Lightening Pistons/conrods And Reusing Bolts

[brianthemagical 1]

i'm rebuilding my engine at the mo and want to lighten the conrods and pistons. both are standard items. i'm not planning on taking too much off but i was thinking about the casting flash on the rods and then smoothing any sharp edges. any opinions on this would be appreciated. does it seem like an ok idea and are there any other areas that can be done?

 

could/should i polish or smooth in any way the dish in the pistons?

 

i have done a search but am coming up against conflicting info. can i reuse the big end bolts and nuts? it will occasionally be near the limiter but only for rare short bursts, i don't do more that 75ish so it will only be high rpm twice in quick succession, other that that it will mostly be used sensible on roads at lower rpm, around 4000ish at the most. the engine will have most expendables replaced and everything cleaned/lightened. it is a 1.9 8v.

 

thanks.

Edited March 9, 2007 by brianthemagical

[petert 585]

save your time and effort, find some Mi16 pistons and rods. The pistons are approx. 100g lighter.

[smckeown 1]

save your time and effort, find some Mi16 pistons and rods. The pistons are approx. 100g lighter.

 

do you know the specific weight of the cast xu9 vs mi16 piston. I'm curious. I'll weigh my group a forged ones to compare

[petert 585]

do you know the specific weight of the cast xu9 vs mi16 piston. I'm curious. I'll weigh my group a forged ones to compare

 

 

approx. 445g from memory, inc. the pin and clips. I recall 8V pistons being 550-570g.

[brianthemagical 1]

i don't have a set of mi16 ones lying around and my time is free. i'm not going for anything major, it's more that i want to do it because i can. if i wreck them i'll chuck them in the bin at no loss. they'll be balanced by a pro. thanks for the relpys.

[matty_gti 20]

Sorry for hijacking your post but can you use Mi16 piston/rods and liners in a 1.9 8v?...is so is it a simple swap with no other mods involed??

 

ThAnKs

[PsychoSimon 0]

the compression ratio would increase i beleive, and you wil have to pocket the pistons for the valves.

 

This is just what I've been told..

[petert 585]

The CR will definitely increase but no modification of the piston crown is necessary. It's a straight forward easy swap of parts which I've done myself. They rev out quite freely! As you would expect.