Hi all

Now at the final planing stages of my locost which is based on the Haynes Roadster book and need to make an engine choice.

I've got the opportunity for a Brand new 2.0 zetec or a slightly used V8.

I think I'd feel more confident with the zetec installation however the appeal of the V8 is very strong.

What do people reckon regarding the choice and the problems with fitting either.

Cheers
PJ

The bigger question is will the V8 fit in the roadster?

Also depends what you want to use the car for and what sort of driving characteristics you want as well.

David

The car will be a road car and I like the idea of the extra power.

The V8 should fit without too much modification but it might be too much hassle for the extra power gained.

It probably depends on how much money you have available to spend on each engine, as power wise there may not be much difference between the two.
And as David says how easy will it be to get the V8 into the roadster

Cheers

Alex

I had a 3.9 V8 powered Robin Hood for 4 years - purely from the driving point of view and the fun the noise the power and the torque -- V8 100%

A

V8s have been fitted into book locosts, so the 2" wider (IIRC) Haynes Roadster shouldn't cause too much of a problem.

Other than the size difference, I don't think the V8 should be any more complex to install than a Zetec. They are quite simple engines when it comes down to it.

Some say that the V8 torque and weight don't align with the Seven philosophy, but screw that - my philosophy is that I wanted a V8 so that's what I'm building.

Scutter is building a Haynes book car with a Rover V8 lump....

V8 noise is always good I think....

cheers guys always looking for that bit mor power and noise!

How about matching the V8 up to the Type 9 box? Will this work or will I have to find a totally different box?

my Hood was mated to a type 9 - had a purpose made bell housing

One major thing to remember is cost with the V8

Remember you need 2 exhaust systems, which could be very expensive (best part of £800-1000) unless you can make them yourself of course, then theres no issue.

Why not use the proper box for the job, the T9 wont last all that long if you are a sprited driver, not with the torque from the V8. I think the LT77 box is the one to go for.

Also bear in mind the added cost of fitting something like a 7.5" cossie diff at the back, rather than the std 7" one again to deal with the torque and power.

Just my opinion.

David

I would check the dimensions of the V8 and work out how/if it will fit. Ive built a chassis that is 4 inches wider than the standard Locost for mine and the V8 only just fits properly. You have to take into account both the vertical and horizontal position as it is obviously desirable to get the engine as low and far back as poss.

Saying that, if it will fit ok I would definitely go for fitting the Rover V8!

The 7" diff should be up to the job, i thought they were capable of something like 250lb ft, but not nessecarily for years and years.

Oh, and for your info I have fitted mine to an LT77 gearbox from a Rover SD1 Vitesse (Twin Plenum) and also used the rear axle from the Rover SD1. It has not been expensive at all (sofar!).

rover v8 is all alloy, zetec is cast iron - the weight difference is not that huge.

rover v8 parts are cheaper than zetec.

how will you fuel v8 - carbs or efi?

a 2.0 zetec with a good EFI system can make as much power as a basic RV8. It will be lighter too. It will be a cheaper install (only 1 exhaust) and will leave plenty of room for the steering column.

Because the zetec's power will be delivered at a higher engine speed, the torque will be spread over a wider rev range, making the car more drivable and the power more tractable. I'd guess that it would use a lot less fuel too.

The lighter weight will improve the handling and the braking.

The V8 makes the V8 noise that some people like. If tuned, it can make more power than the zetec; look at TVRs with the RV8.

for fuel I was thinking Carbs.....

At the moment it seems like 6 of one and half a dozen of the other...

Zetec looks cheaper to start with but the V8 runs close.....

mine used a 4 barrel Holley and with Mallory electrics, lightened and balanced and well set up produced 248bhp at the wheels

V8.... go for it.. Chevy 5.7 or an old Ford big block.

No substitute for cubes

what weight does the chevy come in at?

Isn't this taking it just a bit too far?

Sounds great if it'll work though!

There's no way, even a small block chevy, will fit in a book or roadster chassis.

You would need at least a +442 chassis, or something a similar size to the dax rush.

What engine YOU choose depends soley on your budget, what YOU want to use the car for, and what driving style YOU prefer. Simple as that. Anything can be done.

[Edited on 18/5/07 by flak monkey]

Thanks flakmonkey!

Started to spiral out of reality there!

The dry weight of a 3.5litre Rover V8 is only 170kgs. I believe (but stand to be corrected?!) that this is lighter than a 2.0 Pinto, I do not know how this compares to a 2.0 Zetec.

Well if you need convincing...

quote:

---

Originally posted by drlloyd
The dry weight of a 3.5litre Rover V8 is only 170kgs. I believe (but stand to be corrected?!) that this is lighter than a 2.0 Pinto, I do not know how this compares to a 2.0 Zetec.

---

quote:

---

Originally posted by flak monkey
There's no way, even a small block chevy, will fit in a book or roadster chassis.

---

PS. Here's a picture of my V8 in situ in my +4, which is also an inch higher than the original book chassis. There's plenty of room, so I'm sure it would be doable in a chassis only 2" narrower.


Wheels on for the first time

No contest.
V8
........If it fits.

V8 it you can get one for good money.

chevy V8 would be way to heavy tho it isnt really all that big, we have one in are boat

but since its a RV8 which isnt that heavy go for it i say

[Edited on 18/5/07 by goodall]

Thanks guys you've all been a lot of help.

Think it's gonna be the V8 just gotta check on box and dif and I'm away.

Hopefully there won't be many stupid questions during my build

Cheers
PJ

quote:

---

Originally posted by jobsagooden
Think it's gonna be the V8 just gotta check on box and dif and I'm away.

---

Have to throw this one into the mix.

How about chevy LS1 more compact and ally and 350 BHP out of the crate.
Just not locost but could be a substantial saving over tuning a Rover motor past 250 BHP!!!

I've seen this motor up close and its perfect.

Just a small question.

Has anybody thought of using a Jag back end as opposed to the sierra IRS.

Or has someone already done it

was some not that long ago on here i think that was converting to a jag rear end

Reason I asked is I was told that the Jag rear is good for up to 500 BHP

quote:

---

Originally posted by Blakey_boy
Reason I asked is I was told that the Jag rear is good for up to 500 BHP

---

Having posted this thread a couple of days ago I was thinking of going with the V8.

However having done some more research into power to weight etc I'm leaning back towards the zetec. Initially the actual engine is gonna cost more as it's a new unit but cuts out all the hassle of finding a new box and diff and overall the car will be a lighter easier build.

Just shows it always helps to plan ahead!

Have you thought about an XE? Cost of fitting is similar to a Zetec (if starting from scratch) and the power is much better as standard (NS Dev got around 200bhp out of the box on standard cams and head IIRC, Zetec needs cams and head work to get there)

Alternative a Duratec is a very nice engine for more money, similar power as the XE, but all aluminium.

[Edited on 22/5/07 by iank]

quote:

---

Originally posted by goodall
was some not that long ago on here i think that was converting to a jag rear end

---