New Engine Mods

[1992suburban]

are you looking for more RPMs and TOPENED or more bottom end

Lewis Stout is the man, tell him what you want out of the lil motor and he will set you up

 

[NapO]

i wanna essentially loosen the back tires and get more low end and midrange power and im running 2 speed jack shaft from comet.

 

[motor_head]

m running 2 speed jack shaft from comet.

cool i've heard those things are really neat how do you like yours

 

[oscaryu1]

Yes but try not to run 26lb springs on them.

 

[NapO]

i'm running 18 lbs spring now. y can't 26 lb springs be used with the jack shaft system. i was planning on using them with a new cam. i'll post a picture of my set up. i like the system. it plenty of torque and top end. however there is a soggy spot in the middrange when the clutches are switching.

 

[Rickracer]

My GX 240 carb worked fine with the stock needle and seat gravity fed and pump fed, I didn't have to change anything, YMMV though,
On the flatslide Mikuni for my RM 250 though, I had to drop from a 2.8 or 3.0 to a 2.0 needle and seat to use a fuel pump without flooding. :rolleyes3:

 

[1992suburban]

looking gettin .265 cam from stout. good for the mods i got?

I think he was talking about 26lb springs on the valvetrain.


I dont know if that cam is face hardened.. if its 50 bux prolly not 18lb should do fine

 

[NapO]

lol rookie mistake.. face hardening makes a big difference? oh how do i found what head my gx160 has? it's mid 90's model.

 

[1992suburban]

look for the casting # on the side of the head

should be Letter Number Letter.. Z0T for example thats what I did ????

 

[NapO]

i figure if i get a crazy torque cam from nr-racing or agk i should know my compression right?

 

[NapO]

1992 you mention that a bigger carb will hurt low end in another thread? should i just leave the bored out gx160 i have now and modify the cam and other parts for bottom end and midrange power?

 

[1992suburban]

no.. was simply saying a BOX stock engine with a BIG carb should lose some bottom end but gain topend..

think a 302 with a decent carb say 750AED the motor will suffer down low but will pull like a banshee up top..


the bored out stock one may be enough for you either way..

 

[NapO]

kk i got it thanks

 

[NapO]

hey what do u guys or gals think of the 247 0207 cam? i like how it a higher rpm range and it says it still gives lots of torque. or else i think im gunna buy the 252 0211 cam. so much too choose from lol.

 

[jr dragster T]

lol rookie mistake.. face hardening makes a big difference? oh how do i found what head my gx160 has? it's mid 90's model.

If the cam is not hard faced the 28 pound springs will flatten out the lobes in short time...

 

[1992suburban]

you do understand what those numbers mean right..

the 252 is the lift the 02 and 07 is centerline and lobe seperation..

 

[1992suburban]

the lift makes LITTLE difference its the duration, centerline, and lobe seperation that seperates the men from the boys... in cam selection LOL

others chime in... please

 

[NapO]

kk i starting to get it now.. so then what that i am to look for? im guessing it's dependent on other messurements and parts that are on the motor? i guess what i'm really asking is how do i no what to look for? sorry about all the questions. i like to understand in depth about the parts and i'm still pretty new to all these mods. suburban u've been a great help so far.

 

[NapO]

may be this will simply things my goal is to hit 80 km/h with best possible acceleration and torque. with my current set up i can hit 70 km/h with pretty good amount of acceleartion with soggy spot in the middle of th band. what would guys and gals recommend to achieve this within $150 to $200 range. hope this makes it easier?

 

[1992suburban]

asking questions = best way to learn..


OK sounds like you need either more power up top to pull the speed or more power down low to change gearing to reach the speed..

whats it geared now and what size tire (rollout or dia.)

how many RPMs is it turning at max observed speed???