K-jet throttle body -> D-jet manifold - PeachParts Mercedes-Benz Forum

PanzerSD · #1 11-13-2010, 03:31 PM

Are the bolt patterns the same on these manifolds?

GGR · #2 11-13-2010, 07:54 PM

No, they're not. I tried an early 5.0 65mm and a later 5.6 70mm and all three have different bolt patterns. What's your objective?

mercmad6.3 · #3 11-13-2010, 09:04 PM

The 560 can be fitted if you weld a small adaptor plate to the manifold and bore the manifold to make a nice flow into it from the throttle body.
I have seen a 560 throttle body on a 6.9 and it made a world of difference so you are on the right track by getting more air through the manifold.

PanzerSD · #4 11-13-2010, 09:47 PM

Turbocharging with the re-location of the K-Jet system. using the D-jet manifold because the throttle body is in the center of the manifold. but then I thought, why not just use a D-jet throttle body? Ithink I will need the clearance for air tubing so I'm exploring the thought of relocating the sensor to where the battery is and moving the batt to the trunk...It's a wild idea, but I'm just researching right now..

Wodnek · #5 11-13-2010, 10:08 PM

Quote:

Originally Posted by PanzerSD

Turbocharging with the re-location of the K-Jet system. using the D-jet manifold because the throttle body is in the center of the manifold. but then I thought, why not just use a D-jet throttle body? Ithink I will need the clearance for air tubing so I'm exploring the thought of relocating the sensor to where the battery is and moving the batt to the trunk...It's a wild idea, but I'm just researching right now..

I am guessing that you would need the heads off the djet as well.

PanzerSD · #6 11-14-2010, 12:46 AM

I did a quick check on the part numbers for D/K je t intake gaskets and they list as the same part.. could there be a difference in surface angles and such??

Tomguy · #7 11-14-2010, 01:19 AM

D-Jet mani should bolt right on to K-Jet heads, as long as we're talking M117 to M117. Deck height is taller on a M117 than M116 therefore the intake is wider for the 4.5 than 3.5, that wouldn't work; the rest should be straightforward. I thought of putting a K-Jet one on my 4.5 for better flow at one point but stopped putting work into my 4.5 until I decide what route to go & get time to either part it or restore it!

I would look into S/C vs T/C. I'd think the stock D-Jet manifold bottom opening is in a prime spot for an overhead S/C. Less work to do S/C too (no oil lines to turbos, no exhaust mods required, less underhood space needed, etc). No turbo lag either. Cheaper. I could go on. Your low-compression engine would take to 10 PSI well I'd imagine. Use D-Jet cams with manual studs because K-Jet ones open too late so your exhaust would get pretty hot, may melt a valve or seat...

PanzerSD · #8 11-14-2010, 01:43 AM

Quote:

Originally Posted by Tomguy

D-Jet mani should bolt right on to K-Jet heads, as long as we're talking M117 to M117. Deck height is taller on a M117 than M116 therefore the intake is wider for the 4.5 than 3.5, that wouldn't work; the rest should be straightforward. I thought of putting a K-Jet one on my 4.5 for better flow at one point but stopped putting work into my 4.5 until I decide what route to go & get time to either part it or restore it!

I would look into S/C vs T/C. I'd think the stock D-Jet manifold bottom opening is in a prime spot for an overhead S/C. Less work to do S/C too (no oil lines to turbos, no exhaust mods required, less under hood space needed, etc). No turbo lag either. Cheaper. I could go on. Your low-compression engine would take to 10 PSI well I'd imagine. Use D-Jet cams with manual studs because K-Jet ones open too late so your exhaust would get pretty hot, may melt a valve or seat...

I am aiming for 10 PSI before i have to inter-cool..

I would like to keep the K jet throttle body because of it's size and simplicity, and the upper plenum because it slows better... but then who says that the throttle body has to be in the same place

...

I can see this is going to turn into a monster...

A Question just for tomguy...you speak cam's fairly well there, I have the D jet cams waiting to go onto a K jet head, but I would love to keep my 10mm oiler lines and towers..are the k-jet towers grooved or not grooved?

Tomguy · #9 11-14-2010, 03:15 AM

Honestly, not sure. D-Jet sets varied for example I think the 47/48 and 52/53 are cam grooved while the 56/57 is tower-grooved. I may be messing up which is which but these sets are all D-Jet & all vary.

PanzerSD · #10 11-14-2010, 02:52 PM

I guess I'm not really going to know until I have the K-jet cams out...Oh well...I can't imagine any discernible difference in oil flow from the 8mm tubes to 10mm. The only thing stopping me is the availability, locally of the plastic fittings, and a good solid two or three days off work

PanzerSD · #11 11-14-2010, 04:54 PM

I see the subject has changed somewhat, more cams discussion in THIS thread

PanzerSD · #12 11-19-2010, 10:13 PM

bump

GGR · #13 11-19-2010, 10:43 PM

I did fit a 4.5 Djet manifold on a 5.0 M117 for Megasquirting. I had to grind the plenum for clearance but I guess you will be fine on an Iron block.

You should consider fitting some 560 camshafts. Valves Open more and longer. You could even fit 560 heads: bigger intake valves, bigger intake and exhaust ports and bigger diameter exhaust manifolds.

Given that you will supercharge I wonder if 5mm wider TB will do a big difference. Just increase the pressure a bit. For info the early 5.0 also has a 65mm TB like the 4.5 and AMG kept it on its 5.4. So it may not restrict that much. And BTW your KJet 4.5 TB may be 65mm just like the Djet one.

Keep us posted on your supercharging project, I may consider it for later.

winecountryone · #14 11-19-2010, 10:49 PM

Quote:

Originally Posted by mercmad6.3

The 560 can be fitted if you weld a small adaptor plate to the manifold and bore the manifold to make a nice flow into it from the throttle body.
I have seen a 560 throttle body on a 6.9 and it made a world of difference so you are on the right track by getting more air through the manifold.

I have thought the stock d jet one looked really small for an engine of that displacement.How much more could one expect to get with a bigger throttle body and what other mods would need to be done to appreciate it(bigger injectors,etc)

mercmad6.3 · #15 11-20-2010, 01:06 AM

Quote:

Originally Posted by winecountryone

I have thought the stock d jet one looked really small for an engine of that displacement.How much more could one expect to get with a bigger throttle body and what other mods would need to be done to appreciate it(bigger injectors,etc)

The bigger diameter throttle body allows more air to flow and this opens the fuel distributor faster and quicker under load to supply a correspondingly increased fuel flow. This all equals to more horsepower.
The big advantage of Kjets is that the more the slots in the spindle valve are opened the more fuel is pumped and the injectors will supply far more fuel than you will ever need .
Electronic systems are Ok for easy tuning but the fuel is under less pressure through the injectors. This means that the fuel isn't as properly atomised as it is with the mechanical Kjet which pumps fuel at 3.4bar to 5.0 bar.

I can't give a definite answer on the question of horsepower increase .
On the 6.9 with the 5.6 throttle body the increase was amazing.

http://www.youtube.com/watch?v=3s81bv6tdzU