The dreaded crank endfloat issue.
Turbo Mini Forums

Cheers Vegard!! Yes I will make absolute sure of my measurements before buttoning it all back up again for sure.

Joe- just ran out and got some pics of the crank, looks toit like a toiger to me:


(2nd half):



other side :



And the journal for ref:


They seem sweet to me! No highspots at all. I cant see what caused it other than too little an endfloat, unless it really was just bedding in like Tom mentioned earlier in this thread!!

Either way, its piece of mind I guess.

p.s, glad you like the camp plectrum, ressembles my playing

That's toight as a toiger indeed.

yep, i'm going to go with the

"it was bedding in like Tom said"

well bumet that you took it all apart, but better safe than sorry eh.

So toit like a toiger that the revs drop when the clutch is depressed hahaha

Edited by richminiturbo. on 28th Jun, 2009.

"I told you so".

But the thing is, they will bed in, but after this has happened, the endfloat will be excessive. This is becasue of the extremely rough bearing surface on some of the thrusts available. High-spots gone-> too much endfloat.

Ive never come across a flat thrust washer yet. I always grind them flat and set at 6-7 thou float

Paul

I seriously doubt it!

6-7thou... Worn out in my book.

Race engine - sloppy - nice in my book.

Ive heard of Mini 7 engines built upto 15 thou

Paul

Edited by paul wiginton on 29th Jun, 2009.

I seriously doubt it!

The miglia engines aim for 6-8 thou end float

Team Racing

How much endfloat for me then Vegard?

What happens with excessive endfloat/worn thrusts anyway? I mean, whats the result? Crank walk I guess!

I was told the 6-8 figure by peter vickers yesterday, maybe aim for 6 then, lol

Team Racing

my race engine run 0.006" on anything up to 1380 I run 0.008" on 1400+ the long stroke motors need a bit more clearence to alow for crank flex, an bleve you me the do flex at 8K rpm.
on at turbo motor aim for or less than 0.005" IMO

Edited by PaulH on 29th Jun, 2009.

8 inches?! Fuck!! haha.

Gonna have a crack at it bit later, just found some wet and dry and two gasket sets so its ready to go back together.

Shame I took it apart, oh well!! I'll take the hight spots off the back of them, one less thing to worry about.

On a road going engine, turbo or not, I aim for 3thou, 4 being the max. I've never had any issues with this.

Jims problem is more likely crank whip/flex, too tight a clearance and the flexing crank is always putting pressure on the thrusts, not allowing oil to find its way between the two surfaces and subsequently picking up due to lack of lubricant.

his second attempt at a repair on the trackside was always going to be doomed to failure because it only takes the smalleat piece of material left stuck to the thrust face to accelerate a repeat of the seisure process.

oyu deffo need to oil feed them Jimbo,and increase the clearance,

amn engine builder i know told me they used to run 0.009" clearance on 850 ministox engines years ago,

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Yep talking to a mate who used to race and we were consiidering putting one together with upto 12 thou end float just for the sake of revs. But non tubo of course.

Own the day

12 thou is so excessive that it will be necessary to take steps to retain "normal" oil pressure.

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

me neither. Remember the sideways clearance on my rods Vegard, that does not affect oil pressure at all. This is the same thing. that said 12 thou seems.. well not needed, when the miglias run 5-6

Edited by miniminor63 on 30th Jun, 2009.

Apparently on these engines they are built so loose when the crank pison and rods are all in you can spin the crank by hand

I am only considering doing this as an exercise to learn a little into the thinking of some engie builders I wont be driving it for any purpose.

But I digress.

Own the day

Well, as the crank is so loose it will be forced to one side because of oil pressure, and there will be no oil on the other side. Remember, fluids travel where it's less restriction. You cannot gamble on that there will be oil on both sides anymore.

carl, If you do drill into the gallery to allow oil flow is 9thou about the right end float, on a n/a motor of course? I assume this is because the bead of oil will take up say 2-3 thou in space?

"Cars are a lifetime of pain"