14 replies to this topic

[Hussar]

Righto guy's,
I've got a budget of 3K and I want a fast road engine idealy 1380cc. Something thats reliable as I will be doing some long drives (250 + miles). What spec should I go for. I already know that s/c gears are out (too noisy) no turbo as I want this to be a stealth mini and I do not want to cut into the bulkhead. It needs to be able to hit 100mph easily and cruise comfortably at 90mph with hopefully a 0 to 60 of under 7 seconds. Is this possible at this price and if so what are the most suitable components to use. I will be boring out the original 998cc.

[Sprocket]

I think you are going to have to comprimise in your goal some where.

For starters forget the 'numbers' and just build a fast reliable comfortable crusing engine.

If it were me i would spec the engine like this

73.5mm bore, standard stroke.
Kent MD274SP camshaft
Kent silent timing chain vernier kit
lightened cam followers
aluminium or titanium valve spring caps
35/29mm valve gas flowed cylinder head
ARP head studs
1.5:1 roller tip rockers
Twin HS4 carbs, or my personal preference Fuel injection
Twin HS4 manifold, ported and matched to cylinder head and carb mouth
K&N filters fitted with stub stack
Megajolt mapped ignition (or full engine management, goes with fuel injection)
Maniflow Large bore LCB
Playmini 2" exhaust system
Lightened balanced conrods
ARP rod bolts
Fully lightened balanced cross drilled crankshaft
Center main strap
Light weight EN24T( NOT unltra light) flywheel fully balanced
EN24T pressure plate
AP organic friction plate
AP orange diaphragm
Carefully built gearbox with 3.44:1 final drive (and i dont mean something that costs £150 all in that bearly covers the cost of the new parts) Oh and i would deffo be looking at a cross pin diff!!

That little lot should pull over 100lbft and 100bhp, rev to 7000 rpm easily and for all day if you wanted, have plenty low down torque from 1500rpm upwards, pull like it was a train, and be reliable at the same time as comfortable for crusing, will achieve the 100mph, although i dont know why you want that one? as for times 0 to 60, all depends how heavy your car is but recon on less than 10 seconds.

Hope that helps

[Sprocket]

I will be boring out the original 998cc.

Just spotted this little nugget

It is impossible to bore a 998 to 1380, you need a 1275

[Big_Adam]

I will be boring out the original 998cc.

..no...no you won't.

Few reasons.

1) The crank in a 998 even with 73 pistons wouldn't give 1380. Throw is too short.
2) Block are diffrent heights.
3) Engines don't work with big holes in the bore walls.

You NEED a 1275 block for going up to 1380.

I'd also suggest Vizard book to give you a better idea of what your upgrades and bits will give you on the road.

Edit

Damn, beaten by the Sprocket man.

Edited by Big_Adam, 23 October 2007 - 08:15 PM.

[mineeeeee]

I am not sure you can bore the 998 to73.5mm
i thought you had to start with a 1275 block.

I could be wrong but i sure it will be confirmed


obviously posted at the same time as above

Edited by mineeeeee, 23 October 2007 - 08:18 PM.

[mini_surfari]

Sprockets spec is pretty much spot on, but a SW5 cam and a single HIF44 carb might be a little better for reliability.

[998dave]

EN24T

I use tonnes of this stuff at work for making mundane fixtures, it's our 'commodity' steel... hmmm...

D

[mk1leg]

I purchased a Swiftun Evo2 1380 for £2950 107bhp at wheels, I'm they still build them give them a ring, mine was bench dyno'd run in all I had to do is install it in car and thrash it .....................

[mk1leg]

I purchased a Swiftun Evo2 1380 for £2950 107bhp at wheels, I'm they still build them give them a ring, mine was bench dyno'd run in all I had to do is install it in car and thrash it .....................

Bl***y computor

Edited by mk1leg, 23 October 2007 - 09:54 PM.

[Sprocket]

Sprockets spec is pretty much spot on, but a SW5 cam and a single HIF44 carb might be a little better for reliability.

Just out of curiosity, why would you drop spec on a cam and why is the one i specified, any more unreliable than the SW5?

Twin HS4s are fine, the Single HIF44 is getting close to the limit.

[wolfys_mini]

i dont understand why you say twin carbs. the single hif44 will do the job decent enough

[Jammy]

The twins would be more toquey and responsive, and contary to popular believe they are no more unreliable, or likely to 'go out of tune' than a single SU!

Personally I'd probably go for the SW5 as well, not for any reliability issues or anything, just to see how well they really are. A lot of people who've used them have really been impressed.

[mini_surfari]

Sprockets spec is pretty much spot on, but a SW5 cam and a single HIF44 carb might be a little better for reliability.

Just out of curiosity, why would you drop spec on a cam and why is the one i specified, any more unreliable than the SW5?

Twin HS4s are fine, the Single HIF44 is getting close to the limit.

You're right its not any more unreliable, apologies my mistake, however i have heard that the SW5 has great driveability in a fast road engine.

[Sprocket]

Swiftune have their sales package well set now, not knocking them, or the cam, it is after all business, the cam is indeed excellent.

The Kent MD274SP is the lowest duration scatter pattern cam available, the SW5 is not scatter pattern. The 274 has a longer exhaust duration than the Inlet, The SW5 has the same inlet and exhaust duration. My money is on the 274SP cam being better suited to a road 1380. I run the standard Kent 274 cam and it has an excellent spread across the revs, it just lacks lift, hence the high ratio rockers.

Look at it this way, the SW5 has to be a mild camshaft if it works in the injection engines and 998's. The 274 cam is an injection cam so is comparable to the SW5, the benefit is you can buy this 274 cam in scatter pattern, thus improving the torque, most likely over the SW5.

I doubt you will get over the 100bhp/ 100lbft torque with the SW5

[matty...]

How come you've over looked a turbo unit?

You can get EASILY 100bhp out of these,as they are pretty much that much standard, they are torquey allowing you to use a higher final drive without losing acceleration, and won't be reving its nuts off it on the motorway. It will cruise on a motorway no probs, no need for gash cutouts on the bonnet (like mine..lol) as you won't need an intercooler for that sort of power.

SC gears are honestly fine in a daily driver if you've still got the usual sound deadening and carpet its the drops that makes the majority of the noise. I didn't believe this untill I was taken out in a freinds mini with a SC box and helical drops, in all honesty you could barely notice any difference in noise.

I drove my turbo engine for 3 years without having to do thing apart from, the usual maintainance. That was also going to the Riv run, and many other show miles away from home.

This was mine a year ago...can't get much more stealth than that...lol

Edited by matty..., 25 October 2007 - 11:26 PM.