4 replies to this topic

[joe90]

Hi guys I could do with some advice. I have recently built up 1275 A plus engine. All ready to fit but I thought I would engage the clutch to check. When it is engaged it seems to be putting pressure on the crankshaft and slowing it down with some  resistance . I’m rotating it by hand with a ratchet. The flywheel/  clutch and back plate was brought complete assembly from MED. it is an inertia st2  assembly . 
The crank has all just been reground to plus “20 with new bearings etc. End float is all within limits. Along with primary gear.

i have checked and rechecked everything I can think of but still no joy.

any advice would be welcome as I’m running out of ideas ?

cheers

joe

[mk1leg]

so everything is new including Thrusts...do the dial gauge test at Vpully end and see if it moves too far

[Cooperman]

When the clutch is disengaged from the drive the full load of the clutch diaphragm spring goes into the end of the flywheel.
When an engine is running with neutral selected and the clutch is pushed down it is normal for the revs to drop by maybe 50 to 100 rpm. With a heavy duty clutch this is even more noticeable.
So long as the crankshaft was set within limits when the engine was built you have no problem. It is merely the friction between the crankshaft and the thrust bearing face. In fact, as you are turning it with no oil pressure but with full clutch load being applied you could damage a thrust bearing.

[joe90]

Everything is new internally.
I did drop the engine in last night filled with oil set , up the slave cylinder  and hooked up the starter motor. 
I also set the throw and clutch stop. 
With the pedal depressed and clutch engaged I turned it over with the starter And without clutch engaged 
the engine is slowing down with clutch engaged???

[Rorf]

Everything is new internally.
I did drop the engine in last night filled with oil set , up the slave cylinder  and hooked up the starter motor. 
I also set the throw and clutch stop. 
With the pedal depressed and clutch engaged I turned it over with the starter And without clutch engaged 
the engine is slowing down with clutch engaged???

As Cooperman said there is now a major possibility that the crankshaft thrust bearings are damaged. Never ever try and start or turn over the engine on a mini with your foot on the clutch (depressed clutch that is)