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Old 03-31-2005, 10:24 AM   #1471
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hi pe,
what for a induction timing have the khm cranck??
dieter
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Old 03-31-2005, 07:23 PM   #1472
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Quote:
Originally posted by daniz24
Has anyone tried using them with KHM crankshaft? I believe it has the most torque...
Yes I have. Have you compared it using the JP crank with a normal piston sleeve?
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Old 03-31-2005, 08:46 PM   #1473
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Quote:
Originally posted by InitialD
Yes I have. Have you compared it using the JP crank with a normal piston sleeve?
Yes, but still on practice and have to wait for race meeting to get its optimum result and I'm afraid it will be pretty a while since I don't race too often The torque almost comparable to my JP with harder clutch setting and leaner LSN (same carburetor) while top end is about the same. Fuel mileage still not sure...

What I'm curious the most is this BRB P/S comes with conrod and almost all of them has a very little bit of play in the crank pin even when they're brand new. Do you also have this problem?

I give my one and only .21 BRB P/S which I bought from kitracer (Thanks Chris ) to one of our best buggy driver here and he promise he will test it on his JP FX21 B5 and give me some result.
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Old 03-31-2005, 08:58 PM   #1474
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Originally posted by InitialD
Yes I have.
How's the result?
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Old 03-31-2005, 11:56 PM   #1475
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Quote:
Originally posted by daniz24
How's the result?
KHM is with my 1st gen piston sleeve. It's my fastest engine yet at the moment. I'm still breaking in my new 2nd gen set. Used that combo in Thailand and was very satisfied with the overall performance and fuel comsumption. But you're right about the torque. Using modified flyweights and hard spring, the thing launches very hard out of the corners.
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Old 03-31-2005, 11:59 PM   #1476
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Quote:
Originally posted by daniz24
What I'm curious the most is this BRB P/S comes with conrod and almost all of them has a very little bit of play in the crank pin even when they're brand new. Do you also have this problem?
No, I don't. Maybe the crankpin on the crankshaft has already worned out? On my older Max crankshaft, this is the problem. Too old.

Quote:
Originally posted by daniz24
I give my one and only .21 BRB P/S which I bought from kitracer (Thanks Chris ) to one of our best buggy driver here and he promise he will test it on his JP FX21 B5 and give me some result.
Is your buggy driver trying to run his buggy on onroad tracks?
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Old 04-01-2005, 01:55 AM   #1477
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Quote:
Originally posted by daniz24


What I'm curious the most is this BRB P/S comes with conrod and almost all of them has a very little bit of play in the crank pin even when they're brand new. Do you also have this problem?

I found the same but thought it was the crank worn out. Whats the size and tolerance of the big end hole?

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Old 04-01-2005, 08:16 AM   #1478
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Quote:
Originally posted by daniz24


What I'm curious the most is this BRB P/S comes with conrod and almost all of them has a very little bit of play in the crank pin even when they're brand new. Do you also have this problem?

I will answer on this question.
When we are making hole for bottom end of conrod, we are assuming that cranck pin is in good condition, so according to this we are putting some tolerance. If we will make hole with assumption that pin worn out, it will be too tight on good condition pin. Please check condion for your pin-may be it is worn out already over the limit-some times it happened even after 2-3 gallons on new engines. There can be numerouse numbers of reason-low quality fuel, too low content of lubricant, manufaturing mistake on heat treating of cranck etc.
Unfortunately we can't make conrod's holes for worn out pins, so we are making for good/fair conditions
Edward
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Old 04-01-2005, 08:28 AM   #1479
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Crank pin.....

I have been running a 1st gen BRB set for a long while now.....the crankpin on the crankshaft have worn away and that the flywheel will rock back and forth at TDC. Initially, i thought it was the conrod brushing, coz i did not get any play when the brb set was new, but it turn out 2 b the crank pin !!! Replaced the crankshaft from the back up motor......

Cya

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Old 04-01-2005, 09:31 AM   #1480
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Quote:
Originally posted by InitialD
No, I don't. Maybe the crankpin on the crankshaft has already worned out? On my older Max crankshaft, this is the problem. Too old.
They're brand new (the conrod and also the crankshaft).
I tried with JP crank and NSR crank. But the .21 is nicely fit.
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Old 04-01-2005, 09:33 AM   #1481
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Quote:
Originally posted by xtreme888
Crank pin.....

I have been running a 1st gen BRB set for a long while now.....the crankpin on the crankshaft have worn away and that the flywheel will rock back and forth at TDC. Initially, i thought it was the conrod brushing, coz i did not get any play when the brb set was new, but it turn out 2 b the crank pin !!! Replaced the crankshaft from the back up motor......

Cya

philip
The bronze we use for bushings on conrods is realy good and very expencive. This is why conrod doesn't need to change very often and normaly should last as set itself. I had one conrod last 2 pistons and I am using only O'Donnell fuel. It has the best lubricants package.
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Old 04-01-2005, 10:38 AM   #1482
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Quote:
Originally posted by daniz24
They're brand new (the conrod and also the crankshaft).
I tried with JP crank and NSR crank. But the .21 is nicely fit.
I measured many crankpins and found anything from 4.22 to 4.27 on new set. Check yours and see.

And if your engine is stable and fast, I wouldn't worry too much.


Time to lean your engine and tear the track
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Old 04-03-2005, 07:30 AM   #1483
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Default head shims for BRB

For 12 BRB, I found the best starting point is with 0.5mm head shims. This is for 30% nitro, 5mm stinger and 5.4mm carb
Or 0.1 to 0.2mm more than Standard Nova set.

For 21 BRB, I found best starting point is 0.7mm head shim, for 8mm carb. If you use 9mm Carb, go for 0.8mm head shim.
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Old 04-03-2005, 08:52 AM   #1484
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I'm using 0.4mm clearance, X=1.3mm minus Y=1.2mm(underhead) plus 0.3mm shim with 20% nitro. Still can't get all the power out. Maybe they're still not fully broken in.
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Old 04-03-2005, 09:17 AM   #1485
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Quote:
Originally posted by daniz24
I'm using 0.4mm clearance, X=1.3mm minus Y=1.2mm(underhead) plus 0.3mm shim with 20% nitro. Still can't get all the power out. Maybe they're still not fully broken in.
Daniz. For 20% fuel I will sugest to use 0.3 mm shimming-0.4 is little bit to high.
What temp are running?
Edward
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