Rebuilding an engine

I posted in the 'parts wanted' thread but I guess it doesn't allow for discussion so better to post here...

Basically my coupe is smoking a lot when cold and showing low oil pressure when hot (just below 1 bar at hot idle). Mechanic had diagnosed worn piston rings, and probably valve stem seals too.

At that point it becomes an engine out job, and the sense is to do a proper rebuild.

Countrycruising was his usual helpful self in the other thread, and gave a source for forged pistons, but my car is and will remain standard, so I think that normal cast pistons should do the job?

I have a friend with some mechanical knowledge who has removed and refitted the engine before who will do that part with me to keep the costs down; then I have a proper engine builder lined up to do the engine work - located in Ireland I can't just hand it over to CC or similar, unfortunately.

Anyway, I'd love a little help and advice on what to do (resist the urge to go mad, seriously!) in terms of parts.

I know I need:

Pistons & Rings
Valve stem seals
belts kit
hoses and CHOD
oil & water pump.

What else? Someone has told me to get the cylinders bored, and maybe the crank re-ground (can that be done on these?)

I am happy with the clutch and turbo - they both have <10k miles on them. Manifold is perfect, oil cooler pipes recently refreshed, forge dump valve, and a few other bits.

Anyone with any advice on sourcing the bits I need would be very gratefully thanked - I don't know do Alternative Autos still do bits? Never got a reply to my emails to them a while back...

Probably better phoning Steve at AA (or Tracey) on 01484 865086

Hi

If taking the lump out I would and want to do a proper job
consider also
Crank check
Big end bearings
Little end bearings
Flywheel balance
Balance shaft bearings

Best

Answering from the bottom of your post AA are still about and trading, sometimes you have to wait, or if I can help I could always supply your parts list but I'll need to know bore and journal sizes before ordering rings and shells.
The cranks can be reground, after it would need to be hardened and lapped, tbh if the engine has a healthy oil pressure it'll just need an inspection for size and new bearings, no point incurring extra costs when not needed.
Clutch wise I'd would check the movement of the thrust race bearing, if it spins freely renew it.
Coolant hose kit I always promote Viper, their kits are the best along with their new stainless clips, buying anything else would be waste of money imo.
Oil pumps aren't cheap to buy new, and again if the pressure was healthy why change it.
If I can help further give me a call or email.

Thanks all so far - is this the right hose kit? Does it include CHOD?
https://www.viperperformance.co.uk/silicone-hose-kits_9907_fiat-silicone-hose-kits.html

Any tips on where to get pistons?

That's the right kit for the hoses - set 074 includes the CHOD.

If you're looking for standard pistons that might prove difficult, for rings there are plenty of options.

uh-oh - forged pistons are fairly expensive...

New aftermarket pistons seem to start around the £100 each level, so £500 for a set whereas a set of forged pistons starts around £750 with uprated rods £300 ish.

Since your mate has taken the engine out before I guess it's a no brainer, but pistons/rings could be replaced in situ if the bore wear is OK. But probably best to remove the complete engine and measure / overhaul once on a stand.

Low oil pressure can result from bearing wear, oil pump wear or even low viscosity due to petrol in the oil from overfuelling causing bore wash leading to increased bore/ring wear...

Once you add up the cost, compare that with a replacement used engine, or there's still a new engine on eBay for a shade under £6k

ThNks Dave - any idea where I can get those aftermarket pistons?

I hear you on cost, but I don’t see the value in a used engine unless it’s been rebuilt anyway...

Oh sorry, they are listed on Autodoc and all the various European equivalent country sites, but none showing as in stock That's why people use forged pistons, since they are at least available.

I have seen a new block & piston set at Bielstein in Germany, I have bought stuff from them before but the block is very heavy and it says for delivery only in Germany, unless you can maybe arrange something yourself, 900€ But again it says "notify me when in stock"

Is there a need for replacement pistons if they're not showing wear and you're not doing more than honing the bores? The rings, obviously, but pulling the pistons and rings if they don't need it, why bother?

You'd do the big ends, of course, while it's out, and grind/harden/lap the crank.

Neil

Yes agree, the pistons should be fine so renew the rings only.

And conrods. Forgot them, but the same applies, unless there's wear at the little ends.

Edited to add: when Joe and I rebuilt my 16NA engine at 160k miles, we took one look at the cylinder pressures - better than 220psi across the board - and didn't even think about pulling the pistons or pulling the head.

Hi

Update from the mechanic (https://www.johnburkemotors.ie/) - a great guy who builds a lot of race engines.

Good news - the bottom end and pistons were OK.
Bad news - the top end is not so good, and the cams are beyond saving.

The list of parts needed from John is:
-Big ends std
https://www.buycarparts.co.uk/fiat/coupe-fa-175/7760/10625/big-end-bearings?sort_supplier%5B0%5D=485
£40 delivered

-Mains ends std
https://www.ebay.co.uk/itm/ENGINE-MAIN-SHELL-BEARINGS-FIAT-COUPE-2-0-20V-TURBO-MVParts-/262559604652
£46

-Piston rings std
£ 14,29
https://www.buycarparts.co.uk/fiat/coupe-fa-175/7760/10631/piston-ring-set

-Thrust washers std
£ 3,26
https://www.autodoc.co.uk/glyco/101266

-Full gasket set
£ 172,11
https://www.autodoc.co.uk/car-parts/gasket-cylinder-head-10325/fiat/coupe/coupe-fa-175/7760-2-0-20v-turbo?categories%5B0%5D=560

-Cams x2
Inlet cam:
https://www.autodoc.co.uk/ajusa/7189668
£130

-Lifters

-Cam variator
-Oil pump
-Timing belt kit.
-Timing belt crank pulley
-Water pump
-Oil filter
-Balance belt chain kit
-Spark plugs
-Cam position sensor
-Valve collets x4
-Cylinder head overhaul

That's only the engine - he's flagged some evidence of overheating so I will need water pump, hoses, thermostat and possibly rad too.

So can any of you help me to source these or point to where the problems are likely to arise? I'm doing some googling - belts, rings, etc seem to be available. I'll update this post with my own research of costs as I go, in case it might help others, but input is welcome!

I decided to buy an engine from a breakers, along with a bunch of rebuild parts - gaskets, and the like, as well as pumps, hoses, radiator, clutch... etc.

Good news: The engine is in and running well, with good pressure and very little smoke.

Bad news: I'm not getting any boost - more or less none via the boost gauge.

The Turbo was boosting OK before the change - I think it's fairly unlikely that it's died in the transition. I wonder if there is a problem with the plumbing or if the boost controller is getting the wrong message or something.

Does anyone have any ideas? I have "the book" but it doesn't have any detail on the plumbing of the Turbo - are there any diagrams floating around out there?

Have a look at the workshop manual for the fuel system on the 20vt, it has a schematic for the plumbing including the Pierburg (EBC) valve where you may have mixed up the connections. Ah but wait, you are not a member, so you will have to find an online version (or join up!)

A quick test is loop the vacuum line from the actuator over the the snail as that will give you base boost, if you still don't have anything either the turbine is seized or the waste gate penny valve is open.

Thanks! I have the workshop manual - will get into that and do what CC suggests

Ok so plumbing looks good. Compression excellent but still having smoke at startup, and there is no boost. waste gate is closed, dump valve ok... not sure what else it could be except a knackered turbo.

Anything else? It’s obviously possible that smoke and boost are separate problems. The turbine seemed to spin freely when the engine was out...