Hello from New Zealand - A question on clutches

[Tomorrowcalling]

Hi All.

 

I'm hoping for some advice on Skoda 110 / 120 clutches.   

I don't actually have a Skoda but I do have a Heron MJ1, these were sport cars built in New Zealand in the early 80's. They use a Skoda 110 transaxle, rear suspension and front suspension with a Fiat twin Cam engine (picture below).

 According to my measurements the clutch plate is 170mm diameter - some sources say that it was a "rally" spec clutch back in the day, however all the listings for clutches I can find are for 180 or 190 mm clutches. Is the 180mm a "nominal" size or is my clutch truly smaller?

The clutches were apparently always a weak link in these cars so moving to 190mm  would be a good move, is this possible ?. I'm fully prepared to have a new flywheel machined but I can't change the ring gear diameter.

[Tomorrowcalling]

I'm an idiot, just remeasured the clutch plate, it's 180mm, but my question about changing it to 190mm still stands

[KenONeill]

10 hours ago, Tomorrowcalling said:

advice on Skoda 110 / 120 clutches

My best suggestion is to search for detailed specifications on the Skoda 110R and 130RS models.

 

Incidentally, is the car a Lancia Stratos replica, a Lotus Esprit replica or not actually in the picture?

[Tomorrowcalling]

The yellow car is a Lancia Stratos replica, the grey car is the Heron MJ1.  They were not intended to be a Esprit replica but the styling was inspired by the Lotus (and other  wedge shaped cars of the era).

 

Fun fact - the Heron has a fully composite moncoque  chassis, the process to make it was patented and later sold to Lotus, in some ways it's the ancestor of the Elise

[KenONeill]

1 hour ago, Tomorrowcalling said:

the Heron has a fully composite moncoque  chassis, the process to make it was patented and later sold to Lotus

Interesting, particularly since Lotus made a car (Elite type 14) with a composite monocoque in 1957.

[Tomorrowcalling]

My understanding that it was more a "method" patent rather than the idea of composite  monocoque

[Thefeliciahacker]

Old skoda clutches were 180mm newer are 190mm

[Tomorrowcalling]

Quote

Old skoda clutches were 180mm newer are 190mm

 

Ok -  I've been having a hunt on line but I haven't  been able to find answers to the following questions - can any one help?

 

Does the flywheel for the 190mm clutch have the same ring gear diameter as the flywheel wheel for the 180mm clutch.?

 

Does the 190mm clutch plate have the same spline as the 180mm clutch?

[jikov RON]

Same splines and ring gear tooth counts are the same.

 

The 180mm clutch uses the ring gear to locate the clutch cover where the 190mm one uses the flywheel with the ring gear having a larger internal diameter, clutch covers are not interchangeable.

Also the 180mm clutch has a flat face release bearing, 190mm has a rounded face for the diaphragm fingers.

Pre 1983 = 180mm 

Posy 1983 = 190mm 

[Tomorrowcalling]

Cool - Thank you for that information, exactly what I needed to move forward.