pierburg 1b limitations

[jimbob-mcgrew]

with the jets drilled out, could this carb fuel a 1.3 or 1.4 ok ?

[mowgli]

i ran one fine on my homemade 1400 (1300+1200 pistons) with no modifications at all.

it was also used on early 1300's from the factory iirc

[jimbob-mcgrew]

mowgli, your mind's an encyclopedia

thanks ! lol

[meritlover]

why are you so sentimental towards an inferior carb? why go to the bother of drilling out jets when you could fit something better?

[jimbob-mcgrew]

money - i dont have any

[jimbob-mcgrew]

unless you fancy buying the bits for me ?

[jimbob-mcgrew]

i can pay you in sexual favours

[meritlover]

you give me the bits and then pay me in sexual favours, i would like that.

cant you sell a kidney? ive heard they fetch good money on eBay.

[Steve]

sr's up to 85 had a 1b1 pierburg, i'm looking at putting one on my 1300 because the auto choke doesn't work but i'm not sure whether its going to mess up the performance as it goes really well atm.

A weber carb would be ideal but i can't find one cheap enough as i'm also on a very tight budget lol

Anyone know what the variajet carbs off mk1 astra 1300s are like?

[jimbob-mcgrew]

yeah im in exactly the same boat steve.
slightly iffy fueling, but runs well. not sure about the performance difference (cant be THAT much different ?) im considering it, as id prefer the reliability factor over loosing a horse or 2. plus in all fairness, a lesser carb set up spot on, should outperform a better one that isnt right ? so it might be win-win.

a 32/34 would be nice, but they aint cheap! plus you need to buy adaptor plates top and bottom, and choke and throttle cables, gaskets.

i hear the varajets not bad. they use them in autograss and stockrods apparently.
ive seen a couple of 1600 jetted ones on ebay go for an affordable amount. but, harder to find 1300 jetted ones from what ive noticed

[meritlover]

cant you find out what jets people with 1300s use and buy them separately to fit yourself? surely that would give you more options? i could hold your hand while you do it?

[jimbob-mcgrew]

steve will find that out for us wont you steve ;)

<--- lazy tramp :wtf:

[Steve]

ive got an old 1b1 from my 85 sr but its untested and covered in dust and crap where its been left for so long! I would use it but i need the throttle linkage etc as the 2e3 is completely different. So im getting a manifold, carb and linkage off a 1200 and if it doesnt perform too good ive got the 1300 jets for it ;)

Im sure the haynes manual lists jet sizes? Or thats a different workshop manual ive got ???

[jimbob-mcgrew]

i have stats here from a mk.2 astra manual. no nova manual to compare it against.

1b1 carb for the 13NB engine

main jet - x112.5
aux jet - 42.5 / 155
idle jet - 47.5 / 147.5

let us know how you get on :thumb:

[jimbob-mcgrew]

i think theres subtle differences with part load enrichment valves and air correction jet, might need to switch those too ?

[mowgli]

just slap the damned thing on & see if it works first. that's what i did...

[pottersrebel]

+ rep mowgli just slap it on as for jet sizes just use drill bits to slowly enlarge the jets, proper banger style lol

[marc69]

Thed 1b1 works fine on the 1300s etc but, if your 2e3 is working correctly, about 3750 rpm with your foot flat the 2nd barrel should open and makes a massive difference, the problem is that most 2e3s are not set right and the vacuums are poor.

My1.3 SR was iniitially bad and I was 2 years before I discovered the 2nd barrel, transformed the car, seriously. The auto choke can be set and moved on the screws and again can be very effective. As for fuel economy, normal driving will give normal economy, running two barrels at every opportunity will have an obvious effect-but it's fun.

So in my opinion, spend time on the 2e3, a) it's free if you already have one and b) once it's going it is good for what it is.

[jimbob-mcgrew]

the 2e gets alot of bad rep (usually its choke not setup properly) but its a pretty good carb i think. i recently stripped mine down and rebuilt it with a service kit, blasted all the passageways thru and got a much better understanding of how it works internally.

the only bad thing i have to say about it, is, the secondary throttle only cuts in under load, so its impossible to check how well its doing its job without someone sprawled over the engine with a torch, while you boot it down the road, or in a shop on the rollers.

saying that, it gives me an idea to rig up a camera under the bonnet, and see if its opening 100% whilst driving, now that is a good idea !!

[mowgli]

under load.... so why not support the car on axle stands, & with an assistant with their foot resting on the brake, slowly accelerate with it in gear, while you look at the carb. it will create load, but the car won't have to be moving

[marc69]

I tested mine with permanent marker, put some on the plate, if it opens the fuel will dissolve it.

Another test is drive to a steep hill, take the vacuum hose off the vacuum for the second throttle (the big vacuum at the front left (short pipe) or disengage the lever for the second throttle. Drive up the hill to flat out to 6000 rpm in each gear (not 5th obviously!), then repeat with the pipe reconnected-you will know if it is working by driving it, it really does make that big a difference. It totally transformed my SR and started me on my addiction to speed.

[jimbob-mcgrew]

under load.... so why not support the car on axle stands

not a bad shout there, that would work :)


take the vacuum hose off the vacuum for the second throttle. Drive up the hill to flat out. then repeat with the pipe reconnected-you will know if it is working by driving it, it really does make that big a difference. It totally transformed my SR and started me on my addiction to speed.

another good shout :)

[pottersrebel]

There is a way to check the operation of the second choke stationary as my stockcar`s second choke will open by building up the revs even when parked up. we bloke the dizzy advance pipe and pipe up the carb a bit differently, ive read alot of bad stuff on the web about 2e3`s but they are a good carb to use if they are set up right to gain the best out of them.

[marc69]

I pipe the 2e3 on my track car differently too my SR aswell. I use the vacuum for the dizzy advance for the second throttle, no vacuum on the dizzy but full opening of the second throttle at 3500rpm which again makes a big difference.

[jimbob-mcgrew]

oh yeah marc.... stronger vacuum is it ?

whats that like coming off the throttle ? can you ease off a tad on a bend ok ?

wouldnt that over strain the diaphragm, and shorten its lifespan ?

[marc69]

oh yeah marc.... stronger vacuum is it ?

whats that like coming off the throttle ? can you ease off a tad on a bend ok ?

wouldnt that over strain the diaphragm, and shorten its lifespan ?

Yes, stronger vacuum so 2nd barrel opens fully at 3500 rpm

of course you can ease of for bends, leave the bit on the carb that stops the second barrel from opening unless the throttle is fully down, so you can just drive it normally too.

Probably the diaphragm lifesapn will shoten but it's for a track car. On my SR (road car) I use the carb as it's supposed to be, the dizzy pipe goes to the dizzy!!!

[jimbob-mcgrew]

i might try it

my dizzy AND choke pull down vacuums are both plugged, i dont use either, so i might test it in both, see if i can find a nice medium from either one.
yeh i might just ditch that plastic stop-block from the secondary throttle, it might smoothen the midrange possibly ?

[jimbob-mcgrew]

what you doing running a pierburg 2 on a track car lol, or are you skint like me, heheh

or proving a point, that races can be won using the carb that everyone loves to hate :)

[vauxluva]

I dont mind the peirburg never had any isshues with any of mine. Grew up with carbs on bikes, chainsaws,mums old fiestas escorts. Webber is the top name but. deltoro solex ect are alll ok carbs if set up corectly

[jimbob-mcgrew]

mums old fiesta

lol

[marc69]

i might try it

my dizzy AND choke pull down vacuums are both plugged, i dont use either, so i might test it in both, see if i can find a nice medium from either one.
yeh i might just ditch that plastic stop-block from the secondary throttle, it might smoothen the midrange possibly ?

DO NOT DITCH THE STOP BLOCK......

I did this once drove it round the corner, the 2nd barrel opened full and stayed that way, the rev counter was jammed against the rest needle bit before I got the ignition off. I was lucky that i didn't wreck the valves. Although it was a good test to check that i got the vavle timing right!

[marc69]

I have double webers but not jetted correctly for the car, I got it rolling roaded and then the plan was to put the webers on permanently. I turned up and with the modifications to the pierberg there was a 43% difference in power @ 7000rpm between the single barrel and twin.

The torque however was slightly down and emmissions were mental!

The guy said I wouldn't get much more increase with the webers set up and I spoke to Ricky Gauld who is a well known tuner here who said there would be little more advantage unless a load of money and additional work was done, but bear in mind the car also has a 1.6 head, kent cam and solid exhaust sytem so it can make full advantage of what the carb is doing. He was amazed that the pierberg did that much though.

[jimbob-mcgrew]

the rev counter was jammed against the rest needle bit before I got the ignition off

heheh, bet that made you panic for a moment, lol

i mis-interpereted your meaning of leave. i thought you meant ditch it.

i will have a tinker tomorrow with the vacuum setup.
ive got the fueling pretty good, but it really wants colour tuning to get it good. i might do that while im there. i need to remember the loctite on the screws, it keeps going out of tune if you dont

[jimbob-mcgrew]

thats good what he said about the carb tho, shows you the old hated 2e (with abit of tweaking) isnt a complete bag of turd that everyone makes it out to be

[marc69]

you can't really adjust tthe mixture setting on this carb, it's just different jets that do that, I though the only really setting you can adjust is the idle speed screw?

Yes, panic isn't the word, I assumed I'd wrecked it after all my work and money, the relief after pushing it home (again! this hapened a lot in the initial setting up stages) and turning it successfully...phew

[jimbob-mcgrew]

im pretty sure you can, ive been making adjustments on it, keepin an eye on the condition of the plugs, and its been going from too lean to too rich from just the mixture screw.
the accelerator pump screw makes a massive difference, you have to be carefull with that, i sooted the plugs pretty hard with a little tweak