42 replies to this topic

[roofless]

Having bought the 1420 from Jammy_bustard ( dodgy car park deal in castle coombe ) I now need to work out what the hell to do with it.

my plans are as follows ( this is early days so they will undoubtedly change )

1420 bottom end - probably custom pistons and rings from ROSS
stage 3 head with new turbo capable large valves ( may need to loose a few cc's worth of metal to get to 9:1 compression ratio)
double springs and 1:5 roller rockers
T2 turbo on mirage motorsport conversion kit and pipes
mini-pulleys crank pulley and sensor bracket
emerald ECU
bike throttle bodies and injection system ( not completely clued up on this yet )
moderate intercooler
a few sets of spare pants.

Its early days but if anyone has the genious out there to help me pull this one together I will gladly receive any help.

I have already been told the turbo may be under-sized but the finished engine should have lots of torque.

Final details - its going in my Rover mini cabriolet - full zeemax kit including bonnet, twin upswept turbo exhaust system, 14" wheels with 195, 40,14 bridgestones - cadburys puple pearl paint and grey leather interior.

thanks for reading
Martin Cull ( roofless )





http://myweb.tiscali...iframe_mini.htm

[Jammy]

Hey, good to see you've stuck up a project thread! Sounds like quite a plan for that beast of an engine! Look forward to reading your progress with it.

[dougie_10 :D]

looks like its going to be another flyier. 1420 is a beast and a half.

Cant wait to see progress pics

[Bungle]

can you turbo a 1420 ?

[The Matt]

can you turbo a 1420 ?

It's just like turbo'ing a 1380, only more difficult to get the compression ratio right because of the larger swept volume within the same bore.

What dish pistons you using?

[roofless]

can you turbo a 1420 ?

My optimism says yes - in theory you can turbo anything - whether the 1420 can cope with the boost levels usually seen on 1380's 1290's and 1275's is yet to be seen.

I'm anticipating a low boost level - just enough to make a difference.

[roofless]

can you turbo a 1420 ?

It's just like turbo'ing a 1380, only more difficult to get the compression ratio right because of the larger swept volume within the same bore.

What dish pistons you using?

not sure just yet - I've got 2 firms trying to help me work that one out at the moment - if anybody knows any other companies that can help with this I would be glad to hear of them.
All we can start with is a similar reduction in cc's as seen between a 1380 and a blown 1380, but it is a bit too much fingers crossed for me.
Alternatively one guy has recommended no reduction or dishing to the pistons and have a water injection system instead - seems a bit bizarre?

[Baldspeed Racing]

God it will be like a time bomb waiting to go off!!!

[miniboo]

just to be picky....wasn't Jammy's engin, now yours a 1425??

[roofless]

well the homework is beginning to pay off - MED tried talking me out of it and selling me one of their 1293 units, but the nice man at Avonbar seems to think its not too much trouble - the short engine and head are going on their holidays to avonbar so they can measure up properly for a set of custom pistons ( £316.00 ) and if the bill richards head has had too much skimmed off of it I will use a new Avonbar turbo head instead ( I can use this bill richards one on my 1380 )

The maths of the sitaution is that even with standard dished pistons, and cc's removed from the head we still need to loose around 11ccs in each cylinder - thats either going to be 1/8th inch thick cylinder head gasket or something even more dramatic.

Wall flex is also a concern, but with the low boost I'm anticipating ( probably no more than 10psi ) and if I use an emerald ECU to make sure fuelling is absolutely spot-on through the range I think we're going to be OK.

The guy at MED had an attitiude of why bother? If we all thought like that all our minis would still be 850cc automatics and he would be out of business!

Whats wrong with trying something different - if it doesnt work then at least I'll be able to show you all why.

just to be picky....wasn't Jammy's engin, now yours a 1425??

jammy wasn't sure - I havnt measured - and the guy at Avonbar reckons it might even be a 1460 !!!

God it will be like a time bomb waiting to go off!!!

stand back and light the blue touchpaper

[Jammy]

I'm not surprised you didn't get much of a response from MED, from what I've seen they don't get into turbos much, Avonbar are a far better company to go with for that.

The specs I have is that they are 73.5mm pistons (which is correct) and has a 81.5mm stroke, which makes 1425 I believe.

If you want I can send you copies of the pages in the spec book if it would help?

[Leonard]

jammy that makes 1383


here we go

7.35cm bore =3.675cm radius

area = pi*(radius squared)=42.43

volume = area times height
ie cross sectional area of cylinder*stroke
=42.43*8.15=345.8

*4cylinders=1383cc

i think you gave the wrong stroke figure
standard stroke i believe is 81.3mm

sorry for the maths

Edited by Leonard, 03 October 2006 - 06:43 PM.

[GraemeC]

Need 84mm stroke for 1425.

81.25 is standard 1275 stroke so I doubt that crank will have been stroked just .25mm

[roofless]

I'm not surprised you didn't get much of a response from MED, from what I've seen they don't get into turbos much, Avonbar are a far better company to go with for that.

The specs I have is that they are 73.5mm pistons (which is correct) and has a 81.5mm stroke, which makes 1425 I believe.

If you want I can send you copies of the pages in the spec book if it would help?

yes please jammy - it would take some of the guess work out and stopp me sounding like a retard when I talk to people

Need 84mm stroke for 1425.

81.25 is standard 1275 stroke so I doubt that crank will have been stroked just .25mm

whats the quickest / accurate way of measuring stroke?

[Alburglar]

most likely 83.5 stroke for 1420. bill doesn't normally do 1430's. try and find acompany called green and white as they are pioneers of 1420's I believe