1397 needs a rebuild - advice?

G

GeoffCT

Registered
Hello all,

I recently dropped off my 07 Busa at the shop because it wasn't running right. It has the 1397cc kit. They did a leak down test and said the intake valves aren't sealing well and the pistons need to be reringed. He recommended:

Cylinder hone + x4 piston rings = $1500 parts and labor
Redo x16 valves and port the heads = $1000 parts and labor

Currently the heads are factory and NOT ported. If I opt NOT to port the heads, he said it would reduce the headwork by $750. He did recommend going with new studs to prevent a blown head gasket, as this has happened once before on this motor. He said he could go mild or wild, swapping exhaust cam for intake, getting a genII crank to get it 1441 ($$$), etc. I'm looking to go land speed racing, specifically do 200 mph, and I don't think I need to go too crazy. I did 181 just before the motor acted up on factory gearing @ 10-10.5K rpms with more grunt to go, that was a basic 1397, full exhaust, nonported heads. Motor has 39k miles on it currently.

I may opt for the head porting, but I've read mixed news, that factory cams (even running x2 intake cams) don't take full advantage of the porting and it is a waste.

Not interested in dumping a ton of cash into this bike - I'll probably get it fixed, make a few passes, and then sell it.

Anyone have any advice here?
 
GeoffCT said:
Hello all,

I recently dropped off my 07 Busa at the shop because it wasn't running right. It has the 1397cc kit. They did a leak down test and said the intake valves aren't sealing well and the pistons need to be reringed. He recommended:

Cylinder hone + x4 piston rings = $1500 parts and labor
Redo x16 valves and port the heads = $1000 parts and labor

Currently the heads are factory and NOT ported. If I opt NOT to port the heads, he said it would reduce the headwork by $750. He did recommend going with new studs to prevent a blown head gasket, as this has happened once before on this motor. He said he could go mild or wild, swapping exhaust cam for intake, getting a genII crank to get it 1441 ($$$), etc. I'm looking to go land speed racing, specifically do 200 mph, and I don't think I need to go too crazy. I did 181 just before the motor acted up on factory gearing @ 10-10.5K rpms with more grunt to go, that was a basic 1397, full exhaust, nonported heads. Motor has 39k miles on it currently.

I may opt for the head porting, but I've read mixed news, that factory cams (even running x2 intake cams) don't take full advantage of the porting and it is a waste.

Not interested in dumping a ton of cash into this bike - I'll probably get it fixed, make a few passes, and then sell it.

Anyone have any advice here?
Click to expand...
HI, I would make it a 1507 cc. check out my post my very slow build my # 508-496-5680 my E Mail vn66676869@aol.com.
 
If you are just going to sell it, then don't put any money in it. Sell it as-is. Bikes are money pits! If you feel you must fix it, do it the lowest cost way. Don't port the head, no 1441, etc. Prices don't look too bad if that includes full disassembly and reassembly of the engine.
 
Dennis said:
If you are just going to sell it, then don't put any money in it. Sell it as-is. Bikes are money pits! If you feel you must fix it, do it the lowest cost way. Don't port the head, no 1441, etc. Prices don't look too bad if that includes full disassembly and reassembly of the engine.
Click to expand...

Yeah, I know this is going to cost me one way or another. I'm just hoping to minimize financial outlays.

My first goal is simply to do 200 mph. Sinking $2.5K into the bike for repairs will get me there. My 2nd goal is to go for a record in the production 1350cc class, factory motor, factory frame class, so my idea is to (eventually) move over to a Gen II. Maybe I should just sell the bike as is and just go to a GenII now.
 
GeoffCT said:
Yeah, I know this is going to cost me one way or another. I'm just hoping to minimize financial outlays.

My first goal is simply to do 200 mph. Sinking $2.5K into the bike for repairs will get me there. My 2nd goal is to go for a record in the production 1350cc class, factory motor, factory frame class, so my idea is to (eventually) move over to a Gen II. Maybe I should just sell the bike as is and just go to a GenII now.
Click to expand...
I would bet you can sell at a discount and move to Gen2 and be better off. Decent Gen2's can be bought for under $7k
 
I would agree with Dennis. Go the cheap way and sell the bike and get into a gen 2. Gen2 can do 200mph with bolt ons.
 
dears,
what are we talking about?

max possible speed
or max acceleration ?

or both in one?

the ´99 & ´00 goes around 211 mph in stock version (depending at drivers weight/size) and
if you put of mirrors some 3 mph more will result.

all the laters are restricted at 185 mph (by law)

this restriction at gen1 & gen2 can be flashed away.

also you can change the mappings by using a testbench 5 or more times to optimate the motor power (and the speed) at e.g. higher rpm´s.

@GeoffCT
"They did a leak down test and said the intake valves aren't sealing well and the pistons need to be reringed. "

how exatly did they do these tests?
pistons via pressure test with a tool like this ?
pruefgeraet.gif

- ok

but there are 4 kinds of measuring to get real & safe / comparable bar/psi - values
precondition - all valves clearings set to upper tolerance / controled the cam´s timing?
1. motor cold / room temperature 20-25 °C
2. dito + a little sip of oil into cylinder shortly before measuring
3. motor warm/hot - oiltemp around minimum 80°C
4. dito + again a little sip of oil into cylinder shortly before measuring
(info : the small drop of oil (~ 5cm³ / 1 tsp) seals the piston rings for the short time of the measurement and the compression values increase. )

do you know the bar´s / psi´s when motor was made to 1397 ccm?
what are they now?
what values are we talking about?

but how did they test the leaking of (intake) valves? did they take vacuum at each of their ducts? or how else?

the valves you can grind at 1st (head must be pulled) - they only got 39k miles and i never heard of demaged valves at that milage.
there is normally no need to replace them.

replacing of rings (incl. hone) makes - to me - no sense
youre writing of 1397 ccn - did you bore the cylinders and did you coat em again with nikasil?
then the cyl´s won´t go bad - the nikasil coating makes such a hard surface.


all that at 39k miles?
what the hell did you do to your motor?

your story (in summ 2.5 k $) sounds - to me / at the moment - like a try of a deep grab into your financial pocket.

and
"... because it wasn't running right ... "
what exactly does this mean?

e.g. :
old spark´s or / and old ign. coils cause also a bad motor running
or dirty injectors / fuel filter inside pump.
air filter?

I would change the shop to ask for another opinion before spending such an amount of money.
 
Berlin Germany said:
dears,
what are we talking about?

max possible speed
or max acceleration ?

or both in one?

the ´99 & ´00 goes around 211 mph in stock version (depending at drivers weight/size) and
if you put of mirrors some 3 mph more will result.

all the laters are restricted at 185 mph (by law)

this restriction at gen1 & gen2 can be flashed away.

also you can change the mappings by using a testbench 5 or more times to optimate the motor power (and the speed) at e.g. higher rpm´s.

@GeoffCT
"They did a leak down test and said the intake valves aren't sealing well and the pistons need to be reringed. "

how exatly did they do these tests?
pistons via pressure test with a tool like this ?
View attachment 1612757
- ok

but there are 4 kinds of measuring to get real & safe / comparable bar/psi - values
precondition - all valves clearings set to upper tolerance / controled the cam´s timing?
1. motor cold / room temperature 20-25 °C
2. dito + a little sip of oil into cylinder shortly before measuring
3. motor warm/hot - oiltemp around minimum 80°C
4. dito + again a little sip of oil into cylinder shortly before measuring
(info : the small drop of oil (~ 5cm³ / 1 tsp) seals the piston rings for the short time of the measurement and the compression values increase. )

do you know the bar´s / psi´s when motor was made to 1397 ccm?
what are they now?
what values are we talking about?

but how did they test the leaking of (intake) valves? did they take vacuum at each of their ducts? or how else?

the valves you can grind at 1st (head must be pulled) - they only got 39k miles and i never heard of demaged valves at that milage.
there is normally no need to replace them.

replacing of rings (incl. hone) makes - to me - no sense
youre writing of 1397 ccn - did you bore the cylinders and did you coat em again with nikasil?
then the cyl´s won´t go bad - the nikasil coating makes such a hard surface.


all that at 39k miles?
what the hell did you do to your motor?

your story (in summ 2.5 k $) sounds - to me / at the moment - like a try of a deep grab into your financial pocket.

and
"... because it wasn't running right ... "
what exactly does this mean?

e.g. :
old spark´s or / and old ign. coils cause also a bad motor running
or dirty injectors / fuel filter inside pump.
air filter?

I would change the shop to ask for another opinion before spending such an amount of money.
Click to expand...
HI. Why does most want a Gen 2?
 
Berlin Germany said:
the ´99 & ´00 goes around 211 mph in stock version (depending at drivers weight/size) and
if you put of mirrors some 3 mph more will result.

all the laters are restricted at 185 mph (by law)

this restriction at gen1 & gen2 can be flashed away.
Click to expand...
Not in a million years. The stock Busa hit 194 and that was it in 1999/00. No stock Busa ever hit 200mph. Not sure the Gen 2 will do it either.
 
As far as your 1397, I wouldn't build a 1397 without porting the head. As for cams, I would go 395/395 or 415/395. All motor costs a lot of money. I say if you are going to spend that kind of money, sell it for parts, and buy a Gen 2. They can be found for less than $6k and spend money on that. Or buy a Zx14R
 
greg3852 said:
As far as your 1397, I wouldn't build a 1397 without porting the head. As for cams, I would go 395/395 or 415/395. All motor costs a lot of money. I say if you are going to spend that kind of money, sell it for parts, and buy a Gen 2. They can be found for less than $6k and spend money on that. Or buy a Zx14R
Click to expand...
HI. How are you doing. I worked with Alvin R, great guy. I just ordered my 10 1/2 to 1 turbo pistons today and a set of custom rods from Carrillo. They are designing a custom rod for 1000HP and 13500 RPM.
 
Berlin Germany said:
dears,
what are we talking about?

max possible speed
or max acceleration ?

or both in one?

the ´99 & ´00 goes around 211 mph in stock version (depending at drivers weight/size) and
if you put of mirrors some 3 mph more will result.

all the laters are restricted at 185 mph (by law)
Click to expand...
I'm sure you mean well, but do some research before you make statements that are untrue. No stock 99 or 00 ever went 200 or better. Ever.
And there is no law that restricted the 01+ bikes in the US, it was done by the manufacturers as a "gentlemen's agreement" because they feared such laws would be enacted.
 
greg3852 said:
As far as your 1397, I wouldn't build a 1397 without porting the head. As for cams, I would go 395/395 or 415/395. All motor costs a lot of money. I say if you are going to spend that kind of money, sell it for parts, and buy a Gen 2. They can be found for less than $6k and spend money on that. Or buy a Zx14R
Click to expand...

It already has the 1397 kit, just unported heads. Not terribly interested in going aftermarket cams or dumping a ton of cash for the same reason you mentioned.

The question is - with a full aftermarket exhaust but stock cams, do I get a benefit of head porting? If not, should I do the intake/exhaust cam swap? I'm just looking to hit 200 and call it a day.

I'm also keeping an eye out for a stock gen II.
 
GeoffCT said:
It already has the 1397 kit, just unported heads. Not terribly interested in going aftermarket cams or dumping a ton of cash for the same reason you mentioned.

The question is - with a full aftermarket exhaust but stock cams, do I get a benefit of head porting? If not, should I do the intake/exhaust cam swap? I'm just looking to hit 200 and call it a day.

I'm also keeping an eye out for a stock gen II.
Click to expand...
To answer your question about porting without cams, the answer is yes you will get a benefit. However....you will never be able to take advantage of everything the ported hear could provide with stock cams, so the question back to you is: will the gains justify the expense?
The common cheap alternative to aftermarket cams used to be to throw a stock intake cam on the exhaust side and degree them. Have you considered that?
 
Mr Brown said:
To answer your question about porting without cams, the answer is yes you will get a benefit. However....you will never be able to take advantage of everything the ported hear could provide with stock cams, so the question back to you is: will the gains justify the expense?
The common cheap alternative to aftermarket cams used to be to throw a stock intake cam on the exhaust side and degree them. Have you considered that?
Click to expand...

Yes, the engine builder mentioned that trick with the stock cam swap and I'm considering it. Thanks for clearing that up, I forgot if it was exhaust to intake or intake to exhaust swap.

I believe with my current setup 1397 + unported head + exhaust = 183-185 hp when it was last dyno'd. I think he said with ported heads I'll be in the low 190s. So with exhaust cam swap, maybe 195-197? A quick check on ebay shows that used intake cams are pretty inexpensive, so it would be silly not to do the exhaust cam swap if I'm already going to do the head porting.

The question I need to figure out is whether dropping the $1,100 to do port + stock cam is worth a 10 hp gain. Seems kinda dumb when I'm typing it out now....
 
Last edited:
www.hayabusa.org

Gen 1 busa motor build | All Motor

Hello, everyone, I recently picked up an 00 Gen 1 Hayabusa beside doing all maintenance I would like to build the motor. Please let me know what you guys think. I would like to drag racing the bike maybe run a small shot of nitrous. Race porting and competition valve job/ new valve seals/etc...
www.hayabusa.org www.hayabusa.org

@Boosted Cycle Perf "Also if you’re spending the money for a ported head you’re shooting yourself in the foot running two intake cams. Spend the money and get cams that are matched to the head work, displacement, and compression. "
 
why not get a performance first spray bar. And piece together the rest of the stuff for cheap. Put a 25 shot on it and get your 200 mph. That will be cheaper then doing head work. Ported head is like 1000 bucks and then intake can is another couple hundred. Plus you will have to tune again. Just do a small shot and it will be fine. I ran a 60 shot on my stock motor and now I’m running 55 shot on my 1397. You could go more but a small shot will be fine on pump gas and no need to worry about a controller
 
busakiller said:
why not get a performance first spray bar. And piece together the rest of the stuff for cheap. Put a 25 shot on it and get your 200 mph. That will be cheaper then doing head work. Ported head is like 1000 bucks and then intake can is another couple hundred. Plus you will have to tune again. Just do a small shot and it will be fine. I ran a 60 shot on my stock motor and now I’m running 55 shot on my 1397. You could go more but a small shot will be fine on pump gas and no need to worry about a controller
Click to expand...

Good suggestion. That sounds like the perfect application.
 
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