20 replies to this topic

[madboutmini]

hello

i am planning an engine swap on my mini

i am just wondering what i can do to get the most power out of my mini to make to as quick as possible

i will be buying a brand new 1380cc classic mini engine

what can i add to get lots more power from it then get that power to the road to make a fast classic mini?

i have looked in to other engine conversions but want to stay with the mini engine so no need for you to mention them

also if you have tuned your classic mini engine what rough specs did it give?

thanks

[holmesy]

supercharger or a "k" series head conversion will get the most out of a 1380 i believe but either route it aint gonna be cheap!

[Cooperman]

You need to tell us what you want to use the car for. When you say 'as quick as possible' do you mean quick on acceleration, or quick on top speed, or quick on safe-revs cruising speed? You can't have all three!
Now, you say you are buying a 'brand new 1380' engine. At 1380 it is not brand new, it is re-built and overbored to the safe maximum and that, in itself, is quite a modification as the bores have to be offset from standard. A 1380 cc engine needs a well-modified bigger-valve head or it wll not be able to get sufficient mixture into the cylinders to work well. A better cam will also be necessary for the improved breathing. It might be expected that the engine-builder would, if he knows what he is doing, offer you these items as part of the build. If the builder does not know what he is doing he may not offset the bores, then yoju'll have a real problem (seen that quite recently - it ended up with a scrap block!).
Please tell us more.

[redhot-mini]

supercharger or a "k" series head conversion will get the most out of a 1380 i believe but either route it aint gonna be cheap!

if hes buying a brand new engine he must have a £1200 for a supercharger

[madboutmini]

thanks cooperman for the info im looking to have good acceleration, if i left the engine as it is do u know what specs i could expect

and i have about 5-6k for the engine

Edited by madboutmini, 07 October 2011 - 02:47 PM.

[Cooperman]

Supercharging would be great, but the engine would need to be built with lower compression ratio (C.R.) from the beginning and probably different (Omega?) pistons suitable for forced induction. If the 1380 is being built for performance with normally aspirated induction the C.R. could easily be set at over 10:1 which would be disasterous for a supercharged unit. A different distributor would also be needed to slow the advance curve and prevent detonation. This needs to be determined before the engine build begins.

[Cooperman]

thanks cooperman for the info im looking to have good acceleration, if i left the engine as it is do u know what specs i could expect

and i have about 5-6k for the engine

When you say 'as it is', what is the full spec as you understand it? I mean it may be 1380, but what head, valve sizes, C.R., induction system, exhaust system, etc.?
Alternatively, I and others could recommend a full spec for a 1380 to provide optimum acceleration if that would help.
Sorry for asking so many questions but not yet providing any answers, but all of us on here like to give the best advice we can to avoid disappointment later.

[madboutmini]

thanks cooperman for the info im looking to have good acceleration, if i left the engine as it is do u know what specs i could expect

and i have about 5-6k for the engine

When you say 'as it is', what is the full spec as you understand it? I mean it may be 1380, but what head, valve sizes, C.R., induction system, exhaust system, etc.?
Alternatively, I and others could recommend a full spec for a 1380 to provide optimum acceleration if that would help.
Sorry for asking so many questions but not yet providing any answers, but all of us on here like to give the best advice we can to avoid disappointment later.

the engine is one the same as this
www.minispeed.co.uk/content/1380cc-fully-built-concept37-engine
i dont think will get it from them cause i think have seen it at a better price
exhaust system will be bought seperatly because dont think it has one with it

[MJWarren]

thanks cooperman for the info im looking to have good acceleration, if i left the engine as it is do u know what specs i could expect

and i have about 5-6k for the engine

When you say 'as it is', what is the full spec as you understand it? I mean it may be 1380, but what head, valve sizes, C.R., induction system, exhaust system, etc.?
Alternatively, I and others could recommend a full spec for a 1380 to provide optimum acceleration if that would help.
Sorry for asking so many questions but not yet providing any answers, but all of us on here like to give the best advice we can to avoid disappointment later.

the engine is one the same as this
www.minispeed.co.uk/content/1380cc-fully-built-concept37-engine
i dont think will get it from them cause i think have seen it at a better price
exhaust system will be bought seperatly because dont think it has one with it

If you have seen it somewhere else its not the same engine is it? This is an in house built minispeed engine.

Theres no point throwing money at something if you dont know what direction you want to go in yet.

6K could get you a 16v specialist components engine probably.

[madboutmini]

ok well i dont know that much about engines and stuff im more in to styling and things like that the main reason for the engine change is due to mine having a cracked block and smashed up valves and stuff and im goin to scrap it.

but as i said i do want to keep the engine the classic mini engine so any suggestions great

[Cooperman]

At 1380 cc, should it ever need a re-bore it will probably mean another block.
My recommendation for a good road Mini engine would be along the following lines:

Bore to 1330 cc with Hepolite P21253-60 pistons.
Rob Walker Engineering fully gas-flowed head with 35.6/30.5 mm valves and unleaded seats, compression ratio 10.5:1
Kent 276 cam with duplex timing gears
Twin HS4 or HIF38 SU carbs on a good alloy inlet manifold
All new ARP big-end and main bearing bolts
Metro-Turbo oil pump
Centre main bearing strap
Lightweight Mini Spares steel flywheel
Pre-verto clutch - Cooper 'S' spec
Maniflow LCB and twin-box exhaust system

You could have 1.5:1 rockers, but they would not gain more than 3 or 4 bhp at the top end, although they do reduce valve guide wear a little.

That lot should not cost a fortune and it should be built to a high-quality standard. The gearbox should also be re-built as follows:

Gearbox with centre oil pick-up
3.44:1 or 3.2:1 final drive ratio with a cross-pin diff. (for good acceleration)

The above would give a smooth and reliable engine with good overall performance, brisk acceleration, nice cruising speed up to about 80 mph, the ability to re-bore again if necessary or to sleeve back to standard.

You need to find a block if yours is cracked, although the crank, rods, head etc could be re-used. Try to find a 1275 block which you should get for about £80 to £100.

[RayBoogs]

take a look at places like specialist components and KAD for some decent 16v twin cam engines based on the mini engine, with 6k you could get an absolute stormer!

http://www.twinkam.c...hop_param=cid= (specialist components)
http://www.kad-uk.co...-engine-gearbox

[AndyMiniMad.]

If you dont know much about engines then my advice is not to try and spec one up yourself....Why not phone around some of the reputable mini engine builders, Med, Rob Walker, Paul Inch, Swiftune, to name but a few. Tell them roughly what you will be useing the car for and that you want it to be more of a quick to 60 type car than something that will do 120mph...you may be able to get both. Tell them your budget then sit back, relax and wait...

[MJWarren]

take a look at places like specialist components and KAD for some decent 16v twin cam engines based on the mini engine, with 6k you could get an absolute stormer!

http://www.twinkam.c...param=cid%3D%26 (specialist components)
http://www.kad-uk.co...-engine-gearbox

you couldnt get a 16v engine from KAD for 6k

[RayBoogs]

take a look at places like specialist components and KAD for some decent 16v twin cam engines based on the mini engine, with 6k you could get an absolute stormer!

http://www.twinkam.c...param=cid%3D%26 (specialist components)
http://www.kad-uk.co...-engine-gearbox

you couldnt get a 16v engine from KAD for 6k

http://www.kad-uk.co...x?product_id=46