DII Reliability Upgrades
#11
03-12-2014, 02:18 PM
Rock Crawling
Join Date: Mar 2013
Location: Oregon, north of Salem
Posts: 452
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16 Posts
"Was thinking that for many, reliability is more important than the MPGs, off-roadability or rugged good looks (I have that in abundance!). So what are the top reliability
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The Rover engine uses what are referred to as "dry" cylinder liners, meaning that the aluminum wall in block, behind liners makes full contact with the liners. Original GM, and earliest Rover blocks had that wall of sufficient thickness that it seldom, if ever, cracked due to overheating engine. Only after Rover bored out the cylinder bores for the 3.9/4.0/4.6, making the wall thinner than ever before, did we begin to see wall cracking from overheating, which has been our plague ever since. Some engines, such as the Jaguar V12, and some Peugeot engines, used what are called "wet" cylinder liners, meaning that the liners outside surfaces were in full contact with the coolant; no aluminum wall between water jacket and liners. So, obviously, the wet liners had to be sealed top and bottom, to prevent coolant from getting into oil pan or into combustion chambers. Does anyone know about, or have ideas about converting a dry liner engine to a wet liner engine? That would be the ultimate upgrade, making all concerns about cylinder wall cracking problems no longer relevant.
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The Rover engine uses what are referred to as "dry" cylinder liners, meaning that the aluminum wall in block, behind liners makes full contact with the liners. Original GM, and earliest Rover blocks had that wall of sufficient thickness that it seldom, if ever, cracked due to overheating engine. Only after Rover bored out the cylinder bores for the 3.9/4.0/4.6, making the wall thinner than ever before, did we begin to see wall cracking from overheating, which has been our plague ever since. Some engines, such as the Jaguar V12, and some Peugeot engines, used what are called "wet" cylinder liners, meaning that the liners outside surfaces were in full contact with the coolant; no aluminum wall between water jacket and liners. So, obviously, the wet liners had to be sealed top and bottom, to prevent coolant from getting into oil pan or into combustion chambers. Does anyone know about, or have ideas about converting a dry liner engine to a wet liner engine? That would be the ultimate upgrade, making all concerns about cylinder wall cracking problems no longer relevant.
Last edited by earlyrover; 03-13-2014 at 02:12 PM.
#12
03-12-2014, 02:31 PM
#14
03-13-2014, 08:37 AM
Recovery Vehicle
coolant t hose with bleeder screw:
https://www.google.com/search?q=land...w=1536&bih=778
commong weak point, the coolant rots the plastic out, and the screw is plastic which either strips, rounds out, or blows out after years of service. i believe thiers an updated version, or a brass version. something to have on hand for when it goes, and normally itll go when you need to bleed the system then youre sol
coolant filter kits are everywhere, usually universally. they are mostly used in sandcasted block motors, big rigs, heavy equipment and diesel motors in pickups... all you do is find a place to mount it (pretty easy, drill n bolt basically anywhere) then find lines that fit or combo of adapters. theyd probably work find spliced into to the plastic lines, its trickle through filtering anyway its not like a brita waterfilter where the main flow is constantly being pushed through the system...
https://www.google.com/search?q=land...e=off&tbm=isch
The plastic lines are the small diamater wire lookin ones in these pics, the one that most people break runs on top/behind the radiator by the fan shroud to the coolant resivoir bottle... they are really thin hard plastic and are barely flexible, especially when old... they get brittle and one missplaced elbow and pop! easy repair when they crack is to use a length of rubber hose (fuel line like)... easily replaced just by sliding them over, you could put a small diameter hose clamp on to secure the connection, but i ran with a 12 foot fuel line patch for about a month lol before i recieved my replacement hard plastic line in the mail. consider replacing the hard plastic lines indefinatly with rubber hose is what im suggesting.
https://www.google.com/search?q=land...e=off&tbm=isch
there are also coolant lines that run through a plate under the throttle body that "prevent icing" so the tb doesnt stick open or closed... which i personally have never heard of... ever lol. im sure it must be a problem running on the highway up north in canada/artic maybe on a subzero day at a constant throttle and it happens to be high humidity lol. i had a 96 trans am with a dual 58mm tb with a bypass in new jersey for nearly 7 years... and we get single digits at night jan-feb most years, this year its 65 then 18 the next day, like today for example lol. the underhood temp in my humble opinion for constant movement on the throttle situations such is 90% of us unless you are stupid enought to be using a discovery as a highway commutor haha all the tb heater is doing is killing your intake charge temperature, and tends, like all plastic things that have coolant running through them, to rot, go brittle and leak.
heres the plate and some pics where the coolant lines run through it: you simple joing the two connections to bypass it, and block off the ends or leave em open lol. if you are worried, you simple slip them back on when the temps drop.
https://www.google.com/search?q=land...w=1536&bih=778
https://www.google.com/search?q=land...w=1536&bih=778
commong weak point, the coolant rots the plastic out, and the screw is plastic which either strips, rounds out, or blows out after years of service. i believe thiers an updated version, or a brass version. something to have on hand for when it goes, and normally itll go when you need to bleed the system then youre sol
coolant filter kits are everywhere, usually universally. they are mostly used in sandcasted block motors, big rigs, heavy equipment and diesel motors in pickups... all you do is find a place to mount it (pretty easy, drill n bolt basically anywhere) then find lines that fit or combo of adapters. theyd probably work find spliced into to the plastic lines, its trickle through filtering anyway its not like a brita waterfilter where the main flow is constantly being pushed through the system...
https://www.google.com/search?q=land...e=off&tbm=isch
The plastic lines are the small diamater wire lookin ones in these pics, the one that most people break runs on top/behind the radiator by the fan shroud to the coolant resivoir bottle... they are really thin hard plastic and are barely flexible, especially when old... they get brittle and one missplaced elbow and pop! easy repair when they crack is to use a length of rubber hose (fuel line like)... easily replaced just by sliding them over, you could put a small diameter hose clamp on to secure the connection, but i ran with a 12 foot fuel line patch for about a month lol before i recieved my replacement hard plastic line in the mail. consider replacing the hard plastic lines indefinatly with rubber hose is what im suggesting.
https://www.google.com/search?q=land...e=off&tbm=isch
there are also coolant lines that run through a plate under the throttle body that "prevent icing" so the tb doesnt stick open or closed... which i personally have never heard of... ever lol. im sure it must be a problem running on the highway up north in canada/artic maybe on a subzero day at a constant throttle and it happens to be high humidity lol. i had a 96 trans am with a dual 58mm tb with a bypass in new jersey for nearly 7 years... and we get single digits at night jan-feb most years, this year its 65 then 18 the next day, like today for example lol. the underhood temp in my humble opinion for constant movement on the throttle situations such is 90% of us unless you are stupid enought to be using a discovery as a highway commutor haha all the tb heater is doing is killing your intake charge temperature, and tends, like all plastic things that have coolant running through them, to rot, go brittle and leak.
heres the plate and some pics where the coolant lines run through it: you simple joing the two connections to bypass it, and block off the ends or leave em open lol. if you are worried, you simple slip them back on when the temps drop.
https://www.google.com/search?q=land...w=1536&bih=778
Last edited by grandkodiak; 03-13-2014 at 08:51 AM.
#15
03-13-2014, 11:40 AM
Good info...exactly what I was looking for. I've replaced one of the 2 brittle plastic coolant lines (the one that goes to the TB heater plate), but the one on top of the radiator I've not been able to route to my satisfaction.
Love the brass plug...that's going in my cart ASAP!
The coolant filter I'll have to research more. I'm not convinced that the majority of sediment would make it to the filter, but would stay in the bottom of the radiator. Furthermore, how much does it restrict flow (maybe not much, but it will be some). Finally, anywhere you cut/splice = another potential leak point. Maybe worth it/maybe not.
Regarding the TB heater plate delete, I already thought of that, but then CCRovers brought up some good points against it (kill-joy!). I also am military; have been and may be again stationed in AK or somewhere that redefines chilly so I'll leave it for now. See https://landroverforums.com/forum/di...r-plate-60861/
Love the brass plug...that's going in my cart ASAP!
The coolant filter I'll have to research more. I'm not convinced that the majority of sediment would make it to the filter, but would stay in the bottom of the radiator. Furthermore, how much does it restrict flow (maybe not much, but it will be some). Finally, anywhere you cut/splice = another potential leak point. Maybe worth it/maybe not.
Regarding the TB heater plate delete, I already thought of that, but then CCRovers brought up some good points against it (kill-joy!). I also am military; have been and may be again stationed in AK or somewhere that redefines chilly so I'll leave it for now. See https://landroverforums.com/forum/di...r-plate-60861/
#16
03-13-2014, 12:19 PM
Everyone should have brass diff plugs, hell we sell them for less than $4!
FILL PLUG RADIATOR TDI V8 1989 ON BRASS, PLC997, ERR4686 - Rovers North - Classic Land Rover Parts
FILL PLUG RADIATOR TDI V8 1989 ON BRASS, PLC997, ERR4686 - Rovers North - Classic Land Rover Parts
#18
03-13-2014, 12:49 PM
#19
03-13-2014, 01:34 PM
Recovery Vehicle
I ran no throttle heater for years never had a problem, and for it to stick WIDE OPEN, youd have to be RUNNIG WIDE OPEN and then have enough particulate ice buildup to jam the return spring. your running a disco motor wide open its going to be 230F in 30 seconds anyway hahaha.... more likely youd stick if at all running for awhile on a highway at 30% open if you are doing the speed limit lol, but for it to resit the close spring, it woudl have to be crazy imop, unless of course you are in alaska, canada or perhaps high altitude during a bad morning temp inversion. sticks open? slide her into neutral and tap the breaks, pop the hood and put the coolant leads back on. i personally dont sweat it unless you have a half inch of water in the airbox to begin with. plus it takes 3 minutes with a screwdriver to set and unset so not like its pulling a cam and deciding its not a good idea and want to swap back haha
http://www.ws6.com/image/tb-bypas.gif
denser charge = good (no, thats not a 4.0 )
also forgot, I might be confusing this disco with my trans but one of them or maybe both, have plastic drain and fill plugs on the diff pumkins, might want to grab brass plugs for those too.
http://www.ws6.com/image/tb-bypas.gif
denser charge = good (no, thats not a 4.0 )also forgot, I might be confusing this disco with my trans but one of them or maybe both, have plastic drain and fill plugs on the diff pumkins, might want to grab brass plugs for those too.
Last edited by grandkodiak; 03-13-2014 at 01:38 PM.
#20
03-13-2014, 02:20 PM
Rock Crawling
Join Date: Mar 2013
Location: Oregon, north of Salem
Posts: 452
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There are several upgraded camshafts out there (D&D, Crane, Crower), but none are roller. My GPR block uses the Crower if I remember correctly. Cannibal uses D&Ds. Both make about 15 extra hp which for the money, isn't bad considering a $500 Magnaflow exhaust will net 5 hp.
No, no no. I had in mind a REAL upgrade, a major modification to this engine, converting old fashioned flat top lifters, camshaft, valve train overall, etc. (that are now used mostly only in diesel engines), with modification to rollers, as found on latest engines. "Extra horsepower grind cams don't interest me at all; a complete waste of money, not on this 4.6 L. version V8, which has enough horsepower for purpose already, without any assist needed. You think cam upgrade = more horsepower. I think REAL cam upgrade = more mechanical efficiency; less wear on valve train.