Alfa Home | Engine Rebuild | Engine Mods | HPV-1 | Dyno | Suspension | Interior | Track Time | Repairs
2.0L Euro block - As a '69 GTV, my car should have the 1750 motor, but somewhere along the line someone slipped in a 2.0L engine from a European Alfetta. The European blocks used a different front timing cover that did not have the necessary provision for the Spica pump fitted to U.S. cars (subsequently replaced on my car to fit the Electromotive ignition). Otherwise they are the same. Alfetta blocks differ in a couple of minor ways, including an oil dipstick mounted on the intake side near the oil pump, and an oil pressure sensor mounted on the upper rear intake side. The Alfetta motors also used different oil pans, but this must be replaced with a proper 105/115 series unit to allow the motor to fit in the car.
45 DCOEs - U.S. Alfas from '69 to '80 are supposed to have Spica mechanical fuel injection. Although the Spica is a wonderful system, and through the magic of Wes Ingram, makes slightly more power on a modified engine than carbs, it just doesn't thrill me the same as a good set of Webers. Let's face it, there is nothing quite like the sound of a pair of honking side drafts sucking in huge quantities of air through an open element filter. Oh sure, a true cold air induction system will produce a little more power, as will a good Spica setup, but I'd gladly trade 5HP for the aural excitement that comes with unbridled DCOEs. My carbs initial settings (shown below) were based on the Jim Kartalamakis book How to Power Tune Alfa Romeo Twin-Cam Engines, however, based on conversations with several Weber experts, I expected these settings to change dramatically once I broke in the motor. However, after a few dyno sessions, I've discovered that his set up is virtually identical to what my car likes in its current state of tune:
45 DCOEs - U.S. Alfas from '69 to '80 are supposed to have Spica mechanical fuel injection. Although the Spica is a wonderful system, and through the magic of Wes Ingram, makes slightly more power on a modified engine than carbs, it just doesn't thrill me the same as a good set of Webers. Let's face it, there is nothing quite like the sound of a pair of honking side drafts sucking in huge quantities of air through an open element filter. Oh sure, a true cold air induction system will produce a little more power, as will a good Spica setup, but I'd gladly trade 5HP for the aural excitement that comes with unbridled DCOEs. My carbs initial settings (shown below) were based on the Jim Kartalamakis book How to Power Tune Alfa Romeo Twin-Cam Engines, however, based on conversations with several Weber experts, I expected these settings to change dramatically once I broke in the motor. However, after a few dyno sessions, I've discovered that his set up is virtually identical to what my car likes in its current state of tune:
|
Chokes Main jets Emulsion tubes Air correctors Idle jets Pump stroke Inlet valve Pump bypass |
Initial
36mm 150 F16 175 50F9 16 175 45 |
After Tuning
36mm 150 F16 175 50F6 16 175 45 |
A few important words about the 45DCOE carburetor: the 45DCOE-152 is the only model currently manufactured by Weber and its progression circuit is designed for cars with larger motors than the 1962cc unit in the Alfa. That relatively small powerplant requires very little throttle opening to maintain 2000-3500rpm in 1st through 3rd gears during low load situations (i.e. while travelling on flat, or downhill sections of road). Consequently the throttle plates don't move enough under these conditions to uncover the progression holes and allow the carbs to operate off of that circuit. The result is a slightly annoying lean-rich-lean surge and some spitting back through the air horns that goes away as soon as a little throttle is added. It is not a huge deal for me, but I would caution those thinking of going with 45DCOEs to
consider this issue and to buy older, more appropriate 45DCOEs if they think the less-than-stellar drivability will pose a problem for them.
Pistons - Borgo 10:1 pistons. These give great power in a built motor and work just fine on 92 octane. When they arrived, there was a nearly 4 gram spread from lightest to heaviest piston, which was not acceptable in this motor. Therefore, I spent a couple of hours with a die grinder and shaved away aluminum until 3 pistons were identical to 0.01 grams and the fourth was 0.8 grams lighter.
Cams - My car came with 105020320001 cams, which were stock on the 1600 and early 1750 motors. It is a very mild cam -- 226° duration, 9.5mm lift and according to Jim Kartalamakis rates a 4 on the Shankle scale -- that makes great low-end torque and little else. I had planned to replace them with a pair of 8Ls, but Wes Ingram convinced me to try an asymmetric setup with a 7L on the exhaust side and an 8 on the intake. He felt this combination would reserve a lot of the low-end and still give great power up to 7000 rpm. Wes was definitely right on this one, these cams are great! Delta Cams in Tacoma welded up some milder cams and then reground them to the following specs:
Intake: 253° duration, 11.9mm lift Exhaust: 246° duration, 11mm lift
Steve Haniford Stage 3 head - Steve owns Progressive Automotive, a little hole-in-the-wall shop located in Tacoma, WA that is home to one of the best head rebuilders in the country. Steve went through my car's old head, refreshing where necessary and porting & polishing everywhere else. The head also sports 1mm oversized intake valves and a port matched intake manifold. I had initially considered going to Sperry, but Steve's prices were better and his work is first rate.
Electromotive HPV-1 - This is a cool little unit from Electromotive that replaces the distributor, coil and ignition system with a dual coil, crank-fired setup. Unlike the HPV-3B, the HPV-1 does not require a laptop to program, rather
it incorporates 3 rotary switches to control advance as follows: initial (2 to 25 degrees), 3000 rpm (additional 6 to 25 degrees) and 8000 rpm (up to 7 degrees retard or advance). There is also a fourth dial that controls the soft rev limiter. The downside to using an Electromotive ignition on an Alfa is that you must fabricate adapters to hold the
crank sensor and crank trigger wheel. Fortunately, Jim Steck had a setup from his turbocharged GTV that he wasn't using and donated (okay, sold very inexpensively) to the effort. His sensor bracket mounts to studs located on the Spica belt guard. Of course, my Euro timing cover had no such guard, so it was replaced with a US-spec cover.
Electric cooling fan - Depending on who you believe, the stock, engine driven fan robs between 5-7HP from the engine. Replacing it with an electric fan accomplishes three things. First, it reduces the parasitic losses and frees up those 5-7 ponies. Second, it allows the car to reach operating temperature more quickly since the fan doesn't run until the car hits 185° and third, eliminating the big, stock fan clears up room under the hood. I ordered my fan from Alfa Heaven and purchased their thermostatically controlled switch at the same time. The switch allows you to easily define the temperature that the fan turns on. Installation is simple, just make sure the fan is blowing the right way. When I bought it, I was told that it was a pusher unit, but when I connected the red wire to positive and the black to ground, I got a puller unit. Of course I didn't realize this until I had the occasion to sit in stop and go traffic waiting for an accident to clear.
Lightened flywheel - My flywheel was destroyed when I over-revved my motor, so I bought a used unit that had already been lightened by approximately 7 lbs.
Windage tray - This unit from AutoComponenti is designed to perform three functions: (1) Remove/prevent oil from being picked up by the crank and mixed with air. (2) Stabilize the main caps when the engine is operating at high speed. (3) Baffle the crankcase to prevent the oil from climbing up the side of the block when cornering. Just the thing you need when you're turning 7500 rpm.
consider this issue and to buy older, more appropriate 45DCOEs if they think the less-than-stellar drivability will pose a problem for them.
Pistons - Borgo 10:1 pistons. These give great power in a built motor and work just fine on 92 octane. When they arrived, there was a nearly 4 gram spread from lightest to heaviest piston, which was not acceptable in this motor. Therefore, I spent a couple of hours with a die grinder and shaved away aluminum until 3 pistons were identical to 0.01 grams and the fourth was 0.8 grams lighter.
Cams - My car came with 105020320001 cams, which were stock on the 1600 and early 1750 motors. It is a very mild cam -- 226° duration, 9.5mm lift and according to Jim Kartalamakis rates a 4 on the Shankle scale -- that makes great low-end torque and little else. I had planned to replace them with a pair of 8Ls, but Wes Ingram convinced me to try an asymmetric setup with a 7L on the exhaust side and an 8 on the intake. He felt this combination would reserve a lot of the low-end and still give great power up to 7000 rpm. Wes was definitely right on this one, these cams are great! Delta Cams in Tacoma welded up some milder cams and then reground them to the following specs:
Intake: 253° duration, 11.9mm lift Exhaust: 246° duration, 11mm lift
Steve Haniford Stage 3 head - Steve owns Progressive Automotive, a little hole-in-the-wall shop located in Tacoma, WA that is home to one of the best head rebuilders in the country. Steve went through my car's old head, refreshing where necessary and porting & polishing everywhere else. The head also sports 1mm oversized intake valves and a port matched intake manifold. I had initially considered going to Sperry, but Steve's prices were better and his work is first rate.
Electromotive HPV-1 - This is a cool little unit from Electromotive that replaces the distributor, coil and ignition system with a dual coil, crank-fired setup. Unlike the HPV-3B, the HPV-1 does not require a laptop to program, rather
it incorporates 3 rotary switches to control advance as follows: initial (2 to 25 degrees), 3000 rpm (additional 6 to 25 degrees) and 8000 rpm (up to 7 degrees retard or advance). There is also a fourth dial that controls the soft rev limiter. The downside to using an Electromotive ignition on an Alfa is that you must fabricate adapters to hold the
crank sensor and crank trigger wheel. Fortunately, Jim Steck had a setup from his turbocharged GTV that he wasn't using and donated (okay, sold very inexpensively) to the effort. His sensor bracket mounts to studs located on the Spica belt guard. Of course, my Euro timing cover had no such guard, so it was replaced with a US-spec cover.
Electric cooling fan - Depending on who you believe, the stock, engine driven fan robs between 5-7HP from the engine. Replacing it with an electric fan accomplishes three things. First, it reduces the parasitic losses and frees up those 5-7 ponies. Second, it allows the car to reach operating temperature more quickly since the fan doesn't run until the car hits 185° and third, eliminating the big, stock fan clears up room under the hood. I ordered my fan from Alfa Heaven and purchased their thermostatically controlled switch at the same time. The switch allows you to easily define the temperature that the fan turns on. Installation is simple, just make sure the fan is blowing the right way. When I bought it, I was told that it was a pusher unit, but when I connected the red wire to positive and the black to ground, I got a puller unit. Of course I didn't realize this until I had the occasion to sit in stop and go traffic waiting for an accident to clear.
Lightened flywheel - My flywheel was destroyed when I over-revved my motor, so I bought a used unit that had already been lightened by approximately 7 lbs.
Windage tray - This unit from AutoComponenti is designed to perform three functions: (1) Remove/prevent oil from being picked up by the crank and mixed with air. (2) Stabilize the main caps when the engine is operating at high speed. (3) Baffle the crankcase to prevent the oil from climbing up the side of the block when cornering. Just the thing you need when you're turning 7500 rpm.
