[rick1970]

Picked up a 4k corolla carby for the Sierra, looks a pretty easy swap. Are jetting changes required when doing this swap? Heard/read reports of run as is/bigger primary jet/smaller jets all round ?????????? Any ideas?

Also, best source of jets if required.

Cheers
Rick

[Built4thrashing]

no jet changes required. just bolt it on.


B4T

[foolsp33d]

dont forget to grind the base plate..or spacer bit.. There is a good description somewhere about.. No pics unfort. That i can find.. Use the zook gasket as a template. You will also need choke cable and accelerator bracket.. Air clearer MAY need some small mods to make fit get pics if you can during install.. Makes it easy for next person to do the swap.

[rick1970]

Just got around to kitting and fitting the 4k carb today. I left the throttle cable bracket i made at work so its not drivable as yet but starts easy, and after a few adjustments runs/idles sweet. A lot crisper on the throttle than the std carb.

Mine has no spacer under the carb, but i just laid the 4k gasket on the manifold and marked the vac port hole on the manifold face, then ground between this and the existing port with a die grinder. 4 x M8 studs and nuts and the carbs mounted. Existing fuel line, banjo fitting and bolt fits staright up once the origional 4k flared fuel line fitting is removed. I also fitted a second fuel filter between the pump and carb while was going.

I made a brass spacer for the air inlet about 20mm thick, but as it has a 2" BL the fit (even with the std carb) is pretty ordinary as the inlet adaptor wants to sit lopsided now the filter box is raised. A 1 1/2" - 2" spacer would be good to straighten things up a bit. A sorta mini velocity stack

Not 100% sure on the vac ports on the carb. It only has 3 x ports on the carb and atm the throttle idle dashpot thingy is connected to the port just near the idle mixture screw and the other two are blocked. One of these is on a plate on the side of the carb, bowl/vapor vent maybe??? the other is just near this in the carb body. Anybody know for sure what goes where? Dissy is currantly connected to a manifold vac port.

[Moph]

foolsp33d wrote:

get pics if you can during install.. Makes it easy for next person to do the swap.

That would be me... once lumpa sends me his =) Pics!!! PICS!!!!

[rick1970]

I can pull the carby off tomorrow and take a pic of where i ground the manifold but its pretty self explanitory when you sit the corolla gasket in place. The channel i cut in would be only 10mm long to join up the two missaligned vac ports. Cutting the gasket would most likely acheive much the same thing.

Choke lever would have just touched the air inlet adaptor without the spacer. A hammer would have fix this fairly easily.

Will take a few pics tomorrow.

[Moph]

Cool - thanks =)

[want33s]

rick1970 wrote:

Dissy is currantly connected to a manifold vac port.

Thhe distributor vaccuum advance hose should be hooked to the port just above the main butterfly.
Having it plumbed to the manifold will make it work ass about..
IE: Full advance at closed throttle and no advance at WOT.

[rick1970]

want33s wrote:

rick1970 wrote:

Dissy is currantly connected to a manifold vac port.

Thhe distributor vaccuum advance hose should be hooked to the port just above the main butterfly.
Having it plumbed to the manifold will make it work ass about..
IE: Full advance at closed throttle and no advance at WOT.

cheers

[rick1970]

Ok, swaped carb vac line over to the port just near the idle screw and ditched the vac dashpot all together. Other two vac ports are both blocked.

Fitting of the origional throttle cable to the corolla throttle arm bracket required the hole in the bracket to be drilled out a bit, easy done.

Since i didn't get a throttle cable bracket with the carb, i made up one with some 25x25 angle, then cut and welded it because i made the cable mount to close to the carb throttle arm . The choke cable also mounts to this.

I had some trouble getting full throttle movement, and ended up totally removing the stop bolt under the throttle pedal to fix this. Still have to tidy a few things up, like a propper mount for throttle return spring and do something about the air inlet pipe angles.

Inital drive showed a increase in lowdown throttle response and drivability. It will now pull smoothly from as low as 1000rpm in 3rd gear. Low end torque would appear to be up a bit. Throttle pedal was a bit to light for my liking, so fitted spring from origional carb. Havn't had it a 100kmh cruising yet, so can't comment. Still has origional 4k (KE55 corolla ???) jetting.

Starts very easy when cold. Started and held a low (and smooth) 500rpm idle with no choke this morning @ 12deg outside temp.

Np pics of where i ground the manifold, missus took the car to town with the camera in the glove box