Punto (Mk1) Punto Mk1 1368 Fire Rotrex Supercharged!

[DaveMcT]

Rods tend to break when revs are high on a closed throttle. There is no pressure holding the pistons down, inertial load increases and the rod snaps. This is why sometimes an F1 engineer will tell the driver to only use full revs with full throttle. Paradoxically this gives the con rods an easier time.

RR had the same issue in WW2 with highly blown Merlins. The pilot was required to drop the revs before dropping boost pressure (closing the throttle) or have the engine explode. Max revs were also limited in part boost.

Munkel's engine was so badly wrecked its impossible to say if the rod snapped and separated the big end bolts or the other way around. But with the holes being above the crank its most likely the rod snapped and the broken end punched out the cylinder block. The big end bolts failing (milliseconds) later. At 600 revs the pistons go up AND down 100x per second.

For tensile strength go with forged alloy steel.

 

[HoSDo]

Meanwhile in Italy...

.. this is my favourite shot...

 

[blu73]

that'll polish out that

 

[HoSDo]

This is an experimental double neutral gearbox The second one is placed between 2nd e 4th gear :bang:

 

[HoSDo]

 

[fingers99]

Wonder if the T Jet box will fit? Someone offered me a bellhousing to adapt the 6 Speed box to the T Jet engine, but the other way round..............

 

[HoSDo]

Spent the last week checking the possibility to fit a Mito / Tjet 6 gear trans, but on the Mk1 it's too tricky. Two brackets need to be rebuild, shafts and joint should be modified or custom made, clutch uses a dual mass flywheel so I'd rather have to find a single mass upgrade kit, hydraulic clutch release is the later type with internal actuator so I had to install clutch pump behind my pedal and of course the whole piping...

Too much..

 

[fingers99]

I've heard (don't know if it's true) that the T Jet box is close relative of the box in the FIAT/Alfa twin cam engined cars (1.8 and 2 litre 155, etc.) They don't have a great reputation for strength (at least, in their original applications), but should be tougher than the 1.4 16v one.

Per lo meno, no dual mass nonesense to contend with.

 

[HoSDo]

Tho whole story is that on the Early Typ 199 Grande Punto they only used the 514.5 and 514.6 both on the gas and diesel engines. Same for the Idea/Musa line.

Then with the TJet coming in, they had to fit a stronger transmission so the old 510.5 was placed in but there was a lack of suitable 6 gear transmission in the offer. So they asked opel for their M20/M32 project going under the FIAT code C544 and C542.

This was set on Abarth Puntos, Mito, Bravo Tjet and Mjet, Grande Punto 1.3 90 and 1.9 130.

Once they ceased the cooperation with Opel, C544 was discontinued and so they had to build a new 6 gear transmission, the C635 that could be found on the later Mito and Punto Evo Abarth. 500 Abarth uses the C510.5

So, actually FIAT made the C510 suit to it's Fire engines thus it would be sure easy fitting it on any Mk1 / Mk2 since it was already fitted it from the very start of the projects. Punto GT, Punto TD, JTDs, MJETs and HGT all were fitted with the 510 so any of these frames with a non conventional Fire on it could be converted to a C510 runner!

 

[SamuraiDragon]

bit of t-cut would sort that damage out. just make sure u use a lint free cloth so no dust gets into the box.