1100 shim head with adjustable tappets

[MikeyVeitch]

That title got your attention didn’t it.

I have made a different post about putting the dot head on my bandit engine to replace the shim head that’s in there already.

General response was that the dot had better cams and the shim flowed better. 

May seem like a stupid idea to some but do you think it would be possible to replace the entire rocker assembly in the shim head for the tappet style from a bandit. The difference in castings on the head could easily be rectified by some spaces that I could make on the lathe. Swapping to the the tappet style rockers would make it possible to use the Dot 748 cams as people say that they are the most aggressive of the bunch?

Have fun roasting me 

[Captain Chaos]

Standard answer:

just turbo the fucker and be done with it 

[DAZ]

6 minutes ago, Captain Chaos said:

Standard answer:

just turbo the fucker and be done with it 

Sorry Captain thought it was Clive for a moment......

Edited August 17, 2023 by DAZ

[DAZ]

Is the dot head you have from a gsxr or a teapot? The teapot cams aren't as hot as the gsxr ones,are the cams in the shim head are good ? I wouldn't imagine that the dot head cams are significantly hotter. the impression I have is that the shim heads are better than the equivalent tappet heads though not necessarily the dot heads, as they don't have the benefit of the better short turn into the back of the valve however if someone has any flow data or dyno sheets to prove one way or another that would be great. I

If you have a gsxr dot head ( not a teapot one ) then use it you'll have hot cams and higher compression 

If you have a gsxr1100 m head and cams in good condition then that's better than a bandit 12 head you will just lack some oomph from the compression increase 

[MikeyVeitch]

30 minutes ago, DAZ said:

Is the dot head you have from a gsxr or a teapot? The teapot cams aren't as hot as the gsxr ones,are the cams in the shim head are good ? I wouldn't imagine that the dot head cams are significantly hotter. the impression I have is that the shim heads are better than the equivalent tappet heads though not necessarily the dot heads, as they don't have the benefit of the better short turn into the back of the valve however if someone has any flow data or dyno sheets to prove one way or another that would be great. I

If you have a gsxr dot head ( not a teapot one ) then use it you'll have hot cams and higher compression 

If you have a gsxr1100 m head and cams in good condition then that's better than a bandit 12 head you will just lack some oomph from the compression increase 

I have the dot gsxr head but honestly I can’t be arsed dealing with the problems that comes with putting a dot head in a bandit frame. Is the 91-92 shim head 1100 head and cams better for midrange than the dot gsxr head and cams. I ask this because I hear people say that the dot head and cam swap can destroy the midrange torque. 
Not too arsed about power above 10 thousand because let’s be honest, this is a road bike. 

Edited August 17, 2023 by MikeyVeitch

[DAZ]

Fit the shim head and cams and you basically have a gsxr1100m engine they are not particularly soggy in the middle of the rev range esp if you got 36mm carbs off the bandit rather than the 40s the gsxr had . @Oilyspannerhas tuned his and raves over its road manners 

[Dezza]

Have shim head skimmed then fit to Blandit engine: better flow, increased compression and wilder cams than Blandit, no fitting hassle in Blandit frame .

[Upshotknothole]

Converting the shim head to a tappet is a lot of work. Technically it can be done, but I think parts of the head have to be machined, and most people just don't bother.

Where the power ends up depends a lot on what size carbs you go with. Bandit carbs will keep lots of mid range torque, even with the dot head. Stick on some BST38 or 40 carbs and you'll move the power higher up in the revs. I run a stock 1100m engine with RS38 carbs and it has enough mid range to get around town, but it's boring. Really likes to be high up in the revs now in the twisties to have fun with it, or riding like an ass in town. Smaller carbs would make it way more friendly to normal street riding.

If you have everything apart already, you could do a dry build with the dot head and the 1100m head and check for interference with the carbs and the petcock/tank.

[MikeyVeitch]

4 hours ago, DAZ said:

Fit the shim head and cams and you basically have a gsxr1100m engine they are not particularly soggy in the middle of the rev range esp if you got 36mm carbs off the bandit rather than the 40s the gsxr had . @Oilyspannerhas tuned his and raves over its road manners 

So what hp and torque do you think I’m looking at with the 1100 head?

 

Edited August 17, 2023 by MikeyVeitch

[colinworth79]

I've converted a shim head to run the earlier stye cams and rockers .

Main problem is the camshaft end float . The shim head is larger so you can't drop the cams in . You need to weld up the thrust face where the cam runs to close the gap . 

 

[colinworth79]

10 hours ago, MikeyVeitch said:

So what hp and torque do you think I’m looking at with the 1100 head?

 

Standard 1100 M is about 125hp . Bandit engine has lower compression pistons and a heavier crankshaft.  If is was mine I would keep that shim head that's on there fit a 1216 kit . Decent exhaust and some TMR carbs. 

My 1100 M -  full yoshi duplex system and set of 40mm TMR carbs .

Be more than enough for a bandit chassis .

[Upshotknothole]

10 hours ago, MikeyVeitch said:

So what hp and torque do you think I’m looking at with the 1100 head?

 

Stock 1100m head on an otherwise stock bandit 1200 engine? Bandit carbs or GSXR carbs? My guess would be maybe 120 - 130 HP with a good exhaust and good jetting. 

[Dezza]

Fit TMR carbs....... have you seen how much these things cost? RS's will be a more realistic option for many that haven't had a six horse accumulator come in or their lottery numbers magically align .

[Duckndive]

5 hours ago, Upshotknothole said:

Stock 1100m head on an otherwise stock bandit 1200 engine? Bandit carbs or GSXR carbs? My guess would be maybe 120 - 130 HP with a good exhaust and good jetting. 

I have a  1216 busa piston motor with a 8.4 / 1 CR  topped with a mildly worked 1100m head and with way off RS38s. it made 129 BHP..

 

[Upshotknothole]

7 hours ago, Duckndive said:

I have a  1216 busa piston motor with a 8.4 / 1 CR  topped with a mildly worked 1100m head and with way off RS38s. it made 129 BHP..

 

My stock 1100m engine with RS38s and a full akra did about 120 on the dyno years ago. That engine is begging to have some work done to it.

[Duckndive]

45 minutes ago, Upshotknothole said:

My stock 1100m engine with RS38s and a full akra did about 120 on the dyno years ago. That engine is begging to have some work done to it.

its got the supercharger on it now .....

[Gixer1460]

1 hour ago, Upshotknothole said:

My stock 1100m engine with RS38s and a full akra did about 120 on the dyno years ago. That engine is begging to have some work done to it.

Seems a bit down considering stock M's were claimed 150 with 40mm CVs - I know that was crank but did have quiet exhaust! My L with 36 CVs and a pipe made 126 rwhp!

[Upshotknothole]

4 minutes ago, Gixer1460 said:

Seems a bit down considering stock M's were claimed 150 with 40mm CVs - I know that was crank but did have quiet exhaust! My L with 36 CVs and a pipe made 126 rwhp!

It's never really felt low, I've always chalked it up to the dyno reading low or maybe just conditions on that day. Has a nice torque curve and plenty of power up top.