Throttle bodies

Although the conversion is made and functions well, I wanted to have a look at what other throttle bodies I could have used. Quite rapidly, I decided for Jenvey because they have a good reputation and were included in a kit I purchased. One of the main criteria was the bolt on ease due to the Weber DCOE and/or Dellorto DHLA bolt pattern. The manifold can be maintained if you had such carburettors beforehand. I limited the search for other brands to those which have DCOE-style throttle bodies, but also found a lot of DIY items, ranging from the welded injector bung in the manifold to the complete engineering, milling, turning and manufacturing. So here comes the round-up! Feel free to drop me a message if you know of any other brand manufacturing their own design. I will be more than happy to add them to the display.
Cheers.
(clicking on the name leads to the manufacturer if available, updated February 5, 2014)

ALPINA
(well, if you want to have something special, theseTBs also sport the Weber bolt pattern... and with the original red trumpets, it just looks the lot :-)... as found on Alpina 2002tii (B4) f.ex.

AT

DBILAS

EFIHARDWARE

EXTRUDABODY

INJECTIONPERFECTION

JENVEY

KMS

 

LUEPERTZ

OER

POLITECNIC

RACEHEAD

TITAN

TWM

VGS

WEBCON

Balancing

Every throttle body has an internal link (cyl.1&2 and 3&4). Both throttle bodies are linked and have to be balanced one with the other. A practical tool is the synchrometer, measuring the amount of air aspirated.

This is a rough method during idle, I will repeat it when I can run the engine outside for a longer time.

K&N air filters mounted, inlet finished! I also swapped the fuel rail connector after replacing the faulty O-ring.

Cheers.

Throttle cable

After assembling the throttle linkage, it was time to connect the cable coming from the pedal. Quite a fiddle with almost no access to the pedal underneath the dashboard, but the result is ok. Some adjustment to be done with the engine running.

Two relays mounted and connected, six more to come.

Cheers.

Throttle linkage

What you get: a description and three bags with brackets, bolts and nuts.

What it should look like: the completed throttle linkage.

What it looks like when you disassemble it again and remount it mirror-inverted.

Pivot link between cable operated lever and throttle axis.
Cheers,

Kent Injection

The Jenvey fuel rails are connected with an aluminium tube, sealed by O-ring on each side. Not a happy setup if you ask me. I prefer a screwed connection, that's why I ordered fuel rails with Dash 06 connections each side...

... which made me run into the next problem: the connectors are too close to screw in a coupler. I had to cut two steel connectors and weld them back to back. This is not the final version of the fuel rail. The definite version will be of one piece, but it will be manufactured later.

With the fuel plumbing all done and ready, the ECU repaired and connected, I finally was able to start the engine.

Cheers.

Injection trouble

Ideally, the engine would have started with the injectors plumbed in and connected. My son had the privilege to fill the tank. Unfortunately, injectors 2 and 3 sprayed even with the engine stopped. I didn't see it and cranked the engine, which means it went full of unburnt fuel without starting. First I doubted the injectors, then I assembled everything with the injectors hanging loose ... only to find out that the injectors are ok (swapped the connectors, swapped the injectors, checked and double-checked the harness).

The injectors spray away from the engine bay and I can watch what happens, measure the harness resistance, check the pins, read the voltage a.s.o. I sent all the data and the map to Dave and Karl at Emerald and hope they can help.

With the engine full of fuel, there are some things to do prior to start the engine again (or try to). My method was to unmount the exhaust and with the help of some hose and tissue catch the fuel that already had been spit out. Then I put out  the sparkplugs and cranked the engine (without ignition!!!) ... which means fuel spraying all over the place! What a mess! Even with lots of tissue around, it's very impressive to see how high and far it sprays. After this, more fuel catched in the exhaust. 

For the next tests it will be ok, but before I start the engine for good, I will also change the oil which is contaminated with fuel as well. Now I have to wait for an answer from the ECU manufacturer.

Cheers.

Fuel plumbing - done

The throttle bodies are of DHLA-type, which means two separate double housings. Today I cut the link for both fuel rails and inserted it. The housings are also mechanically linked to operate the throttle and I had to cut the lever to suit my installation. The right housing is at the front of the car where the fuel will enter the fuel rail. Throttle position sensor unmounted from the Dellortos and mounted to the Jenvey throttle bodies ... the principle remains the same, but the TPS has to be recalibrated with the Emerald ECU.

Fuel goes through the rails and is feeded to the injectors, excessive fuel comes out at the end of the rail and goes back to the swirl pot. In between there is the fuel pressure regulator that will be set to 3bar. The FPR is plumbed in and was the last item of a long list. Hopefully fuel plumbing is done now. The check list is rather long with a lot of connections from the tank to the injectors and back.

Cheers.

Fuel pressure regulator

Studs had all different lengths and were too long for the throttle bodies anyway, which took me an hour to measure, cut and mount them with some thread compound.

Fabricated a bracket to mount the fuel pressure regulator near the fuel rail and swirl pot. This gives a nice ensemble of everything around the fuel. And a good reason to try that bender I recently bought from a friend. The bracket is out of 5mm aluminium and is fixed between two chassis rails.

Cheers.

Injectors

There is no color code conspiration. Although I was after it and almost cracked the enigma, there is none. Maybe for some manufacturer, but even there you find remarks like "color may differ from picture" a.s.o. What you must know to identify an injector is the part-number and manufacturer, then you can search for the flow-rate, resistance and all relevant data. Unless somebody already made all the the work for you, like Stan Weiss for example. Have a look at his site here. I downloaded the list and made it available as a .pdf.
To get an approximate flow rate for a 4 cylinder engine, multiply the injector rate in cc/min by the number of injectors and then divide the answer by five. In this example: 272cc/min x 4 = 1088cc/min total available flow. Divide by five gives you 217.6 bhp. That is with the injector 100% flat out at a fuel pressure of 3 bar.  Normally you aim for 80% of total duration making the 272 injectors worth about 175 bhp at 3 bar pressure for my engine. That would be a rather optimistic calculation and my engine will not achieve that amount of power. This is not an exact calculation because it doesn't take in account other parts of the engine responsible for the power output (camshaft, valves, pistons ...).
Oh, and yes, by the way ... mine are pink !
Cheers.

Goodbye carbs

... welcome injection!

Jenvey DHLA style throttle bodies + fuel rails + injectors, trial fit for measurements.

New inlet manifold gasket is inside this kit from Burton. I mounted it with some silicon paste and also sealed the bolt in the middle which plugs a water gallery.

This throttle link commanded the Dellortos but should also be quite practical to link the throttle bodies with the throttle pedal. It's a bolt-on, so if this doesn't suit, I can take it of.

Cheers.