wheres the wear? (inside a street GT3 engine)
Discussion
Interesting and scary in equal measure Neil!
Has this engine done mainly road miles? Or has it been driven as intended on track?
Are the heads and cylinders serviceable with machining etc, or is there a big parts bill involved with this type of rebuild.
I'll be watching with interest. Good post!
ETA - Just re-read it and I'm guessing a big bill anyway due to needing pistons etc.
Has this engine done mainly road miles? Or has it been driven as intended on track?
Are the heads and cylinders serviceable with machining etc, or is there a big parts bill involved with this type of rebuild.
I'll be watching with interest. Good post!
ETA - Just re-read it and I'm guessing a big bill anyway due to needing pistons etc.
Edited by marky911 on Friday 22 February 02:41
To put the above information into perspective be good to know engine history
We know the mileage but what of its service history like oil change's and oil type, plus how many owners, and track life.
Also could it have stood unused for extended periods thus resulting on dry seals and gaskets.
We know the mileage but what of its service history like oil change's and oil type, plus how many owners, and track life.
Also could it have stood unused for extended periods thus resulting on dry seals and gaskets.
Informative post Neil, but am i the only one to be somewhat puzzled over what this means? Ok, so a 90k mile GT3 engine seems to need quite a bit of work. So is this the same type of wear you see (albeit accelerated) after a racing season? Or is this simply saying that a GT3 engine that is used in multiple roles and knocking on 100,000 miles is about to give up the ghost?
Amazing to think that it even ran let alone perform as intended with such internal wear/damage?
Amazing to think that it even ran let alone perform as intended with such internal wear/damage?
Any gory photos for a boring Friday afternoon?Brilliant post, fioran0 - rather puts a lie to the "bullet-proof" reputation of the Mezger engine, does it not? I suspect it would cost an absolute fortune to put all that right. And I must say it rather puts me off the idea of ever owning a GT3, especially with the intention of using it as a track toy.
Very informative post Fiorano
Was anything noticable before the takedown of the engine, that inspired the owner to do the rebuild? Specifically I'm thinking of increase in oil cloud upon start-up of a cold engine or the much talked about "death rattle"? Did the engine pull properly and generally perfomr as expected, or where there signs of fatigue from a performance point of view?
Also, are there any parts that you class as consumables that could have been saved from performing a rebuild earlier on? I'm thinking of the chipped pistons, heads, and jackshaft wear that seems the result of faulty seals and O-rings allowing oil to seep into places of the engine where oil is not supposed to go.
Really appreciate all this information, as an owner of a GT3 myself, that will se regular hard use on track, it's nice to try and work out ahead of time, when the optimum timing is, to take the car from the hotel garage in Nürburg, and down to Manthey Motors for a light breathing
Would also be interested in hearing how the car in general was used (trackdays, A or B roads, city mileage?)
Not to mention what is expected to be carried out on the rest of the car, while the engine is out for the rebuild.
CK
Was anything noticable before the takedown of the engine, that inspired the owner to do the rebuild? Specifically I'm thinking of increase in oil cloud upon start-up of a cold engine or the much talked about "death rattle"? Did the engine pull properly and generally perfomr as expected, or where there signs of fatigue from a performance point of view?
Also, are there any parts that you class as consumables that could have been saved from performing a rebuild earlier on? I'm thinking of the chipped pistons, heads, and jackshaft wear that seems the result of faulty seals and O-rings allowing oil to seep into places of the engine where oil is not supposed to go.
Really appreciate all this information, as an owner of a GT3 myself, that will se regular hard use on track, it's nice to try and work out ahead of time, when the optimum timing is, to take the car from the hotel garage in Nürburg, and down to Manthey Motors for a light breathing
Would also be interested in hearing how the car in general was used (trackdays, A or B roads, city mileage?)
Not to mention what is expected to be carried out on the rest of the car, while the engine is out for the rebuild.
CK
fioranO - An informative post and I understand the distinction you make about engine failure/need to rebuild vs a refresh due to normal wear and tear.
What I am not clear on is whether you are suggesting that this engine naturally wears more than the average road engine, in other words, that the design of it purposely necessitates frequent rebuilds?
Or am I misunderstanding you?
What I am not clear on is whether you are suggesting that this engine naturally wears more than the average road engine, in other words, that the design of it purposely necessitates frequent rebuilds?
Or am I misunderstanding you?
spyderman8 said:
Brilliant post, fioran0 - rather puts a lie to the "bullet-proof" reputation of the Mezger engine, does it not? I suspect it would cost an absolute fortune to put all that right. And I must say it rather puts me off the idea of ever owning a GT3, especially with the intention of using it as a track toy.
It's done nearly 100k for gawds sake...with no idea of how it's been driven or looked after. ttdan said:
It's done nearly 100k for gawds sake...with no idea of how it's been driven or looked after.
^This, added to which you can't heat something up, let it cool down and heat it up again (heat cycling) several hundred thousand times and rev it to 7-8000 + rpm (frequently with lubricant that's contaminated) without it wearing/ losing its efficiency. Just because the Metzger engine gives its performance easily and relatively reliably, doesn't mean it's not highly stressed.
Neil will be able to tell you the rebuild intervals on RSR and R engines, but consider this, the works Subaru Impreza WRC car engine was a turbocharged 2000cc unit, it was expected to start and function perfectly in the freezing conditions of Sweden at -20, the same engine was also expected to work efficiently in the oxygen starved ?k metre high mountains of Argentina and the 35+ degree heat and dust of Greece. They ran approximately 2.5 - 3 bar boost. They needed rebuilding every 1000 kms/600 competitive stage miles . . . . .
Where performance engines are concerend, you never get owt for nowt.
fioran0 said:
mark,
the engine is designed to be effectively refreshed and the key is to do it before the parts designed to be consumable wear out and wear is transferred to non consumable parts.
its a very tough engine, thats why it has le mans victories. it will run and run before giving up but this shouldnt be confused with resistance to wear.
theres no non consumable parts needing to be replaced in this engine so its very cost effective to do. the heads can indeed be rebuilt. the pistons and liners are designed to be thrown away once used up, its a very clever design. the liners pop out and new ones pop in. no machining etc required.
Evenin',the engine is designed to be effectively refreshed and the key is to do it before the parts designed to be consumable wear out and wear is transferred to non consumable parts.
its a very tough engine, thats why it has le mans victories. it will run and run before giving up but this shouldnt be confused with resistance to wear.
theres no non consumable parts needing to be replaced in this engine so its very cost effective to do. the heads can indeed be rebuilt. the pistons and liners are designed to be thrown away once used up, its a very clever design. the liners pop out and new ones pop in. no machining etc required.
yep understood. My main concern really which is sort of a "How long is a piece of string" is what are the "average" costs involved, but I'm not rude enough to ask that on a public forum and I know each engine will be different.
I appreciate the engine is a clever design with regard to the replaceable liners etc, but while the cost and parts required to fix maybe expected and easily taken on the chin by race teams, for a one man "guy on the street" it's a pretty big event in the ownership of the car.
As Slippy says you get nowt for nowt and these are race engines but I'm a bit shocked at some of the parts required such as pistons and liners. Not wanting to go OT but my 964 Turbo (which produce a lot of heat related wear) engine rebuild was bang on the miles at 98K but it needed very little in the way of hardware. Head work, valves and piston-rings mainly. The bores were round and well within tol. as too were the pistons and their ring grooves. My piston rings weren't even half worn.
So like I say I'm just a bit alarmed at the parts list. I'd have maybe expected, valves, rings, and all oil seals, chains etc. but not a full set of pistons and bores.
Anyway, excuse my ignorance, I learn a lot from your posts. This one is certainly an eye-opener. Is this engine someone's we know
If so it gets a much harder life than mine. No bad thing, it's what they're for but it gives me a little hope that mine won't be as bad. Any logic to that?Cheers, watching with interest.
marky911 said:
Evenin',
yep understood. My main concern really which is sort of a "How long is a piece of string" is what are the "average" costs involved, but I'm not rude enough to ask that on a public forum and I know each engine will be different.
I appreciate the engine is a clever design with regard to the replaceable liners etc, but while the cost and parts required to fix maybe expected and easily taken on the chin by race teams, for a one man "guy on the street" it's a pretty big event in the ownership of the car.
As Slippy says you get nowt for nowt and these are race engines but I'm a bit shocked at some of the parts required such as pistons and liners. Not wanting to go OT but my 964 Turbo (which produce a lot of heat related wear) engine rebuild was bang on the miles at 98K but it needed very little in the way of hardware. Head work, valves and piston-rings mainly. The bores were round and well within tol. as too were the pistons and their ring grooves. My piston rings weren't even half worn.
So like I say I'm just a bit alarmed at the parts list. I'd have maybe expected, valves, rings, and all oil seals, chains etc. but not a full set of pistons and bores.
Anyway, excuse my ignorance, I learn a lot from your posts. This one is certainly an eye-opener. Is this engine someone's we know If so it gets a much harder life than mine. No bad thing, it's what they're for but it gives me a little hope that mine won't be as bad. Any logic to that?
Cheers, watching with interest.
Evening Mark, I suspect you didn't need to rev the 964T hard to make it go ? the GT3 needs to be revved to make it perform. As you know, revs = wear. Added to which your 964T would've been running a CR of what 9:1 or less ? The996 GT3 is more like 11+:1.yep understood. My main concern really which is sort of a "How long is a piece of string" is what are the "average" costs involved, but I'm not rude enough to ask that on a public forum and I know each engine will be different.
I appreciate the engine is a clever design with regard to the replaceable liners etc, but while the cost and parts required to fix maybe expected and easily taken on the chin by race teams, for a one man "guy on the street" it's a pretty big event in the ownership of the car.
As Slippy says you get nowt for nowt and these are race engines but I'm a bit shocked at some of the parts required such as pistons and liners. Not wanting to go OT but my 964 Turbo (which produce a lot of heat related wear) engine rebuild was bang on the miles at 98K but it needed very little in the way of hardware. Head work, valves and piston-rings mainly. The bores were round and well within tol. as too were the pistons and their ring grooves. My piston rings weren't even half worn.
So like I say I'm just a bit alarmed at the parts list. I'd have maybe expected, valves, rings, and all oil seals, chains etc. but not a full set of pistons and bores.
Anyway, excuse my ignorance, I learn a lot from your posts. This one is certainly an eye-opener. Is this engine someone's we know
If so it gets a much harder life than mine. No bad thing, it's what they're for but it gives me a little hope that mine won't be as bad. Any logic to that?Cheers, watching with interest.
The Metzger GT3 engine is a fantastic piece of engineering, but it was still ultimately built down to a price. 90k miles for 100 hp per litre n/a engine that's most likely been used very hard (not abused note) is pretty impressive.
But you're right, rebuilding them isn't cheap, especially if you're a perfectionist (which I know you to be) as all the small items that make an engine build look like it was carried out by someone who cares, really add up.
I've eaten my dinner off this before now . . . .
spyderman8 said:
Brilliant post, fioran0 - rather puts a lie to the "bullet-proof" reputation of the Mezger engine, does it not? I suspect it would cost an absolute fortune to put all that right. And I must say it rather puts me off the idea of ever owning a GT3, especially with the intention of using it as a track toy.
By your logic then my M96 engine in my 02 Boxster with 265K miles has to be way more "bullet proof" than the GT3 and its Mezger engine. Tell you what I'll make you a heck of a deal on the Boxster and for less than you'd pay for a GT3.And I'll keep my 03 Turbo with its Mezger engine and with over 105K miles.
marky911 said:
No problem at all, that's the way things need to be sometimes.
Like I say I didn't want to probe for specific info or costs, it's a simple case of "Surprised at the parts list".
If you get time to drop me a pm, great. If not, don't worry about it, I know you're a busy man.
Cheers.
Hi Mark, I'm all too aware I've not responded to your last mail, my humblest apologies. Rest assured, I'm not ignoring you ! ! I'll respond over the weekend Like I say I didn't want to probe for specific info or costs, it's a simple case of "Surprised at the parts list".
If you get time to drop me a pm, great. If not, don't worry about it, I know you're a busy man.
Cheers.
Slippydiff said:
Evening Mark, I suspect you didn't need to rev the 964T hard to make it go ? the GT3 needs to be revved to make it perform. As you know, revs = wear. Added to which your 964T would've been running a CR of what 9:1 or less ? The996 GT3 is more like 11+:1.
The Metzger GT3 engine is a fantastic piece of engineering, but it was still ultimately built down to a price. 90k miles for 100 hp per litre n/a engine that's most likely been used very hard (not abused note) is pretty impressive.
But you're right, rebuilding them isn't cheap, especially if you're a perfectionist (which I know you to be) as all the small items that make an engine build look like it was carried out by someone who cares, really add up.
I've eaten my dinner off this before now . . . .
Yep, I think I just underestimated the high revs thing. Turbos generate a lot of heat, but obviously the speed at which the bits of metal in a GT engine fly round at are equally as detrimental over time.The Metzger GT3 engine is a fantastic piece of engineering, but it was still ultimately built down to a price. 90k miles for 100 hp per litre n/a engine that's most likely been used very hard (not abused note) is pretty impressive.
But you're right, rebuilding them isn't cheap, especially if you're a perfectionist (which I know you to be) as all the small items that make an engine build look like it was carried out by someone who cares, really add up.
I've eaten my dinner off this before now . . . .
As I've said my main surprise was at the need for pistons. I've only ever needed new pistons once and those were in a Ducati bike engine where the swarf due to a failed bearing had removed the teflon coating and scored them a bit.
I'm sure on the overall scheme of the rebuild pistons aren't really a big deal though and if you're unlucky with a 964 rebuild you can need pistons and barrels.
Clean bay in that pic. One of yours? The 993?
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