Sva Using 40's

[Guest Steve Allen]

Can anyone give me advise on passing the SVA using twin 40's.

I took the car for a Pre- MOT today and the only thing they could fault was the emissions. I have tried all day to find a mobile tuning company who can balance them. (Failed) One of the companys i rang siad that there was no way i would get it through. (Any thoughts)

The reason i swapped the original carb for 4o's was due the management system so swapping back to the original carb is not an option.

With the SVA application now in and the car running lumpy as hell panic has now set in

Any one good any ideas.

Steve Allen

[Guest chris]

which engine are you running and what year?

regards chris

[Guest Steve Allen]

Chris

It's A 2.1 Pinto with a fast road cam, 1989 Engine.

Steve

[Guest Stuart Ainslie]

Shouldn't be a problem if they have been professionally set up, i.e. Rolling roaded.

 

Used to run a set of 45's, a BLF 40/41 cam and loads of other engine mods on a Mk2 RS2000 - emissions etc. were spot on...

 

S.

[Guest Steve Allen]

Hi

Thanks, The problem I have how do you get it to a rolling road prior to the SVA.

Also the chap i spoke to said that they would check the Hydrocarbons ! Which would be high and fail, Not sure about this one.

Steve

[Guest Stuart Ainslie]

Steve,

 

I would expect that if the carbs were set up correctly, the hydrocarbons would not be an issue - but then again, I am not the man poking ther probe up the pipe

 

I suppose that trailering the car to a RR is the only way to go unless you are feeling a bit of a rebel - a rolling road set-up does really make a lot of difference though, well worth the effort and money.....

 

S.

[Guest paul mercer]

I thought that as long as you were insured, you could drive your car anywhere as long as it was to get work done on the car and you were pre-booked with an appointment.

[Guest Steve Allen]

I did think about a visit to the scrappy tomorrow to see if i could pick up an old carb and manifold off a Cortina and use it until i get a pass. any thoughts on the feasability, seems a lot of extra work and cost at this stage now. With regards to the Trailor idea, I have thought about it but then there is the cost of a trailor and the rolloing road session, I was banking on doing this at a later date. Dont suppose there is any experts out there who live in or near the Yorkshire area who can balance these carbs? Few bob in it.

 

I like that idea Paul.

Yes the car is now insured, can anyone confirm this is the case, (I.e that i can drive it for a rolloing road session)

Steve

[Guest Steve Allen]

Come on chaps its now the evening and was hoping for a lot of do's and dont's to this post. Not long to go before the dreaded SVA and good advise on the following would be very helpfull.

(a) Do i leave the 40's on and get the car to a rolloing road centre !

( Is it legal to do this with insurance cover !

© Do I take the stance that it will fail on emissions (end of story) therefore go tomorrow to the scrappy and find an old bolt on carb off a Cortina etc.

(D) if you feel changing the carb is the best option what are my options. I am running using an old Dizzy system now which makes things simple.

Thanks

Steve A

[Guest rizla]

you say it failed on emitions wot one

 

co or hydrocarbons

 

the latter is easy to get around by adjusting the timmming and making sure that the plug kv is high

 

co is a matter of carb setting,and idle air flow adjustment

[Guest Steve Allen]

Failed on Both. By a lot as well. The carbs need total balancing and I made the dreaded mistake of getting a mobile tune chap to the house since then things are worse not better. The carbs have been totally re-jetted to suit a 2.1. Could you explain what you mean about easy to correct the later ! an the meaning of KV. The timming is set on a basic dizzy now at around 15 btdc. Not sure this has any connection with what your saying

Steve

[Guest rizla]

plug kv is basicly the stength of spark,many people when they modify engines and increase compresion forget the spark has to work harder,this can be cured by fittig lower resistant leads and making the plug gap smaller,ie increasing the power of the spark,

if you can get the car onto a mot 4 gas analizer,adjust the timming and you will see the hc reading drop,you can put the timming backto where you wish later

this is only a temp fix,the carbs nead to be balanced and set properly,

are you sure your jets are not too large as this will give you high co and hc

[Guest Steve Allen]

Sounds good .

I got the jet settings via the Dave Andrews web site (Think That's the right name!)

Can let you know the full spec if it would help.

Is there an alternative spark plug to use, Or as suggested change the leads and decrease the plug gap.

The car seems to run slightly better from start then gets worse !

Must agree on the carbs being setup better but this were the problem occurs.

Is it legal to drive it at this stage to a rolling road centre ?

Steve

[Bob Tucker]

If it runs better from cold, thats 'cos its running rich.

I'd guess the jet sizes are too large.

I too have failed MOT with my oldish twin 40s, so

I have a spare 32/36 on a manifold just for MOTs.

Shame youre so far away (from Kent) or you could borrow it.

Anyone closer got a spare?

Bob.

[Guest Steve Allen]

Bob

I had a thought while lying in bed, I am going to try the orginal jets back in the carbs that came with them. They were orginally off a X flow so i guess they will run weak but this should get me to lower both emissions, Can but try. Still would like to get it to a rolling road prior to the Sva but not sure of the implications.

Ps I will also try closing the plug gap slightly as well.

I feel quiet confident about the build of the car and it's a long way to go for an SVA knowing that should he pass everything else I am certain to fail on the emissions.

On a similar subject were can you obtain the small devise to stick up your exhaust to drop the noise level slightly ? (Anyone know)

Steve