F4.6 And K4.6

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K

kosss

Member
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37
Location
Grafton Australia
i brought a savage RTR 4.6 (uses a F4.6 engine)a couple of months ago. It has been going great
i got a near new K4.6 off ebay as a spare and was wondering what is the better engine. I have noticed the K4.6 has a mid range needle adjustment on the carb
and a different crank case
Thanks
 
With the addition of the midrange, it's a little better if you're an advanced tuning kinda of guy. However, I haven't heard much of being that much better. If you're looking for a great increase in power, LRP .28 Spec 3, OS .30, Axial .32.. ect..

It shouldn't be a bad mill however. I haven't personally got to use one, but I've heard they are strong as well. I gotta say though, my F4.6 has impressed me, and I can't wait to get my hands on the OS .30 :)

Ohh yeah, welcome to the forum as well man! This is a great place to really learn a TON about the Savage. Everyone here is great for giving advice and free knowledge that you can use to help you with the Savage. :)
 
kosss said:
i brought a savage RTR 4.6 (uses a F4.6 engine)a couple of months ago. It has been going great
i got a near new K4.6 off ebay as a spare and was wondering what is the better engine. I have noticed the K4.6 has a mid range needle adjustment on the carb
and a different crank case
Thanks
Click to expand...

theres not alot of diffence but having the mid range needle would help to get that "perfect tune" but wouldnt be great if you don't know alot about tuning lol and welcome to the forum buddy!!!
 
Last edited by a moderator:
Thank you
yes i joined this forum the weekend i got the savage and read the break in tutorials now i am trying to get the savage to turn a corner with out tipping on two wheels or rolling over
Thanks
 
what holes on the shock towers are you using? for better cornering put your shocks on the inside hole it lowers the truck a bit and makes a bit of a difference and as long as your not launching it off huge ramps and stuff you can take out the shock spacers which lowers your truck alot more, hope this helps!!!
 
Hi
i have tried using the hole towards the centre but will remove the shock spacers tomorrow and give it a go
i have noticed the foam inserts in the tyres move a bit as i am always pushing them towards the centre
Thanks
 
Koss the two motors are made by two different manufactures and are not compatible. The F is made by Force and I forgot who makes the K. Its King something I think. .. So don't try switching parts. Also the mid screw is not a needle. Is a venturi (Hole the the LSN Needle seats into) and it is adjustable but is not meant to be adjusted. You set it flush with the housing and leave it alone. The most a adjustable mid screw needs to move is a quarter turn off the flush setting. You do this if the mill will not return to Idle off WOT and the HSN/LSN are adjusted perfect. It takes allot of tuning Experience to know this condition and I do not recommend touching that screw. As much as a full turn off on it and the mill can burn it self up. Keep an eye on the screw if odd things happen. I have had one move a bit on me. I have not had to adjust mine off the flush setting with a K. But I did on the LRP.
Also they both have the same power ratings. Seat of the pants testers say the F has a little more top end, but that not Dyno proven. As far as the Dyno testing goes I have never seen the F test results. It makes me wonder why that is.... I do suggest the HPI polished pipe for the K mill. You have a good amount of power to unlock over the junk composite pipe. I never kept a F long enough to play with pipes on it.


Hope my two cents is helpful as far as the motor's go.

+1 with NITROADDICT the pulling the spacers to get the truck lower on the handling issue.

Last but not least WELCOME to the forum!!!!
 
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Thanks for the info guys
i removed the spacers today and took it for a run
it didnt even look like rolling didnt even get on two wheels
the engine i got hasn't been started yet but come with a aluminium pipe, header and fuel tank it also has the vented 17tooth clutch bell
 
Save the mill for another day but get that pipe on the F. They are such equal mills its not worth using the K till the F is cooked. Did some one sell it off a Xss? Thats what it sounds like. Get caps for the ports or use balloons to keep it sealed till you use it. Then put it in a zip lock bag or I vacuum seal my spare mills. All adds to its shelf life.
 
Heres a thought ... the K 4.6 is identical in most aspects to the Axial 28 ...only minor differences in the carb between the 2 . Now ...the F 4.6 looks more like the original Savage 25 motors inside and structure wise ...


Gregg
 
tornacl90rx7 said:
Heres a thought ... the K 4.6 is identical in most aspects to the Axial 28 ...only minor differences in the carb between the 2 . Now ...the F 4.6 looks more like the original Savage 25 motors inside and structure wise ...


Gregg
Click to expand...
Yep the K is very close to a Axial almost sisters. But different manufacturers. The other is because the two F mills F 4.6 and F 4.1(25) are both made by force.
 
the biggest difference is the venturi, the f has a 7.5mm venturi, and the k has an 8.5mm venturi. thats about it, it doesnt give you much more power, but it can get more air into the engine i guess.
 
Dreadnaught said:
the biggest difference is the venturi, the f has a 7.5mm venturi, and the k has an 8.5mm venturi. thats about it, it doesnt give you much more power, but it can get more air into the engine i guess.
Click to expand...

Dread its more than that look at what I wrote on page 1.
 
while talking to john from HPI on last Sat....he explained to me that the K4.6 was the older motor. it was said that they had problem breaking cranks in those because there were not enough ports in the engine cylinder to relieve the pressure and stress off the connecting rod and crank. he asked if i had the f or not....i told him that i purchased the truck in Jan?feb of this year and he stated that was when HPI came out with the new F engine. the f engine is a pure beast.........i have not have the first bid of trouble out of mine at all. one hit starting.....holds a tune like you wouldn't believe and power out of the yin yang! guys just don't believe my savage has a stock engine until i take off the body! the f is the newer plant that hpi offer in the later savages past december of 2007...and the better of the two (per hpi).
 
souljas not kidding i watched him race at the finals and didnt see a truck take off like his all day his motor was tuned to perfection. I'm glad i didnt have to race him! oh well blew one motor and broke the other truck he woulda won anyway! lol
 
that f4.6 is a hawse...love to see what it would do with aa mod job and my buku (when i ever put it on)!!! svtman....i didn't touch that truck when i got there.....needed to richen it up as a matter of fact. that f is a damn good low tuning motor....since i've had it i have about 1.5 gallons through it, still runs strong and i've only put 2 glow plugs in it since i've had it. that motor kicks hiney!
 
40 series are fun to have sometimes...I'm more of a yellow dish with the pin tires, but thats personal preference i guess...lighter and kinda has a truggy look..
 
OK i ended up getting pro line crime fighter 40 series tyres
and a set of pro line bead lock 40 series rims
the car sits lower now
took it out on the weekend and handled great but (always a but)
didnt wheelie at all and every time i turned sharp one way the engine would cough and splutter fine in a straight line and turned OK the other way
its a 4.6 x rtr stock except for the wheels and a fuel filter
i am running 20% fuel 10% synthetic 5%caster
i can take photos of the setup if that will help
Thanks
 
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