Quote:
Originally Posted by peterux
I think I have solved the puzzle of the 'Ford' Master cylinder part number.
After double checking and then realising my BMW master cylinder is actually a dual diameter bore size, I decided to go for a 22mm cylinder.
Based on a hunch that the Marlin supplied M/C it was off a Ford Sierra and Mike's info that it is a Bendix OE, I ordered a BMC4052 from Brakes International.
It arrived today and has the magic numbers 383059 on the side.
It's just like Jason's but with the outlets on the engine side.
It is manufactured by an Italian firm called Cifam. ( www.cifam.it)
The logo on the M/c is Ci. It is Cifam part number 202-099.
The Cifam website and catalogue has lots of useful info with pictures, 'where else used' and other suppliers equivalent part numbers.
It is brand new in a sealed box and was delivered to my door about 42 hours after I placed the order!
Manufacturers packing date is 08/07/11 so nice fresh stock.
Total price was £57.96 inc. VAT and courier delivery.
Thanks to Robin for finding www.brakesint.co.uk
I'll be checking all the relevant measurements and post some pictures over the weekend.
...peter |
Peter
Can I ask a couple of questions so that others can consider their options?
Have you fitted standard BMW brake parts in the rest of your system?
Do you know the bore size of your original m/c? - you say it is dual diameter bore size? Are you suggesting the two bores are different sizes?
The reason I ask is you are negating a significant part of the impact of increasing the servo pressure, by opting for the larger bore master cylinder.
Robin has stated his BMW bore size is 20.6mm in his standard set up. I know it does not sound much different, but the pressure in the brake system transmitted by the bore is related to the surface area: the bottom line is the 22.2mm m/c will be 16% harder to press than the 20.6mm. This is significant, given the reason for going to all this trouble is to make the brake pedal easier on the leg muscles.
I chose the 22mm bore m/c as it matches the original Ford Sierra spec to go with my Ford Sierra brake set up. The dual servo gets closer to the original Ford 8" servo, so I should have a system as close to Ford's original spec as possible. By opting for the 22mm bore you are making yours 16% harder to press than in the donor BMW (using Robin's bore figure)
There are, of course, other considerations. The pedal travel on the 22mm bore will be 16% less than the 20.6mm bore and it may be felt that this is worth having - I am in no position to comment as I do not know what it feels like in a BMW based car.
I do not wish to suggest you have got it wrong, but others following this thread need to understand that all our cars are not the same, and that a m/c that works in a Ford set up will not necessarily perform the same in the BMW set up. All other things being the same in the brake set up, my preference would be to opt for a m/c with the same size bore as the donor?
Of course you can suggest Jason has fitted the 22mm bore in his BMW set up and is happy. Given the opportunity to do it again with a 20.6mm bore and 16% less effort, but longer pedal, what would he do next time?
Please take this as a constructive question, for the benefit of others who are still able to choose their set up.
Regards
Mike