Some pics of my Disco :D

Don't like turbos at all, many have recommended turbos over blowers online but you won't see me with one!

Main reasons prefer small compact blower unit and cannot lose v8 engine note

And that's that!

Oh and whatever the weather you are welcome to these pistons mate

Oh kool cheers mate.
I assume its just a piston that sits higher in the bore?
The blocks are the same deck hight right?

what sort of charger you looking at? One that sits on the mani or one that sits elsewhere... forget the names.

Turbo talk now that's my kinda thing I have turboed my mini engine and did endless research on theis talking to tuners and the guy I got to build my short block is a real pro I was advised to keep around a cr of 8.2 for something that has power off boost and will come on to boost nice and easily much below that and you drop in to the realms of increased lag and "gutless" off boost the big key is matching the engine cr to size of the turbo compressor and exhaust wheels to and to the displacement of the engine if you get it right you end up
With an engine like I have in my mini come on boost at 2000 rpm hits full boost between 2500-2800 and pulls right through to 6000-7000 holding boost beautifully the worst thug people do is wack a huge turbo on and think it will produce loads of power it will but at what cost if you take a week to spool it up

Mark, the higher CR pistons simply have a shallower cup in the top

The outer lip of the piston is identical as far as i know and comes up to the top of the deck, just the cup determines the compression

The jaguar xkr 4.2 etc eaton m112 looks pretty ideal for the job, can up the pulley size to slow it dine which could work quite nicely

Would be bolted on top of the inlet mani using a home made plate

James, thanks for stopping in

Interesting you say about 8.2 CR, that's the sort of figure the vast majority are quoting

Similar thing to compressor and turbine sizing on a turbo is same as screw size and pulley size on a blower

I read this morning that a blower turning fairly slowly is rather more efficient than when it speeds up

However on a budget I don't really have that choice, only have options to alter the way boost is built using pulley sizing

Everyone selling rv8 pistons online states the 8.13 units are suited for FI

According to everything I have read zen's motor should be toast, or am I mistaken, I know he is building an SC rover but is his other motor a SC Lexus?

He says it's 10.5:1 @ 10psi

Fairly sure that would be melted if rover

It may be down to the fact that Toyota/Lexus are build VERY well and probly from quality matrials so can take the boost on that comp.. but 10 psi isn't all that much really.

I'd guess the modern engine design is the difference.

Jury is still out for me, only since swishing to zen have I been confused.

Better see how his current rover build runs though I guess!

I had a read of this... Interesting stuff.

Tuning the Rover V8

Also there was an interesting thread here... Turns in to hand bags at the end but some valid info and a nice pic of a tidy v8

http://www.landyzone.co.uk/lz/f42/3-9-4-2-4-6-a-82882.html

Thanks for the PM Dr Evil

Will read ^^^ when I have time

Cheers

Mr Noisy said:

Will read ^^^ when I have time

Cheers

Click to expand...

With the top one I just like his approach to it. It makes sense to me .... Not much does :hippie:

If you do go boosted.. new headers might be an idea, the headmans are good for the standard'ish RV8 but there a tad small once the power goes up.

Thanks mark

Guess they were designed for a 3.5 and that's that

However, id be keen to keep them to keep the low end better, don't need to make figures it needs to drive well!

Oh just reading some of the posts from Teflon about lightened flywheel.

I read or watched somewhere about the difference it makes, on a lighter car it can make a INSANELY HUGE difference... forget the figures, but its not what you expect!

But for a 4x4... well maybe not a good idea? not sure, as it makes going from standstill harder which you do a fair bit.

Mr Noisy said:

Thanks mark

Guess they were designed for a 3.5 and that's that

However, id be keen to keep them to keep the low end better, don't need to make figures it needs to drive well!

Click to expand...

I yea I feel that.

Where do you want the power?

The Inlet does suck also, is it the THOR which is a different design or GEMS? I forget which one.
Whichever it is, it offers more torque over the "normal" ones, but can again, due to the same reasons as the Headmans, restrict power up higher.

Not sure how this would be effected with boost mind you. but If I remember right, the tuning goes out the window somewhat as it becomes the less restrictive the better.

IF that is the case you can just remove the trumpets and port the existing manifold and plenum base out along with the heads.

10 psi is fairly lo boost a standard mini turbo engine is in the region on 6-8psi with a cr of 9.5(i think been a while since I checked) that's on verry very slightly dished pistons 10.5 and 10 psi seems high but if you have forged pistons real good inter cooler a really good map and are safe with the ignition advance then I don't see why not personally I don't no if I'd want to run it as it's probably close to the edge

I run in my mini fully forged engine conrods et 1293 engine with cr 8.2 lo boost is 8psi high is 17-21 running 17 I have 170bhp and 200lb torque and 21 I have 200bhp and even more curlies I'm running a t2 t28 hybrid t2 on the exhaust side meaning a nice fast spool up and a t28 snail and wheel on the inlet means lots of boost from little input as a stock t2 runs out of puff very early I'm good for at least 28psi from this setup if I really push it but I'm being safe with my setup
I recon iv got about 100-200rpm more lag than a stock t2 but far moor boost and perfectly stable.

As for turbo sizing there is an optimal speed range for the exhaust wheel to spin to create maximum boost on the inlet size too small and it will run out of puff ideally u need to have a turbo that cuts in early enough and runs out of puff just after ur peek rpm but that's an ideal world and pritty much impossible lol

discomark10 said:

Oh just reading some of the posts from Teflon about lightened flywheel.

I read or watched somewhere about the difference it makes, on a lighter car it can make a INSANELY HUGE difference... forget the figures, but its not what you expect!

But for a 4x4... well maybe not a good idea? not sure, as it makes going from standstill harder which you do a fair bit.

Click to expand...

Light fly nice for road but bad for off road, it stalls enough as it is!

Ran 14 seconds flat in my honda just with inlet mani, tube header and side pipe, light remap, quaife and alloy fly and cut slicks

Really proved how shedding weight and making grip where it matters made a difference, car was probably only making 200 horse

discomark10 said:

I yea I feel that.

Where do you want the power?

The Inlet does suck also, is it the THOR which is a different design or GEMS? I forget which one.
Whichever it is, it offers more torque over the "normal" ones, but can again, due to the same reasons as the Headmans, restrict power up higher.

Not sure how this would be effected with boost mind you. but If I remember right, the tuning goes out the window somewhat as it becomes the less restrictive the better.

IF that is the case you can just remove the trumpets and port the existing manifold and plenum base out along with the heads.

Click to expand...

Power increase would be good if linear throughout like an extra 50 horses across the board would be well noticed

Thor is the snakes one that is torquey but flat, gems is similar to Hotwire which is considered the best and is most modified.

Yes FI tuning does negate all aspects of NA, you simply want it in and out quick to make high end figures

However i feel that light boost in particular supercharging is more similar to NA as it is a helping hand and does not touch the exhaust

Ie putting fat headers on would increase potential BUT sacrifice low end just like it does NA

Rememver I'm not looking to fit big valve or ported heads so anything past the limits of the head is wasted money

I would like to run a little boost just to give the engine some purpose, ie effectively bolt on some horses but hopefully a good chunk of midrange torque

Tuning it will be interesting, the best way would be to get a knocksense MS kit rigged up and working, so that I can tune fuel and spark to my current AFR table which unless I am badly mistaken will mean it will drive just like a better version of it's current self, with fuel and spark adjusted to allow the big air pump on top to work properly

This of course will ofteb mean more fuel has to go in to keep the AFR the same otherwise combustion temps will be too high, ie melt pistons particularly I would think on cruise BUT with knock control it should be able to retard the spark to keep things in check

Lots of variables but should be fun to see it in motion

Once you've got your head round the basics of engine tuning it's not too bad to understand how it works

The beauty of MS and thus the ability to use Wideband and hopefully knock control will really come into it's own on this build

I mean tbh, if my current setup can't use knock control I will have to ship my ecu off to be modified, I think it is that important

Do you have EGT measuring capability, may be useful in tuning

I don't have EGT mate no

Although I have read about one or two builds using it

I would like to think AFR and knock should tell me what I need to know, on the basis that if the AFR is right and it's not knocking (you would be tuning to the limit regards lean and advance) then it should BE right!

Time will tell on that one though!

Mr Noisy said:

I don't have EGT mate no

Although I have read about one or two builds using it

I would like to think AFR and knock should tell me what I need to know, on the basis that if the AFR is right and it's not knocking (you would be tuning to the limit regards lean and advance) then it should BE right!

Time will tell on that one though!

Click to expand...

True. You could always use a laser temp gun to check if needs be but I shpuldnt think you'd melt pistons unless you're pushing crazy figures or ****e tuning