Boosting a High Mileage Engine?


#1
This example would be for a street bike and not raced at the track. If generating a peak power of 250-300 horsepower via a supercharger (or a turbo) on a used Hayabusa, does the engine have to be low mileage? If so what is low mileage? Does a certain number of miles necessitate internal engine work for this project? We have to assume that we do not have a compression test or other helpful data from the bike seller, but scheduled maintenance has been performed.

Depending on the above, if the transmission will be undercut, then based on having to remove the engine for all scenarios, would such help the case for purchasing a bike that is discounted due to high mileage for the purpose of boosting it?
 
#3
This example would be for a street bike and not raced at the track. If generating a peak power of 250-300 horsepower via a supercharger (or a turbo) on a used Hayabusa, does the engine have to be low mileage? If so what is low mileage? Does a certain number of miles necessitate internal engine work for this project? We have to assume that we do not have a compression test or other helpful data from the bike seller, but scheduled maintenance has been performed.
Hi. If you want it to make power and last and stay together is not cheep. I will have over $40,000.00 in just the motor.
 
#6
This example would be for a street bike and not raced at the track. If generating a peak power of 250-300 horsepower via a supercharger (or a turbo) on a used Hayabusa, does the engine have to be low mileage? If so what is low mileage? Does a certain number of miles necessitate internal engine work for this project? We have to assume that we do not have a compression test or other helpful data from the bike seller, but scheduled maintenance has been performed.

Depending on the above, if the transmission will be undercut, then based on having to remove the engine for all scenarios, would such help the case for purchasing a bike that is discounted due to high mileage for the purpose of boosting it?
If your going to try to get close to 300hp you have to open the engine anyways. I think I have read every turbo thread there is on this sight. 20,000 is the common number you here the experts say. But if your going to pull the cylinder because you will have to put a spacer in why not throw rings at it. We all can read throw $$ at it. Pistons rods......
Your whole post is theoretical so not sure if I added anything worth while.
 
#7
Personally I wouldn't get a high mileage bike and throw good money at it. A stock Busa with 2000 miles might not work either. If the original owner broke in the engine by Suzuki specifications the leak down could be around 8-10% which you would get blow by under boost.
 
#8
If your going to try to get close to 300hp you have to open the engine anyways. 20,000 is the common number you here the experts say.
That is the first number put to the mileage that I have seen, so it is in fact helpful.

What internal upgrades does 250 hp require? I threw out the 250-300 range in ignorance of the differences, trying to provide you some detail. I like the 250 hp point as it replicates a similar power to weight ratio of a race replica. I do like the curves and that is a realistic point that borders on excessive power to me.

Personally I wouldn't get a high mileage bike and throw good money at it.
Educate me on why you would not. In my ignorance I think that the drivetrain is modular and the engine builder is expert at evaluating and replacing anything that is not up to spec., whether the bike has 20k miles or 60k miles on it.

A stock Busa with 2000 miles might not work either. If the original owner broke in the engine by Suzuki specifications the leak down could be around 8-10% which you would get blow by under boost.
I read the Hayabusa break-in procedure, one of those advising to limit the rpms. Yes I see the risk in that. But then the builder sees that failure and includes rings in the build, which is not a big deal, yes?

Jermzfree I get the impression from you that any used bike taken to a builder is subject to providing me truly bad news. My experience is that a seller is not going to provide me with compression tests of the engine, thus I should only consider a bike in a crate if I want a reliable engine build. So what approach for bike shopping do you recommend? What actionable steps?
 

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#9
That is the first number put to the mileage that I have seen, so it is in fact helpful.

What internal upgrades does 250 hp require? I threw out the 250-300 range in ignorance of the differences, trying to provide you some detail. I like the 250 hp point as it replicates a similar power to weight ratio of a race replica. I do like the curves and that is a realistic point that borders on excessive power to me.



Educate me on why you would not. In my ignorance I think that the drivetrain is modular and the engine builder is expert at evaluating and replacing anything that is not up to spec., whether the bike has 20k miles or 60k miles on it.



I read the Hayabusa break-in procedure, one of those advising to limit the rpms. Yes I see the risk in that. But then the builder sees that failure and includes rings in the build, which is not a big deal, yes?

Jermzfree I get the impression from you that any used bike taken to a builder is subject to providing me truly bad news. My experience is that a seller is not going to provide me with compression tests of the engine, thus I should only consider a bike in a crate if I want a reliable engine build. So what approach for bike shopping do you recommend? What actionable steps?
u might wanna actually call a turbo expert.... have a conversation and an acceptable budget… but only if u actually have the funds... don't waste anyones time... a stage one turbo out the door is gonna be 6-7 grand/installed... absolute minimum.... pistons are 600 bucks a set or so..... rods are gonna stay stock..... crank may or may not have to be sent out.... like I said give an ACTUAL EXPERT a call....
 
#10
Dude just boost it. Doesn't matter the miles or anything else. If it runs good turbo it. My old turbo gen 1 busa had 60k miles on it. Ran 5 psi on a stage one kit when the bike turned 2k miles. I bought the bike from the orignal owner. He rode that thing to taIL of the dragon, cali, West coast and east coast. The motor ended up smashing the rod bearings. But that was after the bike was turned up. About 100 track passes and a bunch of roll racing. Bike made 275 on c16 with no mods other then turbo kit. No spacer plate, valve springs, headgasket. We hot lapped the bike pretty bad one day that's why it died. Made 6 back to back passes. No cool down. This is my personal experience.
 
#11
As for mile's 20k miles that thing is just broken in..... 50k miles it's been used but still has plentry of life. I had a buddy with a cbr 929 with 90k on it. Thing still ran strong till he crashed it for the insurance check. Since nobody would buy it. Got a buddy now that has a 2007 r1 with 60k miles and has only checked the valves once. He's out ever weekend street racing pepole with it. Just do a compression check and leak down. If it's not showing major wear let it buck. Turbo it and later down the road drop the motor and rebuild it or build it up. Or do what I do. Buy a bike that's already turbod. Much cheaper that way. Even if something breaks your still ahead of the game. Even if you lose money your still ahead. Gen 1 busa can be had from 4 to 6k then add turbo kit 6 to 7k. Your looking at 10 to 13k to build one. When you can buy one for 8k. I bought my gen 2 turbo bike for 8k. Wife thinks it was 5k. Don't tell her.... Gen 2 non turbo bikes up here go for 7k.
 
#12
That is the first number put to the mileage that I have seen, so it is in fact helpful.

Educate me on why you would not. In my ignorance I think that the drivetrain is modular and the engine builder is expert at evaluating and replacing anything that is not up to spec., whether the bike has 20k miles or 60k miles on it.

Jermzfree I get the impression from you that any used bike taken to a builder is subject to providing me truly bad news. My experience is that a seller is not going to provide me with compression tests of the engine, thus I should only consider a bike in a crate if I want a reliable engine build. So what approach for bike shopping do you recommend? What actionable steps?
I put a turbo on my older bike and had little nagging issues after the build. Tps sensor, intake boots cracked, misc electrical issues that I eventually upgraded the wiring harness to fix. If I did it again I would buy a Gen 2 with low miles.
 

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#13
I’ve never put a mileage on what’s considered safe for boosting. I always scratch my at why people in general think that motorcycle engines are delicate and wear out fast. When in reality there’s more engineering and precision in them then automobile engines of the same design period. Think about it, you got an engine that can rev 11k rpm or better, and stay together on a road worthy vehicle that’s gonna see a lot of miles.

I’ve taken Hayabusa engines apart with less then 500 miles, and as many as 70k miles. I’ll tell you this, a majority of the high mileage engines don’t look, or measure out any worse then a 500 mile motor on the inside. When I do base spacer motors, I always open the ring gaps a touch. But just about all of them had factory gaps on them.

But just like with anything, it depends on how well it was maintained. In my opinion, motorcycles in general get the short end of the maintenance stick. Why? With sport bikes, typically younger people buy them. Of which many aren’t mechanically inclined, not responsible, or simply don’t care to do maintenance. They’re usually the worst. Rev limiter cold start ups, running the wrong fuel, engine mods with no tune etc. I see it every day owning a motorcycle shop.

But with all that abuse, guess what? They still look like 500 mile engines. These engines just don’t ware fast or much at all unless real extreme circumstances. So I’ll go against the grain and say get a higher mileage engine. While on these engines in particular it really doesn’t make a difference, a “looser” engine is more favorable for boost.

I mess with a lot of stock bottom end LS engines. If they have less then 150k on them, I won’t buy them. I want to be able to just change the cam, and valves springs, then feed it 30psi. Can’t do that as easily on an untouched lower mileage engine.
 
#14
I put a turbo on my older bike and had little nagging issues after the build. Tps sensor, intake boots cracked, misc electrical issues that I eventually upgraded the wiring harness to fix. If I did it again I would buy a Gen 2 with low miles.
Thanks for the response. If there are records for all of the scheduled maintenance, then the intake rubber and cooling rubber has been replaced, switches, grounds, and sensor connections inspected and cleaned, etc. If there is fifteen year old rubber under that hood, then it is a no-go or it would otherwise factor into my offer based on a rate of $100/hour to refresh it. Given how people post their vehicles at premium prices based solely on the shine of the fairings, the seller often will not go for this, and so be it that the deal is dead.

Given this, my concerns are more of an engine explosion due to weakened internal components, and the unplanned cost of an engine rebuild.
 
#15
I’ve never put a mileage on what’s considered safe for boosting. I always scratch my at why people in general think that motorcycle engines are delicate and wear out fast.
Thank you very much. Since you would be a potential candidate for any such work your professional view is especially appreciated.

My VFR mirrored the abuse you talk about. With nearly twenty thousand miles on it, I think the oil was the original oil. However after a refresh it runs like new. There's no smoke, no burning oil, and no sign of any problem.

I am seeing a discrepancy between those who worry about a high mileage engine in this case and the massive feedback on this forum about how robust the Hayabusa engine is. That does not reconcile.

I’ve taken Hayabusa engines apart with less then 500 miles, and as many as 70k miles. I’ll tell you this, a majority of the high mileage engines don’t look, or measure out any worse then a 500 mile motor on the inside.
Thank you for this empirical evidence. I have a theory explaining this in addition to the good engine designs: Because of the extreme power to weight ratios of motorcycles, the relative strain on the engine is practically null. A 1.8L car engine pushes around 3000 lbs and lasts for 300k miles. An engine sized proportionately larger for its load is simply under little strain (strain being different from work performed.)
 

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