Betty the Oval - Donovan D - ex-MINCE

[Donovan D]

It could be you are pushing the piston too deep.
Your peddle stop must stop the peddle about 2 mm before you hit the back wall of the MC.
If you do not do this, you can get the piston jammed as well as tearing the cup seals.
Herman

I have also suspected the travel being too much as there is no pedal stop. The pedal stops against the body, will put a wedge in and see where and if it returns.

The master cylinder can be suspect. Is it a rebuild or a new item?

It is a new item, but it was in the box for a good couple of years.

[Donovan D]

Played around with it a bit more yesterday.
Slackened off the rear brake pads a bit with the hopes that the return springs on the brakes might be that bit required to return the master cylinder.
Also added a 1cm thick piece of wood between pedal and body. Still no luck. It still sticks and does not return immediately.

Took the cylinder off and inspected it, rubbers and everything else seem to be in good condition.
The travel on the brake push rod is 26mm, the travel of the piston in the cylinder is 41mm. Which means I have about 15mm left in the cylinder before bottoming out.

@sean where do you get the rebuild kits from ?

[sean]

Played around with it a bit more yesterday.
Slackened off the rear brake pads a bit with the hopes that the return springs on the brakes might be that bit required to return the master cylinder.
Also added a 1cm thick piece of wood between pedal and body. Still no luck. It still sticks and does not return immediately.

Took the cylinder off and inspected it, rubbers and everything else seem to be in good condition.
The travel on the brake push rod is 26mm, the travel of the piston in the cylinder is 41mm. Which means I have about 15mm left in the cylinder before bottoming out.

@sean where do you get the rebuild kits from ?

That doesn't appear to be everything, compared to an original that is. There should be a one way valve at the end of that spring as well as another cup seal. I purchased the kit from Good Hope Spares. I took all the stock, maybe they will have to order. This was for a bus though. Are the diameters the same as beetle? It certainly looks the same in your pic as a bus master cylinder.

[Donovan D]

This is a 21mm unit, I actually see that there is a no 'valve' option on bus MC's which is meant for discs.
Maybe the spring is just the wrong way around as the cap on the spring was on the break switch side and not the rubber against the piston.

This is the order it all came out.

[sean]

This is the layout of how I assemble the master cylinder. It does appear your spring is incorrect.

[Donovan D]

Re-assembled with spring facing the other way and still doing the same.
After doing some online research it seems that the check valve is indeed removed when using discs. Volkspares even sell both bus MC's, one with and one without the check valve. Next try would be the rebuild kits

I purchased the kit from Good Hope Spares. I took all the stock, maybe they will have to order. This was for a bus though.

Please send me the part number for this, I will get them to order.
They only have the beetle kits in stock, which is either 17 or 19mm, bus ones are 21mm. Appears I have a bus one.

[retrovan]

Just remember the stopping will be easier and more effective with the same foot pressure with a smaller diameter MC

As you do not need a big quantity of brake-fluid to stop with disk brakes, the smaller MC would work just nicely.

They used the bigger MC on cars which needed more fluid in there system to not fail.

OMO

Herman

[Donovan D]

A couple of things happened since the last update.
The beetle is going in end of Feb for touch ups, cut and polish. Then its time for the final assembly and getting all the nice chrome bits on.

Tony Z built the engine. Just need to finish up some wiring on my side and then she is good to go.




























































Collection day and taking the engine home.









The exhaust that was built.

[AlanH]

Wow, nice exhaust. What spec is that engine? cc's .....

[retrovan]

Well done D, she's looking lovely

Near time to start and ride.

Enjoy

Herman

[Tony Z]

The engine is built up mostly of CB Performance parts as well as a few other items from select suppliers/manufacturers.
Almost eveything is new. From memory, the crankshaft keys and the flywheel are the only used parts.

It is a 2109cc (76x94) engine with 9.2:1 CR
CB Performance crankshaft
Mahle forged 94mm stroker piston kit
Heads are CB Panchitos
Cromoly pushrods
Stainless steel windage pushrod tubes
CB H-Beam conrods, good to approx 9000rpm, with ARP bolts
cam is Engle W120, with Engle followers
CB crank trigger ignition
New Autolinea crank case
Kennedy Stage 1 pressure plate
lightened and resurfaced flywheel
all the bells and whistles employed to make it work as I feel it should.
We'll have to do some tuning once the car is up and running.


Below is a short video of the engine after I had finished with the 20min break-in period.
Rev limiter was set to 5000rpm at this point.

[AlanH]

I'm jealous.
Think that engine would do nicely in my Westy.

[Tony Z]

I'm jealous.
Think that engine would do nicely in my Westy.

I know you are joking, but I wouldnt build that engine for a bus - you'd end up hating it with the weight of the bus. I'd def build you a different spec.
Thats exactly why I build custom engines to the customers spec, wishes and budget.

[Herbie]

That engine sounds awesome! Well done Tony!

[Tony Z]

That engine sounds awesome! Well done Tony!

I'm sure we'll get a better video once the bug is up and running. Pretty sure that both myself and Donovan are looking forward to getting the full potential out of that engine.