Is the tube thin, yes. Can you weld it, absolutely, low and slow __________________ ***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
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10-24-2016, 02:13 PM	#18
jct842 Join Date: Jan 2015 Location: arkansas Posts: 297	How about over the front wheel and around the head light with flexible hoses going back to the frame? That would be one heck of a motor to stick in a craigs listing that had a road title. there are a lot of older street bikes that motor would fit too.
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10-25-2016, 05:57 PM	#27
jimwildman Join Date: May 2016 Posts: 237	I dont think the Hawk has the backbone to handle much more torque. Normally i would be one to jump at a bigger engine, but this bike already has a noticeable torque twist to it. I suspect the swing arm bushings are the source of the flex. Ive done it plenty of times and have had motor mounts rip out of the frame tubes on better made units. I have no idea what is in the steel but welding it is like a firework show with mig, and with tig it dont want to form an alloy with my filler rods. its a challenge to weld, makes me appreciate the crappy looking welds on the bike. seems they did really well considering what they were working with. nothing is impossible but there is a point where it becomes less value then the effort taken.
	0