She lives
Turbo Mini Forums

Its been over a year since she last was on the road. But all the drama aside and christmas spent with spanner in hand has been paid back by my little beauty firing back to life. The re-built engine spec is as follows.

Plus 20 11cc 20831 pistons
Mini speed turbo cam shaft
ported not polished head 28.5cc chambers
Ss exhaust valves
TAM1061 inlet valves
Phosphor bronze guides
Duplex vernier adjustable timing gear
Cometic head gasket
Matched inlet and exhaust manifold ports to head
Front mounted intercooler
Carbon fibre pipes

I have calculated the static cr to be 7.06/1, this will allow me to run 15psi of boost and a dynamic cr of 14.5ish/1
I spent as little as possible putting this engine together as I really want to have a stronger bottom end and work on the clutch before throwing more money into it.

Own the day

well done mate!!
bet its a really good feeling to get it to fire up for the first time!

i would like to meet up with you one day as your only down the road from me!!

any pics of it?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

nice one i cant wait for the day i get to fire up my turbo lump

Done now needs redoing lol

Nice to hear you got a running motor, I was under the impression that the dynamic cr was less than the static cr due to piston being part way back up the bore before total valve closure?

one day boost will be mine!

7.06:1, thats about the lowest figure ive seen!

I agree with jamie, without a decomp plate or masses machined off the crowns I can't see how you got that figure? I would of thought that would be more around 8.6/8:1 on a 'normal' deck height?

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

Cometic 0.140 head gasket. 0 Deck height, which were all over the place so I used the smallest one.

Edited by Mr Joshua on 3rd Jan, 2012.

Own the day

I put all my figures into the calculator I posted on here a while back and it came out at 7.06/1 static. If I use a standard thickness gasket (0.30") it works out to be over 8.4/1

Own the day

You are all making me wonder about my CR now !

I had it at 8.2/8.3 static with 25.5cc chambers and 14cc pistons and I,m using 16psi.

How thick is your head gasket. When I used both calculators on here I got massively different figures. When I looked into it one of them left out a volume figure, I can't remember what figure it was, either piston dish volume or gasket.
I got my cr down mainly due to the head gasket you can see the difference is quite big compared to the standard thickness gasket.

Edited by Mr Joshua on 3rd Jan, 2012.

Own the day

With the figures you give for the pistons, the head and the gasket, I too work it out at around 7:1 CR

The questing is, why so sluggishly low with only 15psi?

and how do you manage a 14:1 dynamic CR? Is the Minispeed turbo cam some sort of odd ball? or have you timed it in correctly?

what cranking pressures to you get on a warm engine?

You engine will run, but will be miles off its full potential, that said, you could afford to run a chunk more ignition advance

Edited by Sprocket on 3rd Jan, 2012.

Edited by Paul S on 3rd Jan, 2012.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

http://www.minispeed.co.uk/content/head-ga...c-120thou-thick

0.120"

gold price tag too

Aaaaaaaawww much????

In the 13's at last!.. Just

bin the dizzy man,
about time you got an intercooler too

Honestly it is 0.140" thick! I looked at the 0.120" gasket but decided on the thicker one due to me running cast pistons.

The link to the suite that has the compression radio calculator also has a boost compression ratio calculator which takes into consideration your pressure altitude for correction.

Agreed what cam you use will have a marked affect on your cranking compression ratio but from what I can tell the one I installed its a modified MG Metro can shaft.winch is very close to the sw5.

Own the day

Ah! Sorry I made the wrong assumption with my terminology.

To answer an above query when I put the compression tester on I was getting 6:1cr

I ran a n/a mini at 14:1cr so built this engine to achieve that cr while on boost. So running a static cr of 7:1 and 15psi of boost should give me an on boost compression radio of 14:1 roughly.

The issue I have trouble resolving is the affect the chosen cam profile has. In an ideal world you would get total displaced volume compression but as above the piston is travelling back up the bore while the inlet valve its still closing, factor in over lap and valve lift at over lap and the question I ask myself is what compression am I actually achieving at tdc. Is the gauge reading good enough to use that cr figure in my on boost cr calculations as I am sure 5 makes of gauge will give me 5 different readings

Edited by Mr Joshua on 4th Jan, 2012.

Own the day

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."