TOPIC:

next day i was at the dyno...

The fuchs dyno at Superbike Milano is pretty cool, it has built in fan and extractors, so you can run even an aircooled motor as long as you want wihtout overheating or having to rest.

quite better than the old dynojet in the shop that i used to work with.

the guy made quite a few pulls to seat the rings

and at the end guy run out of ink in the printer, so took a shot of the screen

88.7rwhp @ 9500 was pretty nice but after the run plugs were VERY VERY dark with 125 mains. should make it into the 90's with 120-115's, we just run out of time to check!

We also discovered that for the time being the motor likes stock heat grade plugs (BR9ES)
i tried cooler BR10ES and it fouled one or two.

last worrying bit was the the gear change felt super stiff but there wasnt a lot i could do about it until i got on the track. the guy wouldnt let me run a test to feel how the lever...

DPR9EIX-9 NGK Iridium Spark Plugs is what I run. Work great for me.

My GPz550 Cylinders come with the holes in them as you have shown, but not as many.

I have seen a bike using a heat barrier material between the engine and carbs, keeping the heat from getting sucked in:


Thanks for the pictures, and descriptions.

Now I'm off to look for that other thread with the pictures...

yep, thats one solution, Yoshi used to do that, Schwantz's early 750 GSX's and GSXR's had that kind of carb heat shielding.

My plan is to go beyond that and build an actual airbox so that carbs not only suck non-heated air but also air that is still and non-turbulent.

Get the airbox and runner volume right and you can even get a boost from that too. Open carbs are very old school today....motogp and WSBK run airboxes.

I am just at the beginning of the development process for my racer, have plenty of plans and areas for improvement, hei! havent even ported the head yet

just taking some time off being in the garage every night. will pick up development again in the two month break i have mid season.

turboguzzi wrote:

yep, thats one solution, Yoshi used to do that, Schwantz's early 750 GSX's and GSXR's had that kind of carb heat shielding.

My plan is to go beyond that and build an actual airbox so that carbs not only suck non-heated air but also air that is still and non-turbulent.

Get the airbox and runner volume right and you can even get a boost from that too. Open carbs are very old school today....motogp and WSBK run airboxes.

I am just at the beginning of the development process for my racer, have plenty of plans and areas for improvement, hei! havent even ported the head yet

just taking some time off being in the garage every night. will pick up development again in the two month break i have mid season.

I hear you on the development. I progressed my bike almost every race weekend last year, and that was 5 rounds changing carbs, jetting, and big bore. 4 dyno runs as well. You have done a lot to that machine, so leaving things as they are, and concentrating on actual racing, is another thing.

Making a breathable airbox protected from heat will still let the engine breathe.

Are you running an oil temp gauge on that beast? If so, what temps are you getting?

nope, not measuring temp, not worried about it either.

if i'll start hearing the motor pinging I'll know it's getting too hot its definitely not.

build a good working squish area that gives quick burning = less time to heat up the combustion chamber = motor runs cooler

I'm down to only 28 degs full advance right now and the torque peak is still a very healthy 58 lb/ft, as good as a current GSXR750 with four valves and water cooling (just at lower revs, dang!) Stock GPZ750 was 41 lb/ft just to give you an idea, so you can get good torque with late timing too if you have the right turbulence inducing squish in there

TG

On an air cooled bike, those heat barriers are IMO, not effective to any great extent. They could even be detrimental.

They're going to block air between the cylinders and trap more heat in motor anyway. That trapped heat will transfer to the intake ports...etc.

A correctly sized airbox would be more effective to feed the engine cooler air.

If a shielding device were to be attempted, it might best be designed to shield the float bowls front and bottom. The idea being to allow air through the block between the cylinders and guide it underneath the carburetors.... JMO

An air box that completely enclosed the carburetors would be worth the attempt...again JMO.

Larry C

how much piston to head squish clearance are u running? i ran my 1327cc kz motor at .036" and had no problems.

turboguzzi wrote: nope, not measuring temp, not worried about it either.

if i'll start hearing the motor pinging I'll know it's getting too hot its definitely not.

build a good working squish area that gives quick burning = less time to heat up the combustion chamber = motor runs cooler

I'm down to only 28 degs full advance right now and the torque peak is still a very healthy 58 lb/ft, as good as a current GSXR750 with four valves and water cooling (just at lower revs, dang!) Stock GPZ750 was 41 lb/ft just to give you an idea, so you can get good torque with late timing too if you have the right turbulence inducing squish in there

TG

mark1122 wrote: how much piston to head squish clearance are u running? i ran my 1327cc kz motor at .036" and had no problems.

.030"

larrycavan wrote: On an air cooled bike, those heat barriers are IMO, not effective to any great extent. They could even be detrimental.

They're going to block air between the cylinders and trap more heat in motor anyway. That trapped heat will transfer to the intake ports...etc.

A correctly sized airbox would be more effective to feed the engine cooler air.

If a shielding device were to be attempted, it might best be designed to shield the float bowls front and bottom. The idea being to allow air through the block between the cylinders and guide it underneath the carburetors.... JMO

An air box that completely enclosed the carburetors would be worth the attempt...again JMO.

Larry C

with you on this larry, an airbox rather than open barrier is my plan indeed.

larrycavan wrote: On an air cooled bike, those heat barriers are IMO, not effective to any great extent. They could even be detrimental.

They're going to block air between the cylinders and trap more heat in motor anyway. That trapped heat will transfer to the intake ports...etc.

A correctly sized airbox would be more effective to feed the engine cooler air.

If a shielding device were to be attempted, it might best be designed to shield the float bowls front and bottom. The idea being to allow air through the block between the cylinders and guide it underneath the carburetors.... JMO

An air box that completely enclosed the carburetors would be worth the attempt...again JMO.

Larry C

this pic shows the under the float bowl deal.





leon

Dang that is a sweet looking bike. Nice belly pan too.

Dutch, you looking at this???

haha come on sander,make us some belly pans!

i have been searching for a belly pan.
it could be the only un-needed piece that a street bike could have that i want.
i guess it is the wannabe racer boy in me ,haha.

leon

anyone ever seen a link to pans???

great pics guzzi!!!!

wannabe racer boy....here we go again banshee.

trianglelaguna wrote: anyone ever seen a link to pans???

great pics guzzi!!!!

wannabe racer boy....here we go again banshee.

it's me and you tri!

till the bed collapses,or the wheels go square .

leon

Oh I really want a belly pan for when I do my turbo build. I think my 650 doesn't need one.

turboguzzi wrote: the starter mounting bolts were good to hold the cam timing pointer!

I used your idea on the pointer location and just degreed my cams for the first time. Had to make a tool to keep tension on the cam gear between the intake and exhaust, but they are now set to Megacycles's Specs. This isn't as hard as a job as I thought.











I'd recommend buying a drop gauge that has a magnetic base, and making a plate to stick it to. Setting this type of clamp up took a lot of fiddling, but after checking each cam about 3-4 times, to make sure I got it right, I'm all set. Intake is set to 105, and exhaust is set to 108, as per Megacycle's Instructions. Used red threadlock on the cam bolts too.

Thanks for the idea Turbo!

you welcome, just cant see where is the clamp on dial gauge....

Fixed! It was an IMG Fail!

Any updates on this project?