Crank Endfloat
Turbo Mini Forums

Alright men. Picked my engine block up today and started to trial fit my crank. The bearing shells went in mint but after fitting the thrust washers there was no side movement. All bearings are new as a standard size and the thrust washers are also new with std stamped in them. Do you think I should get another set with a thinner thickness or is a tight crank okay on a turbo block as this is my first turbo a series. I've built n/a units before and never had this problem. Cheers guys.

what end float are you getting then?

Virtually none, Well none at all. but the crank spins great.

I had this issue although to an extent it turned out to be my crank. When you say there was no movement, was this checked with a dial guage/ feeler guage? end float should be very small

there are a few guys who lap the face and rear of the thrusts a little to take off imperfections, particularly from the stamping on the back.

fisrt of how many thou endfloat is there?

for std & lower rpm stuff i aim for 2 thou, if its going to see 7k or more i open it up a couple of thou.

also sand the back of thrusts on some wet and dry to knock back the stamping, then mic them up and match them side to side,

also mesure the clearance dry.

I used the classic method of........sight and feel. I get really excited when building an engine and left the dial gauge at work. On previous engines I've built I could feel the movement but on this one I feel nothing. I think I'll try the lapping method.

measure it...

I'd just get a dial guage on it. then its right, no guess work.

and no oil

Cheers guys. Thanks for your advice. I'll be liberating a dial gauge and stand tomorrow from work.

yip - measure it first and worry about it after

If you assembled it with oil (as you should have done) you will not "feel" or "hear" 2-3 thou.

Put a DTI on the end of the crank......

Schrödinger's cat - so which one am I ???

I agree. Virtually no endfloat while the cranks spins freely is good.

I take it that you've torqued the centre main cap up?

I was concerned about this when building mine.

I used the Bill Sollis DVD, in which (wet build), he demonstrated crank endfloat by wedging a screwdriver behind a web on the crankshaft and levering the crank either way. Even on camera there was a destinctive "clicking" as it moved.

I was worried as mine didnt do this, I didnt have a DTI gauge, after speaking to my machinists they said to just carry on and build it as they assured me they machined it ok. They said a littled lower than what it should be, but once its bedded in it'll all be ok.

I have my fingers crossed, as my revs drop at the moment when I put my foot on the clutch, im hoping this is just down to the diagphram and that it'll loosen itself off as they said.

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I agree, I have been concerned since I built the engine but I was eager at the time.

I had a an issue where one thrust went in fine, the other wouldnt go in at all (both STD sized), I took my block down for them to look at and they machined a bit off one of the crank faces, so the thrusts fitted ok, giving about 2-3 thou, I cant remember.

I would have thought it better to fly cut the back off the thrusts, they are easier to replace. But a standard thrust face with a standard thrust bearing and a standard block and cap, there should be the standard tollerence, if its tight, something is wrong? no?

..

Edited by Sprocket on 28th May, 2009.

Thats what I thought, we'll see!! Yes? (gordon ramsay)

blimey , i use 5 thou !!

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

me too Robert

On 28th May, 2009 Sprocket said:

On 27th May, 2009 Rod S said:
If you assembled it with oil (as you should have done) you will not "feel" or "hear" 2-3 thou.

Put a DTI on the end of the crank......

Not sure what you mean by 'should have' assembled it with oil. A dry build is what it says, dry. You cannot use plastigauge to measure the clearancies of the bearings with oil there as well, nor can you properly measure the end float when there is oil present.

Build the engine up with out rings dry, to check all the clearancies, refrain from turning the rotating parts. Build the engine up again without rings, and lube everything and check for any snagging

(says he who just suffered main bearing failure )

Schrödinger's cat - so which one am I ???

Can you roughly measure crank endfloat with the conrods and pistons installed (gearbox not on yet)

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