My DB4 pump showed up today, bought it on Ebay,as is and seized,I'm hoping to salvage the rotor,I did turn it a hair,but it's definitely a little tight.
I have no idea,but it has a AG style governor,and manual and electric fuel shut of. I got it all apart ,the front bearing was the only thing seized,the rest looks like brand new, I will upload pictures later tonight. It is a 4 cyl pumpwith 4 .270 plungers,the 4 cyl can be converted to 8 but 4 plunger 6 cyl can not,2 plunger fits them all. A while back there was a lot of these on Ebay,hopefully there will be more to come, I'm kinda impressed with it.
I install the rotor in an 8cyl head,it must be exact fit,I have several to choose from,and then go with one that is snug but not to tight,its all by feel. This pump came with the bigger drive slot,so I will need to get a spacer made to mate this rotor to the 6.5 pump drive shaft,my other 4 plunger head and rotor had the correct slot for the shaft. I will try to put as many db4 parts into a db2 housing that I can,the advance piston is the same diameter ,and the cam pin is way bigger and better,so a db2 cam ring will need to be machined to accept the pin,the ag style governor is interesting,but more difficult to remove than the automotive style , I believe with the right spring, an ag governor will give more fuel,because it looks like it could be easier to get more travel out of this set up,but it will not easily swap into the db2
I cant wait to see this put together id love to do something like this if their wasnt so many other things falling apart on my truck. Keep up the good work, by the way where in PA are you located? Im just north of Pittsburgh.
It's not a military pump. It's a marine pump. Peninsualr Diesel sells them. They can custom build a Mech IP anyway you want it. They discouraged me from running a DB4. Told me they could build a DB2 HO that would deliver more fuel than the motor could handle.
Db4 pumps are not only made for marine use,and I'm under the impression that Peninsular's 4 plunger pump is a converted db2 and their biggest 2 plunger has only.350 plungers,which is not that huge,stock is .310 on the 6.5 and .290 on the 6.2.
I haven't tried one yet,my 6.2 wouldn"t have made a good test any how since the compression is too low. I don't know how much it will be,but it will be cheap,especially if I didn't test it.