chris-m

bad news today looks like i spun a bearing on my LS1. was pretty mild spec, 220/220 cam and ARP rod bolts. i've dry sumped it for track use (ARE kit) and it has a ported oil pump. at the time i put a new timing chain on and replaced all the seals etc. engine had been running pretty well, making over 405bhp@ hubs on a dyno pack. 3 trackdays completed and only 250miles on track and its started what sounds like a bottom end rattle. :-(

oil pressure was fine and still shows 4 bar hot idle, and i still have oil in the dry sump tank at the right level. the engine was a used example bought second hand, but looked clean and didnt smoke in any way, and ran sweet till today. stil isnt smoky now, and sounds ok on cold oil, once oil warms up a little it starts a rattle from below on light loads and around 2000rpm.

anyway if its now got to come out, what options do i have regarding a rebuild or should i go for a crate (ls2?) bottom end?
i dont have a big budget unfortunately, and am UK based, but with the good exchange rate it may be more cost effective to purchase a crate /built ls from the US as opposed to rebuilding my own bottom end here. i dont need mega spec as the car weighs 1800lb max and 450bhp flywheel is enough.

taking the engine out and stripping it to see whats happened is the first thing obviously. i have been setting my rev limiter to 6500rpm based upon having arp rod bolts and uprated valve springs/pushrods and retainers.

looking for links/ideas really so i can weigh up options on either a new bottom end (peace of mind?) or a full crate motor. alternate way obviously may be as simple as a crank regrind/better bearings etc?

any suggestions appreciated thanks

AFASTYZFR1

iTrader: (55)

I sent my shortblock to Exotic performance and had it re-built with forged internals.....just an option


Or if you have a local engine builder that is familiar with LS1's they can re-build it

chris-m

i'm going to look into all options incl an ls2 bottom end to mate my bits onto if need be, depending upon damage found, as i might not have 100% confidence in a rebuilt bottom end on mine if the crank needs grinding etc.

i assume the ls2 bottom end would bolt up to my ls1 heads etc and accessories? i run an ultralight crank damper pulley and dry sump scavenge (ARE) , with a modified a/c bracket off an ls1 and a modded ls1 alternator bracket, plus tensioners modded to line it all up.

also will my ls1 cam fit into an ls2 bottom end?

racer7088

Cut your filter open and look whats in it. You might have a bad lifter or something rather than bottom end damage. Just see before tearing it all down.

chris-m

what would a bad lifter sound like, and would you exp[ect to see particles in the filter if the bearing had spun?

chris-m

also, is there any check for a broken/faulty lifter before i pull the engine out? i can get the sump off and the valley cover this week to have a look if i can see in there?

racer7088

Yes you could see bearing material in there if it was a bearing that let go and if you took the valve cover off you might see a loose rocker or bent pushrod if you have a collapsed lifter etc.

chris-m

i'll check all the rockers and pushrods then. is anything able to be see with the valley cover off?