Bucket development: A few questions for the wise ones

[Bert]

Hi Bert, buy yourself a copy of port map analyzer http://www.porting-programs.com/anal...lyzerV3.0.html ($23US from memory) it will allow you to compare your time areas form you rubbings plus it will calculate effective changes. Get a copy of Blairs software (pm me for a copy if you dont already have this) to set your motors target BMEP then go back to port map analyzer and work with your time areas until they match, (the biggest problem has proven to be blow down as this has a specific area which also needs to be met) as you know everything needs to work together. My revised timings have come in at 130deg transfers 195deg exhaust (212deg inlet but you dont have to worry about that one)to meet the BMEP and time area requirements.
From memory the TZR125 had a low case compression what with the reed inlet and that ugly crank, Im suprised its so close to 1.5:1.
ps looks like your a lot closer to finishing than I am!

Yip I've got a copy of Walter's porting software, nice to use. but it is getting a little beyond me somewhat; even after playing around with two strokes for a number of years, I'm sure it will click at somestage...

Thanks for the advise on the BMEP calcs (I'll have a look through my software downloads I think I have a copy), I'll go and have a play with this. Joys of being on holiday..
tHATS RIGHT THEY WON'T RUN ON VISA....

So what are you building??

[kel]

Im building a Kawasaki KE125. Goal is 30hp at the crank. I stupidly spent money lifting the power on the FXR so finishing the KE has been compromised for the moment.

How about these figures for your TZR based on Blairs calcs for BMEP of 11bar -

power 30hp
BMEP 11bar
swept volume 100cc
engine speed 12500
exhaust time area .0162
blow down time area .00113
transfer time area .0086
inlet time area .0162

Certainly achievable with a water cooled 100 but again the problem will be in the blow down.
The beauty of 125cc displacement allows the same power at 9 bar and 11500 rpm!

[kel]

So what are you building??

Here it is, plenty still to do.

[F5 Dave]

Certainly is. Probably enough for a whole 'nother thread. I'd consider raising the front sprocket so you don't get a pronounced pro squat effect. I'm not psychic, but trust me.

[kel]

I'd consider raising the front sprocket so you don't get a pronounced pro squat effect. I'm not psychic, but trust me.

Hmm, so you recognise the chassis? Thought it was quite well disguised being so stripped down.

[F5 Dave]

Recognised & ridden

[jasonu]

Here it is, plenty still to do.

What a heap of shit. You must be a real wanker to have brought that...

[F5 Dave]

I hear everyone who touches it turns ghey as it was created by a master poofta & his dodgy accomplice.

[jasonu]

Certainly is. Probably enough for a whole 'nother thread. I'd consider raising the front sprocket so you don't get a pronounced pro squat effect. I'm not psychic, but trust me.

If it were me I would use the biggest front/rear sprocket combination I could find. That will move the chain run away from the swingarm pivot.

Good luck with it mate. I am looking forward to seeing it out there again.

[jasonu]

I hear everyone who touches it turns ghey as it was created by a master poofta & his dodgy accomplice.

You should know, you rubbed your genitalia on it several times.

[F5 Dave]

and strangely I find myself watching cooking programs.

Frame will be man enough for the job, A bigger front spkt may be all required, but a tilt forward should raise the sproket enough to make a pronounced effect

[jasonu]

and strangely I find myself watching cooking programs.

Frame will be man enough for the job, A bigger front spkt may be all required, but a tilt forward should raise the sproket enough to make a pronounced effect

agreed
atleast 10 characters

[Bert]

Silly question one:

I’m struggling to get one of my main bearings off the crank.
I can’t get a puller behind the bearing face. I’ve tried to freeze it and tap it free (but no luck).
I’m about out of ideas on this (don’t want to destroy it).

any other ideas or plans? or is it best to take it to a shop?

Silly question two:
Also, Was thinking about turning down a 420 front sprocket to a 415 (as I have heaps of chains and rear sprockets now). The idea whas to put the entire main shaft in the lathe and turn away the teeth and seat; then round things off again.
I'd be keen to talk to anyone that has attempted this? before i make a meal of it.
(P.S. I can't find a 415 front sprocket that suits the silly spline on my yamaha).

Cheers
Brent

[ac3_snow]

here's the port map with transfer angles into the bore. all ports are flat topped (except the the boost port which is about 60 degrees).
Attachment 228629

just taking a step backwards for a moment. That looks like a big exhaust port and with a 50mm bore whichever way you measure it is above 75%...
Also in this pic the exhaust width is either 40mm or 38mm depending on how you measure, which is the correct measurement?

[Bert]

just taking a step backwards for a moment. That looks like a big exhaust port and with a 50mm bore whichever way you measure it is above 75%...
Also in this pic the exhaust width is either 40mm or 38mm depending on how you measure, which is the correct measurement?

40mm is the Arc length
38mm is the chord length

(38/50)= 0.76 or 76% of bore. I assume my maths is correct here (back to jennings for another read)
yes its big but i guess we will see how badly it all turns to sh!t...