At what stage do you stop spending on a re-build? (standard)
 

I have a 1998 terzo 3 special edition with a knocking bottom end. At what stage should i stop spending?. Im wanting a standard engine putting back in that isnt gonna need a rebuld again for 30-50k. SO far ive been quoted for re grind on the crank, new shells, gaskets fluids etc etc. Im now thinking of new oil pump and clutch. Just wanted to no what you guys think as im no mechanic? The main thing is i want the engine to LAST ! ! !

You cant regrind teh existing cranks (so i've been told)

this happened to me - i ended up getting an STi short block which is stronger.

have a trawl on here or fle-bay

I would have a word with David at api engines if i was you.

Welcome to the API website

Ive been quoted for re grind by an ex subaru mechanic :wonder:

Theres gonna be one or two people who say its fine,(pslewis for one)but its not,Speak to David at API,or Andy forrest or Zen they will give the facts not fiction.

Dont take my word for it, speak to a couple of experts,if only for the good info they will give you.

am i reading this wrong 30-50k for rebuild???

that isn't going to need rebuilding again in 30-50k miles :D

Surely these people wouldnt do a re build knowing it wouldnt last 2 minuites. I spoke to one of the guys who quoted me and he sounded like he knew his ****.

Thing is, new cranks aren't that expensive, and it allows you to use cheaper and more widely available normal sized bearing shells.

Alot of people change and uprate oil pumps without knwoing exactly why they are doing it. They see worn copper bearing shells and think "starvation" - must be the pump....wrong. The simplicty of the design itself dictates it cannot fail. They rarely wear out (seeing they pump lubricant ;) ) and don't break, unless some foreign debris got in there (from some other problem).

However, in a worn engine or an engine with a problem (oil too hot, low oil level, wrong oil for conditions, badly maintained, stuck pressure relief valve, detonation leading to excess wear. etc) can lead to circumstances where demand exceeds the pump's capacity: The pump is not at fault - something else is. Ain't broke - don't fix ;)

Clutch, well that's down to driver and engine mods. A bad driver will see out an Impreza's clutch in 40k miles A sympathetic driver can see it well past 100K. And its a similar case when running more BHP. I think its a case of looking at how many miles your current clutch has done, and inspecting its condition when the engine is removed to assess how much life it has left in it.

The key to your new engine lasting is firstly find the root cause of the last engine's premature failure - make sure it not running too lean on a particular cylinder and detonating (shock-loading bearings), check service history/procedures/intervals and if your using the right oil for your driving style (track days need different grades and service intervals to tottering about town). Secondly, rebuild the engine to good tolerances - a blueprint engine almost always last longer than one built to more sloppy tolerances.

hope you get it sorted daz, could be expensive, but at least when its done your insurance may go down...:)

you should never have sold yours to me. but at least a terzo is a special edition, rarer than a normal turbo matey:thumb:

I would seriously suggest finding out what went wrong in the first place, which if your mechanic doesn't know now will probably find out as he starts to take your engine apart. If it isn't properly diagnosed and rectified before its rebuilt then its likely to happen again.
If the oil pump was the reason for the damage then change it, if it wasn't then leave it. The clutch depends on the mileage you've done and how you drove it, when its rebuilt the mechanic should let you know whether its ok to use or not.

It sounds to me as if you expect future problems but with regular maintenance and treating your car right it shouldn't need rebuilding for a long time. I always run the car for 10 minutes before i go anywhere, might sound stupid since i work 1 mile away but trust me warming your engine and allowing the oil to flow around the engine before putting it under any load is a very good idea. I've also been told that for Turbo models you should keep the car running after driving for 10 minutes to allow the turbo to cool.
Also don't rag the car straight away, i'd also suggest after its rebuilt to do at least 500 miles taking it very easy. Then oil and filter change and bit by bit open it up. IE change gear at max 3k for the first 500 miles, then 3.5k for the next 100 etc etc or thereabouts.
After say 1k miles get a major service done. The more you wrap it in cotton wool to start with the longer you should expect it to last.

Good luck with the rebuild.

You can get the crank reground.
A lot of places cant regrind them due to the narrow jounals.

If you have half a thou taken off you would then need half a thou oversize bearings from the like of ACL which are easily obtainable. Would be very advisable to plastigauge the crank/shell clearance though, to ensure the machining work has been done correctly.

The problem with regrinding cranks, which is what i think puts a lot of people off, is getting 100% of the ****e out of the oil ways.

whats the better option then? New crank as well?

I spoke to a huge number of companies when I needed my engine rebuilt. I settled on a version 9 crank, RCM oil pump, Cometic gaskets and nice bearings which took the cost to just over £3000. Now that I have the car back, and it's run-in I can confirm it now produces more power over a wider rev range than before - testimony to the excellent job done!