Engine on a diet

[Pembo]

Thought I'd share some of my diet tips!

Steel front pully 4.33 Kg
Alloy front pully 1.05 Kg
Saving 3.28 Kg

Dual mass flywheel 11.68 Kg
Solid steel flywheel 11.51 Kg
Alloy flywheel 4.78 kg
Saving 6.9 Kg

Standard clutch 6.67 Kg
Competition clutch 7.78 Kg
Gain of 1.11 Kg

Net loss of 9.07 Kg

Now how much weight can I take off my crank?
Forgot to weigh the crank but will do soon and add it above.
Answers please below.

The above is a lot of rotational mass so can someone do some strange calculations for an engine spinning at say 6000 rpm.

[Mark Halligan]

I think I had about a kilo taken off of mine, but I have seen lighter. I think Jamil may have removed more from his?

[Rusty]

Rotaional mass is a really good way of improving response, good effort with 9kg there, it should really feel spritely when all finished!

Are you sure that the DM flywheel is only 150g or so heavier than the SM one, I thought it was a lot more.

[terrybullwon]

@ Mark, I wish i had weighed my crank but never did when it came back.

@ Pembo, i am at the same mass as you maybe a bit lighter as my fly wheel lost about 3-4kg And my clutch was carbon-ed

[4WheelDrifter]

My crank weighed around 19kg originally IIRC. I had 1.4kg removed from it.

[Rusty]

found this in an old Pembo thread

@Pembo, You could use the 7A item but its heavier than the 3B one. Heres some info i found on the weights,

3B flywheel 10.5kg
7A flywheel 11kg
ABY flywheel 14kg
3B pulley 4.26kg
7A pulley 4.3kg
ABY pulley 5kg

[volcano rs]

I think I had about a kilo taken off of mine, but I have seen lighter. I think Jamil may have removed more from his?

standard crank weighs18.6kg
mine after machining 17.00kg
standard front pully 4.37kg
my alloy one 1.49kg
standard flywheel dahlback one 9.5 kg
after machining 8.00 kg
standard sprocket 223.4 grams
my steel one 255.2 grams
i hope this info helps

[Mark Halligan]

@ Mark, I wish i had weighed my crank but never did when it came back.

James, I am ashamed to say I didn't exactly weigh it accurately, it was just a case of jumping on the bathroom scales holding the crank and then again without it, then doing the math. Not sure what I was thinking at the time

@Stu did you get yours done at BDB? machining looks the same as mine.

I wish I had weighed my ally flywheel properly too...

[terrybullwon]

Must be pretty generic to what can be taken off to keep the blance

Heres mine not done at BDB

[Pembo]

Are you sure that the DM flywheel is only 150g or so heavier than the SM one, I thought it was a lot more.

All weighed on Saturday on the the same accurate balance scale he used to balance his rod end weights and each of the bolts that hold the clutch to the flywheel.

Hope for some serious improvement on pickup when it is all done. Remember I'm still struggling for a block as my AAN might not be repairable so might have to use a 7A with its pistons machined down to give a 8.5 compression ratio once all the calculations have been done.

[S2central.net]

@Pembo - what weights are stated in the homologation papers ?

I never called the RAC-MSA folk yet - must chase up on that other thread...

[Pembo]

No engine component weights are stated in the papers just sizes and dimentions NOT weights. So it could be a real diet as long as it is not a crash diet!

[Jamo]

Well I hate to say I'm going to be a proper fat boy and keep the comfort with it

Some nice diets there, atkins anyone?

[Flat on my back]

Sorry...off topic

There's was a block going from this guy...20Vcqdriver...try him, he may still have it...and he's near you.

[4WheelDrifter]

@Stu did you get yours done at BDB? machining looks the same as mine.

Yes. It was done at BDB, although I think he gets another guy to do the machining. He said more material could be removed but it would involve a CNC machine and a whole load more £££. I was happy with -1.4kg, he said he removed as much as he dared.