donut
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| posted on 23/1/06 at 08:07 AM |
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V8 7's how do they perform?
Going to be a long time until i can go V8 but it's something i really want to do at some stage so have kinda decided to start collecting bits as
they pop up. Before i do though i would like to know from those who have them how they drive. Do they wheel spin all the time, are they particularly
scary or very docile.
Any advice would be gratefully received.
[img][/img]
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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smart51
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| posted on 23/1/06 at 08:18 AM |
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The Westfield Seight has a very similar 0-60 time quoted for it as the hayabusa engined car. Similar performance then, except the V8 has a higher top
speed.
I used to know someone with an Seight. He said it would wheelspin in the dry in all 6 gears. If you pushed him, he would reduce it to the first 4
gears. He had the shift light permenantly set to 4000 as it was too scary to go over that. It was a nice car though.
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Bouldy
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| posted on 23/1/06 at 09:10 AM |
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Andy as soon as i get mine back i will let you know.
we will have to meet up either at a show or somewhere else so you can have a drive and try it for yourself.
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Scotty
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| posted on 23/1/06 at 09:23 AM |
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mmmmmm
interesting question
i wanted the sound of a v8
not overly interested on the speed issue thing (really!) as i have a half decent tin top
but will watch this post
PLEASE NOTE! All comments made by this person are to be considered "Tongue in Cheek" and are not meant to be taken seriously in any way - so there!
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smart51
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| posted on 23/1/06 at 09:30 AM |
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You don't have to have power to have a V8. Rover V8s came is various sizes from 2.5 to 3.9 litres (I think). Some American V8s produce
barely 150 BHP, something a goos 2 litre I4 European engine can manage. Even with a small V8, you get the sound that you're looking for.
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donut
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| posted on 23/1/06 at 09:49 AM |
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Sorry i should have put more info on the 1st post. i'm not interested in a fire breathing monster engine, a std 130-150bhp engine will be enough
as there is enough torque to pull a forest down! [img][/img]It's the noise i really want and the torque. It's the torque that worries me the
most i guess which i why people say they wheelspin so freely. I have an LSD and larger tyres on the rear shouldn't be a problem. Just cos i have
the power doesn't mean i have to use it i guess.
Paul: I'll take you up on your offer of a drive!!! [img][/img]
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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nick205
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| posted on 23/1/06 at 09:53 AM |
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surely we're overdue a discussion on power vs. torque here aren't we 
...by the way Andy, why don't you just give in and build yourself a Cobra kit? I'm sure you can still frequent these pages  although
people might ask why you run th MK Owner's Club!!!
Cheers
Nick
...see I told you the torque was important
[Edited on 23/1/06 by nick205]
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andyw7de
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| posted on 23/1/06 at 10:00 AM |
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I used to have a 3.9 V8 Striker that was only used for the track.
It sounded awesome and had great low down torque, but without serious work on the top end it would rev limit itself at about 4500 / 5000 rpm due to
the hydraulic tappets.
It aso ate clutches, i ran a standard SD1 5 speed gearbox coupled to a 3.0 capri LSD with 10" soft compound slicks.
Im currently building a GTS W7DE and did consider the V8 again but have gone for a 16v XE. more power for less money
Will miss that noise though
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donut
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| posted on 23/1/06 at 10:04 AM |
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I did go down the Cobra route but they do cost too much to build. I decided 2 things.
1st: The Sumo although a decent car is not the best likeness for the Cobra and if i'm honest, if i did build a Cobra i would want it to be a
decent one like AK, GD, Crendon, Ram etc and they really do cost!! Plus i would rather not build again!
2nd: Someone said once, "never meet your idols" cos they are never what you think they are going to be. I love the Cobra and my heart skips
a beat every time i see one thundering past but owning one......dunno. Would it ruin the mistique of the car? I think it might but i will never know
for sure unless i buy/build one.
As for power v's torque....who cares, it's the rumble in the jungle that get's me going!! [img][/img]
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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NS Dev
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| posted on 23/1/06 at 11:44 AM |
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Just found my answer to this question that I posted previously (a long time ago!)
"The fact is that you need an engine with a power/torque curve which approximately matches the ability of the wheels to put that torque on the
road.
Having loads of torque at low revs is of no practical advantage in a seven because the laws of physics (and therefore the traction that can be
obtained) mean that the maximum torque that can be transmitted to the road via the driven wheels is very low.
As wheel rpm increases, you can transmit progressively more power (same TORQUE!) through the driven wheels.
What you really need is an engine with a very wide power/torque band and a very big rev range.....................but then that's what we are
all trying to achieve!!
As was pointed out, all the reasonably powerful engines can spin the wheels of a 7 with relative ease, the difference is that most of them have bigger
rev ranges and their torque tends to fall from the bottom of the power band to the top, hence whilst accellerating, the likelihood of breaking
traction decreases with speed through each gear.
Here the v8 becomes a problem as it's rev range (for the cheaper end of the market!) is limited, and in each gear the torque tends to build to a
peak and then fall off again (remember that for any engine, the power and torque curves (in bhp and ftlb) cross at 5250 rpm, how does that compare to
peak rpm, if it's near the limiter then all your driving will be on the increasing part of the torque curve!!)
The next problem is that with that limited rev range, the time until the next gear is short, and then the problem is repeated all over again!!!
Now contrast that to a revvy 4 cyl or 6 cyl engine (I know this is not scientifically correct, but I am referring to commonly available engines, not
the "ideal world"!) where (for my Vauxhall XE for example) the working rev range is basically 5000rpm to 7500rpm. Torque peaks at around
5000rpm (as it does for most roughly square bore-stroke 4 cyl engines) and then falls all the way to 7500rpm, but the power peaks at 6500rpm ish. This
means that if you can get away from a standing start fairly cleanly, traction should increase through the rev range, whereas with the v8 it will
actually decrease.
Horses for courses though..............v8's sound awesome!!!!!!!!!"
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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MikeR
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| posted on 23/1/06 at 12:08 PM |
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but a thraped v6 also sounds pretty good as well!
(used to love the sound of mates v6 mondeo when it was reved - sounded very angry!)
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smart51
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| posted on 23/1/06 at 12:24 PM |
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I have to say that there is a lot of credibility in the sentiment expressed here that speed is not the important thing but the sound of the engine.
It is not a bad thing to want to cruise around in an interesting car listening to the low down burble of a short shifted V8. If that is what the car
is for then talk of torque curves and power is meaningless. It would be a different story if you were building a road rocket but not everyone wants
the same thing from there car
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NS Dev
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| posted on 23/1/06 at 01:10 PM |
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very true! hence my last line above!!!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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smart51
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| posted on 23/1/06 at 01:16 PM |
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Actually, NSDev, from reading your post about area under the torque curve and wider torque curves are better, I was expecting you to recommend a bike
engine!
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froggy
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| posted on 23/1/06 at 01:39 PM |
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a lot of problems using rover lumps stems from the low gearing they end up with as the vittese sdi had a 2.8 diff on 60 series 15" wheels
compared with most sevens using 3.62 diff or lower, hence why a lot of dax v8,s run 17" wheels to compensate. il have the same trouble with my
car but with 4wd should have good traction even if its geared too low. on the plus side you dont have to fret about biulding the car superlight as a
bit of lard wont affect the performance one bit
in all honesty its the noise that does it for me, its one of those engines that sounds wether your pottering about or giving it a shoeing!
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NS Dev
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| posted on 23/1/06 at 01:41 PM |
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Heh heh!!!
No, I have considered it but it's still not ideal!
If you want to know my ideal engine for a seven then here it is!:
can't get a bigger pic but it is an Opel-Cosworth KF V6. 2.5 litre but absolutely miniscule in size, weighs in at 90kg all up which is a nice
sort of weight for a 400+ hp engine. (on pneumatic valve springs they were pushing 500hp from 2.5 litres at 14,000rpm but that was not on pump
fuel!!!)
Now with wire valve springs and a sensible low rev limit of only 11,000 revs they still push out around 400hp with a nice torque spread as well.!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Johnmor
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| posted on 23/1/06 at 02:04 PM |
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Power vs Torque
I am quite keen to find out peoples assessment of this type of engine in a locost as I am fitting an Alfa v6 in a Viento.
The alfa has approx 190 BHP and about 190lbs torque, but , having a over square stroke is very free revving.
I know the Rover has more Torque at low revs, but in standard form has a lot less bhp and is not a free revving as the Alfa.
The engine is through a type 9 and then a 3.62 LSD. I am hoping for long gears as I have driven An Alfa 24v and it revs to over 7000 easy. This allows
the driver to use the higher gears earlier and then it pulls all the way.
The alfa 164 will slip into 3rd at 20mph and then go all the way to over 100mph with continous accelaration.
I dont want a skittish tail happy car just a flexible, strong pulling, howling,country road, smile enducing machine, that all.
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akumabito
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| posted on 23/1/06 at 02:11 PM |
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BMW V8... got the noise, got the power. Relatively cheap too...
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donut
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| posted on 23/1/06 at 02:38 PM |
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quote:
I have to say that there is a lot of credibility in the sentiment expressed here that speed is not the important thing but the sound of the engine. It
is not a bad thing to want to cruise around in an interesting car listening to the low down burble of a short shifted V8. If that is what the car is
for then talk of torque curves and power is meaningless. It would be a different story if you were building a road rocket but not everyone wants the
same thing from there car
This is exactly what i'm thinking. Couldn't have put it better myself.
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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froggy
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| posted on 23/1/06 at 03:27 PM |
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its unlikely that you would buy an early rover engine now as most sd1 ended up as donors for kits and hot rods. a early nineties range rover or disco
would be the donor nowadays and from 94 the engine improved a huge amount and a stock 3.9 will give gwtting on for 200 at the flywheel. its popularity
is more to do with its longevity than design as its got its faults with poor oil system and main bearing location on the pre 1990 engines but its
well supported for parts and performance stuff .as a road car engine its great but i wish it would rev a bit better too
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donut
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| posted on 23/1/06 at 03:38 PM |
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When are we going to see some pics of your monster then froggy?
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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froggy
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| posted on 23/1/06 at 03:53 PM |
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how do you get them onto the screen? ive got some pics of my bec kitten in the archive but no clue how to set one as my avatar. send me an email and i
can send some but im struggling to put them on here!.id get more done if i wasnt on here so much ive put my weber set up on ebay and bought r1
carbs after seeing rwd kurts car. ive built a coulpe of kittens before ,one crossflow and then a fiat twink, this one will have a good start with
martins chassis under it. ive still got that spare engine you know
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donut
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| posted on 23/1/06 at 04:01 PM |
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U2U sent [img][/img]
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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Agriv8
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| posted on 23/1/06 at 05:23 PM |
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My tuppenth worth.
Regarding the tourque yup baggs of it, too much to be honest, an engine that can shift 2 tone of range rover up a 1 in 4 grassy bank is going to light
up the rear wheels of a seven.
This is my excuse for pilling on a few pounds over christmas as I need a the rear end weight.
As froggy points out a lot of the DAX boys run 17s and 3.14lsd diff on sticky 225 / 245's on the rear ( thus the rather expensive image wheels
to sit them on ). one with 330 bhp.
The other option is be cautious of the loud peddal ( roundabouts while wet especially ). Dailly driver is Passat TDI so low down grunt is what I am
used to.
but as people point out I am after the tail happy v8 burble.
Agriv8
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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mark chandler
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| posted on 23/1/06 at 05:54 PM |
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Rover V8's tend to feel lazy due to the standard cams, the are suited to heavy cars/landrovers etc.
stick in a hybrid 218 cam and it will rev freely to 6000 rpm.
I,ve go a 4.6 under my bench, with a hybrid 228 cam, it revs madly and pushes out around 300 bhp but I am building a blade engined locost because in
theory it will be just as fast but handle as well !
If you do go rover V8, try and buy a late 3.9 classic with serpentine front end, much better oil pump.
Avoid early p6 engines, rope seals and as most donors are range rover elso ensure its 9.35:1 comp ratio (number stamped on block near the
dipstick).
Regards Mark
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