N/A 1046 Injection
Turbo Mini Forums

Brett has nearly completed the engine build for the N/A MK1 project

Sneak preview of the Spec and build

1046cc
10.5:1 comp ratio
MD266 cam
Balanced bottom end
Lightened flywheel
Ported 12G295 with large valves
1.3:1 rockers
Offset keys for timing

I know its controversial but I'm keeping the symplex chain setup to keep the original look of the engine and I'm not after mega power, aiming for around 70bhp and 50+mpg

All credit to Brett Sims Motorsport





Gearbox is the hybrid Guessworks magic wand box with A+ gearsets and cross pin diff

Edited by Ratty on 25th Aug, 2011.

Nothing wrong with simplex in my opinion.

I don't see many posts about them snapping. I'd be quite happy to use a pre-stretched simplex with tensioned on a turbo build etc.

If something is worth doing, it's worth doing half of.

I figure if they are good enough for 70+ bhp on a 1275 then it'll be fine for me. Stretching over time will be an issue but it'll just get changed when needed.

Need to get the injection bits and pieces finished now, paint the shell and start the long process of rebuilding the little car now

Looks nice.

For originality, IIRC, the very early simplex drives did actually have a "tensioner" without any bulge in the cover....

What they had was a wide chainwheel with two grooves machined in it immediately beneath the outer chain links and two rubber "O" type rings in the grooves that pushed the chain outwards.

They quickly stopped being effective as the rubber went hard very quickly in oil and heat.

But that was a long time ago, I'm sure modern synthetic rings would not suffer.

If you could find one of the early chainwheels in good condition of course....

Schrödinger's cat - so which one am I ???

I have never used a duplex. Simplex is more than fine, streach is not an issue.

The reason most people use duplex is that they don't rattle, but you have a tentioner.

Looking good, that's the right colour for 70bhp anyway.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Yeah if he painted it red he would have 100!

If something is worth doing, it's worth doing half of.

Hmmm,

What the photo looks like is a steel backplate of the later type designed to take a tensioner.

I think what Ratty is saying is that he is not going to fit the tensioner and use the earlier (no bulge) cover for original looks.

It won't look truely original as the shape of the later backplate is slightly different.

This came up a long time ago and in this thread is actually a picture of the original "tensioner" and a link to the MiniSpares part number (courtesy of Colin).

http://www.turbominis.co.uk/forums/index.p...tid=251714&fr=0

Schrödinger's cat - so which one am I ???

The back plate is the earlier type and it'll be running without a tensioner

Top right in this pic

My mistake, curve looked a bit too shallow in the photo - I should have just counted the holes.... :)

Schrödinger's cat - so which one am I ???

Easy mistake to make Rod, I had to count the holes as well just to make sure Brett had use the right one as I had left him both types lol

Looks good, what sort of injection are you going to run with it??

rick

Going to use the megasquirt siamese code injection and home made SU style throttle bodies