cheapest power to weight?

[Tight fart]

the rotary has been done before.

there ws one at a club sprint in or

around 1991!

[Paul Turner]

The Rotary referred to was pretty quick, live axle, Mazda 5 speed box, bloody horrid sound, smashing couple who owned it, Jim and ?, are you still out there?

 

Chris, the £3000 is my total spend including the engine which was the cheapest part.

 

Its exactly the same when fitting a K or VX, all the bits add up, when I priced the options the Zetec was the most cost effective plus it required no chassis or body mods. I am not going to enter the Ford v's K v's VX v's Bike argument as they are all Caterhams, drive and enjoy.

 

Paul

[Graham Perry]

I used to quite like the noise Jim Brook's car made. No other 7 sounded anything like it. I am keeping out of the cross-flow v K argument as I am contemplating either for my next engine, so would not wish to talk myself, into or out of either one

[edmandsd]

All logical stuff Oily - I suppose the proof's in the eating i.e. The performance on track.

[elie boone]

cdg,Revving a Rotary hard ? the old group B RX7 rallycars are in Belgium ( made by Warnbold ? )all tree of them and they where very fast even in the early nineties but i never heard them revving hard, i think that the rev. limit was 7500.

[Morls]

Hopefully I'll soon be in a position to say how much it costs to put a 'Blade engine in.

I'll be surprsed if the lot, (including a reverse gear), comes to as much as £3000.

 

I'm doing most of the work myself tho and paying someone's time would no-doubt add plenty.

 

I'm also looking forward to seeing whether these really are as impractical on the road as people (many of whom have no-doubt never driven one) keep telling me.

 

Most of the journo's opinions about road use mention the lack of screen, heater etc. (which would be common to many an R500), rather than any engine characteristics.

 

I still await the opion of someone who has driven both on road and track but have fingers crossed that it'll be worth all the effort.

 

So...keep the crossflow untill June and I'll tell you then.

 

Mark

[cdg]

Elie,

 

The race 13b based engines from WGT in Cheshire make nearly 300bhp and redline at 9500, although apparently they are safe to about 12000.Max torque is at about 7800 (so I'm told).

 

The uprated 13b road engines from Hurley redline at over 8000.

 

Sounds pretty high to me.

 

Chris.

[AMMO]

Tight Fart

 

I can recommend the Zetec. My lightly tuned 1800 has 184 bhp, is extremely docile at the bottom end and goes very well when provoked. I use it every day of the week, all year round. The whole conversion will cost you around £3,000.

 

An engine tuner friend who used to race a Crossflow said the best BHP he ever had was 188 bhp. That was with steel everything, forged pistons etc. Don't know what that would cost but is probably not cheap.

 

My Zetec makes around the same for much less cost and not an oil leak in sight. You could make even more with these engines. 100/110 bhp/litre is good place to stop before you need to start going to fancy steel parts and forged pistons.

 

Did a trackday at Snetterton yesterday and even two-up I don't think I need any more bhp (although I could do with some better brakes and some tuition).

 

Get in touch if you need and more info on Zetecs.

 

AMMO

 

Edited by - Ammo on 3 Apr 2002 08:24:30

[Peter Carmichael]

All logical stuff Oily - I suppose the proof's in the eating i.e. The performance on track.

 

No it isn't. There are too many variables for a track comparison to be anything other than a race - the combination of chassis, engine and driver that on the day achieve an advantage.

 

Oily's point is that if you hold all other things equal (chassis and driver amongst others), then the equation is down purely to how fat the power delivery is and that a 2 valver of equivalent peak power and capacity to a four valver is going to be peakier and therefore slower.

 

It might even be that the same chassis will be less than optimal for one engine or the other (weight distribution). The lighter engine gives you more chance of optimising to an overall superior solution.

 

As long as it's reliable and the power delivery manners are good, the lighter engine that has the fatter power delivery on the dyno will be the faster one in the car. To beat a 200BHP K, a crossflow would have to deliver significantly more than 200BHP peak.

[edmandsd]

We'll have to agree to differ then Peter.

 

8 valve engines are accepted as having a have stronger low down torque spread then 16 valvers and although the ultimate spread of torque may be greater than an 8 valve engine it doesn't necessarily make it faster around a track. Take the old Vecta Ford Racing series (Don't know what it's called now)where it was accepted that more powerful 16 valve engines would trounce the old 8 valvers lap times but they didn't and needed substantially more power than the 8 valvers before they did. If you don't want to use track racing as a comparison then let me know when a genuine 200hp k powered caterham runs a standing quarter mile time of under 12 seconds. Maybe i'm just massively underestimating the power I recorded with a crossflow but I don't think so.

 

A lot of people think that crossflow's are all or nothing in terms of their power delivery and a lot are to be honest, but this wasn't the design basis of my engine. In fact I fitted a large 4 into 1 manifold and gained another 9hp at the flywheel (208bhp in total) and the car was consistently slower over a standing quarter mile eventhough it moved the torque curve further up the rev range - more like a 16 valve engine.

[Peter Carmichael]

8 valve engines are accepted as having a have stronger low down torque spread then 16 valvers

 

It might be accepted by received wisdom but it just isn't true.

 

If you don't want to use track racing as a comparison then let me know when a genuine 200hp k powered caterham runs a standing quarter mile time of under 12 seconds.

Dave, what a perverse little man you are in constructively misconstruing my every word. Seems to me that a quarter mile falls into my definition of a race track with dependence on driver, chassis and luck on the day. My point is that the characteristics of an engine are measurable. So measure and be done. If you can get an inferior engine to power a car to a superior result then you are good at setting up the car and driving. It does nothing to tell you how much better you might be if you similarly optimised conditions for the superior engine.

 

We'll have to agree to differ then Peter

In doing so you prefer religion where I prefer science.

 

 

[cdg]

We kneel before thee Supreme Master.

 

We are not worthy. We are all perverse...

[elie boone]

Sience ? confused.gif There was an article in Classic&Sportscar about Downton. Little sience and a lot of feeling.

[edmandsd]

Seems you're always the first to sink to comments such as 'perverse little man' and to be honest I really don't think that's necessary Peter. Feel free to discuss this opinion with me in person at Curborough if you like but not via this media.

 

You're selective in your references and only refer to the straight line comparison not the circuit racing comparison.......funny that isn't it.

 

I'll stand by my non religious belief as it's based on what i've seen over the years.....in practice.

[elie boone]

Yeah, to much books

[westy]

peter, would not a peaky crossflow with x power and a 6 speed box,not be quicker than a not so peaky 16v with x power and a 4 speed.

All other things beinq equal.

 

Edited by - westy on 5 Apr 2002 19:23:54

[V7 SLR]

There's a lot of people who have xflows on this medium who are resorting to burying their heads in the ground in an attempt to further justifying their position. Fine. If you want to believe that a 35+ year old design is "superior" than a 1990's design then go ahead. Whilst I can understand Dave's perspective that he has witnessed quite astonishing performance of a xflow-powered car, if all things were equal and a K with exactly the same torque curve were placed in that car, it would go faster because it has less inertia.

 

Now, show me a set of xflow plots for an engine that peaks at 200bhp, as mine did recently, and I'll show you a K that has a similar peak, has a wider spread of power and will ultimately last longer... and cost less to boot (I'm not talking about mine in this case).

 

There simply isn't any logical reason for trying to eek out 200bhp from a xflow. Sure, you may have an emotive reason for holding onto such but don't try and justify it as a better choice.

[oilyhands]

I'm sure Peter's remarks werent meant to be insulting, once you've met him and bent his ear you'll realise that they are meant to be tongue in cheek, electronic communications rarely reflect the mood , tone and emotions required, even if you are feeling them as you type.

 

My feeling on the xflow vs K nothwithstanding all the wisdom previously aired is that if you want to stretch the xflow to 200BHP, you'll find it hard, the engine will be shortlived and you will have nowhere to go in terms of upgradebility.

 

A K series at 200BHP has a wealth of upgrade options available and can be put together in your garage on an almost stock bottom end. Once you've driven one you'll know its the better option. There are a couple of blatchatters who have xflow and K engined sevens. One in particular who has an 1800 xflow (165BHP) and a 180BHP 1600 K series car.. guess which one he prefers.

 

Oily

 

Edited by - oilyhands on 5 Apr 2002 22:08:26

[STEVE GILBERT]

I think a tuned xflow may well be a *superior* option given that Mr TF already has one fitted. I can see Daves point that good power can be made from this engine to give Mr TF what he is after, with a K an unlikely option.

Seems to me you need to know your budget and long term objectives then make a judgement after trying a few examples. To get to SLR quick is a tall order and spending a lump of money on a 13 year old car an interesting investment.

 

My bottom line recommendation is go 1.8litre Zetec on carbs and keep every single part to enable you to convert back, then you can flog the Zetec engine and all the parts that form the conversion should you decide to sell the car and pop in the xflow to make it std again.

[V7 SLR]

What are you two doing posting at this hour? Don't ya have families to talk to? wink.gif

[STEVE GILBERT]

Mine are in bed, bless em, that makes this the ONLY time, plus there is bugger all on telly tonight and the web needs surfing for trackday dates! And your excuse is?.....

[hugh]

i think people are missing the point,the cheapest way to more power was the question, the first point i would make is the k series are flavour of the month at the monent which therefore means they are expensive and hard to get second hand where on the other hand crossflows are viewed as old hat and not as sought after, i saw 2 all steel crossflows advertised for £1500 each in motoring news which in theory means you could have a rebuilt all steel crossflow lump in your engine bay giving 150-170 bhp for £3000 a k series must be bought along with new engine mountings ancilleries /sump electronic management system etc combined with a cat exaust add these up and the k series is not so attractive.

i must say the k series has more potential after being blown into the weeds at several sprints by mike bees 235bhp k series ps my car has a bitsa crossflow which i have for the following virtues

cheap to buy, cheap to fix, solid, reliable and a replacement engine won,t cost the earth when it goes bang.

[V7 SLR]

Oh, I've got a really sad story... came home with big headache, went to bed, now recovered and not tired, wife gone to bed, TV crap (agree with you entirely), V7 in garage in pieces for another 2 weeks so I can't go out for a play (although I've spent a half hour staring at it with a smile on my face), have recently read Chris Rees book and feel in need of Se7en-Therapy, hence the web.

 

Liked the Discovery program tonight about rocket failures over the past few decades. Very spectacular.

[hugh]

sorry just come in from the pub, ive lost the plot, forget a crossflow for slr power, try a cosworth bdg,(fits straight in) my mate has just built a new alloy block all steel 250-270 bhp engine only £12000! a fully dry sumped 240 bhp k series can,t be far behind.realistically only motorbike engines provide relatively cheap power.

[V7 SLR]

Someone else internetting at this hour too... wink.gif

 

A K can be bought dead cheap. I've recently seen a 1.6 for 40 quid. I'd have bought it but I'm hoping to move house and can't afford to clutter up the garage any more at this time. I know who bought it though, and may badger him after I've moved if he hasn't used it.

 

I agree that a Caterham sump's not so cheap, and the other ancilliaries to complete an installation in a crossflow Caterham may take you beyond your quote 3 grand despite the cheap purchase price of a K but there are people currently moving from wet sumped K's to dry sumps, so there will be a number of wet sumps available, although I personally think a K needs a dry sump to remain realiable (personal opinion though). Engine mountings can't be that expensive, and all chassis recently built (can't remember from when - it's in Chris Rees' book) are designed for all engine combinations.

 

If you really had 3 grand and wanted an upgrade I'm sure you have options other than an uprated crossflow, but it depends on how much trouble you want to go to. I'm one of those people who decides what I want and then goes out to find the money to do it. This means I sometimes have to wait a long time to get what I want whereas I may have chosen another route and arrived at my goal much quicker.

 

I loved my old crossflow. 135bhp (if you believe the figures) and a great noise and smell. In fact the garage hasn't smelled right since I moved to the injected K, but that could be solved by leaving a jar of petrol open in there. wink.gif

 

It might be an interesting excercise to cost up a conversion from a xflow to a standard K, and then an uprated K compared to your 3 grand for the uprated crossflow. At the end of the day you take your choice. If logic had anything to do with it, would you have bought a Se7en in the first place?

 

Answer: Yes, of course.