The V8 Owners Forum -

Hi,

I've been lurking about on this forum for a while although very rarely post. I drive a '78 ford capri with a 4.2L rover v8 running fuel injection. I've recently spent a fair bit of money getting the car on the road to a point where I can go out and drive it without any problems and it all just works (which makes a change). I've had an OMEX 710 engine management system fitted with a view that I can now put in any V8 I want and can get it re mapped.

There are a number of other things I need to do to the car in the mean time such as fuel cell, rear brakes, a few suspension tweaks etc but I want to put together a plan for the engine. At the moment its a totally standard 4.2l V8 out of a range rover LSE with about 80,000 miles on it. The only difference being the ECU, air filter and pretty crappy 4 branch exhausts. These are strangling it a fair bit (they were glowing bright red when it was on the dyno when any load was put on it) and its currently only 213bhp and 245 lb/ft torque. New headers are definitely needed!

So, what I want is much more power. Somewhere in the region of 320+bhp.

Anyway, I was thinking of whether to get a re built performance rover v8 or go for something totally different. The trouble is the amount of work and price. I thought a BMW M5 engine and gearbox (5.0l V8) would be a good one to go for but it'll be £4000 for it and then there will be a massive amount of work to get it all to go in. A ford 32v V8 would also be nice, less power, less expensive, but equally as much work to try and fit. Obviously, doing these conversions will also require completely new ancilleries, starter motor, engine mounts, exhausts, radiator etc and not to mention I'll probably have to modify the sump and cross member to get it to go in.

The rover option keeps coming back around due to the fact it would be a straight swap and I'd barely have to change anything. (Back axle will need beefing up whatever I do!)

So, the next question, do I tune my current engine and spend thousands and thousands and possibly not get anywhere (I have never built an engine from scratch before) or just go for a fully built engine. I like the sound of this idea, a 5.0l 350bhp monster would be perfect in theory, but that does seem like a lot for a RV8. Would an engine like that actually have any bottom end or would it be so highly strung that it would be a pain to drive sensibly.

There seem to be so many places that do rover v8 rebuilds and I've heard the names come up all the time, but where is the best place to get a fully built engine? V8 developments? Rpi? John Eales?

Anyway, let me know your thoughts, I'm at the very very early stages of making plans and am open to discussion!

Hi

The 4.2 is basically a good engine. The cranks can be a little fragile but on the whole you could build for 350bhp with your current setup if you go forced induction.

You'll need the heads sorted, forged pistons, uprated rods and a decent cam.

Even a 5.0 Rover will struggle to make 350 and to get anywhere near that figure you're into some serious expenditure.

That's a starter for you.....sure someone will drop in and try to convince you to spend £5k on a set of wild heads and build a 5.0

>300BHP is going to cost serious money with a Rover, but as you say it's an easy fit.

What about one of the Chevy LS engines, come in a crate, good aftermarket support?

Chris.

Hi
There are a fair few Ford mod engines on E-bay at the moment at very reasonable prices, 2, 3 and 4 valve head versions, 225 bhp up, the 4 valve jobbies seem to do 260 bhp and over, and take a supercharger very well. Quite honestly when a 4 valve head ford mod engine with a 5 speed box and all ancilleries is up for a buy it now of £1500 with test hours on a dyno it is a bargin and you would probably have change left after selling your rover and buying the Mod.
Best regards
Mike

I agree with what you are saying. Professionally I am an engineer working in motorsport, and what I want is a 32v V8 running with variable valve timing, roller barrel throttle bodies, etc etc. However, the cost and time available is the problem. If I go for the 'high spec' rover engine it will cost a fortune, whereas if I go for a 32v modern engine it will be equally as expensive due to the cost of all the modifications required to fit the new engine. Obviously the newer engine would allow much more scope for further tuning, but would negate all of the work I've already done.

It wouldn't make sense to fit a chevy engine as in my opinion they are no better than the rover.... pushrod, 2 valves per cylinder etc. If I was going to go for this then I'd just go for the BMW engine! What I want to do is go for the more advanced, modern engine, but am held back by what I've already done, the cost, time and expertise of doing it.

what manifolds you using mate?

"It wouldn't make sense to fit a chevy engine as in my opinion they are no better than the rover.... pushrod, 2 valves per cylinder etc. If I was going to go for this then I'd just go for the BMW engine! What I want to do is go for the more advanced, modern engine, but am held back by what I've already done, the cost, time and expertise of doing it."

personally I wouldn't agree with you here, a rover struggles to get 75 bhp/ litre without power adders, it just has never had the development time and aftermarket investment put into it. The SBC is the most produced engine ever and the aftermarket investment in it's development vastly out paces any other engine ever,(just look at the number of cams available from the comp cams catalog) , the result is that a 90+ bhp/litre road engine can be built on a very reasonable budget by anyone prepared to do the research for a very reasonable budget and if you want you can go to a 7.5 litre and 100K plus motor while spending less than it costs to build a 5 litre rover that needs a compleet rebuild every 40k the two engines are very different beasts. Yes I am biased but that is how things are.
The LS series are the ultimate result of all this development plus another 15 years of the same level of investment by the aftermarket and quite frankly leave every one else in the shade cheep real big power in an engine package an amature can develope themselves, have you costed a set of aftermarket cams for a BMW V8?
As for the ford Mod engine, it has 4 valve sophistication if that is what you want but at a price for a whole new engine of the machining work for the beamer.
an example
http://cgi.ebay.co.uk/FORD-4-6-V8-FOUR- ... 5ad1a93cd2
Bolt on £1500 of supercharger kit and you are looking at a 450-500 bhp motor with no other mods, get that out of anything european for the same money.
Mike

or buy a Buick 455

I fitted a small block chevy in my ford capri,although its the old iron block one its pushing out about 350 horsepower,it cost me under a £1000 to rebuild including engine block! When funds allow a set of performance heads will be going on which should get me around 400 horsepower.
Tuning parts for these are unlimited,millions of hot rodders cant be wrong!
Chevy v8s and Rover v8s are worlds apart in the real world,sorry.....

Sorry....I think I should have worded that a little better.

What I meant was that to fit the chevy would be as much work as fitting a 32v V8 and I would rather go with the more modern 32v V8. It is a much better engine than the rover without a doubt, I just meant in principle its still a pushrod engine and I'd rather go for overhead cams and 32v. The BMW M5 engine is 5.0l, 400bhp and possibly more with the cats removed. I wouldn't have to do any tuning work to get it to the power I want, but obviously there's all the work of getting it in.

Headers - I have no idea what they are or who made them (4 to 1) - they came with the car when I bought it. I noticed on the capri power forum you had some new ones done recently - could you recomend anyone?

mine are 4-1 and not had any probs with mine getting red at all mate.
never even got red on the rolling road,
mine are caprisport manifolds but they dont make them anymore.

supercharged 4.2 jag engine for £2750
http://cgi.ebay.co.uk/Jaguar-S-TYPE-R-4 ... 3ca83faf43

thev8kid wrote:mine are 4-1 and not had any probs with mine getting red at all mate.
never even got red on the rolling road,
mine are caprisport manifolds but they dont make them anymore.

I think the pipe diameters are just too small to be honest (they also clash with the steering coloumn which isn't good!) Its a pity CS don't make them any more, that would have been very useful!

Any suggestions for exhaust builders would be greatly appreciated.

The jag engine looks nice, just need to find a gearbox to go with it, or someone to make a belhousing to fit the T5 box I've already got.

Hi,

Just a thought, never heard of headers glowing red because they are too small or too restrictive. This is either fuel still burning in the header, ignition timing, rich mixture. Or its too lean and hence slow burning and excessively hot. It has to be a tuning issue and will be costing a fair amount of power. I would get an A/F meter on it and check timing first. Small or restrictive pipes may cost a little power but will not heat the headers to that extent.

Alan

We mapped it on the rolling road as I'm now running an OMEX 710 engine management system. Under full load its mapped to about 0.9 lambda which is about right for maximum power. I'm using wide band lambdas. The ignition timing was done by using a rough base map and then doing sweeps at wide open throttle for maximum power at different engine speeds. I'm pretty sure that the mapping is right, although might be worth another session at some point.

It makes sense that they heat up when restricted, a little like running fluid through a heat exchanger at a slower rate.