Big end bearing

22Silver · Postby **22Silver** » Wed Mar 12, 2014 9:22 am

So my engine died, I priced new engines, etc.
BUT- it turned out only a big end bearing was done, block and head are fine.

So it needs new rings+pistons+bearings and it "needs" new cams

so that's all getting replaced.
After it's working again, we're going to machine 5-10% of the weight out of the flywheel, then bolt the clutch on and send it off to get balanced.

What else should I do while it's out?

hks_kansei · Postby **hks_kansei** » Wed Mar 12, 2014 10:20 am

New clutch as well?

If you're re-using an old one (I mean properly old, not one that's only been in 6 months) you may want to replace it before putting everything back into the car.

I'd also be looking into why the bearing went.
No point replacing the bearing if the cause of the breakage is still there.

and1 · Postby **and1** » Wed Mar 12, 2014 12:14 pm

Was the piston or bore damaged? If not just new rings and an hone will be fine. Also big end and rod end bearings should be changed as well as valve stem seals in the head.

I ended up getting forged pistons and stronger rods but this required more machine work and added to the cost..

Mr Morlock · Postby **Mr Morlock** » Wed Mar 12, 2014 12:34 pm

- the big end - no surprise and it will be costly. Lightened flywheel for road use - a really bad idea- more revs less pull and torque in a road car is not good. If you are on a race track with the thing being revved flat chat where possible and coupled with other mods ( if allowed under race regs) it might be a proposition but chugging around a lot of Melbourne with the cameras everywhere and up and down hills then a car bogging down on steep drives and hills is annoying.

sailaholic · Postby **sailaholic** » Wed Mar 12, 2014 1:03 pm

Have you ever dríven a car with a lightened flywheel morlock? I have and my experience doesn't match yours description.

Less in gear pull??? What?

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speed freak · Postby **speed freak** » Wed Mar 12, 2014 6:12 pm

sailaholic wrote:Have you ever dríven a car with a lightened flywheel morlock? I have and my experience doesn't match yours description.

Less in gear pull??? What?

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x2

Id highly recommend getting a lightened flywheel and definitely do the clutch now if its an old one, may as well do it now saves pulling the box out later on down the track. I love my lightweight flywheel, I daily mine and its great. Not hard to take off on hills or anything.

Do you know why the big end went? Run low on oil or something?

fastfreddygassit · Postby **fastfreddygassit** » Wed Mar 12, 2014 6:32 pm

sailaholic wrote:Have you ever dríven a car with a lightened flywheel morlock? I have and my experience doesn't match yours description.

Less in gear pull??? What?

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x3

I also recommend a lightened flywheel, having had a TODA flywheel in my NA8. It makes the driving experience sooooo much better! :mrgreen:

For a cheaper alternative, please read the following thread:
Need new clutch for a NA8, 1.6 Clutch setup on a 1.8?

DaveWA · Postby **DaveWA** » Wed Mar 12, 2014 7:40 pm

by Mr Morlock » Wed Mar 12, 2014 12:34 pm

- the big end - no surprise and it will be costly. Lightened flywheel for road use - a really bad idea- more revs less pull and torque in a road car is not good. If you are on a race track with the thing being revved flat chat where possible and coupled with other mods ( if allowed under race regs) it might be a proposition but chugging around a lot of Melbourne with the cameras everywhere and up and down hills then a car bogging down on steep drives and hills is annoying.

"Everyone is entitled to his own opinion, but not his own facts." (Daniel Patrick Moynihan)

22Silver · Postby **22Silver** » Thu Mar 13, 2014 4:59 pm

No idea, the pistons are getting checked today, I'm only replacing what is absolutely necessary/damaged and any consumables.
Flywheel- To machine down, or to replace entirely?
Clutch is like 6000km old (excedy clutch) should be ok?

hks_kansei · Postby **hks_kansei** » Thu Mar 13, 2014 5:14 pm

22Silver wrote:No idea, the pistons are getting checked today, I'm only replacing what is absolutely necessary/damaged and any consumables.
Flywheel- To machine down, or to replace entirely?
Clutch is like 6000km old (excedy clutch) should be ok?

yeah, that clutch should be fine.

My old clutch lasted almost 100,000km before it started to slip, and the last 12months of it's life it did a year's worth of motorkhanas (in fact, the last two bitumen rounds are what killed it completely)
6000km is nothing.

as for the flywheel, if it was machined when the new clutch was put in, it probably doesn't need it again. (I wouldn't bother with lightening it, either get a new lightened flywheel, or keep the stock one, 10% is nothing)

22Silver · Postby **22Silver** » Thu Mar 13, 2014 5:38 pm

Yeah the clutch I replaced was still fairly good too, but a spigot bearing went (wasn't replaced with the last clutch, previous owner). There was a bit of meat left but since it was all apart I took the opportunity to replace as much as I could.
Is it worthwhile getting rotating mass balanced after the engine is assembled with the clutch?

manga_blue · Postby **manga_blue** » Thu Mar 13, 2014 6:28 pm

22Silver wrote:Is it worthwhile getting rotating mass balanced after the engine is assembled with the clutch?

From personal exprience, I'd say yes. It doesn't cost a lot more to get a full balance ($150?) from harmonic balancer through to clutch. On my engine they took some significant amounts of metal off some rods and pistons and off the clutch housing. The crank, flywheel and front components were pretty good already. The engine ended up much silkier afterwards.

edit: balancing is done pre-assembly