12mm head on a 1.6 pump

[fatmobile]

I'd like to put a 12mm head on a 1.6 TD pump.
 I don't want an aggressive cam plate,.. because it'll ramp at lower RPMs than the 1.6 camplate.
,... and really a 12mm pump should supply all the fuel I need.
 I mostly want it because it'll shoot fuel in quicker. Same amount of fuel but the plunger moves a shorter distance.
 I asked Libbybapa about it and he said I need a head from a 4BTA pump.
 Why a 4BTA? and not just a 4BT?
 How much is there to this?
 Just swap the head/plunger?
 It seems like hillfolk tried this and the footprint of the plunger didn't match the cam plate,.. so he had the plunger trimmed down to fit.

[zukgod1]

I did that Andrew..

I found a piece of fuel line that fit over the plunger snugly then put it in a drill, I then busted out the die grinder with a thick grinding wheel/ cut off disk on it, while spinning the plunger I used the die grinder on the outer edge of hte plunger till it was the dimensions I needed.
All is good now.

[fatmobile]

Thanks everyone.
 I have a vice on my drill press, that can hold my angle grinder.
 I also grabbed a piece from a small mill while I was at the scrap yard long ago and the vice is mounted to that. It lets me move the vice right/left, forward/back by turning knobs.
 
 I'd like to clarify what tintin was saying, see if I read it right.
 It sounded like the little spacer disc (between the plunger and cam plate)needs to be the right thickness,... so the collar rides in the right place.
...and that takes a special calibration tool.

The local bosch service center has several new 12mm, 4BT, head/plunger sets he got a few years ago.
 He wants $100 for one.