Ausmini
It is currently Sat Nov 17, 2018 12:39 pm

All times are UTC + 10 hours




Post new topic Reply to topic  [ 37 posts ]  Go to page 1, 2, 3  Next
Author Message
PostPosted: Sat Oct 21, 2017 1:27 pm 
Offline
848cc
848cc
User avatar

Joined: Thu Apr 03, 2014 10:28 am
Posts: 85
Location: Adelaide
I've learnt a lot since I first bought my 76 clubby when I was 17 and in my first year of my mechanical engineering degree. Fast forward 5 years and I've now got an engineering degree which is about the equivalent of 3 squares of toilet paper and I'm also looking to bring my mini into the 21st century. I'm after reliability mainly so EFI was a path I knew I was going to take. After months of thought and not wanting to do a complete engine swap requiring a full front end rebuild, a Twinky conversion kit complete with BMW K1200 head popped up on eBay and seemed to be a good way forward.

I bought the kit off Michael B in Sydney and I think he is part of the forum. Now that I am back home after being away for the best part of the year it's time to start swingin spanners in the garage.

I got in contact with Matt Read of course, and I'm going to start by saying Matt has answered all my questions no matter how stupid, he's prioritized his work well and never kept me waiting. Matt sorted out a 1275 block for me bored out to 74mm and had the block plugged and drilled ready to fit the new head. So even though the build hasn't even begun, thanks heaps, Matt. You're a champ.

Here it is now, note the mini waiting eagerly in the background. She's more than ready to swap out her tired 998 that has done her well for so long.

Image

The block is in great nic and Matt has done an even better job with converting it for the BMW head.
Image

Matt even threw in some pistons to suit! The box is pretty aged, but hey! It's got my initials on it so I think it's pretty cool!
Image
Image

The head seems in really good nic too. Of course it'll need a refurb but it provides a fantastic starting point. Look at all those valvessssssssssssss
Image


The aim of the build is to get reliability and power. Triple figures of the HP variety is what I am aiming for but if it starts and drives well, doesn't cough or change with the weather, I'll be a happy man.

I have some standard 1275 conrods on the way. I am going to go for a lightened flywheel but I am unsure what to do about the crank. Will a standard crank do the trick or should I aim for a lightened crank? Is there much difference between a lightened crank and a standard one is I guess what I am asking.

Those of you that have followed other twinky builds on this forum would know that the original cam shaft still needs to be used to operate the oil pump. I have this small bore cam lying around that I've had for years. I think it's a peg drive variety. If I delobe it, is it suitable for the build?
Image

I think I'll use a basic Haltech ECU to run it all. All I think I need is a crank position sensor, throttle position sensor, suitable sized injectors and some sort of ignition system.

I'll log progress of the build here and I'd say hopefully around this time next year she will be on the road. Don't hold your breath, grab a cuppa and lets go.

Joe

_________________
-----Better is the enemy of good-----
Image
-1976 Yellow Devil Leyland Clubman-


Top
 Profile  
 
PostPosted: Sat Oct 21, 2017 2:11 pm 
Online
1275cc
1275cc
User avatar

Joined: Sun Apr 29, 2012 1:19 pm
Posts: 2982
Location: Wollongong, NSW
That looks like a fun project!

_________________
Image


Top
 Profile  
 
PostPosted: Sat Oct 21, 2017 2:16 pm 
Offline
1275cc
1275cc
User avatar

Joined: Wed Oct 03, 2007 9:04 pm
Posts: 4831
Location: Melbourne, VIC
Great background to your project. Thanks for posting. Looking forward to the trials and tribulations as work progresses. :)

_________________
ex-NSW Police 1970 MK II Cooper S
VMCI #43


Top
 Profile  
 
PostPosted: Sat Oct 21, 2017 2:24 pm 
Offline
848cc
848cc
User avatar

Joined: Thu Apr 03, 2014 10:28 am
Posts: 85
Location: Adelaide
timmy201 wrote:
That looks like a fun project!


Thanks Timmy. The flywheel housing that I picked up from you a few months ago will come in handy for this project!

_________________
-----Better is the enemy of good-----
Image
-1976 Yellow Devil Leyland Clubman-


Top
 Profile  
 
PostPosted: Mon Oct 23, 2017 3:54 pm 
Offline
998cc
998cc

Joined: Mon Apr 05, 2004 11:23 am
Posts: 575
Location: Eastern Melbourne
Hey get a finance qualification and you can make your 3 squares Teflon coated!
Crank balancing would help and loose a couple of pounds in the process. Just remember that crossflow 4 valve head needs rpm (tumbler not swirler) to function well so will pass into a 3rd or 4th crank harmonic. Fit a windage barrier + scraper blade while it's apart to lighten the rotating load and a centre cap strap.


Top
 Profile  
 
PostPosted: Mon Oct 23, 2017 8:32 pm 
Offline
848cc
848cc
User avatar

Joined: Thu Apr 03, 2014 10:28 am
Posts: 85
Location: Adelaide
Besser wrote:
Hey get a finance qualification and you can make your 3 squares Teflon coated!
Crank balancing would help and loose a couple of pounds in the process. Just remember that crossflow 4 valve head needs rpm (tumbler not swirler) to function well so will pass into a 3rd or 4th crank harmonic. Fit a windage barrier + scraper blade while it's apart to lighten the rotating load and a centre cap strap.


With the addition of the centre strap the main cap will have to be machined flat. Once that happens, will I have to get it line bored? Matt had it line bored before it got to me so if I can avoid having it done again that'd be ideal but ya gotta do what ya gotta do. I assume it would need doing.

_________________
-----Better is the enemy of good-----
Image
-1976 Yellow Devil Leyland Clubman-


Top
 Profile  
 
PostPosted: Tue Oct 24, 2017 6:37 am 
Offline
1360cc
1360cc
User avatar

Joined: Sun Apr 11, 2004 11:32 am
Posts: 11186
Location: Sthrn HiLoLands, NSW, Australia
jpodge wrote:

I think I'll use a basic Haltech ECU to run it all. All I think I need is a crank position sensor, throttle position sensor, suitable sized injectors and some sort of ignition system.

Joe


MadMatttheMiniMan is probably a good person to advise on appropriate injection, ignition etc :idea:

_________________
"Show me the Mini!"


Top
 Profile  
 
PostPosted: Wed Oct 25, 2017 8:19 pm 
Offline
848cc
848cc
User avatar

Joined: Thu Apr 03, 2014 10:28 am
Posts: 85
Location: Adelaide
I've had a chat with a few people, mechanic mates and family and with the Haltech I have plenty of options to consider for ignition systems to use. At this stage I think poaching a coil on plug setup from a yaris or something would be not only cheap but easy as to wire in to the Haltech. I had a quick look of their user guide which is incredibly straight forward and literally tells you where each wire needs to go.
http://www.haltech.com/files/downloads/ ... e%20V1.pdf

It's a fair way down the track at this stage though and there is plenty of other hurdles to get over with regards to actually building the engine. Is anyone on here running a Haltech on their mini?

_________________
-----Better is the enemy of good-----
Image
-1976 Yellow Devil Leyland Clubman-


Top
 Profile  
 
PostPosted: Sat Oct 28, 2017 6:22 pm 
Offline
848cc
848cc
User avatar

Joined: Thu Apr 03, 2014 10:28 am
Posts: 85
Location: Adelaide
Got some conrods in the mail the other day. They still had some pistons attached, and bloody hell did they need some convincing to get off.

This is how they showed up. Pistons were buggered but that didn't matter. A good clean for the rods was in order.
Image

I didn't think that the pins would be too hard to get out but that was because I'd never dealt with press fit pins. I've only ever encountered circlip style when I made that postie bike that some of you may have seen. ( viewtopic.php?f=10&t=94808 )

I made up this little rig to try and pull them out as I tightened the nut that was against the vice.

Image
Image

I ended up just stripping the threaded rod. damn. Before I called a shop to do it for me, I though't I'd try and "persuade" them out with a hammer and a socket pressed against the pin. I only had to think about some of the crap from work for them to come out rather quickly! Happy days - and no more pent up frustration haha.


I'm happy with the state of the rods. Ideally I would've gone for forged rods to save the weight and get a really fast revving engine but hey, maybe if I had a better job or you know... won the lotto would I have gone with the swifttune or MED rods.

Image

_________________
-----Better is the enemy of good-----
Image
-1976 Yellow Devil Leyland Clubman-


Top
 Profile  
 
PostPosted: Thu Nov 02, 2017 8:14 pm 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 38584
Location: near Baulkham Hills, NSW
Couple of points:
1. I would lighten those rods by milling 8mm off the cap lumps (edit) and lighten them as per Vizard's book. Fit ARP bolts.
Note, A+ rods are lighter.
2. I would not weaken the cast iron centre cap by milling it flat. When I built my 1412 stroker I cleaned the cap face up then made a stepped strap out of EN25 steel. I dimensioned it to have a .003" gap at each end. When torqued down, the bore was not out of round.
3. It is a big journal crank, they all have poor counterweighting. I recommend you get it wedged. This reduces uneven wear on the centre main journal.

Here's a pic of my 1412's wedged big journal stroker crank and the stepped EN25 centre main strap. The strap was made from an offcut I had, why it looks short but it's long enough. Rods are Cooper S, narrowed to fit the crank.
Image

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank @7000+, 45 Dellorto, RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. Going harder with Stealth Black Box in.:mrgreen:


Top
 Profile  
 
PostPosted: Fri Nov 03, 2017 6:00 am 
Offline
1360cc
1360cc
User avatar

Joined: Sun Apr 11, 2004 11:32 am
Posts: 11186
Location: Sthrn HiLoLands, NSW, Australia
1. ,,,,and at the same time, get them weight matched and balanced...

Doc, I thought the jury was out on centre main strap? Something about, the cranks like to whip a little and by restricting that movement you risk breakage?? :D

_________________
"Show me the Mini!"


Top
 Profile  
 
PostPosted: Fri Nov 03, 2017 6:42 am 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 38584
Location: near Baulkham Hills, NSW
Centre strap is only really useful on race motors, the cap can break on overrun if you overrev the engine to a zillion RPM during downshifts.
As for cap flexing, on all except (maybe) S blocks it is grey cast iron. Doesn't flex, it cracks instead.
It would rather break than bend.
I put a strap on this stroker but have not used one since.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank @7000+, 45 Dellorto, RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. Going harder with Stealth Black Box in.:mrgreen:


Top
 Profile  
 
PostPosted: Fri Nov 03, 2017 8:42 am 
Offline
1360cc
1360cc
User avatar

Joined: Sun Apr 11, 2004 11:32 am
Posts: 11186
Location: Sthrn HiLoLands, NSW, Australia
drmini in aust wrote:
Centre strap is only really useful on race motors, the cap can break on overrun if you overrev the engine to a zillion RPM during downshifts.
As for cap flexing, on all except (maybe) S blocks it is grey cast iron. Doesn't flex, it cracks instead.
It would rather break than bend.
I put a strap on this stroker but have not used one since.


Cheers 8)

_________________
"Show me the Mini!"


Top
 Profile  
 
PostPosted: Fri Nov 03, 2017 7:15 pm 
Offline
848cc
848cc
User avatar

Joined: Thu Apr 03, 2014 10:28 am
Posts: 85
Location: Adelaide
drmini in aust wrote:
Couple of points:
1. I would lighten those rods by milling 8mm off the cap lumps (edit) and lighten them as per Vizard's book. Fit ARP bolts.
Note, A+ rods are lighter.
Image


Sounds good! New ARP bolts are a given but unsure if I'll go down the lightening route. Should I have just gone for the fancy forged rods? Just unsure on the mahcining costs for the lightening you mentioned^^

How far do we go with builds like this? Better is the enemy of good!

_________________
-----Better is the enemy of good-----
Image
-1976 Yellow Devil Leyland Clubman-


Top
 Profile  
 
PostPosted: Fri Nov 03, 2017 8:44 pm 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 38584
Location: near Baulkham Hills, NSW
I have machined those rod caps before on my mill, it's a quick job for any machine shop to take 8mm off.
Worth doing, even of you don't lighten the rod otherwise.
Also sand the ears off the little ends, and then balance the rods and caps to within 1g.
PM sent.

{edit] for clarity.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank @7000+, 45 Dellorto, RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. Going harder with Stealth Black Box in.:mrgreen:


Last edited by drmini in aust on Thu Nov 09, 2017 1:03 pm, edited 2 times in total.

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 37 posts ]  Go to page 1, 2, 3  Next

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 11 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  

© 2016 Ausmini. All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.