Cut Delivery Valves: Has anyone done it? - PeachParts Mercedes-Benz Forum

Ian White · #1 11-30-2009, 12:39 AM

Except for FI

. What have you guys noticed? More power/ smoke? Higher EGT's? What exactly does cutting the DV's entail?I have just completed my engine swap in my 81 300SD. It now houses a 1984 model year 617.952. The alda has never been touched (evidence of this being the metal band around plastic cap over adj nut). I want to remove it soon because it isn't near as peppy as my former benz engine (stock 1981 617.951). I need to check my boost on this .952 and report back. Basically, I am looking for good performance while trying not to sacrifice too much mileage-I know people in Hell want icewater

.

Thanks in advance!

DrewGerhan · #2 11-30-2009, 12:48 AM

From what I've read, messing with the delivery valves is not advised without a flow bench. I've removed the rack limiter and alda in mine and also turned up the torque control. Gave a good bit more power and smoke, of course I wanted both of those things.

Ian White · #3 11-30-2009, 01:02 AM

Quote:

Originally Posted by YoungBenz

From what I've read, messing with the delivery valves is not advised without a flow bench. I've removed the rack limiter and alda in mine and also turned up the torque control. Gave a good bit more power and smoke, of course I wanted both of those things.

Did you remove the IP or just remove the oil filter housing to gain access to the rear cover on the IP... Please elaborate... Whats your 0-60 time?

KarTek · #4 11-30-2009, 08:45 AM

I have a set of modified DV's ready to go into my E300. I'm curious to see how they do.

I just need to buckle down and buy a DV tool...

JHZR2 · #5 11-30-2009, 09:10 AM

Have you checked the banjo bolt and cutoff to ensure that the ALDA actually sees boost?

DrewGerhan · #6 11-30-2009, 11:16 AM

I've taken the pump off and then back on so many times. I feel the actual number is close to two dozen. Once the pump is off, you can take the back plate off and look at all the goodies inside. Be sure to do small increments when adjusting and always mark a point of reference just in case something gets FUBAR'd.

No idea on a 0-60. I do know that it will beat my moms escape, dads ranger, my buddys protege and my other buddies caddy. I need a G-Tech.

Ian White · #7 11-30-2009, 12:55 PM

Looks good; I think I may have more research to do... (FI, here I come)

mytmousemalibu · #8 11-30-2009, 01:17 PM

I have a 2nd set of delivery valves I cut myself. It runs like a raped ape with them! However it idles like crap! I didnt remove the whole collar on them, just ground 2 opposing notches in each one. It required the idle to be lowered when there in. As to why it idles poorly? I know i need new injector nozzles and my compression isnt the greatest but theres more to it that that. It might be some kind of pressure wave deal? I wish i had more time to play with them, try diff pop pressures, timing and stuff.

Ian White · #9 11-30-2009, 01:42 PM

Quote:

Originally Posted by mytmousemalibu

I have a 2nd set of delivery valves I cut myself. It runs like a raped ape with them! However it idles like crap! I didnt remove the whole collar on them, just ground 2 opposing notches in each one. It required the idle to be lowered when there in. As to why it idles poorly? I know i need new injector nozzles and my compression isnt the greatest but theres more to it that that. It might be some kind of pressure wave deal? I wish i had more time to play with them, try diff pop pressures, timing and stuff.

Do you measure EGT's? FI says the increased power is unuseable because of high EGT levels...

Simpler=Better · #10 11-30-2009, 06:32 PM

If I remember correctly cutting the delivery valves increases the duration of the injection.

mytmousemalibu · #11 11-30-2009, 07:25 PM

Quote:

Originally Posted by Ian White

Do you measure EGT's? FI says the increased power is unuseable because of high EGT levels...

ya know I didnt... I know I should have, but i didnt have an extra pyro probe and I do have a bit of diesel experiance so i didnt keep my foot buried into it. Judging on how much black smoke its pushin and how hard it pulls, im pretty confident egt's would be over 1000*F with out much issue. I do have another pyro probe now and im itchin for some speed so I might find out?

Now if I can manage to get a calm'er idle out of it and get things adjusted well, with a bigger more efficiant turbo and an intercooler and keep EGT's manageable, it would make for a pretty quick ride. Specially considering how relaxed these 617's are stock/lightly modded. Just needs more air to burn with all that fuel. Even it its still a bit warm, i dont see why i couldnt make some pump adjustments to get it in the good.

MTUpower · #12 11-30-2009, 08:28 PM

I did it with two different sets of cut DV's. Neither one would idle properly and both wanted to make the engine run away. Make sure your brakes are in tip top shape if you install a set and keep them in. I would not advise cut DV's.

Ian White · #13 11-30-2009, 09:50 PM

What is up with 'slotted DV's'?

Ian White · #14 11-30-2009, 09:56 PM

Quote:

Originally Posted by mytmousemalibu

ya know I didnt... I know I should have, but i didnt have an extra pyro probe and I do have a bit of diesel experiance so i didnt keep my foot buried into it. Judging on how much black smoke its pushin and how hard it pulls, im pretty confident egt's would be over 1000*F with out much issue. I do have another pyro probe now and im itchin for some speed so I might find out?

Now if I can manage to get a calm'er idle out of it and get things adjusted well, with a bigger more efficiant turbo and an intercooler and keep EGT's manageable, it would make for a pretty quick ride. Specially considering how relaxed these 617's are stock/lightly modded. Just needs more air to burn with all that fuel. Even it its still a bit warm, i dont see why i couldnt make some pump adjustments to get it in the good.

Did you cut them or slot them? How awful was the idle?

mytmousemalibu · #15 11-30-2009, 10:10 PM

Well on mine I used a dremel and a cylindrical diamond bit an made a U-shaped channel through the collar round the valves diameter. And put another opposite of it. I looked at how it was stock and seeing how restrictive it was, creating 2 passages through the collar was making a massive improvment on flow. I did it based on the previous observation and I wanted to start small and go bigger if needed. I also didnt want to grind the whole collar off because it does support/hold the DV true in the holders bore. I would have only put one cut in each but i didnt know it if a opening on one side would put a sideload on it and bind the valve. Well the 2 cuts I made seemed to be more than enough! If I could have fit it in, i wanted to cut a "slot" in the collar with a cut-off wheel but the clearance is too close and would have went into the DV seat margin and thus not seal. I'd like to get another set and try some smaller cuts in them.

And yes, the engine will rev up and try to run away if you just pop some in and dont adjust the idle stop screw. I drove on mine for 3 weeks or so with no issues other than crappy idle.

However, Those considering this, Be your own advocate, There are risks involved in this modification.