Engine swap, 617 to ??? - Page 2 - PeachParts Mercedes-Benz Forum

derherr65 · #16 10-10-2006, 04:47 PM

Quote:

Originally Posted by gsxr

The problem with VVT is that you need to control it. How do you plan to do that? The factory VVT systems are computer controlled.

Depends on the actuator. I'm guessing they vary voltage. If so it shouldn't be hard to read the tach signal and send the appropriate voltage. That would have to be mapped manually after some testing.

Quote:

Originally Posted by gsxr

Also, who said the stock pump was good for 200hp? No way...! AFAIK, once you get past 20-25% power gain, it won't idle anymore. Myna Diesel replaces the 5.5mm pump elements with 7mm elements and calibrates it so the engine will still idle. Once they do their magic to it, the sky is the limit... pretty sure the Finns have gotten 300-400hp from the 617.

I'd heard that power figure both here and on other mercedes forums, though no dyno runs to back it up as of yet.
Why would it suddenly stop idling?

gsxr · #17 10-10-2006, 04:56 PM

Quote:

Originally Posted by derherr65

Depends on the actuator. I'm guessing they vary voltage. If so it shouldn't be hard to read the tach signal and send the appropriate voltage. That would have to be mapped manually after some testing.

Ah, but do you want it based on RPM alone, or boost pressure, or throttle position, or a combination of all those? I think this will be harder than you think. I had toyed with the idea myself, but with the idea of a simple on/off trigger, where the VVT would flip to the opposite mode beyond a certain RPM and/or boost level. Done properly this would be fabulous for power delivery but it will definitely take some R&D work.

Quote:

I'd heard that power figure both here and on other mercedes forums, though no dyno runs to back it up as of yet. Why would it suddenly stop idling?

What happens is that as the full-load stop is turned up, it moves the whole rack (richer). In other words, it doesn't just increase the fuel limit, it shifts the entire delivery curve upward (possibly requiring the ALDA to be set leaner after adjusting.) Past approximately 20-25%, it pushes too much fuel at idle, and the idle RPM's end up way too high, and the idle adjustments won't take it back down to normal (600-700rpm). The 617 pump is more of a pain, from what I understand, as it has a different governor design than the 602/603 pumps.

derherr65 · #18 10-10-2006, 05:04 PM

I was going rpm alone for simplicity. Lol, I'll bet you're right, it will be harder than I think.

I see, at which point you'd have to fully understand the working and interrelationship of the IP adjustments to lean it at idle only. I don't believe I've met anyone that knows that, let alone myself. I'm guessing it involves the course idle adjustment or torque control, both of which no one advises you touch.

Rashakor · #19 10-10-2006, 05:35 PM

Quote:

Originally Posted by derherr65

I want a VVT for it's ability to make boost throughout the rpm range. You know, little turbo = no HP, big turbo = no bottom end.
I had heard the stock pump was good to 200-225HP.

Correction the stock pump is good for 200-225 ftlb and maybe 150hp! with the correct motivation (VVT, IC, and Myna) there is no a priori reason 200hp and 300ftlb are unattainable. How to do it is another question...

#20 10-10-2006, 08:12 PM

Quote:

Originally Posted by vstech

how about a 5.9 or larger cummins?
they have massive weight, and are a bit larger than our 617's but they are not computer controlled, and they do have more HP and Tourque than the 617

I hate to rain on the parade, but a 5.9 is about a foot taller, a foot longer, 400lbs heavier, and the torque of even a non-intercooled 160HP unit would have you snapping axles like twigs and twisting driveshafts.

However, a 3.9L 4-banger Cummins would be great. With a "hood scoop", it would be a snap to fit one in a W123. They have the same 120HP as the stock 617 but about twice the torque.

I've seen them "bombed" into the 300HP range with FAR less effort than a 617 would need to do the same.

Hatterasguy · #21 10-10-2006, 09:40 PM

Purchase a 1986-1987 300D, this will accomplish two things:
Gives you a better engine to start tuning with. Out of the box you are already making more power.

Secondly it gives you a W124, this is a plus because of the aftermarket. You can add things like bigger sway bars, larger brakes ect ect. You can really tune one.

vstech · #22 10-10-2006, 10:04 PM

Quote:

Originally Posted by Hatterasguy

Purchase a 1986-1987 300D, this will accomplish two things:
Gives you a better engine to start tuning with. Out of the box you are already making more power.

Secondly it gives you a W124, this is a plus because of the aftermarket. You can add things like bigger sway bars, larger brakes ect ect. You can really tune one.

Eh? Eh?

sixto · #23 10-10-2006, 10:08 PM

A 300D wasn't sold in the US in 86.

Sixto
93 300SD

Hatterasguy · #24 10-10-2006, 11:52 PM

Quote:

Originally Posted by sixto

A 300D wasn't sold in the US in 86.

Sixto
93 300SD

Oh really.

speedy300Dturbo · #25 10-11-2006, 12:09 AM

Quote:

Originally Posted by Hatterasguy

Oh really.

For the sake of nitpicking...

In the US, the OM603 was only available in a W124 chassis for "model year 1987". However, many 1987 300Ds were manufactured and sold in 1986!

derherr65 · #26 10-11-2006, 12:15 AM

Quote:

Originally Posted by derherr65

I was going rpm alone for simplicity. Lol, I'll bet you're right, it will be harder than I think.

Though, if you want to make it really simple... there's a mechanical arm that must be pushed or pulled. There's also a pressure limit you want to set. The correctly sized pressure actuator would move that arm as soon as you pressure limit was hit, reducing blade angle, and limiting boost. With a little dampening perhaps, the turbo would spool quickly up to XX PSI and hold that pressure throughout the rpm range. The only problem being if there is a failure the turbo would default to closed. So you'd have to have a overboost protection system... kinda like the Mercedes overboost protection system. The downside would be a slight exhaust restriction... which may or may not be worse than the current turbo. Oh, and the uncertainty of what the IP does when you have full boost and low throttle position.

bgkast · #27 10-11-2006, 01:09 AM

Quote:

Originally Posted by gsxr

The problem with VVT is that you need to control it. How do you plan to do that? The factory VVT systems are computer controlled.

Here is how a VW guy did it mechanically:http://www.vwdiesel.net/phpBB/viewtopic.php?t=1306&postdays=0&postorder=asc&start=0 Now we need somebody to do it for a MB and write a how to!

Rashakor · #28 10-11-2006, 09:30 AM

Quote:

Originally Posted by ForcedInduction

I hate to rain on the parade, but a 5.9 is about a foot taller, a foot longer, 400lbs heavier, and the torque of even a non-intercooled 160HP unit would have you snapping axles like twigs and twisting driveshafts.

However, a 3.9L 4-banger Cummins would be great. With a "hood scoop", it would be a snap to fit one in a W123. They have the same 120HP as the stock 617 but about twice the torque.

I've seen them "bombed" into the 300HP range with FAR less effort than a 617 would need to do the same.

Well, now you caught my attention! Where can we find that 3.9L? the only ones i have ever seen for sale are the monsters 5.9 and 7+ Liters. Of course i have no intention to do such a conversion but it always interesting as a case study.

gsxr · #29 10-11-2006, 10:45 AM

Quote:

Originally Posted by Hatterasguy

Purchase a 1987 [or 1990-1993] 300D, this will accomplish two things:
Gives you a better engine to start tuning with. Out of the box you are already making more power. Secondly it gives you a W124, this is a plus because of the aftermarket. You can add things like bigger sway bars, larger brakes ect ect. You can really tune one.

I'll second that recommendation.

derherr65 · #30 10-11-2006, 10:49 AM

Great link. Lots of food for thought there.