Hey! I posted this in general 4x4 tech and no-one cares to comment...

Guys" any of you have the balls to at least make a snide remark on this? I could use someone's advise as I've been away from engine building and all for a while...read on!

Thanks!



This is on a land-rover 3.9 engine in a '95 discovery

(edit)come on guys!!! The Rover v-8 is a frigging GM engine, so don't be afraid to speak up with any advise...getting the feeling people think it is an exotic engine! read on and suggest away pulleeze! I'm sure many of yall have done similar in their american engine??



I had my heads off to replace head gaskets again(was given teh wrong "thin steel" gasket instead of thicker composite one, and things still were baad..worse than before replacement) on removal of heads this time my friend noticed that the top ecge of the #3 piston was burned off about 1/8" about an inch around the edge...not wanting to have this get wore, and end up with a grenaded engine in a few months, I decided to pull teh pan and replace the one bad piston..A fellow Land-rover enthusiast on this site is sending me a good similar mileaage(100-120,000 miles) piston/rings...saving me teh $$ of buyng teh nw one for over a hundred so i can get this puppy back on the road...my question is should I be ok with just droppng it in? or should I hone out the bore as I had planned with installing a new piston/rings? or?? or??

waddya say?

I'm planning on eventually replacing this with a larger displacement rover engine or if I can find a 6.2 GM deisel so this is sort of a "patch" to get my by, but don't ant to tar it all apart again in another few months

Paul

Originally posted by androbus
(edit)come on guys!!! The Rover v-8 is a frigging GM engine, so don't be afraid to speak up with any advise...getting the feeling people think it is an exotic engine! read on and suggest away pulleeze! I'm sure many of yall have done similar in their american engine??
Sure, it's a GM engine that GM hasn't used for more than 40 years now :) As far as your piston swap, if you are absolutely positive that they are for the same bore (no oversize), then the swap may well work, for a while at least.

Originally posted by toy283

Sure, it's a GM engine that GM hasn't used for more than 40 years now :) As far as your piston swap, if you are absolutely positive that they are for the same bore (no oversize), then the swap may well work, for a while at least.

yeah! same bore both engies with similar miles, stock never removed so neither overbore.

I know it will work...but wondering if I should hone teh bore at all like you do with new rings? so they wok into the bore? or use my old rings from teh old piston so I know they are matched...or? :D
gawd! I feel like an idiot! I've been wrenching on Airplanes motorcycles and old cars for decades, and after not doing much recently suddenly don't trust my own judgement...life sux when on such a tight budget

paul

If it where me, I would take a bottle hone and brake the glase off the cylinder walls and put new rings on the pistion and reinstall. If you don't brake the glase off I don't think the rings (old or new) will seal very well causing premature failure or oil blowby..

.02$

Originally posted by Lt1Cj7
If it where me, I would take a bottle hone and brake the glase off the cylinder walls and put new rings on the pistion and reinstall. If you don't brake the glase off I don't think the rings (old or new) will seal very well causing premature failure or oil blowby..

.02$
Yeah! what I had thought, but no longer have a bottle-brush hone, and couldn't find one yesterday...I just lined up one to borrow, so am set!

woohoo! soon to be back at the mall with my discovery(why do all the soccer-moms shy away from mine, it's the same as their disco's...just cut out fenders for the tire-clearance, lifted to not scrape over those speedbumps, and a few hundred dings/dents/gounges...:D

Paul

Mic the piston, just in case, then hone it (the cylinder) a little, check the ring end gap and reinstall. If you're using new rings, check for a ridge or lip at the top of the cylinder. If its big enough to catch your fingernail on you should ream it. It can ruin a set of rings. Parts stores usually rent the reamer tool. Ive done this same thing on many GM motors.

Originally posted by 4link95yj
Mic the piston, just in case, then hone it (the cylinder) a little, check the ring end gap and reinstall. If you're using new rings, check for a ridge or lip at the top of the cylinder. If its big enough to catch your fingernail on you should ream it. It can ruin a set of rings. Parts stores usually rent the reamer tool. Ive done this same thing on many GM motors.

ah! yes....I have a ridge reamer in one of my roll-aways in storage..hopefully I can manage to climb up over all the motorcycles, tools and stuff in front of it to get to the box! :mad:
I could almost make out the rec colour of it last time I was there...
will have to look for it..have a couple days before the piston and hone show up anyway..

Thanks !

Paul