9 replies to this topic

[Carlo998]

Hi guys

Just a couple questions about flywheel/starter set up. I currently have my clutch housing (wok) off to replace my clutch and am thinking about fitting a lightened/ultralight flywheel. My question is if i do this am i going to throw things out of balance and have a negative effect on my engine? Also there are different types and weights to choose from, how do i choose what weight i want and how do i find out if my starter motor is inertia or pre-engaged? (My starter motor is currently removed from the engine)

Sorry for the essay, any help will be greatly appreciated

[nicklouse]

verto flywheels are "normally" Pre-engage 129 teeth on the ring gear. early one are inertia starter (less teeth on the ring) both can be swapped but you need the correct starter for the ring gear. any new assy will need balancing. there are a few people who will do this AC Dodd being one.

[Steve220]

Depends if you after a really revvy engine or not. Ultra light weight flywheels are usually for race engines that operate almost entirely at high rpm.

[andyapanel]

I have a Minispares lightened flywheel on the Verto set up on my 998. It is a great upgrade. As mentioned, do not go for the race version for a road engine. HOWEVER, I would recomend 3 blobs of weld to lock the ring gear, as it shifted on my Pick up. 

Go for it.

[Carlo998]

Ok thanks guys, so if i get a new standard flywheel will it still need to be balanced?

[DeadSquare]

Ok thanks guys, so if i get a new standard flywheel will it still need to be balanced?

 

 

.............YES.

 

There are people who are of the opinion that the factory selects pistons of equal weight, ditto the conrods;  also that the cranks were balanced as were the flywheels, and these parts were assembled in each Mini engine.

 

From 50 years experience, I beg to differ.

[Carlo998]

Ok thank you deadsquare. So when we say balance, does this mean i have to strip the whole engine and get the con rods, pistons, crank and flywheel all balanced together? Or is it just a case of balancing the flywheel when is in place? Sorry if these are stupid questions i’m not very mechanically minded ?

[grizzler73]

For a road engine, you just need to get the flywheel balanced so it is not adding in-balance to the engine rotating parts, it's by no means essential but it will help.

The flywheel cannot be balanced in the car. It is a good idea the get the assembly balanced as one and all the clearances checked.

[DeadSquare]

Ok thank you deadsquare. So when we say balance, does this mean i have to strip the whole engine and get the con rods, pistons, crank and flywheel all balanced together? Or is it just a case of balancing the flywheel when is in place? Sorry if these are stupid questions i’m not very mechanically minded

 

On a tour of Longbridge with the Midland Mini Se7en club in the 1960's, we saw flywheels bolted to crankshafts and balanced as a single unit by drilling holes in the flywheel.

 

Although I have balanced pistons and conrods, I have never balanced a crankshaft or actually seen one being balanced, but I have watched a flywheel being balanced in the same way that a tyre is balanced, except that instead of adding weights, holes are drilled to remove weight.

 

Flywheels come off Minis with holes drilled in them, and as they are machined all over, and as is most of the pressure plate, I recon, but I don't positively know, that the holes in Mini flywheels are there to balanced the crank and therefore if cranks and flywheels are not kept together, a new flywheel/crank combination should be re-balanced.

[Carlos W]

Ok thanks guys, so if i get a new standard flywheel will it still need to be balanced?

https://youtu.be/bQWBcCKpeeE