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First Run out after swapping the Pinto
karlak - 27/3/10 at 08:48 PM

Got a chance to take the car out today after fitting the replacement Pinto. The old one was very tired and this one is much fresher.

Have also ditched the DGAV carb and now got a pair of DHLA 40's - fettled by Bogg Bros.


Anyway, much better drive even though havent got full throttle as yet - Cant quite adjust for full throttle and idle on the Linkage.

I have not adjusted any Carb settings so it should be running as set-up prior to removing from previous owners car. However, I am getting a lot of "poppin" from the exhaust on the throttle lift - Sounds nice, but is not right me thinks. Also, When swicthing the engine off... Wait then Bang from exhaust - I reckon at night there could be flames...

My limited understanding and the smell from the exhaust make me suspect it is running very rich. The only difference between my set-up and the previous one is the exhaust. Mine is running the standard manifold leading to a single pipe and a rather small and "loudish" silencer. The other car had a 4 outlet type (possibly MK) Is this what has upset the mixture/tuning ?

I will get it rolling roaded tuned as soon as I sort the throttle linkage. Just curious why it seems to have gone rich. I also guess that this will be impeding the response form the engine by some degree ?

Cheers

john_p_b - 27/3/10 at 08:51 PM

over fueling and ignition a little out i reckon. have you changed the dizzy to get rid of the vacuum advance since fitting the twin 40's?

karlak - 27/3/10 at 09:02 PM

quote:
Originally posted by john_p_b
over fueling and ignition a little out i reckon. have you changed the dizzy to get rid of the vacuum advance since fitting the twin 40's?


Running with the Standard Dizzy at the moment - When funds allow I will go the Megajolt route, so not wanting to spend much on a replacement Dizzy - Unless anyone has a non-vacuum type lying around

Again, I guess no point in getting it rolling road'd until i sort the sparks side of things....

john_p_b - 27/3/10 at 09:12 PM

keep your eyes open on here and ebay, i got a full bestek ignition system quite cheap when i fitted my twin 40's. took them off as they were more trouble than they were worth and i got sick of having the car off the road trying to sort it out but god do i miss the noise they made. annoyingly as well it turned out the problem was actually the cheap sock type filters i was using

pajsh - 27/3/10 at 10:50 PM

I have a 2.0 Pinto with twin DHLA 40's but they are emmision type H which I understand have to be set rich due to fixed air bleeds.

I have megajolt and a wild cam and they spit back out the carbs every now and then and also pop and bang on overrun.

I'd love to change them but the car is going later this year.

Might be worth checking if they are H types.

karlak - 28/3/10 at 09:01 AM

quote:


Might be worth checking if they are H types.


How would I know - The description "written" on the carbs is simply DHLA.

FASTdan - 28/3/10 at 09:17 AM

Hi,

Good to hear you've had it out on the road.

Is the popping on overrun excessive? It used to do that a bit, but not excessive. Also it did used to give a bit of a 'puff' from the exhaust about 2 secs after switching off, not every time but on the odd occasion.

I would be surprised if your standard manifold has thrown the fueling out that much. It might be that the carbs are out of balance with all the disturbance - a carbtune is absolutely invaluable when running twin 40's we found. Makes it so easy to eliminate rough running.

Regards full throttle, we had to play about to get it, but given that you are using the same bracketry for the cable I should think you could get it - unless your pedal offers less travel than ours.

If you havent altered the dizzy since we took it out it should still be running the 10degs static advance that we had it at when rolling roaded at Boggs.

I would really recommend getting a 4 branch manifold for it though, I reckon a cast manifold will restrict it quite a bit.

karlak - 28/3/10 at 11:58 AM

quote:
Originally posted by FASTdan
Hi,

Good to hear you've had it out on the road.

Is the popping on overrun excessive? It used to do that a bit, but not excessive. Also it did used to give a bit of a 'puff' from the exhaust about 2 secs after switching off, not every time but on the odd occasion.

I would be surprised if your standard manifold has thrown the fueling out that much. It might be that the carbs are out of balance with all the disturbance - a carbtune is absolutely invaluable when running twin 40's we found. Makes it so easy to eliminate rough running.

Regards full throttle, we had to play about to get it, but given that you are using the same bracketry for the cable I should think you could get it - unless your pedal offers less travel than ours.

If you havent altered the dizzy since we took it out it should still be running the 10degs static advance that we had it at when rolling roaded at Boggs.

I would really recommend getting a 4 branch manifold for it though, I reckon a cast manifold will restrict it quite a bit.


Sounds about the same as when it was in yours - Yes, it does "pop" on the overun. When the engine is stopped after a second or so it will backfire - Not massively but certainly there.

I had to remove the distributor when installing as a foreign object fell into it, so it could be that the timing is iff a bit. I will re-check to see that it is 10 degrees. I notice that there is a vacuum size type tube on the inlet manifold - did you ever try that ?

I think you may be right about my pedal travel, as I cant see there is enough travel to go from idle to full as it is. Will have a play this week.

Very pleased though compared to the old lump and those twin dellortos sound delicious

[Edited on 28/3/10 by karlak]

FASTdan - 28/3/10 at 07:44 PM

Yeah we tried the vac connection but it is no good as it only comes off one port (you get a pulsed vac advance and you can hear it clicking, not good) - to get a useable vacuum you need to tap all four ports and feed them into a vacuum collector, then to your dizzy. A lot of work for a few mpg extra.

Those carbs sound fantastic, very addictive and something you dont get with bike carbs.