Dot Head Swap On The G Bike

[coombehouse]

25 minutes ago, wraith said:

It's correct with a GPS Speedo 

According to gearing commander, that sprocket setup gives 68.8mph at 4k. It could be wrong though

[wraith]

6 minutes ago, coombehouse said:

According to gearing commander, that sprocket setup gives 68.8mph at 4k. It could be wrong though

Yep. Maybe if it was a standard b12 engine but it's not 

[coombehouse]

29 minutes ago, wraith said:

Yep. Maybe if it was a standard b12 engine but it's not 

Interesting. So are you running a different primary gear or modified gearbox?

[Gixer1460]

59 minutes ago, wraith said:

Yep. Maybe if it was a standard b12 engine but it's not 

Engine mods won't affect speed other than pulling taller gears. Tyre dia may have an effect!

[wraith]

1 hour ago, Gixer1460 said:

Engine mods won't affect speed other than pulling taller gears. Tyre dia may have an effect!

Yes but different cams/carbs etc will affect the power/revs and given speed or why do we tune engines? 

[wraith]

1 hour ago, coombehouse said:

Interesting. So are you running a different primary gear or modified gearbox?

Not arguing who is right or wrong, I know what my Speedo says, I know what my GPS Speedo says and I know what my rev counter says. So I will stick to that and you can stick to your computer 

[Gixer1460]

8 minutes ago, wraith said:

Yes but different cams/carbs etc will affect the power/revs and given speed or why do we tune engines? 

We tune to make more power which will, unless the gearing is changed, will just get to the same speed, faster or pull more revs to go faster. Tacho's are notoriously inaccurate - especially Suzuki's - up to 1000 revs !!!

[wraith]

3 minutes ago, Gixer1460 said:

We tune to make more power which will, unless the gearing is changed, will just get to the same speed, faster or pull more revs to go faster. Tacho's are notoriously inaccurate - especially Suzuki's - up to 1000 revs !!!

So, as I said. I've changed the gearing and tuned the engine, so you're saying I'm right  or your talking bolls for someone who has built some nice powerful bikes.

[coombehouse]

22 minutes ago, wraith said:

So, as I said. I've changed the gearing and tuned the engine, so you're saying I'm right  or your talking bolls for someone who has built some nice powerful bikes.

He's saying that you can tune as much as you like but gearing is a ratio that is unaffected by an increase in horsepower. 

[Gixer1460]

Someone gets it! 

[XXXSpro]

Got hook up from Tiger at NWT with some cams for this project, might be gsxr or 1100f Will found out soon

[XXXSpro]

23 hours ago, XXXSpro said:

Got hook up from Tiger at NWT with some cams for this project, might be gsxr or 1100f Will found out soon

Looks like it’s 1100F cams gettin dropped in early next week

Got everything removed for the head swap, tomorrow will be dropping in the Dot w/ G Cams in until the Fs come in.

 

Pretty straightforward job, and for $300 I’m hyped to see the power increase

 

Will Dyno after it’s all set up!

[Dezza]

80mph at 4k obviously means 160mph at 8k so if the bike revs out in top (9.5k??) that's a mighty fast bike (190mph). That's going to need a whole lotta power, good aerodynamics and weight reduction to achieve. Tachos and speedos are notoriously inaccurate though. My guess is that goes with GPS speedos too .

[XXXSpro]

The Plot Thickens….

So it all started when I was paranoid about putting the head back on.

Next thing you know, I dropped a washer in the cam chain area ( noob mistake, shoulda stuffed rags in there )

Magnetic finder thingy didn’t work so naturally I split the case and fish it out.

After a series of noob mistakes I ended up needing some piston rings (don’t ask) 

 

While looking for new rings I did what you would naturally do.. look for big bore kits.

I didn’t have much of a budget for it but why not look

Mind you  the first owner racked up 70k miles on the G…

Lo and behold I found a set of Busa pistons for $70 shipped, so as a red blooded male with a hard on for modding slow things I pulled the trigger.

So we are going to a 1216, Dot Head GSXF1100 Cammed GSXG 

I read about low compression killing the potential of busa piston big bores, but with some more digging I saw the busa boys get rid of their base gasket to up compression.

I know this is probably gonna give someone a heart attack, but do you think I would be able to get to 11:1 with the dot head and base gasket delete?

Am I gonna die?

I already have a gsxr1000 front end swap for better suspension and braking btw

Edited November 4, 2023 by XXXSpro

[Captain Chaos]

3 hours ago, XXXSpro said:

Am I gonna die?

Eventually, yes.

 

[Gixer1460]

mk1 or mk2 bus pistons ? as you may have just wasted $70!

[XXXSpro]

3 hours ago, Gixer1460 said:

mk1 or mk2 bus pistons ? as you may have just wasted $70!

Off an ‘01! No rods, but I was planning on running the 1127s anyway

[XXXSpro]

6 hours ago, Captain Chaos said:

Eventually, yes.

 

One day ill come to grips with this 

[XXXSpro]

So been waiting on the machine shop the past couple weeks and looks like I’ll be picking up either Friday or Monday.

After doing some digging I had him deck the block 1.2mm, with the 22cc dot heads on the 3mm overbore for the 81mm busa pistons.

My goal is to get close to 11.5:1 or 12:1 comp to net 150hp and over 90ft/lb from this combo and the 1100F cams.

Am I out of touch or within some realm of reality for this? 

I’ve ran the comp ratio calculator a billion times at this point, but there seems to be conflicting info on exactly how low the busa pistons drop comp. 

Edited November 22, 2023 by XXXSpro

[Gixer1460]

You'll only tell with a dry build - which would have been better done before decking the block. CC the chambers for definitive answer.

You may also need to check valve to piston clearances before building up for final time.

[Blubber]

2 hours ago, Gixer1460 said:

You'll only tell with a dry build - which would have been better done before decking the block. CC the chambers for definitive answer.

You may also need to check valve to piston clearances before building up for final time.

<- this.

 

Please do it.

 

It will save you a lot of time and money. 

I checked for valve to piston clearance at 10° before and after TDC and still made an assuption error. I thought 1.5mm was enough on my application ( max 9000rpm ) 

Please use 2.0 mm.

I did not and need 16 custom valves plus a new ported hheadand all the associated stuff. 

[XXXSpro]

2 hours ago, Gixer1460 said:

You'll only tell with a dry build - which would have been better done before decking the block. CC the chambers for definitive answer.

You may also need to check valve to piston clearances before building up for final time.

Will do. The machinist takes weeks for anything and my impatience got the best of me! I figured I’ll adjust with a thicker gasket if need be.

The chambers in the head at 22cc, and piston dish is 8cc.

I will double check the piston/valve clearances and hand turn the engine over to make sure.

I read through a build here of a guy keeping everything stock and just decked the block 1.5mm to see compression changes and he had said there was a bit left even after shaving that amount off.

Anyway, here’s what I got for comp calculations 

Edited November 22, 2023 by XXXSpro

[Duckndive]

4 hours ago, XXXSpro said:

Will do. The machinist takes weeks for anything and my impatience got the best of me! I figured I’ll adjust with a thicker gasket if need be.

The chambers in the head at 22cc, and piston dish is 8cc.

I will double check the piston/valve clearances and hand turn the engine over to make sure.

I read through a build here of a guy keeping everything stock and just decked the block 1.5mm to see compression changes and he had said there was a bit left even after shaving that amount off.

Anyway, here’s what I got for comp calculations 

on that calculator dome volume should be a positive no for busa pistons 

What rods are you using ? 

Edited November 22, 2023 by Duckndive

[coombehouse]

Are you sure about the compressed head gasket figure? Doesn't seem right to me.

I believe the head gasket is 0.7mm, the base 0.2mm

Edited November 22, 2023 by coombehouse
More numbers

[Gixer1460]

16 minutes ago, Duckndive said:

on that calculator dome volume should be a positive no for busa pistons 

Yeah sort of counter - intuitive ! A dome volume should be a minus number ie. subtracted from chamber volume, whereas a dish is a Plus number as its added to chamber volume. A difference of 16cc makes one hell of a difference ! And agree with CH - gasket number is deffo wrong - 3 hundredths of a mill is paper thickness!