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Mid 70s Volvo injection?
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Author:  rlklaus [ Sat Sep 28, 2013 3:13 pm ]
Post subject:  Mid 70s Volvo injection?
This is still in the very early thinking phase. The other day I was scouring our local U-Pull-It yard, and took a long look at a mid 70s Volvo 6 cylinder sedan.
The Bosch fuel injection looks like a good start for a slant six fuel injection conversion. Minimal hoops to jump through, looks like the only part I'd have to come up with is a relay box to generate the signal from the second set of points in the Volvo distributor. The system has no crank or cam sensors, and looks pretty much "Nuts n Bolts".
Anybody done this before?
Author:  emsvitil [ Sat Sep 28, 2013 6:11 pm ]
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What's the displacement of the Volvo engine?
Author:  rlklaus [ Sat Sep 28, 2013 6:48 pm ]
Post subject: 
The 164 engine is 3 liters. Translates to about 185 cu.in. Thinking that it might take some adjustment, but the Volvo engine is made to spin somewhat faster than a slant six, so I'm thinking everything might even out.
Author:  Sam Powell [ Sat Sep 28, 2013 7:21 pm ]
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How is the rpm read on the Volvo?

Sam
Author:  emsvitil [ Sat Sep 28, 2013 7:35 pm ]
Post subject: 
Larger capacity injectors and/or higher fuel pressure can probably also be used to correct for the displacement difference.
Author:  kesteb [ Sat Sep 28, 2013 11:06 pm ]
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Except that the system is obsolete, expensive and didn`t really work all that great back in the `70s.
Author:  Joshie225 [ Sun Sep 29, 2013 11:44 am ]
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That Volvo system is analog and not easily tunable. I would rather use CIS/K-jet and ditch the electronics almost completely than that Volvo D-jet system with its expensive and touchy pressure sensor.
Author:  olafla [ Wed Oct 02, 2013 9:32 pm ]
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I agree with Joshua Skinner, stay away from the electronically based injection systems. A totally mechanically operated Bosch K-jetronic injection system from a Mercedes 2.8 litre six-cylinder, prior to '85/86, could be adapted for use on a SL6. The throttle body is big enough, and the pressure to the injectors can be adjusted to give enough fuel - or replaced by bigger ones.
The K-jetronic is a constant injection system, that is - it deliver fuel all the time the engine is running, so it is therefore very simple, and very comfortable to deal with when it comes to maintenance. I am sure that the 4-cyl version on my car is untouched since 1985 (judging by the worn-out bushings on the adjoining actuation rods, after the 272.000 km run-in period :D ).
The main culprit is the size of the stock air-flow sensor plate, which measure the amount of air that is used by the engine, and adjust the necessary amount of fuel accordingly. A bigger plate will flow more air, for example one from a Porsche. I have not seen the layout of the K-jet used by Porsche, it may well be adaptable to the SL6 in complete form, the engine sizes are comparable.

I believe the legendary Smokey Yunick played with a Mercedes injection system on an OHC Pontiac 6-cyl engine, pumping out well over 300 HP.

In function, the K-jetronic injection can be compared to the system with air-doors and metering rods in old Carter, and modern Edelbrock and Road Demon (Carter system copies) 4-bbl carburettors.

http://www.benzworld.org/forums/r-c107- ... ost3535065

A Volvo K-jetronic site with lots of info: http://www.k-jet.org/

Here you can download the original Bosch K-jetronic overview manual:
http://www.scribd.com/doc/3299223/Bosch ... on-Manual-

Olaf
Author:  pishta [ Thu Oct 03, 2013 9:48 pm ]
Post subject: 
I looked at one of these in a Volvo wagon that left us stranded one night and just shook my head. I remembered telling my friend, " I dont know where to start?" And what happens when you go over a bump? Does that air door plate bounce up and down sending your car into convulsions? Kind of cool but highly proprietary I imagine for the motor its on.
Author:  Joshie225 [ Fri Oct 04, 2013 8:36 am ]
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It's not proprietary at all. You need a certain amount of fuel for the amount of air. This system directly measures the air. Speed density is the one where you infer the air flow through manifold pressure and engine speed tables. Not so with air-flow based systems. Plenty of Euro cars used the K-jet. VW, Volvo, Mercedes, Porsche, BMW and I'm sure other names that may or may not have appeared on our shores. There was a guy adapting the K-jet to other applications. Real money comes into play when you start making up custom fuel lines for the injectors.

The air door mechanism is balanced. Give the engineers some credit.
Author:  olafla [ Fri Oct 04, 2013 9:13 am ]
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You forgot the most famous and powerful; Bentley and Ferrari! :lol:

This link show the top off the trottle body, and the unit dismantled. It gives another view and make you relate the pieces in a different way, I agree that the first view of all the pipes and gizmos can be frightening!

http://www.benzgarage.de/technik/k-jetr ... ronic.html

There is a very fine fuel filter in the system that protects the internal pieces, and the very few moving parts are well designed and well proteced. The maintenance of a system once is adjusted correctly, is virtually non-existent. The 3-angle intake tract for the air-door is very carefully designed, and despite it's simplicity, gives a surprisingly accurate air/fuel ratio over the entire RPM range.

Olaf
Author:  WagonsRcool [ Fri Oct 04, 2013 12:19 pm ]
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Yes, those "CIS" injection systems were great when they worked. Very precise. When they broke things could get ugly/ pricey. Almost nothing in the system was field-repairable (if you touched anything that held gas it would likely leak there after). Water-rust contamination in the fuel system was the "kiss of death" - just junk the car. Now parts are only from specialty places (there probably aren't very many parts-countermen who have clue as to what a "warm-up pressure regulator" is. Used to do LOTS of those, back in the day)
Author:  pishta [ Fri Oct 04, 2013 2:24 pm ]
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Wow, i bet those mechanics either cried or jumped for joy when their stable went to efi. Cried because the cash cow was dead, or celebrated because that system was dead! Interesting stuff though, sort of the thermoquad of injection: at its mechanical peak. So that entire part could be set on an edelbrock intake manifold and it would almost work with a proper fuel system? I asume the injectors are in/could Be in the runners? Hey, i give all the credit to the engineers, those guys/gals get paid to think up this stuff.
Author:  olafla [ Fri Oct 04, 2013 4:59 pm ]
Post subject: 
Yes, the injectors are in the runners. The detatched pipes in one of the photos, are those coming from the pressure regulator in the lowest photo, and go to the injectors. The Thermoquad comparison is correct, same principle as the spring loaded secondaries' air door.
Quote:
if you touched anything that held gas it would likely leak there after
It is a high-pressure system, and the slits in the regulator are only 0.2mm wide, so they are sensitive to dirt, and connections need to be tight. There is a very fine filter next to the fuel pump, and another one in the intake pipe to the regulator. I would guess that the fuel used in USA nowadays may create problems, especially with those garaged cars not used regularly.
Quote:
So that entire part could be set on an edelbrock intake manifold and it would almost work with a proper fuel system?
You mean, something like this setup from a 5.0? (OHC heads, plenum in the empty 'valley' under the runners!)
Image

You would need the fuel pump, with the fine filter, cold start valves and other small details, but yes, it's a bolt on for a handy fabricator.
(One nice thing with my MB wagon, or an old 123-series 240 diesel for that matter, is that almost all Mercedes engine/transmission combos are bolt-ins...)

Olaf
Author:  pishta [ Fri Oct 04, 2013 6:09 pm ]
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That is a nifty system, wonder why there are not more conversions out there using this. How does it respond to hopped up cams?
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