Engine rebuild

Engine rebuild

Author
Discussion

Dr G

13,861 posts

192 months

Monday 21st January 2019
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Trev450 said:
Thanks for taking the time to provide an update. It makes for very interesting reading and you clearly have a talent for elequent prose.
Absolutely, really interesting stuff. Thank you.

Matty3

367 posts

34 months

Monday 21st January 2019
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Super pics there - look forward to the before and after comparison of the engine bay.

Bring on the next instalment smile - I hope there are no major issues/surprises lurking within...

4321go

Original Poster:

518 posts

137 months

Monday 21st January 2019
quotequote all
Dr G said:
Trev450 said:
Thanks for taking the time to provide an update. It makes for very interesting reading and you clearly have a talent for elequent prose.
Absolutely, really interesting stuff. Thank you.
You’re all very kind. Frustratingly, although I can probably string words together into vaguely intelligible formations, I’ve never progressed beyond typing with one finger, so my rather long-winded posts can take an absolute age to type!! And thank the Lord for spelchequers.......

Dr G

13,861 posts

192 months

Tuesday 22nd January 2019
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Matty3 said:
I hope there are no major issues/surprises lurking within...
I hope we discover the sump had been used as a smuggling vessel for an international diamond thief; the proceeds of which OP decides to spend on a couple of turbochargers...

4321go

Original Poster:

518 posts

137 months

Tuesday 29th January 2019
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Another brief update. After a bit of a fight, the engine is out. In fact, it may even be stripped by now.



After further discussion with Ricky, I’m now much more au fait with where we’re probably going with the heads. Once off, they will be totally stripped and cleaned. If we replaced nothing else, then the valve springs would be a must. But after years of hammering in and out of their seats, best practice would be to replace the entire valvetrain. Whether or not the valves are renewed, the valve seats will nead to be recut.

Options and pricing: OE inlet valves (20), exhaust valves (20) and springs (40): £1508.40. Supertech valvetrain kit: £1750. The Supertech kit already contains the retainers and valve collets that would bring the price of OE up to the same price as aftermarket. The advantage of the aftermarket kit seems to be newer materials technology resulting in both lighter valves and better heat dissipation. So Supertech it will be then. Seat cutting will be done by the same outside contractor that’ll be doing the sleeving of the block: £400 (that’s £10 per valve seat).

The one unknown here is the state of the valve guides. If worn then they’ll need renewing at £320 (or £8 each) and installing (at the same time as the valve seats) for a further £400 (or again, £10 each). Before reassembly, Ricky will be lightly porting and polishing the tracts to improve the breathing. As standard, the head castings are quite rough and have some ugly steps!



FWIW, the crackle finish to the intake plenums and the air filter boxes will be renewed and then clear-coated in the hope that doing so will aid longevity. The plenums were last done four years ago but the combined effects of heat and rain have led to their current, leperous state.

(And here I can pass on a rather esoteric bit of info that I gleaned several years ago, when I was looking to refinish the cam covers of my F355; the “correct” term for the crackle finish used on exotica is “vermiculated” (from the Latin “vermiculus” meaning “little worm”).)

jakesmith

5,988 posts

121 months

Tuesday 29th January 2019
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Great update!
It really does look so similar to the R8 with the engine and bits out

Trev450

5,862 posts

122 months

Tuesday 29th January 2019
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Thanks for the update. Every one is an education. smile

hyphen

12,113 posts

40 months

Wednesday 30th January 2019
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Trev450 said:
Thanks for the update. Every one is an education. smile
yes

PompeyReece

726 posts

39 months

Wednesday 30th January 2019
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Thanks for the update, really interesting stuff.

I walked past your engine on Saturday when dropping mine off to Ricky so erm.... good to put an engine to the thread smile

dexion7

4 posts

59 months

Wednesday 30th January 2019
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really interesting thread and top marks for providing details of costs etc.

i wondered if by 105k miles any other parts of the car have shown their age and required attention e.g. gearbox, suspension, trim etc?

Flatteraxe372

31 posts

15 months

Thursday 7th February 2019
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Having a high mileage Gallardo myself I find this thread extremely interesting. Mine is a Euro LHD so measures in Km's obviously and the clock is currently showing 108k which equates to roughly 67,000 Miles.

I honestly thought I was a contender for the highest mileage Gallardo until I saw this thread!

Mine burns oil too but nothing like yours, I think it does just under a litre per 1000 miles. I had mine de-catted by Sonny at BHP in 2013 so hopefully they didn't get to do too much damage before they were removed, although as my car is an 06 they may have had time to start breaking up.

Thanks again for the thread and I will wait eagerly for the next installment.


paulmnz

395 posts

124 months

Friday 8th February 2019
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4321go said:
FWIW, the crackle finish to the intake plenums and the air filter boxes will be renewed and then clear-coated in the hope that doing so will aid longevity. The plenums were last done four years ago but the combined effects of heat and rain have led to their current, leperous state.

(And here I can pass on a rather esoteric bit of info that I gleaned several years ago, when I was looking to refinish the cam covers of my F355; the “correct” term for the crackle finish used on exotica is “vermiculated” (from the Latin “vermiculus” meaning “little worm”).)
You might want to try redditch shot blasting - they are quite well known for re-finishing Ferrari intake plenums as they have managed to find a decent colour and texture match for the OEM red. The website is quite oldskool, but they do a good job - I believe they have done lambo intakes as well, so they should have the right shade and texture.

They powder coat, so it should last a lot longer than re-painting.

4321go

Original Poster:

518 posts

137 months

Friday 8th February 2019
quotequote all
paulmnz said:
You might want to try redditch shot blasting - they are quite well known for re-finishing Ferrari intake plenums as they have managed to find a decent colour and texture match for the OEM red. The website is quite oldskool, but they do a good job - I believe they have done lambo intakes as well, so they should have the right shade and texture.

They powder coat, so it should last a lot longer than re-painting.
That’s a really useful lead. I’ll look into it. Thanks!! (The air filter boxes, which don’t get hot and aren’t under the engine lid louvres are just starting to go, so will also need refinishing.)

Davo456gt

657 posts

99 months

Sunday 10th February 2019
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This is where you can get the proper Ferrari Wrinkle paint from:

http://www.kcolors.com/vernice-raggrinzante-liquid...
(note I've linked to the Lamborghini one here)

Needs baking on - see videos on the site

4321go

Original Poster:

518 posts

137 months

Sunday 17th February 2019
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Firstly, thank you for the suggestions and advice regarding refinishing the vermiculated (wrinkle!) paint on the intake plenums and air filter boxes. As I’ve mentioned before, whilst satisfying to look at, it’s not always the most robust finish. But then again, it’s a rather harsh environment.

As you can see in previous photos, the plenums look particularly scabrous! The original finish gave up at about eight years old, although it’s only just starting to fail on the air filter boxes after thirteen. But then, they don’t have to survive the same temperature extremes. The red vermiculated paint on the cam covers of my old F355 began to flake away much earlier still. Audi paint verses Fiat paint; discuss.....



I repainted the plenums about five years ago, using wet paint from rattle cans. The correct paint is available from several UK stockists, being VHT Wrinkle Plus paint imported from the US. https://www.vhtpaint.com/high-heat/vht-wrinkle-plu...

As the VHT product never seems to last as long as the original, I did wonder what process is used by the OE manufacturer. And it turns out to be powder coating. So thank you for the heads-up on that too. Ricky already has a box of brackets that will be media blasted and powder coated, and I was going to suggest that everything be dispatched together to the powder coaters previously linked to. But it turns out that wrinkle-finish powder coating is far from rare, and that the local refinishers in Swindon have done plenty of previous such jobs to his satisfaction. It’s a much more durable finish than wet paint and should hopefully last much longer.

Anyway......

I paid Ricky and the patient a visit last week. The engine was almost completely stripped, with just the heads to tackle. Several fasteners had proven troublesome as Ricky removed the engine, the last being some of the exhaust manifold nuts. He was anticipating the need for heat and mild violence/swearing in their final battle. Hopefully by now, the heads have been stripped and will have been sent away with the block for the required engineering work.

And now that the block has been stripped, we’re finally able to see the extent of the bore wear caused by the long-term ingestion of the gently degrading cats. If the following photos don’t persuade fellow owners of pre-LP, 5.0 litre Gallardos to investigate the removal of their cats, then nothing will! (For clarity, this seems to be a flaw in the design of the 5.0 litre engine, but not the later 5.2, which has a different (4.2 rather than 4.0) Audi V8 as it’s progenitor.)

And before the photos, an aside:

I’ve heard from at least one fellow owner who looked at a couple of examples before finally buying another. In both cases, he unearthed evidence of complete engine rebuilds at surprisingly low mileages. At the time he assumed that it was either bad luck, or that the cars had been ragged hard as “track experience” or hire cars (both were pre-LP SLs). My own opinion is that I’m fortunate that my car has always been used regularly and on longer drives. As such my cats have gently deteriorated with age, breaking down into a fine “sand” that has caused the bore wear. I’m aware of numerous cars that have suffered catastrophic failure at much lower mileages when much larger pieces of the cats have been ingested. Could this be the result of numerous short trips, maybe cruising through the local town, with the car parked up for extended periods of time between and condensation forming in the barely-warm cats, leading to more extensive corrosion of the plates?

So, time for the “money shots”.......

There are a lot of pieces squeezed into the engine bay of a V10 sports-car. Not everything in this first one is from my vehicle, but most of it is! That manky lump in the foreground is the Graziano manual gearbox. On the top shelf of the nearest trolly are the pistons and rods and the oil pan. It’s a stressed part of the block assembly and will be bolted back to it to provide rigidity during the machining processes. That’s my crank on the shelf below. The incongruous bag of Catsan might be for the works cat, but is probably of much more use for absorbing the inevitable oil spills that disassembly will have created. (In the background Ricky squats, contemplating what expletives will best accompany the removal of the exhaust manifold nuts):



The block itself is a surprisingly small part of the whole:



Thankfully (!), bore wear aside, the internals appear to be in good nick; the crank will require nothing more than a polish. Here you see two of the “main” and four of the “big end” journals. The “stripe” on the main journals is caused by the oil access groove cut into one half of the bearing shell.



But, Oh! the bore wear. Here’s two of the cylinders at random (9 and 10, I think):





And the corresponding witness marks/gouges on the skirt of one of the pistons. No wonder the poor old girl smoked like a kipper!:



Please keep the comments and advice coming. I’m not sure when I’ll next have a significant update for you; the major castings have to receive their machine work before we get to the reassembly stage. I’m not pushing Ricky for timescales; I’d prefer that the work is done well rather than quickly! Besides, it’ll do no harm to miss a winter of road salt..........

Trev450

5,862 posts

122 months

Sunday 17th February 2019
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Thanks for the update. Good to hear that progress is being made and that you have given Ricky the opportunity to expand his range of expletives. Those bores and piston skirts are certainly looking sorry for themselves. More than sufficient evidence for any owners contemplating cat replacements.

br d

7,323 posts

176 months

Sunday 17th February 2019
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Apart from the degrading cats and unavoidable wear and tear I think things look pretty good! That crank seems virtually bullet proof, they built these things to last.

Thanks again for the updates Go, great thread.

The Surveyor

7,117 posts

187 months

Monday 18th February 2019
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Really enjoying this thread.

Can somebody explain how the steady break-down of the cats has caused this deterioration?

With the cats being so far down-stream of the engine, how is the grit from the cat being sucked back into the engine rather than being blown down the exhaust?


mike01606

511 posts

99 months

Monday 18th February 2019
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The Surveyor said:
Really enjoying this thread.

Can somebody explain how the steady break-down of the cats has caused this deterioration?

With the cats being so far down-stream of the engine, how is the grit from the cat being sucked back into the engine rather than being blown down the exhaust?
The cats are actually quite close to the engine. Valve overlap and exhaust tuning cause pressure waves in the exhaust system... particles can 'ride' these waves back into the cylinders.

4321go

Original Poster:

518 posts

137 months

Monday 18th February 2019
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I’ve a degree in aeronautical engineering, but it’s gathered dust for the 25 years since I graduated. I fly them rather than design them! So if we’ve any fluid dynamicists here, or even engine designers, feel free to help me out........

In one of the photos above, you can see most of the disassembled engine on trolleys. The heads are on the middle trolly with the exhaust manifolds still attached. And the constant diameter, kinked pipes pointing backwards from the manifolds are the cat bypass pipes. So you can see that the cats are positioned quite a way back from the heads. Yet it IS fine sand from the cats that has been dragged back into the bores and has caused the scoring. And it seems that several unfortunate owners have had much larger bills than I’m facing at much lower mileages, when quite large portions of the cat’s plates have broken free and been ingested. How?

Well, I expect that you’d need some pretty accurate computer modelling of the exhaust system, a good computational fluid dynamics (CFD) programme and quite a bit of computing power to replicate things, but....

As the piston starts to descend at the start of the induction stroke, the inlet valve is open to allow the fresh charge to be drawn into the cylinder. But initially the exhaust valve is also still open (valve overlap). This allows some of the incoming charge to both purge the last of the exhaust gasses and to also cool the hot exhaust valve. It’s during this overlap period that the cat material can be drawn back into the bore. And I’m guessing that it’s not so much under high load, but at low revs and particularly during start up that the “sand” is drawn into the bores. But as I said, that’s just a guess.

As for debris being “blown” out of the exhaust, exhaust gas streams are surprisingly low speed and pulsed. It’s not a roaring gale, rather a rapid series of light puffs. And if you’ve ever seen inside a cat, you’ll have been as surprised as I was as to how restrictive the matrix seems. If a piece with any dimension greater than about 3mm broke off on the engine side of the cat, then it’s staying on the engine side!

Seems to be that Lambo got the exhaust architecture a little wrong on the 5.0 engine. It’s quite different on the later, Audi developed 5.2.

If anybody can answer this more definitively then, please do!



Edited by 4321go on Monday 18th February 19:28


Edited by 4321go on Monday 18th February 19:31