Judder at constant speed..
Turbo Mini Forums

My 1330 naturally aspired finaly running and starting great. Realy Strong and reliable. Pulls like a horse.

Just one thing that bothers me. When driving at fixed speed 50 kmh 70 kmh ... i feel a judder. ( like engine goes on off on off) mostly geld 4th gear 50kmh around 2000 rpm. But also at other speeds when driving constant.

Became much better with 20w50 oil in dashpot and timing Set at 32 degrees at 4000 rpm No vac attached. But still noticable. Drives it with and without vac. Stays the same.

Could this be because the cam ( md296) or does the carb need a stronger spring? ( Standard spring now) bdl needle.

Not hearing any detonation on load and revs very happy. ( although not yet Got the most out of it. Stille running in)

Search did not bring up anything. Its all abortus judder when accelerating not with constant speed.

Edited by Rammie2000 on 11th Mar, 2023.

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

Many decades ago I tried a Kent 286 in mine, and it was absolutely horrendous.

Total rubbish down low, and just mediocre up top
With the turbo setup, all it seemed to to was push the power band up around 1000-1500rpm or so, and totally decimate anything below3500-4000rpm

So it went ok from say 4500-8500rpm, and was complete rubbish everywhere else.
Long before mappable ignition etc
I put a milder cam back in, probably MG Metro and the car was a million times better. Ended up with the SW5 eventually, circa mid 90's

SO if you're turbo, I can't imagine a 296 doing you any favours for normal driving and performance below 4000rpm

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

edit post. its a non turbo engine.

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

What flywheel have you got ? I had a similar experience after fitting a 286 in mine. I had the old style Ultralite flywheel with the 3 long slots, turns out it was a hymonic balance issue cured by fitting a Cooper S bottom pulley and damper.

standard a+ flywheel balanced but not lightend.

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

Without Knowing how your engine is set-up, its pointing to the cam. I ran a 286 on what was basically a standard set-up and it was the worst drive I ever have experienced even worse than my Mk1 fiesta popular plus ended up putting a mini speed turbo cam in it which is basically a MG cam or SW5.

Own the day

I have run a 286 cam and had no issues at all. I would say have you checked the valve clearance, it should be wider than standard and that does have a big impact with how it runs. Also 2000rpm is off the cam if you have recommended timing. That’s not to say it wont run ok, but it wont come onto cam until at least 2500 in my experience.

How much should the valve clearance then be at? Cant find much info on it.

Made a booking at a rr to fine tune it. Been figgeling with mixture and ignition and it begins to behave very well but want it spot on.

I know its not the most smooth cam at all but its a car for fun. I have my good Sunny Days Princes to.

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

15thou with standard rockers

0.38 mm. Okey. Any documentation on that?

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

It's on the data sheet that came with the cam.

you can do anything if you set your mind to it...
i rather blow it up winning than keep it together losing.

finish date set for project 1... march 2018

So it might not even be a proper 286, previously owned by someone with a set of stamps lol
I'd scan it but my scanners foooked