21 replies to this topic

[MINI 1]

it could well be , the springs i used were just single springs , the rockers were MED LD 1.5 roller rockers , and the cam was a mini sport , road / rally one.

the pistons and rods arnt balanced , i personally think its down to the cam being very cheap and the crank jernals having slight pitting on them.

ash

[Jordie]

Regrind the crank
New camshaft and new followers
Work out what lb springs you need and fit them

Try again..

[MINI 1]

So if the crank wasnt brilliant.

Did it rotate with just a couple of fingers effort when placed in the engine with the main caps bolted/torqued up?

The crank should spin relatively freely with just the mains torqued up. if it ever got tight or hard to turn from there on, you would have needed a regrind or ofcourse, the bearings would get damaged relatively quickely.

I build my own engines, so I arent just passing comment if the above was aimed at me and sproket.

ye , when we built it up the engine it turned great , very smooth with mains and big ends attached .But when when we stripped it down and turned it it had a tight spot , but as soon as we removed the pistons and rods so the crankshaft was just in it was free again. so it may well be down to the shell ends being scorn.

all i know is when we built it up it wasent like that.

ash

[Rosslin Racing]

balance the rods and pistons, you will find you have a pair that maybe very simular in weight example 750 gram and 748 grams and 710 grams and 712 grams try to use these in pairs on the crank ie the pistons that are bother tdc at the same stroke

[Jordie]

Also worth checking u kept the big end caps in the right order and they are on the right way (tags at the same end)

[Nightrain]

The cam wore out simply because yo used secondhand followers, that had already hardened. With a new cam which was still soft, if you run something that is hard against something thats soft which do you think will wear ?
Just put it down to been part of the learning experience.

[MINI 1]

ye i think it may well of been , so i suppose i have learned my lesson .. the hard way . their is things am going to change with the engine anyways whilst its out , going to get a piper cam insted of a cheap nasty one.

thanks

ash