From my experience I think you'll probably find you need to run race plugs (eg Champion race plug) due to the high compression, or it will misfire. Probably won't need to go as 'cold' as a race engine as you won't be loading it up (full throttle/high rpm etc). Ideally elec ignition but not essential.

Quote:As I previously wrote, electronic ignition, to generate the highest voltages possible.
Platinum or Irridium plugs will fire across a given gap at a given compression pressure at a lower voltage than regular types. If you can get the compression up to a goodly figure, then you will need all the help you can get & this is the way to do it.
The objective is to get the plug opened out to the widest gap where the plug will still fire every time so experimentation will help there.

Lean mixtures are hard to light but very lean mixtures are even harder so a nice long fat spark will be needed, even if it means that the coil is working near the limit of its output, so just make sure you mount it in the cool airflow somewhere.

So good plugs at stock heat range with proper high energy electronic ignition, & that part of the problem will be under control.

update: 9/27/08

I've got a couple of things to report. Firstly, the A13 engine did not materialize. The car turned out to be a '75 [A14] and not a '74 as the owner thought. I was disappointed to say the least.

Secondly, I decided to try using my hot rod 1608 engine by removing the side drafts and bolting on the stock intake and carb. It runs terribly. Way too lean! No power. The Crane cam and double valvesprings that this engine has are no good for economy use. It was a complete waste of time trying to detune my hot rod 1608 for this.

Currently: I dug my spare [23,000 original mile] '76 A14 Honeybee engine out and did a leakdown test. It failed miserably. The valves were leaking like crazy [from sitting for 15 years outside before I got it]. So I took the open chamber low compression H72 head off and am readying my high compression "990" round port head for it. The bores look great and the flat top A14 pistons will work nicely with the small heart shaped chambers in the 990 head. I welcome having the stock cam a valevsprings back again! It will be a bit of work this week to get it together and swapped in for next Sunday's Economy Run. But that's the plan. Wish I had more time to test and tune. This event will be the baseline I guess. There is much more to be done after that. I've located a 3.54 diff in a junk car in the woods. I'll have to get it out of there in the near future. My 3.70's will have to do for next weekend.

The 1608 comes out, the 1397 goes in....




Repainted the 20 year old Pacesetter header.




Here's how far along I was this morning.




In the past I've never liked the non crossflow type cylinder head arrangement on these engines because the exhaust heats up the intake manifold and costs power. But for fuel efficiency, it's perfect.

Got it running today and road tested it. It runs quite well and is very quiet and smooth. I still have few bugs to work out. It is still a bit too lean with an air/fuel ratio of about 16.4 to 1 while cruising. I'll have to go into the carb and richen it a bit. What A/F ratio would you guys be aiming for, for the best low speed part throttle economy?

Also I found that the 31 year old vacuum advance diaphram does not function. Vacuum advance is definately something you want to have working properly if you're interested in getting good fuel mileage.

I'm pretty happy so far though. The event is Sunday.

I do hope you posting the 1608 over to perth for me.,. ha ha

good luck with the trial..

14.7 is the ideal A/F ratio for economy, 12.6ish is considered best for power.

Well all of my efforts came to fruition last Sunday, at my car club's Economy Run event. This was a 118.7 mile loop through the southern Adirondack mountains of New York. First allow me to update you all on the completion of the engine and tuning it before the event.

Engine:

To recap, I am using an original 23,000 mile '76 A14 shortblock that had been sitting for many years. The bores looked OK so I decided not not to remove the pistons and hone the cylinders because that just adds drag to the recprocating assembly and being two days before the event, I didn't have any time for break in miles. You can grab the crank pulley [with the plugs out] and easily spin the long block over by hand. I even chose to leave in the original 32 year old crankshaft oil seals because they looked ok, and are certainly "looser" than new ones. I purposely set the oil level one quart low and added a hotter 195 degree thermostat.

Tuning:

Upon road testing, I quickly found that the engine ran very lean at about 16.4 to 1 on my wide band A/F ratio meter. The combination of the Pacesetter header and 2" mandrel bent exhaust system, [plus the removal of the egr system] were surely causing this. I replaced the standard 105 primary jet with a richer 109 and tried it again. Bingo. It was pretty much spot on then, with a 14.6 to 15.0 A/F range at cruise.

The last issue was the pinging. Boy does this thing pre-ignite under even light loads. I was running with the standard 10 degrees of timing and this was on 93 octane premium! Obviously the high compression end of this combination was showing itself. The lack of an egr system was not helping either. I didn't have time to add a water injection system or anything else, so at this point I simply added two gallons of 110 octane race gas to the tank. That quieted it right up.




On to the testing. I topped up the tank to the rim and then carefully drove a 64 mile loop the afternoon before the event. I refilled the tank [right to the rim again] and it took 1.1 gallons of gas. I was very happy with this 56 mpg test! As you can see, the car is far too high off of the ground and this brings very poor drag coefiicient. This was not a full-on attempt at the best possible mileage. I need much more time to prepare. There are many other things I can and will try in the future, but this was the way it had to be last weekend.




So I went home that night and tried to help the poor aerodynamics at least a little. I added a makeshift front chin spoiler, clear plexiglass headlight covers, and blocked off half of the grill to reduce wind drag.

The next I morning I completed the event and carefully drove the 118.7 mile distance. During the post event refill it took only 1.91 gallons of fuel. This equates to 61.53 miles per [US] gallon!

Might this be a new record for the A-series?

Well done mate!

My friend uses molly grease with added oil stabiliser in his racecar wheelbearings and it works a treat - the wheels spin for AGES and reduces drag by quite a bit. What you do is get the kitchen blender and get some molly grease. You then slowly add oil stabiliser little by little, mixing it in, until it is very slippery but still a greasy consistency. Might be worth giving it a shot.

Cheers

that's awesome mate, congratulations. i think that is even better than i get on my motorbike.

for the record that converts to about 3.82 L/100km.

Holy smoke! that's pretty much diesel territory. What are the rules regarding body modifications? cos I have been playing around in my head for quite some time with someting like this for the car.




It would require the guards to be removed and that unit to be modified to mount on the car correctly but with tah done and an extended fibreglass bonnet it might be worthwhile. Actually it might be really costly but the other fiberglass alternative would be to make on of thes fronts that would suit the shape of our car