12 replies to this topic

[Ciaran]

Hi, Im new to this site and i was just looking for peoples opinions and experiences with these carbs on a 1380??

My engine is 1380cc, stage 3 minispeed head, 286 cam, Im not sure what rockers are in it but they look standard. it's currently running with a electronic aldon dizzy and lucas coil. twin su hs4 1.5 carbs with .090 jet and AAA needles(kit supplied by minispeed) Final drive is 3.44 and its a standard box. for what its worth leads are bosch and plugs are NGK bp6es

My problem is the carb, Im convinced it has somthing up with it, as the engine just isnt performing as id like, it was on rollers a few years ago with the same set up and achieved 96bhp.

Ive colourtuned the mixture to the best setting i could achieve and the airflow is balanced, not sure about airleaks tho.

before i colour tuned it and balanced the carbs it was running dangerously lean at 0.12% co2 and not burning all the fuel as the hydrocarbons were off the scale at 1700PPM. I can put some of the hydrocarbons down to the overlap but ideally i want to get under 1200PPM and below 3% co2.

Now with the colour tune its at 0.13% PPM but the flame is blue all the way through.

I have the original HiF44 that came off the cooper engine that was originally in it.

Which would be the better carb, id be hoping the engine could easily achive over 100bhp and perform considerable better than it is at the min.

I reckon 0-60 is approx 9 secs, although it does go from 60 to 100 very quickley.

any advice or experience with tuning these engines?

Thanks

Edited by Ciaran, 20 October 2008 - 07:03 PM.

[Ciaran]

nobody has any experience?

[taffy1967]

Well JCG fitted twin carbs to their 1400S carb conversion: -

http://z11.invisionf...p?showtopic=179

But the HIF44 is good for well over 100bhp.

It's just that twin carbs are more suitable as they fuel the engine better, or at least are supposed to.

Edited by taffy1967, 22 October 2008 - 02:10 PM.

[Ciaran]

Well JCG fitted twin carbs to their 1400S carb conversion: -

http://z11.invisionf...p?showtopic=179

But the HIF44 is good for well over 100bhp.

It's just that twin carbs are more suitable as they fuel the engine better, or at least are supposed to.

cool, thanks for the reply.

I may stick with the twins if JCG had them on, my problem must be elsewhere.

cheers!

[Guess-Works.com]

what sort of plugs are you running, it may just be something as simple as changing the plug, as you say yourself you're not getting the required combustion..

Alternatively, check you compression ratio's

High HC could also be attributed to oil

[Ciaran]

what sort of plugs are you running, it may just be something as simple as changing the plug, as you say yourself you're not getting the required combustion..

Alternatively, check you compression ratio's

High HC could also be attributed to oil

It aint burning oil tho??? ive already checked for this, revved it as far as i dared....... 7k RPM was a bit of smoke but not enough to warrant a oil leak, all engines consume some oil at high RPM, not a sniff of it at idle(around 1000rpm).

the plugs are NGK bp6es, calver(i think) reccomended them on his site for my engine spec.

when idling it does smell terribly rich, but , the co2 readings and colourtune say otherwise??? odd.

the exhaust is black, could these deposits give a bogey reading??

[taffy1967]

You've got electronic ignition on your Mainstream Cooper, so you should really be using NGK BPR6ES plugs.

[Guess-Works.com]

also try going to 7's instead of 6's... cooler running sparkie may help things along....

Is the electronic unit in the aldon a petronix ( ignitor ) and sports coil ? if so the BP's will be fine

[BJst416]

BP or BPR will make no difference in performance.

A colder plug (7) could yield some interesting results. However the black smoke could be due to richness of the mixture, I´d think that a couple of AAA neddles are a lot of fuel to be burned.

Just as an example a single HS4 with AAA neddle is sometimes on the rich side for a 998.

How much oil are you losing/burning? just remember that all A series/A+ burn oil if you drive them hardcore everyday. Even more so on overbored blocks.

Edited by BJst416, 23 October 2008 - 06:08 PM.

[rozzer1275]

96hp is good, you may loss a few hp going to hif44 but gain on simplicity.
you say it not performing as you would like, do you mean you think is lost performance or do you want more?
I take it you have done the usual, clean set plugs, ignition, rocker gaps etc
how many miles has it done? you said its been a few years since its been on the rollers. if a lot could do compression test valves may need reseating, or check cam timing and lift.

might be worth talking to minispeed maybe getting it on there rollers and see what its doing under load!

fitting 1.5 rockers gave me 6hp (with my setup, I run a minispeed 1380, concept 37 head, 286cam, 1.5 rockers, hif44 may not with yours) and made the engine very camy, lots of misfire till 3,000rpm then big rush of power.

[Ciaran]

96hp is good, you may loss a few hp going to hif44 but gain on simplicity.
you say it not performing as you would like, do you mean you think is lost performance or do you want more?
I take it you have done the usual, clean set plugs, ignition, rocker gaps etc
how many miles has it done? you said its been a few years since its been on the rollers. if a lot could do compression test valves may need reseating, or check cam timing and lift.

might be worth talking to minispeed maybe getting it on there rollers and see what its doing under load!

fitting 1.5 rockers gave me 6hp (with my setup, I run a minispeed 1380, concept 37 head, 286cam, 1.5 rockers, hif44 may not with yours) and made the engine very camy, lots of misfire till 3,000rpm then big rush of power.

96bhp in 2005. in my opinion it is considerably less at the min, was in a standard mpi cooper and it was in and around the same, kinda frustrating!!LOL although it will get you to over 120mph, the mpi didnt.

So far ive balanced the carbs, done the mixture, new leads, plugs, did the tappets to the cams spec, i think it was 14 thou??

Its not done too many miles, the car has 55k miles since new and the engines alot less, maybe around 15k.

I was going to change the needles to BDK as these seem to be a bit leaner at the idle, ive done the timing, my strobe light decided to break(can you take a live off the coil?? i had to bodge up a line from the battery as i didnt really want to use the coil as i wasnt sure), so timing was done by listening and its as good as i could get it,(admittidly its probably a few degrees off).

The compression is good in the engine, there is the tinyest of backpressure coming up through the rocker cover, you can barley feel it.


Im just kinda puzzled, i think maybe the best bet is the needle at this stage.
Does anybody know the needle cooper garages had in their 1400s conversion?

Im not putting bigger rockers on as i think this may make it even more of a pain under 1,500 rpm.


I kinda put down the smoke at 7k down to the revs as it is old and well we do like to thrash them , thats what they are there for!LOL

Im in ireland so i dont really want to shell out a lot of money just to get it through a emissions test, then back a hour later to get it running right, also its expensive experimenting with different bits as mini parts and carb needles are expensive here!
dont mind paying for a RR to get it right, not to get it not right for the sake of emissions.


what do you reckon the colder plug will do? promote better combustion?

so you reckon that the twins are good, and better on my car than a hif44?? its a needle problem??

Edited by Ciaran, 24 October 2008 - 02:03 PM.

[taffy1967]

Why not join the Mainstream Cooper Register as there's a few members on there who own the JCG 1400S conversions.

Or just get it set up on the rollers, that way you'll get the best needle and results for sure.

[Ciaran]

Why not join the Mainstream Cooper Register as there's a few members on there who own the JCG 1400S conversions.

Or just get it set up on the rollers, that way you'll get the best needle and results for sure.

I think i might, i spent a entire day on that website once LOL.

thanks for all the help[ lads/ladies!!