Quote:Dodgeman,

Thanks for the excellent and comprehensive reply. You are right, I'm not getting as warm an intake air as I thought. I would need to remove the header and put the stock exhaust manifold back to use the heat riser tube for truly hot air. Then I could reinstall the egr system and drop the threshold of detonation some too. Or better yet, find an A12A and drop that in. Anyone in the northeastern US got one?

Mike

Quote:The interior is completely intact. Just the spare and jack were removed from the trunk. The aero pieces I plan on using are very light. Just lexan and thin aluminum channel to support it.

Mike

Quote:

Yea, I'm sure that drip rail on the 'A' pilar isn't doing you any favors. Some creative use of tape may help.

Good job and congrats!

Quote:If you are drawing air from behind the radiator then you are drawing luke warm air at best.

The cooling system will circulate the coolant within the engine itself untill it reaches the correct pre-determined temp when the thermostat opens a little & allows SOME of the coolant to flow into the radiator.
This is replaced by cool, or even cold water [coolant] from the bottom of the radiator flowing into the engine & eventually a balance is reached where the flow of hot coolant out & cold coolant in maintains a CHT [cylinder head temp] that is within specs.

Now in economy mode you are running very low throttle opening & the resultant low fuel burn produces very little heat [compared to full throttle] & the result is a very low flow of heated coolant into the radiator. A good radiator in fully serviceable condition will shed this heat very quickly & this process will take place right across the core & in the top few inches as the coolant flows from top to bottom.
Your smallish intake duct will draw air from a very small surface area of the radiator core & the net result will be air that is heated to a very low degree.

The best place to draw heated air from is the exhaust manifold. Later models had bosses cast into the exhaust manifold & these were usually drilled & threaded. A pressed sheet metal cover was bolted to these holes & a fitting for the air dict was built in.

Intake air was drawn into & under the edges of this cover & it had to pass over the hot manifold [which heats up much faster than the radiator does] & is drawn directly into the air cleaner & carb at a higher temp than you will ever see in air drawn from behind the radiator.

Clearly you are even now converting most, if not all, of the liquid fuel that is drawn from the carb into combustible gas which means that you are making power from every dropletof blowing some of it out of the tail pipe as unburned hydrocarbons like many stock vehicles do.

Those factory engineers were clever little fellers so using their hot air intake components will be another smart move in your quest for greater mileage.

For Aussie readers, that 77 miles per US gallon equates to about
93 miles per Imperial gallon or
20.33 miles per litre or
33 Kilometers per Litre or
3 Litres per 100 Kilometers [100 Kilometers is close enoughj to 62-1/2 Miles]

Whats the interior like?? Is it all gutted?

should maybe look into fiberblass panels and bonnet, to offset the added weight or the aero package.

I was just telling my fabricator buddy about the 210 milage car, literally like 10 minutes ago...................now I have to call him back with the new mpg number. I love all the mods and can't wait to see what you do with the front end.

Tom

Got it. Didn't know you were already running so lean.

Dont forget the thermal tape :)

Quote:Thanks all,

David, I did rejet the carb for the hotter summer air and ended up with running between 14.8 to 15.4 to 1 A/F. That's fairly lean for this old technology. The lean burn systems that Honda employs use specific cylinder head chamber shapes and phasing of the cams via the vtec-e system. Here's a quote from Wiki:

Honda uses one of the newest lean-burn technologies available in automobiles currently in production uses very precise control of fuel injection, a strong air-fuel swirl created in the combustion chamber, a new linear air-fuel sensor (LAF type O2 sensor) and a lean-burn NOx catalyst to further reduce the resulting NOx emissions that increase under "lean-burn" conditions and meet NOx emissions requirements.

This stratified-charge approach to lean-burn combustion means that the air-fuel ratio isn't equal throughout the cylinder. Instead, precise control over fuel injection and intake flow dynamics allows a greater concentration of fuel closer to the spark plug tip (richer), which is required for successful ignition and flame spread for complete combustion. The remainder of the cylinders' intake charge is progressively leaner with an overall average air:fuel ratio falling into the lean-burn category of up to 22:1.

If I were to try running much leaner my guess is that I would lose power and raise fuel consumtion. I am running somewhat of a temp controlled air cleaner right now. I've sealed off all openings to the stock air cleaner except for the heat riser tube and main snorkel. Both are plumbed to the back of the radiator, to draw warm air only.

I think any future gains might come from more aero work. The wind noise on the road tells me the car is not nearly slippery enough. I plan to do some front and rear end aero mods in the future to see if we can reach the 80's.

Very very well done. Im sure I speak for everyone when I say you made the datsun comunaty proud!