82 replies to this topic

[bigmatt4]

ive gone back to the electronic dizzy. it has new cap and leads fitted firing order is correct 1 3 4 2 in a counter clockwise direction the dizzy is in that way round for looks but it is timed up correctly and if it was wrong it wouldent drive nice its only the idle that is the problem engine goes really well ive done about 80km in it to help bed the rings in drove real nice and clean up to 5000rpm. (thats my rev limit for new engine )little bit of flatspot off idle i have some new plugs for it trying bosch plug and will have another go at the weekend gotta get radiator and waterpump back on so i can run it for more that 1 minute at a time also thought of putting a large pipe between the manifold ports to help balance the pulsing in the engine.really need a su carb or carbs to try get rid of dcoe weber im starting to run out of options but one step at a time



i will get a video of it running this weekend me removing plug leads and stuff

Edited by bigmatt4, 24 August 2011 - 10:56 PM.

[jaydee]

We all had a doubt because:

The dizzy turns anticlockwise, and usually leads go this way:
3 1
4 2
CORRECT

Fitting them clockwise you messed up cylinder 2 and 3
2 1
4 3
WRONG

Note that this will keep cylinder 1 and 4 firing..

IF the problem is encountered at idle only, well you need to set up carbs using a lambda sensor to iron out the lumpiness as much as possible, but wild cams will always have some sort of irregular idle.
Rise the idle revs a bit, try 1.1k rpm or 1,2k rpm and see if it cures the problem.

Edited by jaydee, 24 August 2011 - 11:47 PM.

[Yoda]

My 1380 with 286 cam, bladed and balanced crank, high comp skimmed and flowed flowed head, decked block, twin SU's with an Aldon A100 dizzy, ticks over irregularly at any idle below 1000rpm, but at 1100 rpm, is fairly smooth and regular, so once everything is set up properly, it is very driveable. Something simple is wrong here!

Edited by Yoda, 25 August 2011 - 04:13 AM.

[b34k3r]

Glad you guys are helping out here, it's actually my mini Matt is working on and im equally frustrated with it, I should buy shares in the company that makes manifold Gaskets... I will apologize for his lack of being able to use these things we call full stops & paragraphs, and if you need an interpreter.. I can help I do have a video of it running somewhere but that was first fire up. The Dizzy is out of a MG Montego I think, It as built up by a guy who rebuilds them for this purpose, It was also recurved to throw out to maximum advance around 3000rpm by relocating the pin the springs sit on, It was curved matched to the Original one I removed from it. Im really relucant to have to go to Twin SU's or a HS4 / HIF44 to resolve the issue.

[Yoda]

As we have tried to point out, with a lumpy cammy setup, its worth ( as long as everythig else is confirmed good ) setting the tickover at around 1100/1200 rpm. the engine appears to run well above these revs, and if this solves the problem, it will also help prevent clutch judder when pulling away from standstill with a lumpy cam like that.

Ideally you will need to get it rolling roaded to get the mixture perfect, or you may end up with holed pistons if its too lean at top end!

I have little experience with Weber carbs on an A series engine as i have always preferred twin SU's for drivability, but i have heard so many people complain about getting the idle right, i will never bother with a Weber now except for out and out, foot on the floor driving

[bigmatt4]

ive come to the conclusion its gotta be cam timing I must have f#%@$d it up some where it cant be anywhere else i fitted the 4" manifold today with a perfect running weber from my escort still with the 850 head and still exactly the same. i have had a lot of experence on webers and delortos tuning them from 1500 cortinas to full steel 2.1 pinto engines and had awesome results with no dyno. got a mate comming over on saturday to help me nut it out hes very oldschool and we gonna start again with the basics we not gonna give up on this one.
like everyone has said to me its gotta be somthing real simple i just havnt found it yet.

Edited by bigmatt4, 25 August 2011 - 08:10 AM.

[bigmatt4]

We all had a doubt because:

The dizzy turns anticlockwise, and usually leads go this way:
3 1
4 2
CORRECT

Fitting them clockwise you messed up cylinder 2 and 3
2 1
4 3
WRONG

Note that this will keep cylinder 1 and 4 firing..

IF the problem is encountered at idle only, well you need to set up carbs using a lambda sensor to iron out the lumpiness as much as possible, but wild cams will always have some sort of irregular idle.
Rise the idle revs a bit, try 1.1k rpm or 1,2k rpm and see if it cures the problem.

thing is that its not lumpy at all ticks over as smooth as a bog stock standard japanese nana car on 2 cylinders. Even at 1200 rpm just sounds like a high idle

Edited by bigmatt4, 25 August 2011 - 08:18 AM.

[bigmatt4]

ive come to the conclusion its gotta be cam timing I must have f#%@$d it up some where it cant be anywhere else i fitted the 4" manifold today with a perfect running weber from my escort still with the 850 head and still exactly the same. i have had a lot of experence on webers and delortos tuning them from 1500 cortinas to full steel 2.1 pinto engines and had awesome results with no dyno. got a mate comming over on saturday to help me nut it out hes very oldschool and we gonna start again with the basics we not gonna give up on this one.
like everyone has said to me its gotta be somthing real simple i just havnt found it yet.

i have also fitted the original lucas points distributor as per book and set ign timing a 10 deg static to keep things simple again and also fitted a new set of champion n9yc spark plus with a new set of ht leads.

[Yoda]

Please be sure to let us know what you find though! it will help us in the future if a similar issue crops up.

And by the way, if you dont, the boys will be round to see you

Edited by Yoda, 25 August 2011 - 10:11 AM.

[b34k3r]

Great, send the boys around, maybe they can fix it , do they like longhaul travel?

[asahartz]

Have you tried those Bosch plugs yet? As I had a similar issue a while back with some faulty NGKs, and it wasn't until the set in my other car, from the same box, began to show similar symptoms, that I twigged it. Your car went well on the initial test drive, then began to deteriorate - so did mine. I know of others that have had trouble with NGKs as well. They're off my shopping list now. The plug below had done only 500 miles...

[b34k3r]

Update

Possible reason found. Matt suspected that the issue could perhaps be exhaust blockage related, the Mini has a set of LCB extractors, Extractors removed and no blockage found, but running the engine with open headers it appears to be idling on 4 cyl with the expected lopey idle and clear blue flame out each port. Original 12G940 head needs to be re-fitted and cam timing re-set before it can be confirmed it will still idle on 4.

The thought pattern that the exhaust stroke from Cyl 1 is back pressuring to Cyl 4 and Cyl 4 back pressuring to Cyl 1 & so forth. Indicating that the branch leading to the main pipe is possibly too restrictive.

the pipes appear to be approx 1" to where they join just under the floor, are 1" branches the standard size? seems a little small to me.

Edited by b34k3r, 27 August 2011 - 04:20 AM.

[bigmatt4]

Update

Possible reason found. Matt suspected that the issue could perhaps be exhaust blockage related, the Mini has a set of LCB extractors, Extractors removed and no blockage found, but running the engine with open headers it appears to be idling on 4 cyl with the expected lopey idle and clear blue flame out each port. Original 12G940 head needs to be re-fitted and cam timing re-set before it can be confirmed it will still idle on 4.

The thought pattern that the exhaust stroke from Cyl 1 is back pressuring to Cyl 4 and Cyl 4 back pressuring to Cyl 1 & so forth. Indicating that the branch leading to the main pipe is possibly too restrictive.

the pipes appear to be approx 1" to where they join just under the floor, are 1" branches the standard size? seems a little small to me.

engine appears to be running on cylinders 1 and 4 alot better still not as good as 2 and 3. plugs now run dry and clean removing leads 1 and 4 just take away the pulse
and engine runs smooth like before on 2 and 3. removing leads 2 and 3 drop idle but not as much as before. ran without the exhaust manifold on and no1 and 4 exhaust port ran blue flame. no flame from centre but lots of heat at idle

[bigmatt4]

Have you tried those Bosch plugs yet? As I had a similar issue a while back with some faulty NGKs, and it wasn't until the set in my other car, from the same box, began to show similar symptoms, that I twigged it. Your car went well on the initial test drive, then began to deteriorate - so did mine. I know of others that have had trouble with NGKs as well. They're off my shopping list now. The plug below had done only 500 miles...

no mine never run right from day dot think i have it sorted will keep you posted

[AndyMiniMad.]

That exhaust does sound a little restrictive...I inch manifold??