DOT head on Bandit 1200

[GS1150Pilot]

Anyone here ever swapped on an early GSX-R 750 "DOT" head in exchange for their stock Bandit head? I've read quite a bit about the effect (seems to be worth about 10 hp and a fair bit of torque with no porting or skimming) it has on the B12, and it is on my list of things to consider. Porting is soooo expensive that it seems to be a worthwhile alternative. Anyone who has done something like this able to comment on its effect on the powerband? Rideability? MPG?

 

[TxGSrider]

Im sure RapidRay knows all about this.

 

[GS1150Pilot]

Yeah, agreed. I haven't seen evidence of Ray around lately.

 

[fbody_mike]

https://www.maximum-suzuki.com/forums/

You can also try max Suzuki. I've heard good things about the dot head but it changes the carb mounting that requires things like the petcock to be moved. That is what I read over at max Suzuki.

 

[tbirdhd]

RAY has had some family matters he is taken care of in KC, MO

 

[tbirdhd]

Get a hold of

stetracer he also knows Bandits ​

 

[GS1150Pilot]

Good point about Stetracer.

Yeah, I've read about the need to replace the petcock. A number of folks have made Yamaha FZ petcocks work in that application.

 

[Roger P.]

You be DAMN careful when doing this. I went by the book and it destroyed my engine.

https://advrider.com/f/attachments/20180904_111329-jpg.1519857/

https://advrider.com/f/attachments/20180904_111321-jpg.1519859/

https://advrider.com/f/attachments/20180830_175126-jpg.1519861/

Don't expect to just paint by numbers and have it all work out.

From my ADV Rider post...

"Bandit 1200. RIP.

Recipe was oil cooled GSXR/Katana 750 head. 88 - 97. 4cc smaller combustion chamber, gives 10.5ish :1 comp ratio. Has same valve sizes as the Bandit 12 head. Throw in some hairy GSXR750 cams (88-89) or GSXR1100/Katana 1100 cams, gives much more top end at the expense of some midrange/low end loss. Not really an issue as it revs RIGHT NOW with those cams. Throw on a performance pipe (RS-3 Yosh + Black Widow headers (UK)), and you have about 130hp at the wheel. I went ape and spent another $1300 CAD for a set of RS38 pumper carbs. Bent the exhaust valves when I fired it up. Chalked it up to a bad timing job. Spent another $500 on Vesrah exhaust valves. Made DAMN sure timing was spot on. Went for a ride, and the power was everything I was hoping for. Opened her out to see what she could do. I had the carbs dialled in perfectly and the bike would just yank your arms straight with a turn of the throttle. Gave it hell. It gave me hell back. Huge smokeshow, obvious piston/valve interference. Cannot for the life of me figure out what went wrong as this is generally considered a very safe first step in hopping up these motors. I saw the cams come out of the bike I bought them from. Unless they were a regrind with some wild lift figures, I can't see why it went pear shaped. I bought a used GSXR1100 motor and installed it. It was a bit of a pooch, with obvious oil control issues. I slung in a new set of rings and called it good enough to resell. It will be moving on cheap next summer, put mostly back to stock. Moral of the story, if you want a faster bike, buy a faster bike. Also, a 14 year old Bandit 12 should be parted out when it blows up, and not have more money sunk into it! I guess I felt guilty for trashing that magnificent motor. C'est la vie!"

 

[thebrandonbeezy]

What cam sprockets did you use. Why did you just crank the engine with out turning it over by hand? Ive read if you use the wrong sprockets this will happen

 

[GregT]

The moral of the story is to take nothing for granted. Dial the cams in and check valve to piston clearance. Easy to do on the rocker arm heads too.

 

[GS1150Pilot]

You be DAMN careful when doing this. I went by the book and it destroyed my engine.

https://advrider.com/f/attachments/20180904_111329-jpg.1519857/

https://advrider.com/f/attachments/20180904_111321-jpg.1519859/

https://advrider.com/f/attachments/20180830_175126-jpg.1519861/

Don't expect to just paint by numbers and have it all work out.

From my ADV Rider post...

"Bandit 1200. RIP.

Recipe was oil cooled GSXR/Katana 750 head. 88 - 97. 4cc smaller combustion chamber, gives 10.5ish :1 comp ratio. Has same valve sizes as the Bandit 12 head. Throw in some hairy GSXR750 cams (88-89) or GSXR1100/Katana 1100 cams, gives much more top end at the expense of some midrange/low end loss. Not really an issue as it revs RIGHT NOW with those cams. Throw on a performance pipe (RS-3 Yosh + Black Widow headers (UK)), and you have about 130hp at the wheel. I went ape and spent another $1300 CAD for a set of RS38 pumper carbs. Bent the exhaust valves when I fired it up. Chalked it up to a bad timing job. Spent another $500 on Vesrah exhaust valves. Made DAMN sure timing was spot on. Went for a ride, and the power was everything I was hoping for. Opened her out to see what she could do. I had the carbs dialled in perfectly and the bike would just yank your arms straight with a turn of the throttle. Gave it hell. It gave me hell back. Huge smokeshow, obvious piston/valve interference. Cannot for the life of me figure out what went wrong as this is generally considered a very safe first step in hopping up these motors. I saw the cams come out of the bike I bought them from. Unless they were a regrind with some wild lift figures, I can't see why it went pear shaped. I bought a used GSXR1100 motor and installed it. It was a bit of a pooch, with obvious oil control issues. I slung in a new set of rings and called it good enough to resell. It will be moving on cheap next summer, put mostly back to stock. Moral of the story, if you want a faster bike, buy a faster bike. Also, a 14 year old Bandit 12 should be parted out when it blows up, and not have more money sunk into it! I guess I felt guilty for trashing that magnificent motor. C'est la vie!"

I have to disagree with your conclusion. The "Just buy a Busa" philosophy is a recipe for generic nothingness. I've never left a motorcycle stock, and the B12, as Dale Walker has shown, is an absolute perfect blank canvas for performance mods. I do wonder whether the head you bought had been skimmed already, and I have read a lot of good things about the DOT head swap (in fact, yours is the first truly dismal report I've come across). The nugget I can take away from what you suggest is exactly what I want: A great power increase for modest outlay on a bike that I totally adore (seriously, I don't think I've ever had a bike I like more, and I didn't go in expecting to fall in love).

Thank you for the warning, though. You guys here are definitely my wardens when it comes to doing this right.

 

[GS1150Pilot]

An additional note: As for cams, my plan is to use the stock B12 exhaust cam and run the GSXR 750 intake.

 

[trippivot]

do you have the parts yet?

 

[GS1150Pilot]

do you have the parts yet?

Nope. I passed on a DOT head last month, but have been looking at a couple.

 

[Guest]

Those heads from a teapot are still out there but, good luck finding the gsxr cams.... I have a short stroke 750 motor in my '83. I've run both style cams kat and gsxr and the difference is undetectable imo. I'll bet 10hp maybe.... I've dragraced it for years and, the newer oil boiler is only 4 or 5 tenths quicker in the 1/4 than the original motor was.

 

[GS1150Pilot]

Those heads from a teapot are still out there but, good luck finding the gsxr cams.... I have a short stroke 750 motor in my '83. I've run both style cams kat and gsxr and the difference is undetectable imo. I'll bet 10hp maybe.... I've dragraced it for years and, the newer oil boiler is only 4 or 5 tenths quicker in the 1/4 than the original motor was.

Dale Walker sells the cams. To me, 10 hp is generally noticeable-maybe not on a 1/4 mile slip (I stopped drag racing motorcycles when I sold my FZ1 back in 2010), but in roll-ons and how the bike moves through the powerband.

 

[thebrandonbeezy]

Too bad you're on the other side of the country.

 

[Roger P.]

Dale Walker sells the cams. To me, 10 hp is generally noticeable-maybe not on a 1/4 mile slip (I stopped drag racing motorcycles when I sold my FZ1 back in 2010), but in roll-ons and how the bike moves through the powerband.

The cams in the GSXR-1100 and the Katana 1100 are the same. Look for a B stamped in the end of the intake cam shaft. The 88 750 exhaust will also have a B, but the 89 will have a G as they changed exhaust timing in 89.

All things considered, I should have just kept my 1100E!

 

[Roger P.]

I used the stock 1200 sprockets, as the 1200 uses a Hy-Vo type chain. I did spin it by hand and met no resistance. The only thing I can think of is the chain may not have been seated in the teeth of the crank sprocket and it pulled in under load, but you'd think all 4 cylinders would have yakked their valves at that point.

 

[Guest]

I meant good luck finding them cheap/used.... New, is easy.