Tu Tuning, I Just Want 100Hp

[michael_jenkins 2]

 

What size is your mini filter on the rocker cover? I want to order one but don't currently have the car at home to measure.

 

Cheers,

 

Mike

Edited April 23, 2012 by michael_jenkins

[309jazzpanda 41]

right vtr engine it is then

[batespeed 0]

sorry to hijack your thread, but im interested in the SU carb conversion

 

.

ive got a mini with a tu3s engine in it and there is very little clearance between the carb (twin choke solex) and the master cylinders, this modification would help no end (and if it gives more power as well its a win , win, situation)

any idea which SU it used, and what needle? it looks like a hif 44 off a MG metro or late mini cooper.did you use the standard twin choke manifold ? in mini circles they say that this carb is ok up to 100 plus bhp, so it should flow enough with the right needle.

 

(i did this in reverse a few years ago, i put a twin choke solex off an XS onto a 1275 mini,on a home brewed manifold, i had to put a bigger main jet in it to run right, it was a lot of fannying about but it worked ok in the end).

 

.

Edited May 10, 2012 by batespeed

[batespeed 0]

i knew i had photos of it somewhere

[309jazzpanda 41]

Well head gasket went last week, head off skimmed 30 thou off the head, enlarged the exhaust ports quite a bit and took some casting marks off the inlet found a bent valve oddly enough. Car ran fine though big mark on the piston, found it had bent at the top (valve spring end) its back together now and goes like stink though I'd like a bit more ha ha

[welshpug 1,661]

crikey, a fair chop then

[309jazzpanda 41]

Yeah and the lad that skimmed it said, we could take more off, I'm thinking about getting a cam next but also tempted to find a 106 rallye engine

[MiniGibbo 142]

106 1.3 rallye in a 309

 

 

Lad

[309jazzpanda 41]

Is this a runner yet, the 309 I mean

[MiniGibbo 142]

To add to this I'm currently rebuilding my 106 Rallye engine with a 1360 bottom end, I'm tempted by the domed pistons as the xs bottom end I have is flat..

 

But I'm dubious just how much the compression will drop with my Rallye head....

 

I'm aiming for 110hp btw.. 100hp is so last engine

[allye 530 3 Cars]

I'm aiming for 110hp btw.. 100hp is so last engine

 

110 with the solex?

[MiniGibbo 142]

No.. I don't live in the dark ages.......

 

I'm keeping my entire s1 106 Rallye engine but swooping the bottom end for a 1360 one, so it'll Basicully be a 1.4 mpi revving to 7250.

[309jazzpanda 41]

Hmmm sounds interesting sir

[MiniGibbo 142]

Yeah it should give it a bit more poke and be nice having a freshly built engine.

 

Just unsure how the slightly lower compression ratio will affect it..?

[trogboy 17]

Unless you change the pistons or reduce the volume of the combustion chamber you won't see any better power, in fact I expect that you will loose it. By using the stock TU3 bottom end you are only gaining 66cc (~5% over the 106 engine) but loosing big time on the compression front. I think I have said it before but from memory that combo works out around 8.5:1.

[MiniGibbo 142]

the compression actully plays that bigger part..?

[tdr_1976 41 1 Cars]

Standard TU3S bottom end, Kent PT02 camshaft with vernier Pulley, Ported head with std valves, 4-2-1 manifold and custom exhaust system and a set of Twin 40 Dellorto's = 105 bhp for me.

 

Why complicate things?

[welshpug 1,661]

100% standard tu3j2 will match that and use less fuel.

[tdr_1976 41 1 Cars]

No doubt it will.

 

I love the sound of my 40's, regardless of how much fuel it uses!

 

I could have got more power out, but I wanted to keep it from working too hard, as she's my daily driver......

[trogboy 17]

the compression actully plays that bigger part..?

 

Yes. 8.5:1 is turbo charger territory so I imagine it would be like driving a motor with a goosed turbo - very lazy

[MiniGibbo 142]

Think I'm going to get my self some domed pistons from a s1 106 xsi in that case then to pick the compression back up..

[309jazzpanda 41]

Or put a turbo on with such low compression, (does evil laugh)

[MiniGibbo 142]

Just seen this lol..

 

I actually got offered a 8v turbo set up not long ago. Not this time round I'm affraid.

[joed66 4]

oh so i can turbo mine by just putting a vtr head on to drop the compression.

[309jazzpanda 41]

Didn't think this warranted a new topic but, is it correct the early vtr had 90bhp but the 106 rallye had 105bhp?. What's the crack there then?