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Brad Bradford (Brad)
| | Posted on Tuesday, June 11, 2002 - 04:49 pm: | 
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I know that these little 4.0 V8s are capable of a lot more HP than they have. Has anyone put a Cam Kit in their truck, or Hi-Rev Lifters?? What is the easiest way to squeeze out more HP out of these old engines? Super chargers are out of the question. Has anyone dumped all the electronics and put a new manifold and 4-barrel on? I don't have the cash to buy a 4.6l but I need a little more grunt. Thanks in advance. |
Jason Vance (Jason)
| | Posted on Tuesday, June 11, 2002 - 06:01 pm: |
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Speed costs money...how fast do you want to go?
Cams: cams can offer greater HP, however, they are not the magic bullet by any means. Cams alter how the engine breathes, by increasing the lift of the valve, by increasing the duration the valve is open, or both. When using a cam, you need to consider the limitations of the heads. You don't want to lift the valve any higher than what the heads can benefit from (e.g. at some point, greater valve lift does not offer greater flow). Also, by increasing the duration, you can also increase the overlap of the intake and exhaust valves being open. Usually, more duration means more RPM is required to reap the gains, effecting low-end torque (which a 6000 lb Rover really needs!). More duration often requires more static Compression Ratio since much of the dynamic CR is bled off during valve overlap at low RPMs. This isn't even considering picking the right base circle diameter which may effect the total overlap.
The cam is the last thing you should pick when considering an engine combination. How a cam effects an engine is highly dependent on the bore and stroke, head-flow, induction flow, exhaust flow, compression ratio, and GEAR RATIOS (understand that in any gear, if the engine RPM is not within the cam's respective powerband, you can be waiting all day to accelerate before coming "on the cam")!
Obviously, if you are considering picking up a Piper (or any relatively mild grind) to increase torque, then this may reap some modest gains that you can feel while maintaining drivability. But if you are talking 300+ degrees of duration, over .500" lift at the valve, and 6000+ RPM, it's time to start working on the heads and finding some new gear ratios to make use of your increased (but relatively narrow) powerband.
And then when you get there, you need stiffer valve springs, stronger pushrods, and more cam changes as a flat-tappet lifters love to eat cams when high spring-pressures and high-RPM are concerned.
For the amount of money necessary to rebuild a Rover V8 into a hi-po engine coupled with the decrease in drivability (don't fool yourself here), adding a supercharger could be a bargain without sacrificing drivability and relative reliability. |
Ed H
| | Posted on Tuesday, June 11, 2002 - 09:48 pm: |
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Professor Vance,
How can a supercharge help the rover engine? Will it help at low speed? |
Eric
| | Posted on Tuesday, June 11, 2002 - 10:11 pm: |
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The original 215 buick has a small 4 barrel carb and a fairly progressive cam. With a few tricks it tipped the dyno around 200hp.
Then there was the TR8 and the MGC which made use of the Rover V8 and Stromburg carbs for about 225hp with a few tuning mods.
I have not seen much more than that comming from the little V8 anywhere else. The question with all engine mods is how much life will be extracted to gain more power?
Eaton makes a sweet little roots type blower that could add another 50% at the bottom end, where it would do the most good for a 4X4 so that could boost the 188hp to 260 or so.
But the added heat and stress on the bottom end of the motor would shorten the life, who knows how much.
I would vote for a small turbo charger with a minor amount of boost, say 6psi. Nothing too radical. It would really help the low end torque, maybe improve milage, and it would give the Disco a cool whine.
A kit has to exsist somewhere.
Eric |
Erik G. Burrows (Erik)
| | Posted on Tuesday, June 11, 2002 - 11:32 pm: |
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Can someone explain to a newbie gearhead like me why we can't just put a high-flow electric fan right after the air filter? |
Jason Vance (Jason)
| | Posted on Wednesday, June 12, 2002 - 12:23 am: |
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An electric motor/fan could not supply the volume and pressure of air needed to meet the current normally aspirated airflow of the Rover, let alone exceed that airflow to adequately pressurize the manifold for a performance gain.
However, an electric blower can supercharge a Briggs and Stratton...
Ed, with respect to your question, a supercharger is powered off of the engine's crankshaft (e.g. mounting an auxillary drive hub to the accessory hub, much like the accessories drive off the crank). It pressurizes the intake manifold, flowing more air through the manifold/cylinder heads into the combustion chamber than could the engine naturally pull without the aid of the supercharger. The more air-fuel mixture in the chamber, the greater the cylinder pressure upon combustion, equalling more power (well, torque leading to power). The supercharger is always being driven by the engine at all engine speeds (though there is a period of pressure increase at low RPM...) and the engine is benefiting from this added boost at all RPMs (as long as the net increase in HP is greater than the HP loss due to parasitic drag). The other option is a turbocharger which is powered off the engine's exhaust, has no parasitic drag, but has a lag period where the turbo is spooling up, usually at low RPMs. You can argue all night home until the cows come home which is better, a supercharger or a turbo (or for that matter, a big shot of the happy gas)...both offer a very flat and wide torque curve that can yield a wide power-band, as compared to a normally aspirated engine that may produce the same peak HP, but have a narrow and peaky powerband.
In a nutshell, head work and cams help get more air/fuel mixture into the chamber for more power in a normally aspirated engine; in a super/turbocharged engine, the blower forces more air into the chamber, allowing less radical cam profiles and heads, as well as less RPMs to produce the power.
Sorry for the diatribe...just got done teaching Anatomy... |
Mel A. (Krawlrovr)
| | Posted on Wednesday, June 12, 2002 - 10:11 am: |
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Yeah, but if the turbo blows up on a turbocharged engine, your entire engine is screwed. Also, I don't think that the Disco's compression ratio is fit for a supercharger. Our headers are pretty restrictive to get maximum performance from a supercharger too. But a turbocharger is not a bad idea. The key to this is to have a strong engine block and pistons. There are other parts that take a lot of stress too, but these are the main ones. I'm not sure if the Disco's engine is built for this, anybody? Turbo lag would also be a problem. Since we want massive amounts of torque at a low RPM, the turbo would have to spool before 2500RPM. Which is hard to achieve with one turbo. Maybe a twin turbo kit would benefit us. But if somebody does make a turbo kit for the Disco for under $2000, I might put it on. |
Kyle
| | Posted on Wednesday, June 12, 2002 - 10:32 am: |
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Ok , we have gone over cams and turbos and this and that,,,,blah blah blah... First off. WHY? What do you think all of this will gain you ? Aside from any personal prefferences one thing I know for sure it will gain you and thats "Issues". When you start adding more components you start adding more complexity. When you add complexity you open the door for "Issues". Aside from that you are taking an engine thats underpowered for its package and making it work more and produce more. That should tell you pretty clearly that it wont last as long. There arent any quick cheap power gains that you are even gonna feel in the seat of your pants short of giving it a little shot down the intake runners of a little something that it aint really gonna care for either unless you roll the timing back and fatten the system up a little. But your question is "Can I get more power easily out of this engine?"
Well how long would you like it to last ? Once you start running things at their peaks they dont tend to last very long. For instance. Bumping the timing up on an engine as far as you can get it to go with available gas and no pings will certainly give you faster throttle response and will bump power to damn near what a cam kit would give you. BUT , that signifigantly advanced engine is not going to last as long as the one running where it should be.
Bottom line is "There is no replacement for displacement" If you want smooth reliable power stroke the thing and get it over with...
Kyle |
Randall Smith
| | Posted on Wednesday, June 12, 2002 - 11:20 am: |
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Brad
I would agree with Kyle that increasing the engine stroke will do more for low end torque, without really screwing up longevity. "there is no replacement for displacement"
The first thing on your list of things of engine mods should be: replace the exhaust system. I would put camshaft near the bottom of the list.
Randall |
p m
| | Posted on Wednesday, June 12, 2002 - 12:03 pm: |
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Randall,
is the stock exhaust really that restrictive? I'd love to see some numbers.
speaking of the max power you can get from an engine, i've noticed that (on average) japanese, french, and italians get close to 100hp per liter of displacement, germans about 70, and american engines are near 50. if you look at the makes/models known for their long life, most of them are in the 45-55 hp/liter neighborhood. And none of them is a V8...
peter |
M. K. Watson (Lrover94)
| | Posted on Wednesday, June 12, 2002 - 12:50 pm: |
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i believe Kyle has it exactly right,,,,SIZE DOES MATTER!
mike w |
Phillip Perkinson (R0ver4x4)
| | Posted on Wednesday, June 12, 2002 - 01:21 pm: |
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350 |
Don Collins (Donc)
| | Posted on Wednesday, June 12, 2002 - 01:36 pm: |
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Eric... MGC's had the straight 6 in them. The MGBGT V8 and the MGR V8 are the ones that came with the V8 engine.. =-)
Sorry MG nut here..
DonC
96SE7
69MGB
71MGBGT (soon to be a V8) |
Kyle
| | Posted on Wednesday, June 12, 2002 - 01:44 pm: |
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Whats your experience with the 350 there Phillip ? You had many ? Been around many ?
Kyle |
CEJB
| | Posted on Wednesday, June 12, 2002 - 01:59 pm: |
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Adding hp is an expensive hobby....NRP/K&N/Timing adjust probably costing $1500, replacing the cam has a tendency to move the torque curve in the wrong direction for our heavy trucks
a 4.6 and rechipped engine is the best way but $$$
But what about lowering the gearing to say 3.8 and sticking with stock tires? That will give you some more kick in the pants feel- which after all is what your looking for. |
Kyle
| | Posted on Wednesday, June 12, 2002 - 02:02 pm: |
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Yep CE , but , that aint "Cheap" either and they tend to frown on that.... 
Kyle |
pwp
| | Posted on Wednesday, June 12, 2002 - 02:04 pm: |
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Peter
Not disagreeing wih your statement but...
on average japanese , french 100hp per liter....?
I think price as well as type of vehicle is a larger factor than country of origin. With the only exception being US made vehicles, can't agree with you more on that.
honda = 100hp/ltr....ouch
acura = 100hp/ltr.... probably
vw= 70hp/ltr.... probably
bmw 330i = 225hp (75hp/ltr)
bmw M3 = 333hp (100hp/ltr)
porsche 911GT2 = (126hp/ltr)
Peter |
Jason Vance (Jason)
| | Posted on Wednesday, June 12, 2002 - 02:06 pm: |
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Kyle,
I completely agree with you. I was just answering the question by pointing out that it is not a simple bolt-on to add power, but rather a complete redesign of the engine and driveline to make use of such considerations.
However, if I wanted cheap power, and considering all things (except increasing displacement), I would add a blower. Using either a copper head gasket or increasing head cc's to decrease compression ratio, and decrease the full advance of the timing to reduce detonation on pump gas. As far as effecting longevity, without considering the option of a bigger engine and modifying the smaller engine, I'd say you are accepting the fact of a shorter engine life. Personally, I am quite happy driving my 3.9L slow...I get better gas mileage and it allows me to slow down and enjoy life instead of rushing around getting pissed off in traffic! |
Brad Bradford (Brad)
| | Posted on Wednesday, June 12, 2002 - 03:30 pm: |
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I already have a Flowmaster and have cut the resinator off. I put a K&N, but from what I can tell I didn't matter anyway. My engine has over 120k on it and I think a supercharger would probably blow the engine up. Again I am just curious. I would like a little more power, but I can live with my truck the way it is. |
p m
| | Posted on Wednesday, June 12, 2002 - 04:02 pm: |
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Peter (PWP),
of course there are outliers, Saab's blown 2.3 cranking 225hp, etc. But none of high-performance engines lives long. The BMW's 5.4V12 with 330 hp dies an painful and expensive death shortly after 100kmi (in most cases). You won't find many 400hp Porsches with 100kmi on the clock, either.
German Ford and Opel are all very close to 70hp/liter, as is mainstream BMW and DC.
from the top of my head, 3 long-lived engines - Toyota's 22R, Volvo's 2.45l I4, and Mercedes' 3 liter I6. All of them are under 50hp/liter.
peter |
Eric
| | Posted on Wednesday, June 12, 2002 - 04:03 pm: |
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I thought the original Buick back in 1960 was actually designed for a turbo, in fact I am almost sure it was. And the car it came in was not very light weight either. So maybe the engine design is tough enough for a turbo without any concern.
Turbo lag would be acceptable for most off road situations, especially with an automatic. People often associate turbos with fast sports cars, but there are alot out there on trucks, boats and airplanes?
The ECU and injection system shoulf be able to tolerate a mild level of boost, especially if the boost comes in mostly at low RPMs.
Eric |
Kyle
| | Posted on Wednesday, June 12, 2002 - 04:08 pm: |
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"Boost" raises cylinder pressures. Increased cylinder pressures are hard on an engine. I am sure it will kick ass , I love a Turbo. But , ask yourself , "What for?" Also , how much faster is your Turbo equiped Disco that has coughed up a head and sitting on the side of the road , then , lets say , my tired ass normally aspirated Disco that has its heads in tact ?
Kyle |
p m
| | Posted on Wednesday, June 12, 2002 - 04:34 pm: |
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Eric,
i would enjoy watching the face of an offroad driver trying to make his way over a pile of rocks in a truck with a turbo lag. it would make a nice soundtrack, too.
in fact, i have a difficulty imagining the situation off road when i wouldn't care about the turbo lag...
peter |
Jason Vance (Jason)
| | Posted on Wednesday, June 12, 2002 - 06:40 pm: |
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I don't know of a single gasoline powered truck that uses a turbo (I could be wrong...maybe those Isuzu bobtails that Ryder rents out?). Most trucks, big and bigger, that use a turbo are diesels, and since the RPM range is small, a small enough turbo (respective to the RPM range a turbo chosen for a gasoline engine must work under) can be used to eliminate lag off idle.
Regardless, turbos are used all the time offroad...World Rally Championships!!! I doubt they have too many issues with turbo lag; mostly just trying to finish with the car in one piece (or many pieces dragging along...).
But I digress, and I think many of us can agree that a hi-po Rover engine is probably going to be lost under the 3 tons of girth it has to drag along. |
Jason Vance (Jason)
| | Posted on Wednesday, June 12, 2002 - 06:41 pm: |
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Oh, wait, I've just thought of a truck that has a turbo, gasoline engine: Toyota made a few models in the late 80's/early 90's...
any others? (don't wanna get flamed here...) |
Gil Stevens (Gil)
| | Posted on Wednesday, June 12, 2002 - 06:57 pm: |
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world rally championships?? that a long way from 2-5 mph crawling over roots and boulders. i know i wouldnt want a "surge" of power as im trying to creep over a very difficult section of trail. its one thing to be turboed blasting down fireroads at close to redline with ultimately no concern for the vehicle itself, or the money it will take to rebuild it after every race. its a whole different ballgame when your in low speed off-camber sections of trail, in a vehicle that is used daily and paid for with hard earned loot. i would say ixnay the turbo idea. |
Erik G. Burrows (Erik)
| | Posted on Wednesday, June 12, 2002 - 07:13 pm: |
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Why can't you put a turbo on a clutch like the A/C compressor? Turn it off for wheelin' and on for the feeway. |
p m
| | Posted on Wednesday, June 12, 2002 - 07:31 pm: |
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Turbo on a clutch?
you must've seen too many movies from the 70s
peter |
Erik G. Burrows (Erik)
| | Posted on Wednesday, June 12, 2002 - 07:57 pm: |
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Why not? Too much power to put through a clutch, or will the engine starve if the turbo isn't under power? |
Jason Vance (Jason)
| | Posted on Wednesday, June 12, 2002 - 08:00 pm: |
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Unless I stuttered in my previous message, I'll say it again...turbos are used all the time offroad. Yes, WRC is a far offshoot of "offroad" and does not really compare to any of the offroad driving a Disco may experience. However, many diesels utilize a turbo (which was the point!), including a fairly economic diesel produced by Rover overseas. I'm not saying you would want a turbo on your gas fed Disco...I never even brought it up as a recommendation; I brought it up to describe the other options of forced induction. I'm frickin' glad I didn't bring up the Miller Cycle as a possibility either...we'd have to replace our piston-return springs and muffler bearings after the clutch goes out on our turbo. |
Craig M. Highland (Shortbus)
| | Posted on Wednesday, June 12, 2002 - 08:08 pm: |
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Take it from somebody that's been there.....
ROVER ENGINES DON'T LIKE BOOST!
I don't care how much bottom end beef you stick into it....
Needless to say, I run a 4.6L now, and couldn't be happier..
fwiw-
Craig |
Anonymous
| | Posted on Wednesday, June 12, 2002 - 08:12 pm: |
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OK if a NorthStar can be fitted to a Fiero not a real challange to stuff one in a Disco.
Nothing a large wallet and good maching shop cant solve |
p m
| | Posted on Wednesday, June 12, 2002 - 08:22 pm: |
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like a 454 in a LUV?
peter |
Anonymous
| | Posted on Wednesday, June 12, 2002 - 08:27 pm: |
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Yep |
Blue (Bluegill)
| | Posted on Wednesday, June 12, 2002 - 08:40 pm: |
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shit, if your wallet is large enough, you could stuff the whole damn fiero in the engine bay of the Disco |
p m
| | Posted on Wednesday, June 12, 2002 - 08:44 pm: |
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Fiero's not big enough to be a portable RTI ramp...
(just checked on the way to work)
peter |
Dee
| | Posted on Wednesday, June 12, 2002 - 09:11 pm: |
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Hell PM a ramp, shit your lucky your Jeep can stay running on flat ground.
It still amazes me they let you drive that around in La Jolla watch out for flying Lates |
p m
| | Posted on Wednesday, June 12, 2002 - 09:46 pm: |
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reminds me of the movie "Black Dog" with Patrick Swayze...
(after a pothole)
- what was it?
- a Mazda...
peter |
jim
| | Posted on Wednesday, June 12, 2002 - 10:00 pm: |
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I know that there is no replacement for displacement. I would personally love to put in a 5.2 from RPI or a 4.6 but I do have a supercharged disco with some additional mods to the motor and ecu and borla exhaust k&n filter and it still runs strong going on 90k since the supercharger and still as strong as the day I put it on. More pull that a RR 4.6 HSE. When this motor goes I will be going for the 5.2 in my D1 and make it my trail rig. Just waiting for the 2003 Disco to come out for a second Disco |
Mel A. (Krawlrovr)
| | Posted on Wednesday, June 12, 2002 - 10:12 pm: |
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How about a Chevy 350 small block? Here's a pic of one in a D-90.
 |
M. K. Watson (Lrover94)
| | Posted on Wednesday, June 12, 2002 - 10:50 pm: |
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i believe that in the 80's or there about there was a chev s10 truck that had the buick v6 turbo motor in it, i believe it was called typhon or something like that. it was a limited run truck but was wickedly fast. also as a note building a turbo motor that will last requires alot more engineering than just straping one on. ford did some expermenting with the four banger in a mustang. it was fast but a gernade. this straping on of a blower continued on with chrysler and the mitzy motors they used. good idea but some poor thinking led to alot of air and fuel in a moderate compression motor. to get the thing to work they cut the piston face creating and ashtray type piston that would allow for the increase of cylinder pressure as the turbo spooled up. i have a real turbo motor sitting in my drive (hyundai scoupe turbo) it works really well, if tuned correctly. the lag is margainal and when it hits it screams. when its sick (like it is now) the dished pistons leave you with the thought of getting out and running beside it to get anywhere. my thought if it is a typical NAS disco it will be using an auto T R A N N Y (manuals are a bit easier to use with turbo) and the lag would be more of a problem than the gain, esp. if dish the pistons are used to get them to work right with the turbo pressure. in a diesel its not a big deal due to its ability to develop awesome torque from idle. you could beat the lag by fogging some NOX into the turbo air inlet but thats some scary shit. too much can go wrong with rush you will get from horseys running amuck. anyways i have learned to live with what i got and take advantage of what LR put into its design.
IMHO
mike w |
Eric
| | Posted on Thursday, June 13, 2002 - 12:49 am: |
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Miller cycle? Wow that would be cool. Hey as long as we are dreaming what about a small turbine engine? Only 26% fuel converson efficiency but a nice high power to weight ratio.
I tend to agree with two things, one that LR has done a fair job supplying a reliable engine with more than enough power for the typical crawl, and two; that anything which reduces engine life changes the essential purpose of the Discovery.
But.... some of us can't leave well enough alone. Yeah, turbo trucks are 99% diesel, yeah lag could bump at the wrong moment, and yeah a turbo is not just slapped on like a new air filter.
But turbos do well with a heavy load and a narrow rpm range, like a heavy vehicle with a slow turning motor. When is the Disco ever not under load? Well except for driving downhill?
A small turbo with a wastegate on the exhaust that kicks in around 1000rpm and then bypasses at 5psi boost and then putters out around 4000 rpm would not have the kind of lag that a porsche 911T has. The Porsche turbo just starts to kick in around 3500rpm and yeah when it does you run into the car in front of you.
Remember the Gale Banks 454 boat motors? Gobs of torque at the 1800 to 2800rpm range, aircraft piston motors peak at 2500rpm? It is not far fetched at all.
The turbo also has increased heat recovery which should improve milage if sized correctly. A roots or centrifugal engine driven blower would only make milage worse.
Eric |
cooper
| | Posted on Thursday, June 13, 2002 - 01:22 am: |
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I took the engine out of my Rover all together. Yeah... and then i cut the bottom out and I just use my feet to pedal. It works great and there's less weight. |
Norm
| | Posted on Thursday, June 13, 2002 - 03:13 am: |
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Mel --
Just curious...how much time and money did it cost to get that 350 Chevy motor to work in the Defender? Is that fuel injected? What transmission are you using?
Norm |
Kyle
| | Posted on Thursday, June 13, 2002 - 08:37 am: |
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HE shoulda saved the money on that pretty air filer Norm. The foam in those Eldelbrock airfilers comes apart and gets into the air bleeds on the carb. Its a real nice experience...
Kyle |
muskyman
| | Posted on Thursday, June 13, 2002 - 09:29 am: |
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eric,
you make some very valid points about 100% dutycycle turbo usage
the world automobile industry has always flown in the face of industrial/commercial standards and pushed the dutycycle way to far,and Turbos are a perfect example
almost every Turbo car ever built was built pushing the performance envelope for that engine to within 5 to 10% of the meltdown point.
where in commercial use such as boats ,trucks,heavy equipment, airplanes...ect ect the engines are set up to run at only about 40% to 50% of there Potential.
so if you really wanted a gas turbo Disco there would be two options
A "strapped on" afterthought maybe intercooled low boast but still hard on the stock motor kinda thing that needs constant attention to spark plugs and oil to keep it running right. And at the low boast maybe makes 18% more power.
or
a redesigned from the start engine that has forged low compression pistons ,o-ringed heads,and a pre/post oil system , a new fuel system .this lower compression motor makes less power off boast then stock giving you less off idle torque. once on full boast it makes about the same as the stock motor if you govern it to a true Comercial dutycycle that guarentees it a very long life. it would get better MPG then stock but not by much.
option #2 sounds expensive |
hendrik
| | Posted on Thursday, June 13, 2002 - 10:44 am: |
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If someone would like some literature on that topic:
"Tuning the Rover V8 engine" by David Hardcastle.
see:
http://www.amazon.com/exec/obidos/ASIN/0854299335/qid%3D1023979259/102-2887854-7382539
It also covers nitrous oxide injection on turbo engines.
if only I could afford a 4.6
(and if only I could afford to get enough fuel for the present 3.9 ....)
Hendrik |
Eric
| | Posted on Saturday, June 15, 2002 - 01:23 pm: |
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Muskyman,
I agree with you. So I guess the final analysis is that any improvement to the stock engine that makes more power is going to reduce the engine and drivetrain life.
Eric |
p m
| | Posted on Saturday, June 15, 2002 - 02:21 pm: |
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lol Eric,
quite a revelation, that is!
peter |
MR (Keebler)
| | Posted on Saturday, June 15, 2002 - 04:39 pm: |
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The weakest link in the chain always breaks. If you modify one part, then the next one down the line becomes "The Weakest Link." A MILD increase may not be bad, but how deep are your pockets? It can get REAL expensive REAL fast! Like Jason said early in the thread, "how fast do you wanna go?"
Just my .02
Oh, M.K. you are correct. Chevy/GMC Syclone (truck) and Typhoon (Blazer/SUV) were turbo'd
4.3 liter V6's. The pickup was capable of 4.3-second 0-60 times. Hella fast, AWD (40-60 split),
all kinds of factory go-fast goodies! One even holds the Bonneville record for a production truck(203 MPH, I believe). But everything on them was beefed up to handle the power......
Matt |
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