Same ole K&B questions..........

[topfuel443]

Same ole K&B questions..........

Hey guys, Ive never been a K&B person before ( if for no other reason than ive never had one) unitl now....... I had the oportunity to purchase two complete 3.5 engines and enough spares to build three more and then some for 300.00 bucks. not a bad deal. I have a few questions and I appologize for asking them because im sure they been answered six times over somewhere on here before. what are the bore specs on the gold, red and black carbs? are the bore sizes the only thing thats different? I have 12mm and 13mm cranks, what is the reason for the change? were the 12's breaking? are there any other differences to the cranks other than the shaft size, like the intake window dimensions? I have six sets of piston and liners, all of which have different porting configurations, some without an exauhst bridge some with a bridge and pipe porting, can someone send me a pic of a STOCK sleeve so I can see the ports? Is everyone running around 8 thou. on the head clearance? what are the good timing specs.? finally i have six connecting rods, that consist of about four different manufacturers, what is the best rod for this engine? This is the older style K&B not the ss. Thanks for the help in advance.

~ James ~ The newest member of TEAM K&B

 

[Ron Olson]

Re:Same ole K&B questions..........

I'll give it a shot, someone let me know if I'm wrong. I don't have the specs on the carbs but the black carb is the older, smaller carb, the gold is the preferred carb for a 3.5 and the red one is actually for a 7.5 engine but can be used if you run it slobbering rich.

The larger 13mm crank will let more air flow to the crankcase with a larger hole through the crank.

Head clearance should be around .012".

The rods must be aftermarket or different versions from K&B. If you have an RPM rod, that might be your best choice.

Looks like you'll have a lot of fun experimenting with different combinations.

 

[Slideblues]

Re:Same ole K&B questions..........

I will kick in the carb bores:

Black carb .265

Gold carb old .308, From 94 on, has brighter color .312

Gene ;D

 

[Slideblues]

Re:Same ole K&B questions..........

James I sold all my K@B stuff last fall,

Found this:

 

[_laxmasta2039]

Re:Same ole K&B questions..........

James,

do you have any extra gold carbs you are willing to sell?

i dont think i've got anything you wanna trade for 'cept some fuel tanks and alot of elec. stuff...

Joe

 

[not2bright]

Re:Same ole K&B questions..........

i got a question too. if you want extra hp can you put a ss sleeve in a standard k and b, i want to keep the engine "stock" cause i race it

 

[Jerry Dunlap]

Re:Same ole K&B questions..........

N2B,

In District 8, you can run any piston/sleeve you want in your 3.5 k&B.

Jerry D.

 

[topfuel443]

Re:Same ole K&B questions..........

Joe, No I dont have any extra gold carbs, only have one gold, but I have three of the smmall black carbs that I want to bore out to gold specs. as long as that was the only difference between the two? also have a red one that may be a little big for the 3.5

Gene thanks for the pic and the info, It'll help. do you know what the differences between the carbs were other than bore size?

 

[Slideblues]

Re:Same ole K&B questions..........

Got this one:

 

[Slideblues]

Re:Same ole K&B questions..........

James,

The biggest difference that I know of is the eary models had a barrel stop screw and the later ones did not, I have swapped needles and such, but not main parts.

Hope this helps,

Gene ;D

 

[topfuel443]

Re:Same ole K&B questions..........

Hey Gene, thanks for the cool charts they will be good to have. do you happen to know any good mild porting specs. (degree wheel?)

It looks like if I bore out the way to small black carbs that I have to gold carb specs Ill be ok.

Joe if this is the case Ill send you one that I bore out if you want to try it.

~ James

 

[_laxmasta2039]

Re:Same ole K&B questions..........

yes id really like to try one, just let me know when you've bored them out.....

while we're on the subject of carbs, has anyone tried extending the stack on a nitro carb? the velocity stacks on a gas are substantially [sp] longer, compared to thier carbs of course, and i've heard that they really do make a diff in performance. this may sound like a stupid Q cuz i dont really know what a velocity stack does, but hey.

Joe

 

[Atious]

Re:Same ole K&B questions..........

A velocity stack stabilizes the turbulent air coming into the carb throat. The longer the stack the more stabil and faster the air will flow(length within reason of course) You can also add a minute amount of swirl by milling a line in the venturi similar to that of rifling. But the benifit is so minor I don't think you could notice without a dynomometer. I.E. turbulant air flows slow, stable air flows fast the velocity stack smooths the air out.(or would you say IN? LOL)

 

[_laxmasta2039]

Re:Same ole K&B questions..........

Atious,

i guess that would mean that unless you had a carb in a strange position as far as airflow, the small stack on the venturi would suffice to sort of "straighten it out".

James,

i'll send you a PM with my address [it might be in my profile but im not sure]

Joe

 

[topfuel443]

Re:Same ole K&B questions..........

Joe, will be boring the carbs out on saturday, will send to you monday.

~ James

 

[topfuel443]

Re:Same ole K&B questions..........

Joe, its on the way! check your board meesages

~ James