29 replies to this topic

[Andymc]

Hi Guys, just finished (95%) a nut and bolt restore of my mini.

It is now a 1380cc Engine that has been decked and has a cooper 940G head with larger valves, skimmed polished and ported with roller rockers 1.5 (minispares).

Cam shaft is a Kent cam 286.

The clutch flywheel is lightened to approx 5kg.

It has electronic dizzy from mini spares, specially for a kent cam 286.

LCB (fletcher) Maniflow inlet with double HS4's and K&N's.

 

The thing is when I am driving and give a good bit of throttle and only when the revs are high it sounds like fuel is igniting in the air filters against the tin k&N cover ( sounds like a tractor)

Not a knocking noise from the engine or bearings.

what could it be (maybe just that, fuel ?)

I have also had a bit of bother with ignition timing and starter motor not wanting to turn, so backed off the dizzy and that helped that...

However I am a bit worried that something is not quite right with the set up ....

Any guys out their with some sound advice please will be welcomed ....

 

Andy

 

 

 

 

Mini spares advice for timing: Using the idle adjustment screw on the carb, increase the idle speed to near-enough 2,000rpm. Now slowly and carefully advance the ignition timing by turning the dizzy clockwise whilst keeping your eyes or your assistant's glued to the tacho. As the dizzy is turned, the revs should start to rise. Keep advancing the ignition until the revs stop rising, then retard the ignition by turning the dizzy anti-clockwise until the revs drop by around 250rpm. If the revs don't rise, retard the ignition until you get a marked decrease in the rpm shown, then progress as previously outlined. Once satisfied, turn the ignition off, and nip the dizzy clamp bolt up. Try to do this in a reasonably swift manner to prevent any possible over-heating. Let the engine cool for a while, then re-start and re-set the idle speed. Don't forget - for cams with very sporty profiles that cause rough idling - DO NOT set the idle speed as standard (750-800rpm). This will cause premature valve train damage, let alone cause a mechanical cacophony! An idle speed of 1,000 to 1,100rpm should be your goal.

To double check you're not running into detonation problems, drive the car around using minimum loading (part throttle and use the gearbox) to get the engine up to running temperature. Then drive the car at about 25mph/40kph in third gear and slowly apply the handbrake to two-thirds operation, then accelerate swiftly (i.e. don't just floor it). If any rattling/pinking (detonation) can be heard, back the ignition timing off by a very small amount statically and try again until detonation is eradicated. Alternatively, if no detonation occurs, you can advance the static ignition timing until detonation registers then back it off. The idea is to test the engine at it's most critical rpm range for detonation - around 2,500-3,500rpm (dependent on cam type). If the engine just bogs down, try a slightly higher speed with the aforementioned rpm envelope in mind.

Once happy you've achieved the required goals, check what ignition advance you have at 2,000rpm using a strobe, engine hot, vac-pipe disconnected, using the standard timing marks/pointers if there are any. If not - contrive a pointer that's easy to use. Doesn't have to be exactly at TDC, it's just a reference should you need to disturb any of the ignition components in the future for whatever reason. Make a note of the reading some place safe.

Edited by Andymc, 22 March 2018 - 09:37 AM.

[dyshipfakta]

If your starter was struggling to turn it suggests timing as an issue.

[nicklouse]

so what is the timing set at?

 

and get it set up on a rolling road.

[Andymc]

Starter was but not any more after backing of the timing..

If your starter was struggling to turn it suggests timing as an issue.

[Andymc]

Hi, set up the timing using a rpm gauge as explained by minispares:Using the idle adjustment screw on the carb, increase the idle speed to near-enough 2,000rpm. Now slowly and carefully advance the ignition timing by turning the dizzy clockwise whilst keeping your eyes or your assistant's glued to the tacho. As the dizzy is turned, the revs should start to rise. Keep advancing the ignition until the revs stop rising, then retard the ignition by turning the dizzy anti-clockwise until the revs drop by around 250rpm. If the revs don't rise, retard the ignition until you get a marked decrease in the rpm shown, then progress as previously outlined. Once satisfied, turn the ignition off, and nip the dizzy clamp bolt up. Try to do this in a reasonably swift manner to prevent any possible over-heating. Let the engine cool for a while, then re-start and re-set the idle speed. Don't forget - for cams with very sporty profiles that cause rough idling - DO NOT set the idle speed as standard (750-800rpm). This will cause premature valve train damage, let alone cause a mechanical cacophony! An idle speed of 1,000 to 1,100rpm should be your goal.

To double check you're not running into detonation problems, drive the car around using minimum loading (part throttle and use the gearbox) to get the engine up to running temperature. Then drive the car at about 25mph/40kph in third gear and slowly apply the handbrake to two-thirds operation, then accelerate swiftly (i.e. don't just floor it). If any rattling/pinking (detonation) can be heard, back the ignition timing off by a very small amount statically and try again until detonation is eradicated. Alternatively, if no detonation occurs, you can advance the static ignition timing until detonation registers then back it off. The idea is to test the engine at it's most critical rpm range for detonation - around 2,500-3,500rpm (dependent on cam type). If the engine just bogs down, try a slightly higher speed with the aforementioned rpm envelope in mind.

Once happy you've achieved the required goals, check what ignition advance you have at 2,000rpm using a strobe, engine hot, vac-pipe disconnected, using the standard timing marks/pointers if there are any. If not - contrive a pointer that's easy to use. Doesn't have to be exactly at TDC, it's just a reference should you need to disturb any of the ignition components in the future for whatever reason. Make a note of the reading some place safe.

 

so what is the timing set at?

 

and get it set up on a rolling road.

[Northernpower]

You've obviously spent a lot of time and money on this project. You'll get a great benefit from taking it to a rolling road. No amount of static DIY tuning will substitute for a run on the rollers by a competent tuner. You'll be so surprised by the increased drivability.

[nicklouse]

 

Hi, set up the timing using a rpm gauge as explained by minispares:Using the idle adjustment screw on the carb, increase the idle speed to near-enough 2,000rpm. Now slowly and carefully advance the ignition timing by turning the dizzy clockwise whilst keeping your eyes or your assistant's glued to the tacho. As the dizzy is turned, the revs should start to rise. Keep advancing the ignition until the revs stop rising, then retard the ignition by turning the dizzy anti-clockwise until the revs drop by around 250rpm. If the revs don't rise, retard the ignition until you get a marked decrease in the rpm shown, then progress as previously outlined. Once satisfied, turn the ignition off, and nip the dizzy clamp bolt up. Try to do this in a reasonably swift manner to prevent any possible over-heating. Let the engine cool for a while, then re-start and re-set the idle speed. Don't forget - for cams with very sporty profiles that cause rough idling - DO NOT set the idle speed as standard (750-800rpm). This will cause premature valve train damage, let alone cause a mechanical cacophony! An idle speed of 1,000 to 1,100rpm should be your goal.

To double check you're not running into detonation problems, drive the car around using minimum loading (part throttle and use the gearbox) to get the engine up to running temperature. Then drive the car at about 25mph/40kph in third gear and slowly apply the handbrake to two-thirds operation, then accelerate swiftly (i.e. don't just floor it). If any rattling/pinking (detonation) can be heard, back the ignition timing off by a very small amount statically and try again until detonation is eradicated. Alternatively, if no detonation occurs, you can advance the static ignition timing until detonation registers then back it off. The idea is to test the engine at it's most critical rpm range for detonation - around 2,500-3,500rpm (dependent on cam type). If the engine just bogs down, try a slightly higher speed with the aforementioned rpm envelope in mind.

Once happy you've achieved the required goals, check what ignition advance you have at 2,000rpm using a strobe, engine hot, vac-pipe disconnected, using the standard timing marks/pointers if there are any. If not - contrive a pointer that's easy to use. Doesn't have to be exactly at TDC, it's just a reference should you need to disturb any of the ignition components in the future for whatever reason. Make a note of the reading some place safe.

 

so what is the timing set at?

 

and get it set up on a rolling road.

 

so again what is the timing set at? that tells us nothing.

 

what is your static set at? what is it at say 1000 rpm

and a dizzy for a 286 sure it might be or it might be way off.

[The Matt]

...It is now a 1380cc Engine that has been decked and has a cooper 940G head with larger valves, skimmed polished and ported....

 

 

 

....I have also had a bit of bother with ignition timing and starter motor not wanting to turn, so backed off the dizzy and that helped that...

However I am a bit worried that something is not quite right with the set up ....

 

 

 

Do you know what compression ratio you are running?

 

I do agree that you really do need a proper rolling road tuning session to get the best out of it, I'd try that as a first port of call.

 

You need a proper advance curve to suit your build.

[Dusky]

The tinny sound aso sounds a bit ( mind the pun) like an exhaust leak.

[Andymc]

 

...It is now a 1380cc Engine that has been decked and has a cooper 940G head with larger valves, skimmed polished and ported....

 

 

 

....I have also had a bit of bother with ignition timing and starter motor not wanting to turn, so backed off the dizzy and that helped that...

However I am a bit worried that something is not quite right with the set up ....

Hi i dont know what compression ratio i am running sorry a bit useless, I do now realize  though its going to be a rolling road.

 

 

Do you know what compression ratio you are running?

 

I do agree that you really do need a proper rolling road tuning session to get the best out of it, I'd try that as a first port of call.

 

You need a proper advance curve to suit your build.

 

[Andymc]

Hi guys thanks all for your help I am going to get it rolling roaded, i have not set up the ignition in terms of degrees.

My timing cover doesnt have any degree indicators. I simply put cilinder 1 at TDC and pointed the rotar arm at (cilinder 1) it from the dizzy (1-2 oclock).

After this I balanced the carbs a bit and mixture and idle.

Then i disconnected the vaccum pipe, blocked it off and turned up the idle to 1500rpm and turn the dizzy clockwise until the revs didnt get higher then I lowered it 250 rpm (turned it anti clock).

Tried this and found the starter still had a little bit bother so turned it anti clock another 150rpm.

connected the vaccum pipe up and bobs your uncle or in my case my dad and fannys your aunt.

re blanced carbs..

[Andymc]

 

...It is now a 1380cc Engine that has been decked and has a cooper 940G head with larger valves, skimmed polished and ported....

 

 

 

....I have also had a bit of bother with ignition timing and starter motor not wanting to turn, so backed off the dizzy and that helped that...

However I am a bit worried that something is not quite right with the set up ....

Hiya Matt how can i find out the compression ratio ? and may i dare ask ?? how can my setup benifit from knowing this ?

Cheers Andy..

 

 

 

Do you know what compression ratio you are running?

 

I do agree that you really do need a proper rolling road tuning session to get the best out of it, I'd try that as a first port of call.

 

You need a proper advance curve to suit your build.

 

[Andymc]

Hiya useless i know, my dizzy from mini spares is this one:C-27H7702  DISTRIBUTOR ELECTRIC EVOLUTION FOR 285-296 CAMS (minispares)

 

 i have not set up the ignition in terms of degrees.

My timing cover doesnt have any degree indicators. I simply put cilinder 1 at TDC and pointed the rotar arm at (cilinder 1) it from the dizzy (1-2 oclock).

After this I balanced the carbs a bit and mixture and idle.

Then i disconnected the vaccum pipe, blocked it off and turned up the idle to 1500rpm and turn the dizzy clockwise until the revs didnt get higher then I lowered it 250 rpm (turned it anti clock).

Tried this and found the starter still had a little bit bother so turned it anti clock another 150rpm.

connected the vaccum pipe up and bobs your uncle or in my case my dad and fannys your aunt.

re blanced carbs..

 

 

 

so what is the timing set at?

 

and get it set up on a rolling road.

[mini13]

stop ****** guessing snd get it set up properly before you melt a piston or somthing!

[Andymc]

Good advice but i need to get it sort of set up to get it to the rolling road..

Are you really going to suggest i stick a modified plug in the cilinder head ( tdc cilinder 1) and hand crank the block in both directions to find TDC the weld on a degree comb ?

I still wont know how many degrees it has to be. All i need really i guess is just to get it safe to drive to the rolling road..

once again thanks for your efforts..Andy

stop ****** guessing snd get it set up properly before you melt a piston or somthing!