The great comparision table of injector piston-barrel elements for Bosch MW pumps for our beloved Mercedes cars.
Hello all fellow visitors, colleagues and especially, my dear, beloved lab rats.
The long promised table of many MW injector pump elements is at http://spreadsheets.google.com/pub?key=pZMMSqp3uSZdyqyAJ0XqRCA
I hope you appreciate the long, hard work :)
Now some notes for those visiting this page directly, it is about replacing 5.5mm diameter piston-barrel MW injector elements with 8mm, 9mm, 10mm (preferably) or even 11mm types.
As far as the superturbo modification go, please, take care so that the maximum combustion pressure will not blow the head gasket away, nor terminally damage rod bearings.
To do that, you may really want to limit the maximum fuel delivery and keep all the limiters in governor inside, you really may appreciate that they are there to save your engine!
Also, you will want to experiment with injection timing and bring the beginning of injection closer to TDC. One of the reasons is that the injection of the same amount of fuel may be finished 2x to 4x sooner than originally designed, so the fuel will have more time to combust and therefore reaching peak pressure sooner and we want this happen at or after the top dead center. (YRMV)
This, under extreme settings, may bring more white smoke, but under lead foot the maximum pressure peak may be dissolved in rapidly proceeding expansion due to piston downward movement. This will rob you of some horsepower, but it also greatly reduces stresses on your piston, head, gasket, bearings. I suggest this move for maximum power modifications, or any other application where emissions are irrelevant, but absolute maximum achieveable power is important. You can see something like that in tractor pulling, where start of injection begins at 50°before TDC and ends in a similar fashion. But hey, 2MW is not what we want here, right?
Injecting much fuel after, say 30°TDC will increase power output without increasing stress, but the efficiency of doing so is lower than with injecting fuel well in advance.
Also, overall injection time will be one third of original for the same engine power output and this gives you great chances on reducing engine emissions.
My advice is then: keep the maximum pressure down and heat will also be less of a problem, even if the temperatures will be high, it is the pressure what deforms objects, heat only makes them weaker.
My last advice: different, more durable bearing material for the crankshaft and piston rods. If you are going to increase the stresses, you have to prepare the bearings accordingly.
P.S. I am great fan of synthetic 10W-60 oil too, used in short exchange intervals.
As you will notice, I added a Donate button, yes I dropped down that much, I simply have to admit that spending countless hours doing research means doing less (or no) work I might be paid for.
If anyone here after reading that long page will need any aid in purchasing a specific element set, I will go to ask distributor(s) if or when they will be able to provide web interface for you.
Thank you for your input.
The long promised table of many MW injector pump elements is at http://spreadsheets.google.com/pub?key=pZMMSqp3uSZdyqyAJ0XqRCA
I hope you appreciate the long, hard work :)
Now some notes for those visiting this page directly, it is about replacing 5.5mm diameter piston-barrel MW injector elements with 8mm, 9mm, 10mm (preferably) or even 11mm types.
As far as the superturbo modification go, please, take care so that the maximum combustion pressure will not blow the head gasket away, nor terminally damage rod bearings.
To do that, you may really want to limit the maximum fuel delivery and keep all the limiters in governor inside, you really may appreciate that they are there to save your engine!
Also, you will want to experiment with injection timing and bring the beginning of injection closer to TDC. One of the reasons is that the injection of the same amount of fuel may be finished 2x to 4x sooner than originally designed, so the fuel will have more time to combust and therefore reaching peak pressure sooner and we want this happen at or after the top dead center. (YRMV)
This, under extreme settings, may bring more white smoke, but under lead foot the maximum pressure peak may be dissolved in rapidly proceeding expansion due to piston downward movement. This will rob you of some horsepower, but it also greatly reduces stresses on your piston, head, gasket, bearings. I suggest this move for maximum power modifications, or any other application where emissions are irrelevant, but absolute maximum achieveable power is important. You can see something like that in tractor pulling, where start of injection begins at 50°before TDC and ends in a similar fashion. But hey, 2MW is not what we want here, right?
Injecting much fuel after, say 30°TDC will increase power output without increasing stress, but the efficiency of doing so is lower than with injecting fuel well in advance.
Also, overall injection time will be one third of original for the same engine power output and this gives you great chances on reducing engine emissions.
My advice is then: keep the maximum pressure down and heat will also be less of a problem, even if the temperatures will be high, it is the pressure what deforms objects, heat only makes them weaker.
My last advice: different, more durable bearing material for the crankshaft and piston rods. If you are going to increase the stresses, you have to prepare the bearings accordingly.
P.S. I am great fan of synthetic 10W-60 oil too, used in short exchange intervals.
As you will notice, I added a Donate button, yes I dropped down that much, I simply have to admit that spending countless hours doing research means doing less (or no) work I might be paid for.
If anyone here after reading that long page will need any aid in purchasing a specific element set, I will go to ask distributor(s) if or when they will be able to provide web interface for you.
Thank you for your input.
posted by Mario. at 11:54 PM
3 comments
