[S13RR4]

Has anyone had any experience rebuilding their carby?

I was thinking of rebuilding mine with bigger jets (then putting on my extractors and getting a 2'' exhaust) to get a little more go out of my 1.3.

So whats peoples experiences, good, bad, awesome, terrible.....

Also, does anyone have any info/ideas on the bigger jets side of things?

Joe

[gypsy]

use the secondary jet in the primary and a primary jet from a 1.6 corolla in the secondary

[christover1]

Main issue I had was idle jet clogging.
But dunno if a larger one would cause more issues than it solved.

I re co'd my carby with a $40 kit from an Auto shop.
Cleaned out fuel tank, lines and fitted a new fuel pump and inline filters.
Never had a carby issue ever again.

Its crud that kills the carbs,
often from a disintegrating fuel pump,
so an extra filter there is wise too.

Undo stuff carefully, I had a spring fly out,
which took 2 days to find,
and a lot of head scratching to refit in right spot )

Much luck is wished for you.

[S13RR4]

I don't know if my carby is under performing as such, but was hoping to improve its performance with the bigger jets, so I'm unsure whether a rebuild is necisary.
The fuel line, pump and tank clean out does sound like a good idea though.
How did you go about doing that?
Did you have to remove the tank?


Joe

[christover1]

S13RR4 wrote:

I don't know if my carby is under performing as such, but was hoping to improve its performance with the bigger jets, so I'm unsure whether a rebuild is necisary.
The fuel line, pump and tank clean out does sound like a good idea though.
How did you go about doing that?
Did you have to remove the tank?


Joe

Mine was a 1.o litre tank, it had a drain hole,
you wouldn't believe the shit that came out.
But I actually fitted a new tank, new old tank anyway,
a 60 L from a 260c into my tray, so I cleaned it out before fitting.
Fitted new rubber lines, and blew through the hard lines.
I think I used a commo EFI inline filter,
much better than stock, was only $20 from auto shop.
They last much longer and filter better.
Then fitted a ryco filter just before carb.

[Lokidog]

[Teracis]

[steve]

Here's something else to read....

http://auszookers.com/index.php?name=Forums&file=viewtopic&t=4160&highlight=carby

[S13RR4]

[S13RR4]

steve wrote:

Here's something else to read....

http://auszookers.com/index.php?name=Forums&file=viewtopic&t=4160&highlight=carby

thats really good info there Steve

[zook95]

tht was a good read thanks for sharing worth a though

[S13RR4]

had a chat with a carby dude today, he said the main problem with rebuilding a sierra carby with bigger jets is that, all though you can increase the fuel delivered, the air flow through the two throats is insufficient to enable an increase in the cars performance.

The replacement carby he showed me had significantly larger throats which would obviously allow more air and fuel through. It also had a mechanical second throat instead of the vacuum secondary on the original sierra carb.

what are peoples thoughts on this

[Teracis]

Sounds interesting, got any idea of the model of carb? or at least what it came off?

Mechanical secondary would be pretty useful if you were going to use positive displacement shouldn't it?


Also, won't larger throats slow down the air flow?

[mr_ron]

I run a Datsun 1600 'Nikki' carby, bolts on without any adaptor plate and runs really well.. also have alot less issues with the bowl emptying on hills..

I also have a Fully rebuilt, Chromed and 1.3 jetting Holley 180 carby here and adaptor plate, however im converting to efi so havnt had teh chance to use it yet but yeh the reason i bought it was fo rthe larger air intake...

[Taylor74]

Early toyota corolla carbys work well. Bolt straight on aswell only need to change the bolts for studs and play a little with the acc cable conection.
Sorry im not quite sure what model but can find out if needed

[royce]

S13RR4 wrote:

what are peoples thoughts on this

I think numerous sierra owners saying I did this and it worked vs one carby dude trying to flog a random carby, the sierra owners win

More power isn't just about forcing more air through something, its about using as much of the available air as possible to help burn as much fuel as possible to make the biggest bang possible, the stock carby is a bit lean so bigger jets make it a better mixture for power

[S13RR4]

it was a similar design to a webber, but made by a different company.

Was more interested in the larger throats argument to allow greater volumes of air into the engine.

But I wonder if the holes on the intake manifold are larger than the sierra carby, thus any increase in the carby throats is going to be limited by the intake manifold...

the guy took me through every option and pricing, including kits and parts to rebuild my own carby, to rebuilt sierra carbies to webbers etc. so I don't think he was trying to flog off some old carby

[JrZook]

S13RR4 wrote:

it was a similar design to a webber, but made by a different company.

Was more interested in the larger throats argument to allow greater volumes of air into the engine.

But I wonder if the holes on the intake manifold are larger than the sierra carby, thus any increase in the carby throats is going to be limited by the intake manifold...

the guy took me through every option and pricing, including kits and parts to rebuild my own carby, to rebuilt sierra carbies to webbers etc. so I don't think he was trying to flog off some old carby

Similar design to a weber then its a holley 180, pretty much teh same thing! The stock 1.3 head has ~30mm diameter intake runners to the valves so thats no issue. IF you do put a weber or bigger carb on you just grind out nteh base of the intake manifold to match the base of teh carb. There's heaps of meat to grind away.

On another note if your struggling to get to 100 or 110 on flat ground with 235's and no gearing, assuming your engine is in good nick, there could well be an issue with your stock carb holding it back ie secondaries not opening etc.

Dan

[Teracis]

JrZook wrote:

S13RR4 wrote:

it was a similar design to a webber, but made by a different company.

Was more interested in the larger throats argument to allow greater volumes of air into the engine.

But I wonder if the holes on the intake manifold are larger than the sierra carby, thus any increase in the carby throats is going to be limited by the intake manifold...

the guy took me through every option and pricing, including kits and parts to rebuild my own carby, to rebuilt sierra carbies to webbers etc. so I don't think he was trying to flog off some old carby

Similar design to a weber then its a holley 180, pretty much teh same thing! The stock 1.3 head has ~30mm diameter intake runners to the valves so thats no issue. IF you do put a weber or bigger carb on you just grind out nteh base of the intake manifold to match the base of teh carb. There's heaps of meat to grind away.

On another note if your struggling to get to 100 or 110 on flat ground with 235's and no gearing, assuming your engine is in good nick, there could well be an issue with your stock carb holding it back ie secondaries not opening etc.

Dan

I can get to 110 and stay there unless I hit a serious hill if I use 4th gear. Holding the engine at 4000 rpm is fine until after a couple of minutes it starts to surge, If I back off and go back on fine, but I haven't let it just keep surging because I couldn't be sure it was just a fuel issue. I'm hoping it's just the fuel bowl running low or something because of the float level but I'm guessing it's more like fuel pump or something?

[S13RR4]

JrZook wrote:

S13RR4 wrote:

it was a similar design to a webber, but made by a different company.

Was more interested in the larger throats argument to allow greater volumes of air into the engine.

But I wonder if the holes on the intake manifold are larger than the sierra carby, thus any increase in the carby throats is going to be limited by the intake manifold...

the guy took me through every option and pricing, including kits and parts to rebuild my own carby, to rebuilt sierra carbies to webbers etc. so I don't think he was trying to flog off some old carby

Similar design to a weber then its a holley 180, pretty much teh same thing! The stock 1.3 head has ~30mm diameter intake runners to the valves so thats no issue. IF you do put a weber or bigger carb on you just grind out nteh base of the intake manifold to match the base of teh carb. There's heaps of meat to grind away.

On another note if your struggling to get to 100 or 110 on flat ground with 235's and no gearing, assuming your engine is in good nick, there could well be an issue with your stock carb holding it back ie secondaries not opening etc.

Dan

it was a empi, or epsi, or emps or something, pretty close replica I think except the new model he showed me had an electric choke.

was thinking this, that's good to know

it's not long since rebuild.

the guy said that was one of the main problems with the stock sierra carb. the vacuum second taking so long to kick in or in some cases failing to open at all. The one he showed me had a mechanical second which if you put your foot down its guaranteed to open the second

some times it will drive on and past 110 (on the speedo) in 5th, but most times I'll get to 100 (on speedo) in 4th, go to 5th and it dies...

[JrZook]

Teracis wrote:

I can get to 110 and stay there unless I hit a serious hill if I use 4th gear. Holding the engine at 4000 rpm is fine until after a couple of minutes it starts to surge, If I back off and go back on fine, but I haven't let it just keep surging because I couldn't be sure it was just a fuel issue. I'm hoping it's just the fuel bowl running low or something because of the float level but I'm guessing it's more like fuel pump or something?

That does sound like a fuel issue. How old is your pump and filter? May be worth replacing. It is possible that your float level is too low but assuming your carb hasn't been fiddled with Id start with the pump and filter first before pulling it apart.

Dan

[JrZook]

S13RR4 wrote:

it was a empi, or epsi, or emps or something, pretty close replica I think except the new model he showed me had an electric choke.

was thinking this, that's good to know

it's not long since rebuild.

the guy said that was one of the main problems with the stock sierra carb. the vacuum second taking so long to kick in or in some cases failing to open at all. The one he showed me had a mechanical second which if you put your foot down its guaranteed to open the second

some times it will drive on and past 110 (on the speedo) in 5th, but most times I'll get to 100 (on speedo) in 4th, go to 5th and it dies...

Yea they are pretty much the same thing, nothing special there. Mechanical secondaries will aid in engine response but can cause flat spots if the throttle is applied to quickly as the intake manifold looses vacuum.

Unless your secondary actuator has a tear or the vacuum port its connected to is blocked with carbon it should work sweet!

What are you planning to do with the car? If its more a DD and not for full on serious offroading the empi/weber/holley carbs will give you a nice boost in performance.

Dan

[S13RR4]

its a DD, with camping and 4b trips when I can fit them in, so no, not a serious offroader

[JrZook]

S13RR4 wrote:

its a DD, with camping and 4b trips when I can fit them in, so no, not a serious offroader

Then you will be fine with a weber or sorts. No yes they do have there issues with steep angles etc but overall i found them to work quiet well. I had one on my old rig for near 4 years and never had an issue, whilst still being to drive the descent tracks at ormeau and landcruiser park. Tuning is simple and if who ever cant get it tuned or running right go find someone else because they are as simple as they can get carb wise!

Dan

[Teracis]

I've got the transfer out of mine atm putting gears in tomorrow, but maybe next weekend I'll rebuild the carby, I've had the rebuild kit for a while and while I'm confident to rebuild the thing myself, it's the tuning that I'm worried about, it's so easy to stuff up. Might do some research as to a standard "wind the screw all the way in then back out two and a half turns" type instruction that works and use that?

[JrZook]

Teracis wrote:

I've got the transfer out of mine atm putting gears in tomorrow, but maybe next weekend I'll rebuild the carby, I've had the rebuild kit for a while and while I'm confident to rebuild the thing myself, it's the tuning that I'm worried about, it's so easy to stuff up. Might do some research as to a standard "wind the screw all the way in then back out two and a half turns" type instruction that works and use that?

Tuning the stock carb after a rebuild, mate there aint much to it. Idle speed and idle mixture screws apart from the choke setup. Try the 2.5 turns out as a base line then start turning what ever way that gives you the best and highest rpm at idle when warm. Done.

Dan

[S13RR4]

what are peoples thoughts on vitara carbies?

is the jetting on vitara carbs better?

are they much better then sierra carb?

which would be better option>
a) rebuild sierra with bigger jets?
b) vitara carb (possibly rebuild to make a level playing field)

joe

[S13RR4]

Teracis wrote:

I've got the transfer out of mine atm putting gears in tomorrow, but maybe next weekend I'll rebuild the carby, I've had the rebuild kit for a while and while I'm confident to rebuild the thing myself, it's the tuning that I'm worried about, it's so easy to stuff up. Might do some research as to a standard "wind the screw all the way in then back out two and a half turns" type instruction that works and use that?

when you say rebuild kit...

whats included in the kit?

[JrZook]

S13RR4 wrote:

what are peoples thoughts on vitara carbies?

is the jetting on vitara carbs better?

are they much better then sierra carb?

which would be better option>
a) rebuild sierra with bigger jets?
b) vitara carb (possibly rebuild to make a level playing field)

joe

Dude overall what are you looking for from a carb?

[Teracis]

S13RR4 wrote:

Teracis wrote:

I've got the transfer out of mine atm putting gears in tomorrow, but maybe next weekend I'll rebuild the carby, I've had the rebuild kit for a while and while I'm confident to rebuild the thing myself, it's the tuning that I'm worried about, it's so easy to stuff up. Might do some research as to a standard "wind the screw all the way in then back out two and a half turns" type instruction that works and use that?

when you say rebuild kit...

whats included in the kit?

I'm not sure exactly what is in the kit, there's heaps of stuff, I'll let you know when I've done it, but things I do know: All the gaskets for a rebuild, new accelerator pump plunger, new needle, no jets or anything you just clean those.

Also, you're better off rebuilding the sierra carb as far as I've read. If you can set it up right it's the best one for the 1.3 bar the fuel injection.