engine question

[stig730@hotmail.com]

Hi
I am after some advice please, fitting a 1.6 zetec se in a J15 before i fit the engine to g/box is it worth lightening the flywheel ?
I have never seen light fly wheels for sale for this engine, hence the question is it worth it ? i have somebody local who can do it for im sure a reasonable price
My last car with a 2.0l zetec e it did make a difference

Any advice please

Nick M

[Chet]

I believe that a lighter flywheel would be beneficial due to the light weight of the J15.


Chet

[sean737]

I am pretty sure I have seen them and I think it was Shawspeed. A lighter flywheel will not give you more power whatever the blokes down the pub say. The benefits are:

1 Lighter overall mass of car
2 Less rotating mass so quicker engine acceleration. (think motorbike engine being revved at idle, ie. the revs rise and fall very quickly)

Disadvantages:

1 less smooth idle
2 Easier to stall (again because the lighter flywheel has less kinetic energy)

I personally think most of it is psychological. It certainly sounds faster with a lumpy idle and faster rising and falling revs as you sit at the traffic lights revving the engine. If you are taking everything to the nth degree than it is probably worth it and certainly with such a light car the flywheel does not need to be so heavy.

[petercoll]

Just make sure the person doing the lightening knows what they are doing. A flywheel disintegrating at 6,000 rpm in one of our cars could inflict a lot of damage to your body.

Pete

[stig730@hotmail.com]

Thanks
The fella who would do it is top notch he is just learning to master the art of casting white metallistic bushes at the moment for classic cars, he has become a friend from helping me out with those little jobs that the home builder cant do with a previous build, i would probably have to force him to take any payment !
Bought the engine brand new from Powertorque as i want this car to last rather than rebuilding a scrapyard engine as i did with my previous one.
I drive in the old fashioned style with very little brakes but good use of gears (probably cos i learnt in a Landrover) so i like the better braking effect of a lighter flywheel. The build is coming on well but i havent got to the engine in phase so havent done much research on the sigma yet.
My intention overall is to build as near to Sylvas original spec as i can the lightwieght cornering agility is preferable to me than outright power (if i have the money though it will still be throttle bodies).

Thanks

Nick M

[sean737]

Make sure that the material is only removed from the perimeter of the flywheel. That is partly due to structural integrity and partly as that is where it will have most effect.

[Chet]

I believe the lighter flywheel will actually give you less braking effect than the factory (heavier) flywheel unless you mean that you are downshifting.

I concur with your thoughts that the overall light weight is the ideal approach with the J15. The balance of your car with the SE should be very good!

I'm having a very difficult time finding a similar suitable engine here in the USA for my customers.

Chet

[stig730@hotmail.com]

Hi to All
Yes i meant when downshifting and the white metal casting was for shell bearings on cranks/conrods.
I built another kit that i sold to finance the J15 but that build was to prove and learn that i could do it ! so now i want this one to be perfect but cost is always lurking in the background, i drive past Sylva everyday on my way to work so i assume thats why Jeremy hasnt given me a build manual ! or he saw my last car and thought he knows what hes doing !!!! (sometimes).
The precision of the chassis is perfect the last build was a rubber mallet long lever screwdriver and buckets of sweat to put the suspension together but Sylvas work is to the mm, brilliant.
With the spec i opted for the zetec on the last build instead of a pinto which the car was originally designed for and that created most of the problem jobs, it wasnt that difficult but just made it harder and longer.

Thanks

Nick M

[RobMsport]

Personally I'd definitely lighten/balance the flywheel even if you don't intend modifying the engine in any ' kit ' weight car . The response on the throttle will be so much more sensitive BUT please balance it too Smooth running wont be a problem , mine was fine even on 45's .