Why do Disco's have so many slipped sleeve issues?
#31
12-03-2012, 04:13 PM
There seems to be many different opinions and stories associated with slipped sleeves. From what I can gather, there are more issues with later model 4.6 engines like the 03 and 04 DIIs. The 4.6 in the P38s don't seem to have the same level of sleeve problems. The old tooling and poor quality control theory seems to be pretty much on target. Earlier Rover engines never had a machined lip at the bottom of the cylinder bore but only slipped sleeves when the engine became extrmely hot. The 4.6 had a lip but the liner was often not installed all the way in so it had the potential to move. Add a mild overheat and the coolant gets between the liner and the block and it slips. If the block has a slipped sleeve but no cracks, it can be re-sleeved with top-hat liiners for a permanent fix but that isn't cheap. Someone recently posted about pinning their liners and fixing their tick. Try a search. I'm a little bit leery of placing those kind of stresses on a small machine screw but it seems to work.
#32
12-03-2012, 08:18 PM
#33
12-04-2012, 05:18 AM
Baja
there are 2 main reasons we have problems with these engines. The first reason is that when Rover first took control of the engine they changed it from a steel cast block to an aluminum block how to reduce weight. The second reason is the sleeves are steel inside of an aluminum block. There used to be a rough surface between sleeve in the cast iron block, Rover decided to use Press in steel sleeves in aluminum block. this would help them save money on the production line.thanks to the law of thermodynamics the aluminum block and steel sleeves heat up at different rates which allows friction between the 2 and considering it's smooth surfaces it allows liners to slide.
#34
12-04-2012, 06:20 AM
there are 2 main reasons we have problems with these engines. The first reason is that when Rover first took control of the engine they changed it from a steel cast block to an aluminum block how to reduce weight. The second reason is the sleeves are steel inside of an aluminum block. There used to be a rough surface between sleeve in the cast iron block, Rover decided to use Press in steel sleeves in aluminum block. this would help them save money on the production line.thanks to the law of thermodynamics the aluminum block and steel sleeves heat up at different rates which allows friction between the 2 and considering it's smooth surfaces it allows liners to slide.
GM did try cast-in sleeves, but this was a PITA and lead to a lot of scrappage in production, so Rover adopted the method used by many (and still today) of an interference fit between the liner and block.
The liners are not just "pressed in" but the liners are chilled, and the block heated - basically you want to have a greater delta of block to liner temp during assy than it will have in operation (approx 140 degrees C).
Anyways, The problem with this is that when you take the block to a cold climate, you create massive tensile hoop stresses in the walls of the block, which are especially thin in certain areas - and this, coupled with some thermal cycling and general engine stresses - is why the problem of block cracking behind the liners has always been a problem for the Rover V8 - because it is simply too thin between the walls (the block is plenty thick everywhere else).
Somehting else to consider - tapping that was a liner noise - traditionally was accompanied by water loss. in the last few years of production, it seemed to be you can have a ticker with loose liners, which doesn't loose any water. Also, the engine might never have been overheated for it to start ticking (since when has a truly overheated RV8 never needed new head gaskets? - so this is easy to see).
I believe (not through "i read it on the internets" but through consideration of real engineering principles) that some genius at LR decided to lessen the interference between the liner and block - probably to reduce the cracking that had plagued so many P38's - but that this was just a step too far, and lead to the "loose liner" syndrome that afflicts 03&04 but without loosing water.
As regards claims of overheating causing liners to become loose because the block has warped, really??? What happens when you overheat an alloy engine? It usually warps the head becuase of the various stresses from fasteners doesn't allow it to just expand and contract like a plain block of alloy would. To think that a straight bore, with a straight liner pressed into it would somehow "warp" and allow the liner to then slide is simply crazy; it just doesn't happen.
What is clear from the youtube videos is that the liners and cyliners are perfectly straight, but will happily slide relative to each other when the block is heated on a grill, then as it cools, the alloy contracts more and it is held in place again.
Finally - I suggest some of you might find this interesting:
Alloy used in the casting of the Rover V8 blocks and heads. - Land Rover Forums : Land Rover and Range Rover Forum
Also, if you read this, you might learn a little more about engine design:
http://www.sfsa.org/tutorials/eng_block/GMBlock.pdf
Regards,
Dave
#35
12-04-2012, 06:59 AM
Super Moderator
The addition of modern computer programming to hold the pointer of the coolant temp gauge at an artificial 50%, regardless of wide heat variation, adds to the problem. An owner can't see the close-to-overheat conditions or headed-toward-trouble conditions unless they add an aftermarket gauge or OBDII based device like the Ultra Gauge. Some engine problems are reduced by keeping temps within a more narrow range. I'd like to know if my engine is running warmer than normal (like one member's pix). I don't like shake & bake, extra crispy, deep fried, or bar-b-que when it comes to engines.
Note in pix of the Skylark interior that they needed aftermarket gauges as well (the days of idiot lights began early). And for inquiring minds, that big gauge on the center console was factory, it is a vacuum gauge, the "power" vs "economy" thing.
Seems like I have seen some posts from ROW areas where non-factory network mechanics crimped the edge of the liner to stop slipping. Perhaps with a small center punch, etc. Such a practice falls in with drilling two screws into a dead visocus clutch to link the halves; might work for a while, might have other consequences.
Note in pix of the Skylark interior that they needed aftermarket gauges as well (the days of idiot lights began early). And for inquiring minds, that big gauge on the center console was factory, it is a vacuum gauge, the "power" vs "economy" thing.
Seems like I have seen some posts from ROW areas where non-factory network mechanics crimped the edge of the liner to stop slipping. Perhaps with a small center punch, etc. Such a practice falls in with drilling two screws into a dead visocus clutch to link the halves; might work for a while, might have other consequences.
Last edited by Savannah Buzz; 12-04-2012 at 07:04 AM.
#36
12-04-2012, 07:31 AM
Super Moderator
#37
12-04-2012, 08:13 AM
Baja
The Buick/Olds/Rover 215 cubic-inch (3.5 liters) V-8 motor is one of the most fascinating and long-lived engines in automotive history. Originally conceived as an economy powerplant for GM mid-size cars, the "215" has been built in both the US and Great Britain, and has powered an astonishing array of vehicles, from sedans to sports cars, SUVs to racing cars. So, take a closer look at this history of this incredible engine, and check out the high-performance options available to the "215" enthusiast.
Buick 215 history
The Buick/Olds/Rover 215 cubic-inch (3.5 liters) aluminum V8 was originally announced in 1960 as a potential lightweight economy engine destined for General Motors new line of compacts: Buick Skylark, Olds Cutlass and Pontiac Tempest. First appearing in the 1961 model year, production ended in 1963 after over 3/4 million engines were produced. Two versions were available: Buick's model and the Olds, which featured different heads, valve train and valve covers. Pontiac used the Olds version.
The reason production ended so soon was a high rejection rate during the casting process, as GM utilized pressure casting of the Reynolds 356 aluminum alloy around steel sleeves. The assembly was then heat-treated to T-6 condition; but the heat treating caused the steel sleeves to shift and thus rejection of the entire block.
Eventually, GM cured the casting maladies, but the advent of new thin-wall iron casting techniques soon rendered the aluminum motor too expensive. The General quickly adapted the V8's architecture to cast-iron, lopping off two cylinders to create the workhorse Buick V-6. And in 1965, negotiated production rights with the British Rover Cars company. Rover, seeing the motor as its salvation for an aging product line, found that sand casting the block and installing press-in sleeves, (rather than cast in place), at a later point precluded any production problems or costs, but the beginning of longevity issues. This is where the liner issues began. In the Rover mass production techniques, the outer wall of the liner design was changed from a very coarse finish to a fine polished finish, for an easy mass production press fit. The thermal bonding in the cylinder cast in place assembly process, was eliminated completely. This allowed the smooth external walls of the new liners to provide easy installation but allowed the smooth walls to thermally expand at different ratios under the laws of dissimilar materials. Head gasket life would suffer indefinitely and plague this engine throughout its new design.It was destined to never again achieve it’s once robust popularity, as when General motors took the extra time not to cut corners.
The engine went on to power the ancient P5 Rover sedan, then the modern 3500 (a transplant into the 2000 TC), and finally the legendary Range Rover. It continues to power Land Rover products today in 4.6 liter guise.
The first company to realize the 215's performance potential was the exotic Apollo GT, a Ferrari-like sports car styled in America and built in Italy . Only 88 cars were sold before the company went under. The engine also found favor among European racing teams, powering several sports-racing cars (including the original McLaren), and in Repco-modified Olds form, propelling Sir Jack Brabham to two world Formula One championships in the mid 1960s (certainly NOT your father's Oldsmobile!). In 1969, the tiny Morgan company rejuvenated its archaic 1930's-era sports car by injecting it with the Rover V8. Zero-to-60 times of around six seconds were common...
In 1970, MG (now part of the vast British Leyland empire and sister company to Rover) was looking to improve the performance of its MGB sports car. An outsider, Ken Costello, actually showed them how to do it, as he had begun small-scale production of V8-engined MGBs. MG's own version appeared in 1973, just in time for the first oil embargo, and lasted only two years. Only some 2591 cars were produced, all in "hard-top" GT form.
Original 215 configurations
The original 215 aluminum V8 appeared in the Buick Special and Skylark models, while the Old's version was offered in the Olds F-85, Cutlass, and Jetfire models as well as the Pontiac Tempest.
The Buick version used only five bolts per cylinder to mount its heads, and the heads had a combustion chamber following contemporary Buick practice. The heads were also angled "upward" to create a "flat top" look common to Buick engines of the day. Buick altered compression ratios via piston height and design. You can bolt a Buick head to an Olds block.
Olds engineers went their own route with cylinder head design, preferring a Chevy small block-like combustion chamber and an extra bolt (six in all) around each cylinder to mount the head. The valve cover was also more conventional looking. (Ken Costello built his first MGB V8 using an Olds engine picked up in Belgium !). The valve train is also different. Old used different heads with the same pistons to produce higher compression ratios. An Olds head will not work on a Buick block because of the extra head bolts. For performance applications, you'll want either 829 heads (10.25:1 C.R. for '61-'62 4 bbl auto and manual cars, '63 4 bbl manual cars), or 534 heads (10.75:1 '63 4-bbl automatics). Two bbl heads (No. 746) have low compression ratios and aren't suitable for any performance work.
Rover configurations
Managing director William Martin-Hurst purchased the rights to the Buick version of the 215, and set his engineers on improving production techniques. Rover began installing an improved version of the 215 in the ancient P5 Saloon (sedan) in 1967. The same motor was installed in the more modern P6 2000 to create the 3500 (3500 cc or 3.5 liters). It soon found its way into the new Range Rover of the 1970’s.
A 3947 cc unit (created by increasing the bore to 94 mm) appeared in 1988 in the Range Rover, and later in the 1993 Discovery. A 4.2 liter motor soon appeared as the result of a longer-stroke crankshaft. In 1995, Rover launched the 4600 cc engine, using an even longer-stroke crank and a reengineering block with cross-bolted main caps.
Components for early engines are virtually interchangeable with the 215. The 4.6 liter engine, however, is different.
Original source missing. Current Source: http://www.aluminumv8.com/tech/tech.htm
Buick 215 history
The Buick/Olds/Rover 215 cubic-inch (3.5 liters) aluminum V8 was originally announced in 1960 as a potential lightweight economy engine destined for General Motors new line of compacts: Buick Skylark, Olds Cutlass and Pontiac Tempest. First appearing in the 1961 model year, production ended in 1963 after over 3/4 million engines were produced. Two versions were available: Buick's model and the Olds, which featured different heads, valve train and valve covers. Pontiac used the Olds version.
The reason production ended so soon was a high rejection rate during the casting process, as GM utilized pressure casting of the Reynolds 356 aluminum alloy around steel sleeves. The assembly was then heat-treated to T-6 condition; but the heat treating caused the steel sleeves to shift and thus rejection of the entire block.
Eventually, GM cured the casting maladies, but the advent of new thin-wall iron casting techniques soon rendered the aluminum motor too expensive. The General quickly adapted the V8's architecture to cast-iron, lopping off two cylinders to create the workhorse Buick V-6. And in 1965, negotiated production rights with the British Rover Cars company. Rover, seeing the motor as its salvation for an aging product line, found that sand casting the block and installing press-in sleeves, (rather than cast in place), at a later point precluded any production problems or costs, but the beginning of longevity issues. This is where the liner issues began. In the Rover mass production techniques, the outer wall of the liner design was changed from a very coarse finish to a fine polished finish, for an easy mass production press fit. The thermal bonding in the cylinder cast in place assembly process, was eliminated completely. This allowed the smooth external walls of the new liners to provide easy installation but allowed the smooth walls to thermally expand at different ratios under the laws of dissimilar materials. Head gasket life would suffer indefinitely and plague this engine throughout its new design.It was destined to never again achieve it’s once robust popularity, as when General motors took the extra time not to cut corners.
The engine went on to power the ancient P5 Rover sedan, then the modern 3500 (a transplant into the 2000 TC), and finally the legendary Range Rover. It continues to power Land Rover products today in 4.6 liter guise.
The first company to realize the 215's performance potential was the exotic Apollo GT, a Ferrari-like sports car styled in America and built in Italy . Only 88 cars were sold before the company went under. The engine also found favor among European racing teams, powering several sports-racing cars (including the original McLaren), and in Repco-modified Olds form, propelling Sir Jack Brabham to two world Formula One championships in the mid 1960s (certainly NOT your father's Oldsmobile!). In 1969, the tiny Morgan company rejuvenated its archaic 1930's-era sports car by injecting it with the Rover V8. Zero-to-60 times of around six seconds were common...
In 1970, MG (now part of the vast British Leyland empire and sister company to Rover) was looking to improve the performance of its MGB sports car. An outsider, Ken Costello, actually showed them how to do it, as he had begun small-scale production of V8-engined MGBs. MG's own version appeared in 1973, just in time for the first oil embargo, and lasted only two years. Only some 2591 cars were produced, all in "hard-top" GT form.
Original 215 configurations
The original 215 aluminum V8 appeared in the Buick Special and Skylark models, while the Old's version was offered in the Olds F-85, Cutlass, and Jetfire models as well as the Pontiac Tempest.
The Buick version used only five bolts per cylinder to mount its heads, and the heads had a combustion chamber following contemporary Buick practice. The heads were also angled "upward" to create a "flat top" look common to Buick engines of the day. Buick altered compression ratios via piston height and design. You can bolt a Buick head to an Olds block.
Olds engineers went their own route with cylinder head design, preferring a Chevy small block-like combustion chamber and an extra bolt (six in all) around each cylinder to mount the head. The valve cover was also more conventional looking. (Ken Costello built his first MGB V8 using an Olds engine picked up in Belgium !). The valve train is also different. Old used different heads with the same pistons to produce higher compression ratios. An Olds head will not work on a Buick block because of the extra head bolts. For performance applications, you'll want either 829 heads (10.25:1 C.R. for '61-'62 4 bbl auto and manual cars, '63 4 bbl manual cars), or 534 heads (10.75:1 '63 4-bbl automatics). Two bbl heads (No. 746) have low compression ratios and aren't suitable for any performance work.
Rover configurations
Managing director William Martin-Hurst purchased the rights to the Buick version of the 215, and set his engineers on improving production techniques. Rover began installing an improved version of the 215 in the ancient P5 Saloon (sedan) in 1967. The same motor was installed in the more modern P6 2000 to create the 3500 (3500 cc or 3.5 liters). It soon found its way into the new Range Rover of the 1970’s.
A 3947 cc unit (created by increasing the bore to 94 mm) appeared in 1988 in the Range Rover, and later in the 1993 Discovery. A 4.2 liter motor soon appeared as the result of a longer-stroke crankshaft. In 1995, Rover launched the 4600 cc engine, using an even longer-stroke crank and a reengineering block with cross-bolted main caps.
Components for early engines are virtually interchangeable with the 215. The 4.6 liter engine, however, is different.
Original source missing. Current Source: http://www.aluminumv8.com/tech/tech.htm
Last edited by hilltoppersx; 12-04-2012 at 08:22 AM.
#38
12-04-2012, 08:18 AM
Baja
May be you will find this interesting, no where does it say to reference yourself when writing to prove a point.
How to Reference Properly | School of Information Technology and Electrical Engineering
How to Reference Properly | School of Information Technology and Electrical Engineering
#39
12-04-2012, 08:57 AM
So where's DiscoMike to chime in with, "So why do you think it's a slipped sleeve?"
If you're going to buy a DII for keeps, plan on rebuilding the engine at some point in your budget or don't buy one. Hat's off to those who've pinned the liners as that was truly ingenious, however as my DD, that wouldn't be acceptable to me without a long list of examples and time-proven data. A Top hat liner conversion (or an engine swap, with a different engine that is) is the only sure thing to fix this. It's also $5-6K depending on what other options you want (hot cam, ceramic coolant duct treatment, ARP studs...), so it's not for everyone, but I believe at some point, this will be necessary, at least for the 03-04s. I've found 4 shops that do this/3 are reputable. In the Spring, I'll ship mine off.
If you want to buy one to see what all the hype is about, or if it's an extra vehicle for you, spend a lot of time on buying and less time maintaining. If/when it goes ****-up, do whatever is in your means and makes you smile!
If you're going to buy a DII for keeps, plan on rebuilding the engine at some point in your budget or don't buy one. Hat's off to those who've pinned the liners as that was truly ingenious, however as my DD, that wouldn't be acceptable to me without a long list of examples and time-proven data. A Top hat liner conversion (or an engine swap, with a different engine that is) is the only sure thing to fix this. It's also $5-6K depending on what other options you want (hot cam, ceramic coolant duct treatment, ARP studs...), so it's not for everyone, but I believe at some point, this will be necessary, at least for the 03-04s. I've found 4 shops that do this/3 are reputable. In the Spring, I'll ship mine off.
If you want to buy one to see what all the hype is about, or if it's an extra vehicle for you, spend a lot of time on buying and less time maintaining. If/when it goes ****-up, do whatever is in your means and makes you smile!