HELP ...Fuel and Air Intake Issues

[SimonSpeed]

Can anyone help me with my carb / needle set-up or point me in the right direction.

I finally have my Mini Van back from Deon at DJ's Minis but we are having issues with the fuel/air intake.
Deon has rebuilt the 1275cc A+ engine to 1293cc, added stage 3 race head, JanSpeed Supercharger kit installed and a Facet fuel pump.

The van runs very well and is very fast but you have to edge the gas pedal down slowly, too quickly and the engine begins to stall, once up at speed if you back off on the gas pedal slightly , you go faster!!!

Not sure if it is too much fuel, not enough air or vi sa versa.
Deon has tried different needles but cannot offer any more help.

Any help is most appreciated as I have been waiting three years to get my van back and I just want to get out and attend Mini Events.

Thank You....Simon

[MINIMAD]

Can anyone help me with my carb / needle set-up or point me in the right direction.

I finally have my Mini Van back from Deon at DJ's Minis but we are having issues with the fuel/air intake.
Deon has rebuilt the 1275cc A+ engine to 1293cc, added stage 3 race head, JanSpeed Supercharger kit installed and a Facet fuel pump.

The van runs very well and is very fast but you have to edge the gas pedal down slowly, too quickly and the engine begins to stall, once up at speed if you back off on the gas pedal slightly , you go faster!!!

Not sure if it is too much fuel, not enough air or vi sa versa.
Deon has tried different needles but cannot offer any more help.

Any help is most appreciated as I have been waiting three years to get my van back and I just want to get out and attend Mini Events.

Thank You....Simon

Tough to answer with a charger on it.
Sounds like the needle is off. To do it correctly, you'd need various needles to try and put it on a dyno and/or exhaust analyzer. To me it seems LEAN at idle and RICH at top end. Just a guess though. There's hundreds of needles. You might want to call technical help at Minimania as they used to sell supercharger units a few years ago. They may be able to advise you a little on your problem.

There are some online needle software packages that can give you a hint at where to start.

http://www.winsu.co.uk/

http://www.teglerizer.com/sucarbs/index.html

[SimonSpeed]

Thank You, Deon has tried over dozen needles. We both have called Minimania and the only advise they called give us was to upgrade the Facet fuel pump which Deon has done and a different float. We spoke to the various companies in the UK that sell these packages and I think the needle Deon said we had to have is BCG but nobody in the UK carries them anymore.

I am not very technical, so I hoping someone can suggest a shop/garage that is old school and can work on Carbs and understands needles. The one we have in there right now is custom made and is doing just as you have mentioned, lean at idle and rich at the top end.

My original build was set for $15k, I’m already at $26k including the $2,500 for the Supercharger kit, the last resort is to remove Supercharger but as I have invested so much money, it’s a shame to quite so early.

Do you know of a shop/mechanic who knows about Carbs and Needles and has a dyno?

[MINIMAD]

Sorry for your troubles. Here is a link to someone who knows SUs in & out. He may be a resource in finding better needles or links to others.

http://joecurto.com/

[MINIMAD]

Use the winsu software to cross-reference this to another needle that is close...

BCG needle (0.100) part number: CUD1154

profile:

1 .099
2 .095
3 .0914
4 .0886
5 .0837
6 .0786
7 .0736
8 .0665
9 .0582
10 .0493
11 .0414
12 .0331
13 .0331
14 .0331
15 .0331
16 .0331

These are the needle profiles (thickness) at the various stages for a BCG needle. Thinner is richer, thicker is leaner when comparing needles.

What about the spring in the dashpot? Was that changed to match for a supercharger? Needing more/less spring pressure?

[MINIMAD]

Other shops who build & race Minis

http://www.7ent.com/

http://heritagegarage.com/-/


Is your system SUCK-THRU or BLOW-THRU? What make?

[MINIMAD]

http://www.hi-flow.com/HP4FAQSuper.htm

[SimonSpeed]

wow....THANKS John, these are great leads and I will contact these companies and see what they say.

I just spoke with Deon, he did change the spring out in the dashpot with a new spring that came in the kit designed for our HIF44. The charger is a "suck thru" and he had the current needle custom made which is not perfect, but better than all the others shipped over from the UK. Deon mentioned a Sunshine Mini Club Member in Ft. Lauderdale that had the same problem and ended up using a BGC needle ( i got it the wrong way around earlier ) and he is going to call him to see how his system is working. Deon has the Win Su software and still could not match up the needle.

Other than this issue, Deon has done an amazing job and the van really performs, on I-4 this past weekend we took her upto 90mph but it got a little scarey at those speeds and backed off and the smell of fuel was a little overwhelming.

I will try the companies you have listed and if I have no luck, then I guess we will go back to twin 1.5" SU's and try to sell the charger kit. Deon did mention that the new style in the UK for chargers are with fuel injection ...so that maybe an option if we can buy the parts to go with my supercharger!!!

[MINIMAD]

BGC profile:

1 .0990
2 .0962
3 .0939
4 .0917
5 .0891
6 .0864
7 .0839
8 .0814
9 .0785
10 .0756
11 .0727
12 .0698
13 .0668
14 .0639
15 .0610
16 .0580

BGD slightly richer from step 4 up
BGB richer yet

[Alecs Minis in London]

The thing with a supercharger is it has to be set up on a Rolling Road. I am not sure if in America your Rolling Roads are Mini friendly. Try these in England they may be able to give you a good starting point for needles and help

http://www.jonspeed4minis.co.uk/shop/index.asp

http://vmaxscart.co.uk/

[SimonSpeed]

Thank You Alecs Minis in London.
I am almost at my end, the kit i have is from JonSpeed and he has been a big help but you are right, this needs to be set-up on a "Rolling Road" and so far, nobody in Florida can help and I have tried everyone including the "Back Street Road Racers".

I hate to say it but I think I only have two options left:
1. go back to basics with a single or twin carb set-up or
2. ship my Mini back to the UK for set-up (about $1,900 from Port Canaveral to Southampton round-trip plus TECH fees and parts for the set-up) which is an option as I am already so far over budget, whats another $2k !!!
(just don't tell the wife - LoL)

Cheers...Simon

[Alecs Minis in London]

Thank You Alecs Minis in London.
I am almost at my end, the kit i have is from JonSpeed and he has been a big help but you are right, this needs to be set-up on a "Rolling Road" and so far, nobody in Florida can help and I have tried everyone including the "Back Street Road Racers".

I hate to say it but I think I only have two options left:
1. go back to basics with a single or twin carb set-up or
2. ship my Mini back to the UK for set-up (about $1,900 from Port Canaveral to Southampton round-trip plus TECH fees and parts for the set-up) which is an option as I am already so far over budget, whats another $2k !!!
(just don't tell the wife - LoL)

Cheers...Simon

In for a penny in for a pound as they say. Sounds drastic but needs must.

Have you managed to contact Stuart at Vmax he can be elusive. Another option http://www.minispeed.co.uk/ they have a rolling road and they fit Superchargers.

I will be working on my friends Supercharged engine next week I will see what needle he has fitted.

Chin Up

[captbj]

I agree that when you get into the 'hard stuff' the most common recommendation is that you can only tune an SU set up with a "rolling road" and someone who really knows Mini's .... altho I read into that a bit. They don't need to know "Mini" they really really need to know is SU and I think THAT'S the problem we're seeing.

We have dyno's a plenty around here, and the rolling road recommendation usually says you need to be connected to a good gas analyizer for the exhaust - again easily found....but the SU expert....hmmm

Could you mitigate that factor? What about a different carb....say a Weber? Easier to tune and find an expert?

Another thought b4 you send it to England. I had mine looked at by ABACUS Racing of Virginia Beach once. These guys are a top notch full service race car builder, classic race car builder and restoration shop. The owner has a collection of Healys and classic racers . . . might be worth a call to see if they think it would be worth a trip? They diagnosed my SU problem 5 minutes after I got there . . . of course I was living there then so it wasn't out of the way....

http://www.abacusracing.com/
example of work http://www.britishv8.org/MG/KeithBurnett-MGBGTV8.htm

[MINIMAD]

Not much esoteric or magical about an SU's operation. It'd be hard to find a simpler carb setup. What it takes is fundamental understanding, patience, willingness to learn (inquisitiveness) and proper equipment (plus a handful of needles). I agree with captbj about finding a race car shop wiling to tackle a dyno session with it. It should give you a good read on what directions you need to go. Certainly the least expensive option. There is a shop here in Tampa that does BMW racecars. PHILTHY can link you up to them. Maybe http://europeanautohausinc.com/_wsn/page17.html

Or in Orlando research:

http://www.titanmotorsports.com/services.html
http://www.mikenorrismotorsports.com/Dyno___Tuning.html

Lamotta Performance Function/Expertise : Installation, parts, dyno tune
715 N. Hwy. 17-92
Longwood FL
32750
407.695.4549

[captbj]

problem is finding a shop that knows these 'very simple carbs' tho ain't it??????? Ancient technology . . . y ships had all kinds of very simple systems that had been out of production for 30 years. Getting them fixed wasn't easy.

Abacus is one that I can certainly attest KNOWS this system .... unfortunately it ain't near by.

If you want to save the driving I've used AutoTrain twice - it takes you to Lorton outside of DC and than leaves you several hours from Va Beach .... but WAY less than driving the entire thing and WAY less than the cost of trucking.

[MINIMAD]

You're not going to find a shop that "knows" these carbs. Although side draught carbs have been used for a century on cars and motorcycles.

I suggest sussing through central FL resources to find out if there's any dyno shops around that may help. You may find a qualified mechanic with enough smarts, patience and a willingness to lend a hand. An initial dyno session is what you need. The readout will tell you where you are lean/rich. You don't need anything/anyone special to get that part done.

The readout is s starting point. It will guide you to a selection of needles for the next (more extensive) dyno session. Then, you will substitute profiles to see which gives the best curve at all speeds.

Needles run $15-$17 each. Joe Curto is your best bet for needles. He stocks 800+ profiles including needles for methanol...and rarer design carbs. He makes many SU parts. (a former airplane machinist)
http://joecurto.com/

Joe Curto Inc.
22-09 126th Street
College Point, NY 11356

(718) 762-SUSU (7878)
(718) 762-6287 (Fax)

I might also suggest calling Glenn at http://glennsmg.com/ He is knowledgeable and may have advice to help you out. It isn't any different applied to a Spridget A series motor or even a B series. He may have some experience there.

[SimonSpeed]

We are getting somewhere, I found out that my 1293cc is running to high on compression, should be 8.1 and is currently at 8.8. Deon forgot about this. We initial set the engine up for a standard 1275cc with a Stage 1 Head, then at the last minute and the need for speed, I changed my mind and added a Stage 3 Race Head, Fast Road Cam and a SuperCharger, so the engine compression ratio was forgotten.

Deon has set-up the engine/supercharger in a way if I ever sell the minivan (over my dead body), the new owner has the choice of keeping it supercharged or retuning back to carbs/webber etc... without too much modification.

Deon knows what to do, we have to reduce the compression from 8.8 to 8.1 (down to 42cc). Once this is done, we can order several needles and go from there. I also found a gentlemen here in Longwood that knows everything you need to know about SU/Stromberg Carbs, Webbers etc... and also knows of a dyno we can use once Deon has modified the compression. Joe Curto in NY has also been a big help.

Thanks to you ALL for your input and recommendations.

Hope to see you on the road soon!

[moken]

The ERA Turbo Mini runs 9.4:1 with 7-8lbs max of boost (4lbs is plenty fast for around town). Your boost is relative to your compression ratio. How much boost were you running? It makes more sense to change your boost instead of the high cost to drop the CR. Higher boost also creates more intake heat, above 8lbs is when the compressed air gets really really hot which creates detonation.

[Alecs Minis in London]

We are getting somewhere, I found out that my 1293cc is running to high on compression, should be 8.1 and is currently at 8.8. Deon forgot about this. We initial set the engine up for a standard 1275cc with a Stage 1 Head, then at the last minute and the need for speed, I changed my mind and added a Stage 3 Race Head, Fast Road Cam and a SuperCharger, so the engine compression ratio was forgotten.

Deon has set-up the engine/supercharger in a way if I ever sell the minivan (over my dead body), the new owner has the choice of keeping it supercharged or retuning back to carbs/webber etc... without too much modification.

Deon knows what to do, we have to reduce the compression from 8.8 to 8.1 (down to 42cc). Once this is done, we can order several needles and go from there. I also found a gentlemen here in Longwood that knows everything you need to know about SU/Stromberg Carbs, Webbers etc... and also knows of a dyno we can use once Deon has modified the compression. Joe Curto in NY has also been a big help.

Thanks to you ALL for your input and recommendations.

Hope to see you on the road soon!

I would not like to run an 8.8:1 on the road a bit low. Good Luck in all the changes.
How are you going to lower the compression ratio?

[MINIMAD]

just found this....

http://www.mgexperience.net/article/how ... an-su.html