Hyosung GT250R custom engine | Page 2 | GTAMotorcycle.com

Hyosung GT250R custom engine

And that's only the beginning. If that crankshaft is to be sufficiently strong, it has to be made from a forging. Good luck with that.
 
I'll say! I will confess to not knowing much about specialty aftermarket like that ... I have a rough idea what the OEM process is. An OEM crank will start with a forging. If you machine a crank from one solid piece, that is a huge and really expensive chunk of alloy that you will have to machine away 80% of.
 
I'll say! I will confess to not knowing much about specialty aftermarket like that ... I have a rough idea what the OEM process is. An OEM crank will start with a forging. If you machine a crank from one solid piece, that is a huge and really expensive chunk of alloy that you will have to machine away 80% of.
The material is likely the cheapest component of the process I assure you ;)

Im not entirely sure, you can make ONE forging for cheaper. You need to make the tooling to make the forging, that needs engineering, machining, etc.....$$$$
 
The material is likely the cheapest component of the process I assure you ;)

Im not entirely sure, you can make ONE forging for cheaper. You need to make the tooling to make the forging, that needs engineering, machining, etc.....$$$$
Material cost will be an even smaller portion of the bill since you are looking at ~60 hp spread across four pistons. No huge forces there (assuming it is balanced properly). I think the OP has an interesting idea, but I don't think he realized that he was likely looking at >$10,000 in costs plus his time to get it done. That assumes that the design worked as intended and you don't have an oopsie that requires a new part.

I knew you ran machines, but didn't know the machines spent their time making fun engines. That's awesome Rob.
 
LOL, a 30,000 dollar machine today is considered garbage, and shops that have one likely cannot make a crankshaft (unless you're a hobbyist and have OOODLES of creative time on your hands in your hobby shop). You need a half million dollar CNC multiaxis mill/turn, that likely has 50-100k in tooling in it, with a highly skilled and costly cnc programmer to program/run it, and a shop that likely charges $100 an hour or more to do such a custom project, at Id say no less than 60 hours. And of course, a solid model, that is accurate, and engineered so you're not wasting the shops time with drawings on a napkin.

You're also going to need to grind it after heat treating, so another shop is going to have to charge you similar for their time.

This project isn't for the light hearted. It's done by people in the industry that know what they are doing.

Point being, I don't think you can find a compatible crank already made (god bless if you find something), you're gonna have to make one! Thats a lot of money for one component of your fancy idea! Good luck!
Thanks for the advice! I talked around and threw the idea of making my own crank when there is a crashed bike shop near me that sells engines. And the one engine they had was a VFR750 engine with only 50,000kms. The engine is so compact and the fact that the GT250r has the frame from the GT650r with alot of space I should be able to Frankenstein this engine into fitting in the GT250r.

Then I will call up ecotrons custom fuel injection company to make a throttle body for this carbureted unit. And before you ask why I'm doing this is because insurance is way to high for a 21 year old for me with anything more than 400cc ($675/mo for my 2009 fz6r). So with the GT250r VIN number I should be able to get a low price in insurance but with the power I want.
 
Thanks for the advice! I talked around and threw the idea of making my own crank when there is a crashed bike shop near me that sells engines. And the one engine they had was a VFR750 engine with only 50,000kms. The engine is so compact and the fact that the GT250r has the frame from the GT650r with alot of space I should be able to Frankenstein this engine into fitting in the GT250r.

Then I will call up ecotrons custom fuel injection company to make a throttle body for this carbureted unit. And before you ask why I'm doing this is because insurance is way to high for a 21 year old for me with anything more than 400cc ($675/mo for my 2009 fz6r). So with the GT250r VIN number I should be able to get a low price in insurance but with the power I want.
Be careful with that game. If the ins company is ever looking at a big payout they will look at the bike. It will be pretty obvious that you have a honda 750 in there and didnt tell them. Insurance void. All the money you ever earn in your life gone.
 
Point 1: The cost of doing this properly and getting it running will dwarf what it would cost to insure any normal production bike you care to name.
Point 2: You might have a hope if you stay within the Hyosung family. If the 250 and 650 share the frames then you could simply buy a blown-up 250 and a crashed but still running 650, and put all of the working bits of the 650 onto the 250. Engine, wiring harness, ECU, instrument cluster ... everything.
Point 3: Insurance companies don't like engine swaps. While you could potentially pull the wool over their eyes in the short term, you could also find yourself in a situation of having to make a claim, and the insurance company denying on the grounds of you having fraudulently obtained coverage ... and you won't have a leg to stand upon.
 
You could weld safely weld the ends of the cranks together (wrt balance anyway). You don't start to run into serious balance issues until you start relocating the support points (eg if you wanted to get the engines closer together and wanted to eliminate one of the previously outboard bearings to make a smaller package).
Sorry for the late reply been busy with exams. I decided it would be safer to just buy a already made motor from a crashed vfr750 near my house. The motor is very compact and the bike is carbureted so I don't have to worry about a ECU. I'm doing this mainly because I'm 21 and insurance on a motorcycle with more than 400cc in Toronto is too high, as my 2009 Yamaha fz6r cost me $675/mo. I plan on selling the 600 and buying the GT250r with the aggressive position I want, however with more power from the VFR750 motor at less than $400/mo for me.

It may cost some money to get the engine mount custom made along with an Ecotrons Digital Fuel Injection. However it's worth it in the end for a more affordable ride later on and unique as no one will have the same bike as me.
 
Point 1: The cost of doing this properly and getting it running will dwarf what it would cost to insure any normal production bike you care to name.
Point 2: You might have a hope if you stay within the Hyosung family. If the 250 and 650 share the frames then you could simply buy a blown-up 250 and a crashed but still running 650, and put all of the working bits of the 650 onto the 250. Engine, wiring harness, ECU, instrument cluster ... everything.
Point 3: Insurance companies don't like engine swaps. While you could potentially pull the wool over their eyes in the short term, you could also find yourself in a situation of having to make a claim, and the insurance company denying on the grounds of you having fraudulently obtained coverage ... and you won't have a leg to stand upon.
Very good points however the insurance company I have is very ignorant compared to the last one I was with. They go by cc and not the class of motorcycle which is very annoying since my motorcycle is not a super sport. Also they don't speak to the public when my 2009 fz6r got backed into last month by a careless driver they didn't even show up to the scene to take pictures they just told me to email pics and then they sent the money to repair it at my dealership.

It's very annoying because the adjuster who showed up knows nothing about bikes and he didn't even repair my mirror since I kept telling him it shakes violently at highway speeds since the drop. So I understand about be fraudulent, but this alpha insurance doesn't know anything about motorcycles.
 
They'll figure it out in a big hurry if they have to pay out a big claim.
 
Very good points however the insurance company I have is very ignorant compared to the last one I was with. They go by cc and not the class of motorcycle which is very annoying since my motorcycle is not a super sport. Also they don't speak to the public when my 2009 fz6r got backed into last month by a careless driver they didn't even show up to the scene to take pictures they just told me to email pics and then they sent the money to repair it at my dealership.

It's very annoying because the adjuster who showed up knows nothing about bikes and he didn't even repair my mirror since I kept telling him it shakes violently at highway speeds since the drop. So I understand about be fraudulent, but this alpha insurance doesn't know anything about motorcycles.
That's because they were looking at a small payout. If they are looking at six or seven figures, you get the A team doing a very thorough examination.
 
Hope you never actually need that insurance because if the payout is sizeable they'll retroactively cancel your policy in about 2 seconds when they find out you misrepresented the policy by "forgetting" to tell them you jammed a bigger engine in the bike and they weren't actually insuring what you told them they were insuring.
 
Sorry for the late reply been busy with exams. I decided it would be safer to just buy a already made motor from a crashed vfr750 near my house. The motor is very compact and the bike is carbureted so I don't have to worry about a ECU. I'm doing this mainly because I'm 21 and insurance on a motorcycle with more than 400cc in Toronto is too high, as my 2009 Yamaha fz6r cost me $675/mo. I plan on selling the 600 and buying the GT250r with the aggressive position I want, however with more power from the VFR750 motor at less than $400/mo for me.

It may cost some money to get the engine mount custom made along with an Ecotrons Digital Fuel Injection. However it's worth it in the end for a more affordable ride later on and unique as no one will have the same bike as me.
Why not get a Ninja 250 for the street, pay $150/mo for insurance for 4 years, learn how to ride then get get the bigger bike when you age and experience deliver decent insurance discounts?

If you're hellbent on going fast, keep the 600 and take it to the track. Should be about the same cost and you have the best of both worlds -- safer and cheaper for the street, wild and crazy on the track for cheep too.

By the way when you get insurance you will be asked about modifications to the bike - if you lie and ever have a claim you in double trouble. First they may not pay out the claim due to insurance fraud, then getting tagged for ins fraud puts all your insurance cost up - wanna pay $1000/mo tio insure a Yaris? Is it worth the risk?
 
Thanks for the advice! I talked around and threw the idea of making my own crank when there is a crashed bike shop near me that sells engines. And the one engine they had was a VFR750 engine with only 50,000kms. The engine is so compact and the fact that the GT250r has the frame from the GT650r with alot of space I should be able to Frankenstein this engine into fitting in the GT250r.

Then I will call up ecotrons custom fuel injection company to make a throttle body for this carbureted unit. And before you ask why I'm doing this is because insurance is way to high for a 21 year old for me with anything more than 400cc ($675/mo for my 2009 fz6r). So with the GT250r VIN number I should be able to get a low price in insurance but with the power I want.

You are good right up until the insurance person says 'have any modifications been made to the motorcycle?' then you are completely euchred.



"It's very annoying because the adjuster who showed up knows nothing about bikes and he didn't even repair my mirror since I kept telling him it shakes violently at highway speeds since the drop." :unsure: are you serious? you want your insurance company to fix the vibration in your mirror!
 
Thank you for a very entertaining read. I needed that.
Another thing to remember is with great power comes great responsibility.
No wait
Another thing to remember is with power you will need handling and braking to match or its all for nothing. Putting a 750cc engine in a bike that lets face it wasn’t great when it had a 250 is just going to create a fast death trap.
I know this all to well as I own a car that weighs 2100lbs and has 500hp/450lbs.
It has standard steering/ standard brakes and is the epitome of you should never build or meet your hero’s. I could go much faster with less power in today’s factory produced cars for less money.

Another aspect of going fast is skill. You can’t go fast for long without it.
I once modified my race atv more than doubling my investment only to find out my skill was the limiting factor. That said some people never learn, my current ride is well out of my skill set also. Maybe I need a ninja 250 after all.
 
Also a very good friend is currently building a Mustang with an engine swap.
Seems simple enough. 1993 Mustang lx Car came with a 5.0 v8 250hp
the swap 2016 5.0 v8 with twin turbo, the goal 850hp on pump gas.
His 93 Mustang has now cost about $35,000 and isn’t on the road yet.

building fast isn’t cheap
and it’s not cheap to insure
 

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