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EFI AH Initial Test Day...

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HealeyPassion

HealeyPassion

Jedi Warrior
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Healey guys,

I haven't posted in years, but thought there might be some interest in my long term EFI AH project. This is (or will be when I get it done) the second EFI Healey I've built. I took a different approach on this one. I'm sure traditionalists will be unhappy with it, I also love originals, but for a moment think "evolution." Please no hate mail, I get it if you don't like what I've done. In my defense, I have kept all the original parts in plastic containers for posterity... "no animals were harmed...".

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Here is a link to short video (1 1/2 minutes) taken Saturday. You may notice other cameras setup... so, yes, I have more footage but this one was thrown together to show the engine after about 15 minutes of tune.



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The engine has a bit over 100,000 miles on it and never been rebuilt. The ECU is a MegaSquirt 2 3.4.3 with sensors for manifold absolute pressure (MAP), water temp., air intake temp., throttle position, wide band O2 and idle air control. The distributor is a GM HEI (high energy ignition) EFI unit that was machined to fit, so it connects to the ECU and gives the ECU full visibly of the RPM and timing advance (the curve can be set by the ECU). The fuel pressure regulator is set to 45 psi and is mounting in a very temporary position. The throttle body is a Mustang 65mm unit which may be a bit too large, we're going to be testing a 60mm TB shortly. There is much to do and the engine will be completely rebuilt before final tuning. The wiring test harness will obviously be replaced with a permanent harness after the engine rebuild.

So, this effort was just intended to check all the electronics and establish a baseline tune before the complete rebuild.
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The EFI intake has been a work in progress for about 10/11 months. The custom designed intake has 6 injectors, one injector for each cylinder ... so a multi-port injection system. I began with Weber manifolds and went from there. The beautiful manifold fabrication is the work of Chris Mack. I should mention that Chris did the beautiful header/exhaust system that you can't see in the video. The wiring and tuning, as seen in the video, are the work of EFI guru Ric Navarro.

It was an exciting day for me as I've spend a year or so getting to this point.

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Cheers,​
Steve​
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nevets said:
Very nice...what kind of performance difference is there?
Click to expand...

As I recall (haven't looked it up in years), conventional wisdom says some where in the 16 -20% range... I'm sure someone could provide other percentages. On my last one, we dyno'd 2 Healey's back to back... a completely stock BJ7 and mine with EFI. There was about a 18% improvement. My EFI car was a BJ7 with a BJ8 cam and stock exhaust (there were articles about it detailing car). This time I have a truer multi-port injection system and a header/exhaust system (my last one got a header/exhaust system after the dyno experiment)... so not sure, we'll see.

That said, there are a number of other benefits to EFI beyond raw power numbers. The throttle response is quicker, the cold start capabilities are awesome (turns out the engine is capable of very quick starts even cold given the right ingredients,... no choke, ECU handles it with the idle air control (IAC)), fuel economy is up (got 24 mph on one measured economy run), and it runs cleaner (constantly monitoring the A/F ratio to optimize it).
 
Thanks Rick!... the goal was to make it look like it could have been a factory piece...albeit... maybe more like Aston Martin:rolleye:. It is fundamentally, 9 major pieces (22 including the pieces for the fuel rail). After it was all welded up, it was metal finished to make it look like a single casting.

11.1 AH EFI Manifold build S50 4650.jpg
 
It occurs to me that in "advantages" I neglected to include an advantage that is a big deal to anyone living, or driving, at varying altitudes... automatic altitude compensation. At sea level your induction system has the advantage of 103 kPa (kilopascals) of pressure... thus more oxygen. At my elevation, roughly 6,800 ft., I have about 78 kPa. So, I have roughly 24% less air pressure (oxygen) to deal with in contributing to A/F ratios and combustion. As I'm sure you know, carburetors can't modulate the fuel to accommodate the reduced (or increased) oxygen. The ECU in an electronic fuel injection has a manifold absolute pressure (MAP) sensor that knows that the pressure has dropped (if I go up to higher elevations for a drive, as I do) and adjusts the fuel pulses to compensate for the change. It also compensates if I drive to a lower elevation like Texas where it gets more oxygen at higher pressures.

This isn't a big deal if you tune for your altitude and don't take drives that vary elevation dramatically. For me, living at a relatively high altitude and driving both higher and lower... this is a big deal.

This doesn't give you more power, but it does help my AH engine to run cleaner in all altitudes... you still have less HP at higher altitudes.
 
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