52 replies to this topic

[Midas Mk1]

Hi All,

 

Having a right nightmare with my Mini. Last few months i've put in a new 1380 build, (mini medics built), 1380, 276, 1.5 rockers worked head, crank, sc box etc.

Timed in perfect using a belt drive, cam bed in for 20 minis 2-3k,  ran in for 300 miles then setup on the rollers, putting out 107bhp at under 6k.

 

Ran like a dream, got home from the dyno, dropped oil, no bits, and replaced with normal millers. Set tappets to 16 thou, as per roller rockers and cam suggestions.

 

Left if two weeks, went to drive to L2B, and it had no, if any power, wouldn't even move out of my road which has a slight incline. 

 

There was a loud roller tapping noise too, we put this down to roller rockers (full roller titans).

 

Anyway, every ignition component bar dizzy swapped with no luck, still like a random misfire.

 

Took the rockers off to find that the roller tips were like 50p's with lots of flats on, and one slightly bent pushrod.

 

Fitted fancy treated pushrods off my other engine, along with a set of new MED 1.5 roller rockers, together with shims, and there is still a large clicking noise when the engine is turned.

 

Valve springs changed for swiftune ones, rockers free'd off, even swapped to a spare head for a dry build - still clicking (with pressed rockers too).

 

 

 

 

I'm now thinking it's cam follower / cam thats worn / broken, is there anything else I can check before taking it out?

 

I'm out of time, money after throwing it all at this engine, feel pretty sick right now.  

 

 

 

Thanks 

 

Sam

http://vid907.photob...zpshlygz9dd.mp4

 

[Carlos W]

Valve spring binding?

[Midas Mk1]

Tried a spare head with incredibly strong valve springs in, which previously ran with a sw10, exact same sound. Even with the rockers fully slacked off the same noise is reappearing :/ 

[Carlos W]

It's not about the strength of the springs, it's about the loops of the spring coming into contact with each other.

 

That may have caused the damage to the valve train

[Midas Mk1]

MED rockers are brand new, and tried with old pressed steels too, which ran fine previously (also swapped head which is skimmed less) - no change  

[ACDodd]

Check lobe lift using dial gauge to see if you have wiped the lobes.

Ac

[Midas Mk1]

Check lobe lift using dial gauge to see if you have wiped the lobes.

Ac

Thanks AC,

 

If i'd wiped the lobes would I have noticed poor performance or?  Will test using a dial gauge, weird how its suddenly happened, not a gradual drop off

[Dusky]

Not the cam gear comming loose by any chance?

[Midas Mk1]

Don't think its the cam drive, it's got a belt system that was all tightened / checked during assembly. Sounds like spring binding but i've swapped the heads and tried using a known 'good' setup

[absx2]

Hi, mark the back of the push rods with a thin line of white paint then crank the motor over to check they are all spinning around. If they are not its a follower/cam problem.

[mikal]

I wasn't aware pushrods are expected to rotate. Followers yes, but pushrods?

[absx2]

I wasn't aware pushrods are expected to rotate. Followers yes, but pushrods?

I`m no expert bit I read it when I picked up a motor with a light metallic knock. My pushrods turned when I checked it so I stripped the motor to find it was the pistons.

I should have known better as the radiator was practically empty so it probably got cooked.

I guess the spinning followers turn the pushrods ?

[Gr4h4m]

I run MED 1.3's and during my build something didn't feel right when I was torquing the studs up.. On closer inspection the underneath of the rocker arm was catching the spring retainer just before the roller tip touched the valve stem. I had to use spacers under the rocker posts.

Might be worth checking when you swapped them over

[Midas Mk1]

http://s907.photobuc...lwkv5e.mp4.html

Tried again with standard head and rockers

[gazza82]

So cam and/or followers possibly ...