I made it so the pressure don't vary so much with rpms,and a stiffer spring. It screws with the timing as a side affect. I didn't think it helped a whole lot. With bigger plungers or four, there would be a bigger difference.
You've got nearly 35cc on me. Mines @125 at 2000 Engine RPM, and as mentioned the 101cc to 5500. But, this thing has all the driveability manners as a stock one.
What did you do to the metering valve? I've got another pump that's nearly new I'd like to mod, this pump we've been playing with is getting a little worn.
Just when I was gonna get bored with the 4974 and throw on the DB4, looks like we have more to go...
Gathering parts up for a compound turbo setup, guess I'm not impressed with just the one.
Seems that more and more guys are looking at compound set-ups, we figure it might be a good direction also. Go figure, that only 2-3 years ago we would have been laughed off the sites for contemplating compounds....LOL.
I drove it a little yesterday. It now has a Military 6.2 ,with new pistons and rings. It's all stock except orings and 12.9 head bolts,reused the original bearings. I have less than $300 in this motor,crack free. I reused the turbo and injector pump,and used the Mercedes injectors. I only got on it half throttle,and boost instantly went to 30 psi. I tried to drive it at 10-20 psi,but it just smoked,about 1/4 throttle. It seems to be overfueled more,since the motor is smaller. I built a small four plunger pump,and tried that,but the head and rotor must be too loose,it started hard,and has a weak idle. 3200 psi pop injectors,just make it worse.
Very neat stuff! Any video of this motor running? Are the mercedes injectors the same as the stock injectors? What are the benefits to running those injectors?
The main reason was for better quality Monarch brand. I tried them in my 6.5 with 17.6-1,and it hazed a lot. I figured they would work better with stock compression. There is lots of different nozzles that fit the 6.2 long body injector,no doubt there is a better one than what I got. It's still better than the 6.2 nozzles.
On the small four plunger pump that you built are you using a DB4-427 type pump say off a John Deere engine? I've seen these around here and there and looks very similar to the DB2-8xx pumps on the 6.2/6.5, except the top housing looks slightly different where you would normally have your fuel solenoid, HPCA, etc. Head and rotor looked just about identical besides having only the 4 delivery valves at the rear, compared to 8. I have a DB2-829 and DB2-831, but no 4 plunger. Really would like to learn and convert the two like you have, but I've never had a pump apart.
That's what I did. Would be a nice pump if you can find a good match to a 8 cyl head. I also had issues with the drive slot ,and not enough end play. Two .060 shims takes care of the drive slot,but the input shaft needs shortened. This could be some of my problem of hard starting. The old .310 head and rotor is going back in for now.