Drag strip trip.

wireman wrote: Its been a while since Ive been to our local 1/8 mile since I sold my 1327,but from what i remember strapped down busas were running 6.70-6.90 range with a little motor tweaking and a pipe around here in the 1/8 around here anyway with decent riders.
best I ever got out of the 1327 was a string of 6.15-6.18s /115 and change with no bar and lots of traction issues

Those were some poor riders on those Busas... On the other hand, your old big block as working quite well for foot shifting and no bar

zukdave wrote: So you're saying don't mill the head and wait till I do the 810
and let the bigger bore rise the compression ?

Another question you think going to a larger dia.
header tube will help or hurt the power ?
Nobody makes a sidewinder to fit so was thinking a KZ900-1000
pipe cut to fit as a step header set up.

I never like to see a head decked more than enough to make it straight. It's a cheap way to compression ratio increase with adverse affects for moving parts clearances.....

Now granted .020" isn't a huge amount and can be brought back with a base gasket pretty quickly. Trouble with that though is padded up cylinder blocks create potential for oil leaks.

Things just always go so much smoother when you use correct parts...

You might well find a hair increase in ET and MPH with the baffle plate removed. I'd lean more toward the MPH increase.

You might also pull the header off and make sure the crushed copper O ring hasn't smooshed [technical term] to the point where it's partially blocking the roof of the exhaust port. While it's off, decarbon the primaries.

Some sort of stack on the 29's would be worth the simple effort to install as well. Look for every possible way to reduce drive line friction...perfect wheel alignment, free running chain...etc. It gives you something to do during the week while your chomping at the bit for race day

Before you swap pipes, try pulling the rear section right off your pipe and make a couple of passes with just the header portion. Might require a jet change.

LarryC wrote:

wireman wrote: Its been a while since Ive been to our local 1/8 mile since I sold my 1327,but from what i remember strapped down busas were running 6.70-6.90 range with a little motor tweaking and a pipe around here in the 1/8 around here anyway with decent riders.
best I ever got out of the 1327 was a string of 6.15-6.18s /115 and change with no bar and lots of traction issues

Those were some poor riders on those Busas... On the other hand, your old big block as working quite well for foot shifting and no bar

Nope its just piss poor air we have here on the corn coast! :woohoo:

All this racing talk has me thinking,I might have to go play spectator tomorrow night :woohoo:

So I got a chance to make some dyno run's this past weekend
Best rear wheel was 77.77 HP and 100.21 ft. lbs.

Rpm's in this pic. read 1/2 the true rpm's for some reason but
the bobble at the end is the rev. limter gettin mad.

I think the 117.5 main's I put in killed the power around 8000
so back to the 120's or maybe the 122.5's I have.

Id say thats pretty impressive power for a stock motor with a set of carbs

Have you worked out the traction issues yet?

Is that dyno chart supposed to be from a KZ750 with an 810 kit with stock cams?

I don't want to rain on your picnic but that's just freaking over the top

If it is, that's one more example of a f'kd up dyno jet reading. There's not a snowball's chance in hell that thing is laying down 100 ft.lbs of torque at the rear wheel.

The photo isn't very clear when I downloaded it to see the chart better. Anyway, do the math and the torque value is way out in left field.

Example:

Say that 77HP is at 8500 RPM. The toque value would be about 47 ft.lbs.

Say the peak torque happened at 7000 RPM. That's 134HP :whistle:

Larry I'm not sure he had it set up right as the rpm scale
at the bottem only go's to 5500 rpm's.

as for the motor it's a bone stock never opened 8500 mile 83 gpz750.
Will be rejettin and going back for some run's so maybe then I can get a better reading.

More rain...
My full silly race bike from that era (also based on a kz750 , kinda :0 ) was straining to make 122hp and 63 ft/lbs .
and yes Larry , that was right before it blew up (that week) .
Don't get me wrong I loved that engine but at anything approaching 110 hp , 10000 rpm or just one blown down shift it was back to square one .
I even had one unload just chopping the throttle from 4k rpm no load .

~kop

I have no doubt the dyno operator hands out charts they feel are accurate.... But I'll stand right up and call bullshit when I see it

Larry I didn't post this to bragg about my junk
making these number's I know better.
I posted because I got a chance
to put my junk on a dyno and the number's seemed fucked up to me.

Like I said before the 77hp seem's reasonable but the 100ft. lbs.
is a bull shit number and I know that.
The read out is just wrong
I think your 47 maybe low 50's would
be more in the ball park.