View Full Version : New Cobra Build. Which Engine - rover or ford?

14-05-01, 11:38 PM
I have recently started to build my self a cobra replica and have had great fun so far. I'm building an economical Sumo, and I am currently at the stage of choosing the Engine. 3 Months ago when I started I was going to use the 2 litre Pinto but I soon gave that up for a bad idea and got wrapped on the idea of the Rover 3.5 for which I have sourced an Engine builder who is able to provide an overhauled stage 2 Longblock with webber Carbs, piper cams and modified head for just over 2k which I guess is reasonable. I have recently however been thinking about putting a monster chevy in my little snake but before I get 2 wrapped up in the idea I thought it would be a good idea to ask the experts opinion. Would it be worth my while to invest in such a large engine for my Sierra based Sumo? I've read articles that say the Sumo frame, although it can support a ford small block can distort due to torque forces through the diff. Is this True? Would I be better of sticking to my original plan of a rover 3.5 and getting a chevy when/if I was to build a second Cobra? I know this is a dumb dumb question; would I see much of a performance difference? Does any one know good websites with stats? probably the most Important consideration would be the MPG, it would be nice to be able to afford to run my car : ) Would any one have stats on average conssumption for a rover 3.5 and chevy 5.7?

Suppose I was to keep the rover, as I understand it the Rover gearbox (LT77) is Hydrolic, An my footpedals arn't (Sierra). I have spent alot of time rubbing off the yucky black coat and polishing and alot more time making replica footrests to fit the pedal box I have - I know I should have read through the build manual before hand :( On the Video 'A car is born' it's mentioned that the chevy is also haudralic and requires an additional piece to accept the cable. Is it possible for a similar approch to be taken with the Rover?

All pointers eagerly received.

15-05-01, 10:31 AM
Re: clucth operation - Both are nominally hydraulic. But Pilgrim have a method of adapting them to match up with the sierra pedal box. On my rover, it just involved drilling the arm at the gearbox end to fit the cable, and making a retaining bracket. I beleive if you buy a new Chevy from Pilgrim then the mod is already done - but be careful about buying a new engine re: emission regs and SVA!

Pilgrim chassis is OK for standard Chevy, but I wouldnt put a heavily modified one in a Sierra based chassis. You will also need at least the 2 litre sierra diff, preferably one from either a cossie (LSD) or from the 2.9V6 car.

I have a rover because I got a complete one cheap from a GD owner - they're very light and reasonably economical on fuel. Didnt want a Chevy because i wouldnt be able to run it - I want to drive it to work in the summer! But I guess Chevy is the ultimate in performance. I'm sure others can comment on Chevy's better than me.

15-05-01, 11:12 AM
stick to the rover much easier and enough poke in it to keep you happy also they sound nice as well.Look at the RPI v8 site for prices on rover engines they are very good .

15-05-01, 01:24 PM
Yep, stick with the Rover is my advice too !. Love Chevys & Fords, but , the downsides are a lot more weight (even lugging the bits around the garage is a pain ) - the Rover based car is very well balanced front/rear when built around the Ford axle / gearboxes are hard to get 2nd hand / clutch release can be difficult to source parts for at a decent price. Also, when you decide to start tuning a Chevy / Ford, you'll need to make sure that the diff's up to the job.

If you look about, you should still be able to pick up a 3.5 SD1 motor with manual box - phone round & scour the free add papers ! - the firt 3.5 that went in my Sumo cost me 90 complete with 5-speed manual box & bell housing !.

I recon that anyone whos up to building a Cobra is easily capable of rebuilding a V8 too. I wouldn't recommend rebuilding the 'box at home as its usually just as cheap to get a specialist to do this for you. 2k sounds quite a lot actually - you should be able to build a really good 3.5 for around half this amount if you take your time sourcing the bits. When purchasing parts, always compare prices from RPi/Real Steel/Rimmer Bros & on occasion try your local motor factors (I found my SD1 water pump cheapest here).

If your down South, I know of at least three complete 3.5 engines / two dismantelled engines and a couple of gearboxes !


15-05-01, 04:06 PM
Thanks for the advice. I'm really impressed with the speedy response from people. I am some what in the unfortunate position of being 200 miles away from my garage, as I work in London during the week and spend my weekends in Devon (More accuratly in a garage in Devon }> ). I would be interested to know where you have noticed the gearboxes (I may also be interested in the engines as I have somewhat calmed down from the chevy idea). I travel up and down the A303 on Fri/Sun Evenings so a detour from my route shouldn't be too much bother.

I have another question for people. I have heard that it is possible to fit ford engine rocker covers to the Rover heads. if so, is this true to all rover heads or only a select few? The reason I ask is I would be insterested in putting the 'Cobra - powered by ford' etched rocker cover (I may tipex that bit out and put rover :) ). looking at photo's of the 2 it appears the bolt positioning is the same but can anyone confirm it form me...

I have also read a few of the other articles on this site re: lpg and am lucky enough to have a local garage that offers lpg. Does any one have any experience of fitting or having fitted an lpg kit to a rover engine? does the engine still rumble or does it sound more like a gas cooker? would I be able to patch my stove in when I'm out camping in the wilderness of Devon ( ;) )?

Dan 'Were all these nuts used before?' Man

David Large
15-05-01, 05:37 PM
I've got a 3500 old (P6) in my BRA 289 and unless you want a real flyer then this is quite adequate. Mine was hobsons choice anyway, when we built the car between 1985 and 1989 the chassis wouldn't take a small block yank engine. You have to be certain that all the running gear and suspension, brakes etc. are up to the weight and repetitive high speed braking. It's not just about power to go but also stopping and durability.
But,while on, is there anybody out there who has got lying about a timing pointer to fit the timing cover of a high compression P6 engine (I'm told by RPI that an SD1 bit will fit), mine has gone missing and having just replaced the distributor and stage 1 heads I need a pointer to set the timing accurately.
If anybody can help I'm going to be a happy bunny :-)

David Large
Silver Surfer with a 289

15-05-01, 09:24 PM
I've just got a Rover Vitesse engined AK on the road and boy am I having FUN. The car is v.fast through the gears but lacks torque in top gear, which is 30mph per 1000rpm, but bear in mind this is bog standard 100,000 miler,and not yet running right probably due to the less restrictive exhaust and air intake f****ing up the fueling. This will shortly be rectified with an Emerald M3D engine management system which I should get in a couple of weeks time. The rocker covers for the Rover are sold by a guy who advertises in Snake Torque. 2k for a rover engine seems a bit steep to me, I would shop around a bit. There is a company in Wolverhampton who sell complete engines out of write offs, they charge around 1400 for a complete 3.9, up to 3500 for a 4.5 TVR with all ancillaries.

welcome to the fold

15-05-01, 10:03 PM
Re "Cobra Powered by Ford" rocker covers for Rover V8s, John Hammond makes these and advertises regularly in Snake Torque.

Good luck with the rest of the build.

Nigel B

15-05-01, 11:56 PM
I've heard mention of snake torque several times on the site, But have no idea what it is. Is it a magazine or online site? can someone please enlighten me.


Dan 'Were all these nuts used before?' Man

16-05-01, 12:17 AM
>I've heard mention of snake torque several times on the site, But have
>no idea what it is. Is it a magazine or online site? can someone
>please enlighten me.


Snaketorque is the magazine of the UK Cobra Replica Club. Its is a colour mag 6 issues per year for the grand sum of 25 quid, a very good buy. Joining instructions are on the front page of this site.

>Dan 'Were all these nuts used before?' Man


The Whistler!

16-05-01, 12:22 PM
If you want to call in/talk Sumos/ pick over my sort-of-almost-finished Sumo/Rover V8 cob on a Friday evening let me know - I live just off the A3/A31.

Might be on your way home?


16-05-01, 03:04 PM
The Sumo chassis has been reciently tested and proved to be able to withstand the torque of a Chevy or ford short block.So if you want one nad you have alate chassis with the diagonal cross braces from the tunnel to the B pillar go for it. However with the engine position of aSumo it will handle better with a ligher engine so I would chose a Rover but you must remember that a Rover will never run the numbers of a Ford or Chevy short block. The cable clutch conversion is not difficult you just have to understand how it works. Sierra diffs are dirt cheap if you break one just go get another. the Rocker box covers from John Hammond are Cobra Le Mans no t powered by for unless hes changed them but they llok great I got a set. Good luck and happy building.