53 replies to this topic

[Leonard]

don't go too big on the valve sizes, this reduces air speed past the valves, and this reduces torque. this is partly why 16valve heads are good for torque, because they generally have smaller valves

[flamejob]

Aluminium's not a very strong metal either.

Pure engineering science in a sentence.. I love forum logic

Also look into using an Estate or van, more weight means you can tow more!!

Isn't the Van one of the lightest variants??

[skidMarkNZ]

I need some help on this one, its a project for next year.

The plan is to make an aluminium trailer big enough to carry a mini and tow it with a mini.
The help i need is on the engine, i want to build an engine of very high torque and as cheap as posible.
I know i need a long stroke and a small carb to produce torque, but not sure what valves or head or block to use, large or small valve head. I am thinking it may be just a case of mixing standard mini engine parts together instead of buying modified parts, any help please.

just remember don't make it wide enough for just the mini remeber you gotta somehow get in and out hahahahahahaha

[fikus01]

16 valve heads produce more power at higher rpm, at college and in training for my old job, we were told the 4 small valve idea was to get the most out of the available cylinder head space and keeping the source of ignition in the centre of the combustion space!! unfortunately the air speed isnt helped till higher rpm!

you often find that the 8 valve variants of performance cars produce more torque at lower revs, 2 prime examples are the puegeot 106 gti and rallye!! and the 2.0 litre vauhhall lumps!!

gti has 16v and pruduces more top end power, rallye has 8v bags more torque and its available lower down!!!! (see the french do know half of what they're doing)

same story again with the vauxhall lumps, 16v for ultimate power but 8v has more torque at lots lower revs!!

[Sprocket]

You will still find it difficult to get the train weight within regulations. Expect 250kg for a proffesionaly built comercialy available micro ally trailor so your mini should weigh in the region of 400kg. Now that must be some Mini you have.

Also dont be surprised if you get pulled by the police ALL the time. A Mini towing a Mini with a trailor looks dodgey.

You will struggle to get within the limits.

This has been discussed on another forum.

Oh and another thing, will your licence allow you to tow a trailor of 750kg + If you have recently replaced your paper licence with the new two part one, id check, they are dropping catagories of licences that you had on your old paper one.

for reference

"Drivers who passed a car test on or after 1 January 1997 are limited to vehicles up to 3.5 tonnes maximum authorised mass towing a trailer up to 750 kgs, or a vehicle and trailer combination up to 3.5 tonnes MAM providing the MAM of the trailer does not exceed the unladen mass of the towing vehicle. You will need to pass an additional driving test in B+E if you wish to tow a caravan or trailer combination which exceeds these weight limits."

Sticking with my thoughts that it cant be done

Edited by Mini Sprocket, 03 December 2006 - 04:32 PM.

[koss]

Right every one forget about the trailer .
i know about all the regs, I want torque, i am old and i have put people through the midas test for D1 etc as i work with the local authority/ Just wanting to know how to get some torque

[fikus01]

big cc, long stroke crank, small valves and eityher twin 1 1/4" or single 1 1/2"carb!! sensible cam with small lift!! mg cam is short on lift!! but so is kent 256 high compression

dont polish the ports at all!!

by small valves i mean a non mg head has smaller inlet valve then an mg!! and something tells me i've read a large exhaust valve can help low down torque but eont quot me on that!!

a 1098 has the longest stroke of any production a-series but you're limited by the cc there so id go with a big bore, 1380 with a long stroke crank to 1500cc!! make sure you use ARP bottom end bolts with that tho!! just in case you miss a gear and rev the nuts off it!! and a 4 bolt centre main strap probably wouldnt be missed either

ooh and it mite be worth investing in something like megajolt for the ignition as you'll need a pretty perfect advance curve to get good low down torque!!

dont forget the gearbox will probably be your weakest link!! 4 pin diff and straight cut drops esential with the above setup!!

Edited by fikus01, 03 December 2006 - 07:56 PM.

[*DJH*]

Have You Tried Buying A Dozen Donkeys?

[fikus01]

Have You Tried Buying A Dozen Donkeys?

maybe you could build an engine that could torque the hind legs off them!!

[Sprocket]

1380cc

Best cam for torque and not drive pants low down has to be the Kent 274SP

Was originaly designed for the injection but has bags of torque, very good emissions and is still very driveble, its operating range is 2k to 7k rpm

Dont knock it just because its an injection cam. Its the lowest spec scatter pattern cam Kent do, idles real well and not temprimental in the lower revs like the 286 seems to be.

I know of one of these cams in a 998 turbo engine pushing 140bhp

Edited by Mini Sprocket, 03 December 2006 - 09:01 PM.

[*DJH*]

Have You Tried Buying A Dozen Donkeys?

maybe you could build an engine that could torque the hind legs off them!!

Ho Ho, That's A Cheap One....

[koss]

Right, firstly thanks for all the info i think i will go for a similar build as the one on MLmotosport.
I have 3 minis at the moment and dont want a van or a large car to tow the trailer because this would mean selling a mini to make space.

mini 686kg + 13x7 super lights
100kg snapon tool chest
60kg jack
roof rack with 4 wheels and tyres on it
race gear helmet overalls etc
fuel
me
the gf
food


zcars monte carlo on a custom lightweight trailer manafactured by myself with low sides so i can open the doors

So if the police stop me and take me to a weighbrige i should be ok

ps i have no where to keep a dozen donkeys

[Guess-Works.com]

Long stroke crank is the obvious way to get bags of torque...

FYI, the maximum towing weight for a mini is just over 400kg's, I think above that, you're in serious danger of ripping the back subframe out of the vehicle.

Just an idea, if the car is road legal, what about an A frame instead of the trailer ?

Edited by GuessWorks, 04 December 2006 - 10:46 AM.

[koss]

What a great idea but i dont think an A frame will go under
have a look http://www.zcars.org...carlo/clips.htm

[Guess-Works.com]

You could manufacture some mounting points for a frame through the grill onto the frame of the car ?