Engine question - Rover, Chevy or Ford

[chris m]

Dear all,

This is my first question to the forum, although I have been enjoying the content for some time! I intend to build a GD (jag). I haven't ordered the chassis yet, simply because I haven't decided on what engine yet! My car would primarily be for "fast"/fun road use.

I guess these questions have been asked 100 times before, but what the hell I'm gonna ask them again!!

My original intention was to put a rover 3.5 (SD1) engine into the car, but having phoned around a "good recon" giving about 200Bhp seems to be in the region of £4000, (inc. Carb. and distrib.), which seems a bit expensive. Further increase in BHP would be very expensive and produce "peaky" performance that I would like to avoid. Also I think in a few years time I might be disappointed that I hadn't gone for more power at the outset.

For that sort of money I could go to US V8 power. I have phoned Real Steel (who were a bit vague about prices - they didn’t seem to have any engines in at the moment) and Repower who had a various Chevy 350, Ford 302 and 351W engines and a gearbox package.

Which brings me to my questions….

1. Most people seem to go for the Chevy over the Ford (302), it's cheaper and I have also heard parts are cheaper than the Ford.
(a) Is there any other reason?
(b) Is it more tuneable/upgradeable?
(c) What would you recommend for a GD (JAG)
(d) Driven the same way, is there much difference in mpg between the Rover, Chevy and Ford? (boring but necessary question!)

2. Which gearbox do you use/recommend, the most popular seem to be a TREMEC TR3550 or a T5. Also, does the Tremec have a "longer" 5th gear than the T5, or is that something I would have to specify when I order? (Is it a good idea to have one)

3. Finally…If I buy a US engine then I assume I need to specify I want a pre-94(?) one + proof of age to avoid having to fit a "cat" etc.

So much to find out!!

Chris

[STEVE T]

You've opened a can of worms with this one !
Right I went with the rover 3.9 in my Dax was'ent fast enough I then got a brand new 4.6 270hp 290 lbs it was OK but it cost nearly £4k with my own injection system and this was nearly 2 yrs ago .
I sold it and now have a GD and i have a chevy 383 supposed to be 420hp and 430 ft lbs cost was just over £3k an old 69 block with fuely cast iron heads the rest all new .So for the same money you get a lot more hp and torque.and with the GD the balance is right .
And the Gd is the DOGS dangly bits compared with the DAX.


Regards Steve T

[wilf]

Dear Chris - what a question to kick off with. I guarantee enough different answers so as to thoroughly confuse you!. But welcome anyway.
Here's my 2c's:

Rover - £4k for a std 3.5 is well over the top. Find a reasonable base engine, recon it yourself being careful with the pennies, and you would probably knock a zero off that figure. However, if you want a GD, then that level of performance may not measure up to your expectations.

Chevy vs Ford US V8 - my own prejudices are blatantly out in the open if you look at not too many threads on this here forum - I like FORDS! But I defend the right of all to make their own choice. The bottom line is, that prejudices aside, there is little difference. I have not carried out a detailed cost per BHP personally between the two, and the general perception appears to be that Ford comes out more expensive - I am not totally convinced about that myself.
But if you are going to buy from an engine builder you should be able to get comparitive costs - make sure you are comparing like for like. Ancillaries and things like engine mounts/exhaust flange plates/air filters etc can add up.

In exactly the same way as for the Rover option, how much work you do yourself, and what level of tune you aim at, will dictate the cost. More BHP = More £££'s. In any event, going for a big displacement US V8 puts up other costs, like gearbox/fuel delivery system/cooling system and so on. You won't be able to match the cost of a Rover V8 engined car.
I am of the firm belief that there is no substitute for cubes, so would always go for a 350/351 over a 302 as a base engine. But there again I love surfing a wall of torque rather than revving things hard (well actually I do that as well).
Make sure that whatever you go for, it has the capability of being "extended" in the future - you WILL get used to the performance and yearn for more.

MPG?? You want a Cobra and you care about MPG?? Wait untill you find out what fun it is to run hard up through the gears and then tell me if you give a stuff about MPG. On the track I have achieved 4mpg out of mine, on a road run about 15. I would expect a chorus of complaint from those more concerned about running costs about that! Personally I could care less - not. The tall 5th on a tremec will help with long-run cruising mpg - see below.

Gearboxes - if you get carried away with engine spec, or think you will upgrade it in later years, don't go for a T5 - many folks swear by them, as many swear at them - they can't take the torque of a big lump because they weren't designed to, and most especially will break if you ever power shift.
For up to 350lbs ft of torque a tremec 3550 is OK - over that go for the TKO version. 5th gear is well overdriven as std on the tremecs at 0.68, although there is a (Difficult to find) TKOII version with a 0.8 5th. More dosh tho'. Make sure you get your rear axle ratio right to match the box you use. Your kit supplier should advise - if the don't/can't, find another kit.
A furher gearbox option is the Getrag (jaguar) 5 speeder. I am not actually sure of it's torque rating, maybe otehrs will chip in here.

As far as engine age is concerned, pre '92 is (I think) the cut off for 'cats, pre '86 even better. If your engine supplier cannot quote chapter and verse about these regs, find another. I have heard of BS from certain suppliers.

There you go - I hope the other forum users will be proud of the fact that I did not just shout GET A FORD!!!

HTH

WIlf

[callum]

Yes, but a commendably balanced line from Wilf. I think you'll find the GD balances marginally better with a Chevy which is several pounds lighter than a 351W or 351C Ford. There is probably a small premium to pay for Ford power but not enough to factor into build costs. I think it comes down to originality or weight and that's a personal choice not a totally scientific judgement. I went Chevy but I don't spit at Fords. Pity Wilf hasn't worked out how to hand onto his spittle! I suspect most Rovers secretly wish they were Yankee iron. (Now let's see what that sparks!)}>

[Dan]

I'm a pretty good spitter myself, But I tend not to do it in public. I don't know if my 2'cs are worth the paper there printed on, but I decided upon the Rover 3.5 for my car because of it's weight and power output against the V6. I never seriously considered the ford or chevy as I didn't want anything too powerful in my car as my intention is to tour with it not to race (I have my Fireblade for that . I'm sure that sounds lame, but I also had a large learning curve to overcome (Still do) and I didn't fancy making mistakes on a costly ford or chevy block - Much rather muck about with a good ol Rover. My Unit has cost £2500 to get to stage 2.

If I was building a more prestigous kit like A GD I would certainly go with either the Ford or Chevy... May be next year...


Dan 'Were all these nuts used before' Man
www.cobra.kitcar.btinternet.co.uk

[JimT]

Chris,

I'm a real newbie when it comes to engine building, however over the past few months I've been having great fun rebuilding a 3.5 injected Rover V8. What I like about the Rover blocks is how light they are - the aluminium block meant that getting the engine out of the Rover Vitesse was pretty simple (much thanks must also go to my dads grinder for this) and lifting it about is not problem, the bare block can be physically picked up without popping a disc. The weight is also where it has an advantage over the American V8's, since power-to-weight ratio is extremely important when it comes to performance, a standard lighter smaller Rover block could out-perform an larger American block when rebuilt and tuned properly....I certainly can't wait to get my car down to the track to face the American lumps.

The argument against the Rover V8's is usually price, "more bangs to the buck" is a phrase often used to describe the advantage of the American blocks over the Rover V8. Admittadly, Rover parts seem a little more expensive than American parts but if you go to the right place you should get a good deal ([link:www.v8tuner.co.uk|www.v8tuner.co.uk]).

As I mentioned, my block was out of a Rover Vitesse and has had the following work done/parts renewed:

Work:

- Block/Heads/Rocker Covers acid-dipped (heads also bead-blated)
- Heads skimmed
- Cylinders Honed
- Flywheel lightened (5Lbs off) and balanced
- New Valves
- Re-cut valve seats
- Crankshaft reground
- Injectors Ultrasonically cleaned

New Parts:

- Core Plug set
- Full set main and big end bearings
- Viper Hurricane camshaft
- Cloyes Duplex Chain Kit
- Piston Ring set
- Followers

Price for all this was almost spot on £800 inc. vat. I'm hoping that with a tubular exhaust, custom made air-filter and rising-rate fuel regulator I'll be putting out around 230bhp - power to weight ratio equivalent to a 355bhp Chevy.

I think £4000 is a bit steep. Take a look on v8tuner.co.uk and they've got a fully balanced short 4.6Ltr for £1400.

Cheers,

Jim.

[JimT]

For your information:

Ford 351 Cleveland - 550 Lbs
Ford 351 Windsor - 510 Lbs
Chevy SB V8 - 575 Lbs
Rover V8 - 318 Lbs

Correct me if I'm wrong.

Jim.

[Bowtie]

I am surprised that no one has mentioned the sound factor? Don’t get me wrong, the Rover got a lovely song but not really as convincing as an American SB (a BB sounds even better but I think that it would be quite unpractical to put one in a GD, but I could be wrong).

I personally selected a Chevy mainly because I love Chevy’s. There is nothing wrong with Ford but the Chevy SB is a real evergreen. How many has been produced? Enough to offer a huge market of parts and knowledge generally to a bit better prices than the Ford (but I have to agree with Wilf, a Ford engine doesn’t have to be more expensive if you got the right knowledge, contacts and patience).

One nice thing with Chevy’s (at least for me) is that the Chevy SB family offers a huge selection of interchangeable parts. I am starting out with a low budget 305 ripped out of a truck (most of you know why)! The engine is good enough to start with and I got it including gearbox almost for free. The money I saved will be spent on other parts of my Cobra project to speed up assembly.

I will probably exchange this engine in the future. I then got the option to exchange if with a 350 and it will fit the chassis and gearbox with a minimum of changes because the 305 and 350 share the same block. A lot of parts could also be moved from the truck engine to the new block (like alternator, cable harness, air cleaner etc.)

To me Chevy is flexibility both when it comes to parts, assembly and cost. I don’t know but maybe Ford is offering this too?

One thing for sure is that they both sound great!

Good luck / Bowtie

[dave]

Hi Jim.
When you calculate power to weight ratio don't forget to add the weight of the car to the equasion,as a 355 bhp chevy will leave for dead a 230 bhp Rover,what it is is that a Rover powered Cobra kit will weigh about 100 or so kilos less than one with a small block Chevy , and if the Chevy car weighs in at 1100 kilos then the Rover car will weigh in at around 1000 kilos actually making the car 10% lighter,if you take this figure away from the Chevy powered car you still end up with around 320 bhp per ton,and that's 90 more than the Rover....Me thinks you're going to come away from your summer of racing mighty depressed.

On tuning costs,I picked up yesterday the engine for my current build,this is a turnkey unit with everything from the front pulleys back to the fly wheel based on a 1985 block,it is a stroker 383 Chevy and has been run in and dyno tested at 449 BHP and 447 Ft Lb torque.The engine is built from all new parts except the block and cost £5300 inc vat. The only down side to this is that it needs a Tremec TKO to handle the power....More expense.Total price "nose to tail" around £7400.

My personal choice:- If you're going for a GD you've got to do it justice and fit an American engine,although you might get upto 10mpg more out of a Rover,but lets face it, if you seriously want economy wouldn't you be better off with a Nissan Micra.

[wilf]

Dan - I hope you didn't read any criticism (or even worse, smug superiority) into my original reply - I had a Rover 3.5 in my first car, and as an alternative to the (to my mind overweight/underpowered/untunable) Ford V6 it is excellent. They make the right noises, properly built (and with frequent oil changes - a must) reliable for huge mileages, and go quite well. For a "touring" car, an excellent choice if for no other reason than 25+mpg.

But if one is to build a more expensive Cobra - GD or the like, these cars really do cry out for the thump in the back only a big yank V8 will give, despite any weight penalties, which pale into insignificance when you calculate power to weight ratios.

I can only wonder, however, why people spend ££££'s getting a rover engine's output anywhere near what you get in near std form from a cheap as chips 302/351. (Note that I am talking torque and torque delivery here - far more important than ultimate BHP). The power delivery characteristics get worse as you up the state of tune, so do the chances of breaking components being stressed above their design limits. The £2500 you have spent on your engine would get you a good reconned Chevy/Ford, with bags of potential for upgrading later.
As I said earlier, many Cobra builders get used to their power outputs and start wondering about more. I do it myself - NO2 might find it's way in there one day.
I could be starting another controversey here, but I do seem to have a track record for that, and it is not in my nature to shy away from it!


Wilf