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 Post subject: Re: EFI orientation help
PostPosted: January 3, 2018, 3:49 pm 
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Joined: June 5, 2016, 7:03 am
Posts: 215
Location: ontario
KB58 wrote:
How about going the other direction -

1. Get the car running with a completely stock - carbureted - engine.
2. When ready, upgrade just the ignition to electronic.
3. Once that's working fine and you've learned the system, then add injectors.


Thanks KB58 and Bentwrench below. You just caught me with my hand on a credit card, about to place my EFI order to SummitRacing.

Both your arguments make me think again.
I will shelve the EFI idea for a while, build my engine with 4 carbs and a mechanical distributor, run it, and then further study electronic engine management: both fuel and ignition and buy the hardware. I will also look for more feedback on TBI systems and make a final decision.


Last edited by phil on January 6, 2018, 4:38 pm, edited 1 time in total.

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 Post subject: Re: EFI orientation help
PostPosted: January 3, 2018, 4:19 pm 
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Mid-Engined Maniac

Joined: April 23, 2006, 8:26 pm
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Talked you down, have we? :)

When I suggested adding ignition then fuel, I didn't make clear that I was speaking of using a full EFI setup and connecting only the ignition first. That allows you to learn the system, reuse all the wiring when you add the fueling functions, and at least stretch out the expense a bit more. It also allows you to continue driving the car while you fabricate an all-new intake manifold with injector bungs on it.

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 Post subject: Re: EFI orientation help
PostPosted: January 3, 2018, 9:44 pm 
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Joined: October 19, 2009, 9:36 pm
Posts: 2085
Location: meadview arizona
if you are going to use any throttle body injection you must be stupid, there is no point spending the money that it costs when you could use it to do the job properly

i too have installed aftermarket injection systems, i know that at least half of them have returned to carbs because the support is really really bad but they have your $2000.00 so what do they care.

if you think a throttle body system is good for you then just take everything you need from a 6 cylinder car and make it fit but do not use a spider system from an astro.

first thing to do is install a junk yard tank with a internal pump, get one with a return line, if it pumps the volume and makes 65 lbs of pressure you can regulate that down to about 5 lbs and continue to use your carbs till you need to take the next step.

then go for electronic ignition in any form you wish but as mentioned earlier you may need a distributor just to drive the oil pump so if its there use it for the trigger.

many here will tel you to go mega squirt and if you are up to the challenge you can do that.

but look into a factory system of any make that is similar to your engine combination although i do not know how you will deal with a coolant temperature sensor on an air cooled engine, if you could solve this then maybe a subaru six or porsche system would work,
you just need to know the parameters of the water sensor and get one calibrated to air with the same parameters (0-5V), maybe an air cooled aircraft sensor would be available.

the webber carbs don't know they are on a corvair, why should the injection system

Bent Wrench i have felt your pain when dealing with aftermarket EFI systems, i even had to diagnose and rectify a holley system in England by e mail, i am in Arizona, it turned out that the o2 sensor was too far down the long tube header

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 Post subject: Re: EFI orientation help
PostPosted: January 3, 2018, 10:37 pm 
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Location: ontario
KB58 wrote:
Talked you down, have we? :)

When I suggested adding ignition then fuel, I didn't make clear that I was speaking of using a full EFI setup and connecting only the ignition first. That allows you to learn the system, reuse all the wiring when you add the fueling functions, and at least stretch out the expense a bit more. It also allows you to continue driving the car while you fabricate an all-new intake manifold with injector bungs on it.


Sorry I misunderstood.
Would modifying the 1965 Corvair distributor to electronic in order to gain a hall effect trigger and buying Megasquirt II be a step in the right direction in setting up the ignition control?


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 Post subject: Re: EFI orientation help
PostPosted: January 3, 2018, 10:43 pm 
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[quote="john hennessy"]if you are going to use any throttle body injection you must be stupid, there is no point spending the money that it

Thanks,
Your points are well taken. As you can tell I am still very much on a learning curve. No I do not want to waste my money on hardware that will not perform better than what I have :)


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 Post subject: Re: EFI orientation help
PostPosted: January 4, 2018, 2:15 pm 
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Location: meadview arizona
Phil,

i was not implying that you were stupid, the moderators get picky about that.
its just that off the shelf aftermarket throttle body injection systems cost a lot of money for mediocur performance.

tel us about your car, is it a corvair or what?

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 Post subject: Re: EFI orientation help
PostPosted: January 4, 2018, 3:10 pm 
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john hennessy wrote:
Phil,

i was not implying that you were stupid, the moderators get picky about that.
its just that off the shelf aftermarket throttle body injection systems cost a lot of money for mediocur performance.

tel us about your car, is it a corvair or what?



Hi John.
Don't worry, I did not feel insulted. Throwing $1600 + at a throttle body that would not improve the current 4 carb system would be indeed stupid. I had no way to know, having no previous computer management engine experience.
My build is my second seven. The first one was launched in 2009. (see Philippe's diesel seven in the finished build section) First as a diesel VW TD powered rig and then later as with a conventional 1.9L VW jetta gas engine.
My current build will be powered by a 1965 6 cyl flat 2.7 L Corvair rear engine with IRS which I am rebuilding . I have changed the seven chassis design to accommodate this rear engine. The 1965 Corvair engine that I have produces 140HP @ 4500 rpms stock with four carbs. I have bought a mild race cam and a header., as well as a small supercharger which I plan to run at a moderate 6 psi. My hope is to get 180 hp out of this mill.

As the Corvair is air cooled, heat is a challenge. I have designed the chassis to provide large air flow intakes in front of the rear wheel wells . The engine will be equipped with a larger oil radiator with electric fan. I have also built a 6 gal water tank which will provide direct water injection (mixed with intake air) at the blower level (this system has not been finalized yet). I was advised by Corvair owners on the Corvair forum that injecting water or a mix of water and ethanol in the intake would greatly help keeping the heads cooler and would also enhance performance.

There you are John. Thanks for your interest. :cheers:


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 Post subject: Re: EFI orientation help
PostPosted: January 4, 2018, 4:48 pm 
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Location: central Arkansas
At 6 PSI I'd keep the carburetors if they're in good shape. Hugh McInnes' "Turbochargers" book tells how to modify carburetors for blow-through operation if necessary. Use the same ignition curve as the factory turbos and you shouldn't have any trouble.


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 Post subject: Re: EFI orientation help
PostPosted: January 4, 2018, 5:14 pm 
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TRX wrote:
At 6 PSI I'd keep the carburetors if they're in good shape. Hugh McInnes' "Turbochargers" book tells how to modify carburetors for blow-through operation if necessary. Use the same ignition curve as the factory turbos and you shouldn't have any trouble.


Thanks for the tip. I will buy McInnes' book and explore what you are suggesting :cheers:


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 Post subject: Re: EFI orientation help
PostPosted: January 4, 2018, 5:55 pm 
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Joined: February 23, 2017, 12:45 pm
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Location: Austin, TX
You may want to look into just running the motor on E85. You get all the nice cooling and anti knock effects you mentioned but no second tank. Filling stations with it are more common than I realized. When I looked into for a build we're doing at work there were a 1/2 dozen in my "metro" area. Not as ubiquitous as a gasoline station by a long shot but still readily available.

https://www.afdc.energy.gov/fuels/ethan ... tions.html


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 Post subject: Re: EFI orientation help
PostPosted: January 4, 2018, 5:58 pm 
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Mid-Engined Maniac

Joined: April 23, 2006, 8:26 pm
Posts: 5917
Location: SoCal
E85 availability is extremely regional - be sure to check first before building something that demands it . I have an aftermarket ECU that allows a flex-fuel setup. It avoids worries about being unable to get E85.

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 Post subject: Re: EFI orientation help
PostPosted: January 5, 2018, 12:11 am 
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Location: ontario
banzairx7 wrote:
You may want to look into just running the motor on E85. You get all the nice cooling and anti knock effects you mentioned but no second tank. Filling stations with it are more common than I realized. When I looked into for a build we're doing at work there were a 1/2 dozen in my "metro" area. Not as ubiquitous as a gasoline station by a long shot but still readily available.

https://www.afdc.energy.gov/fuels/ethan ... tions.html


Thanks for the idea.
However the main ingredient in my mixture is H2O, not ethanol or methanol although the latter have often been used in the 50-50 water mix. Ethanol is there to keep the water from freezing. Yes it burns too and contributes to prevent detonation. Water is the main thing in head temperature reduction. All this dates back to WWII. In my system I have made a 6 gal aluminium tank. I still have to figure out metering. nozzles , a pump, etc. I expect a fair bit of trial and error too. My engine is a 6 cyl air cooled engine with a 9.25-1 compression ratio. Adding supercharged boost would place the heads (valve seats) in great danger of overheating . My hope is that water droplets will prevent that and even add a few horses.


Last edited by phil on January 6, 2018, 9:04 am, edited 1 time in total.

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 Post subject: Re: EFI orientation help
PostPosted: January 5, 2018, 11:08 am 
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Joined: March 30, 2011, 7:18 am
Posts: 1434
Location: central Arkansas
KB58 wrote:
E85 availability is extremely regional


Not just regional, but variable. Ten years ago we had E85 all over the place. Five years ago it essentially vanished; at least, I saw no pumps in my usual areas. Recently, a E85 pumps have reappeared at a handful of places.


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 Post subject: Re: EFI orientation help
PostPosted: January 5, 2018, 11:13 am 
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Location: central Arkansas
phil wrote:
All this dates back to WWII.


NASA scanned the original NACA technical papers on the subject. Then they changed their web site to make stuff almost impossible to find, but HM Government maintains a mirror with the old interface at http://naca.central.cranfield.ac.uk/

The IMechE squats on the British equivalent like trolls, so the equivalent work by the Brits is still locked behind a paywall.


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 Post subject: Re: EFI orientation help
PostPosted: January 5, 2018, 11:59 am 
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Joined: February 23, 2017, 12:45 pm
Posts: 52
Location: Austin, TX
phil wrote:
Thanks for the idea.
However the main ingredient in my mixture is H2O, not ethanol or methanol although the latter have often been used in the 50-50 water mix. Ethanol is there to keep the water from freezing. Yes it burns too and contributes to prevent detonation. Water is the main thing in head temperature reduction. All this dates back to WWII. In my system I have made a 6 gal aluminium tank. I still have to figure out metering. nozzles , a pump, etc. I expect a fair bit of trial and error too. My engine is a 6 cyl air cooled engine with a 10-1 compression ratio. Adding supercharged boost would place the heads (valve seats) in great danger of overheating . My hope is that water droplets will prevent that and even add a few horses.


I don't think you've got that correct. The methanol is what is giving you the cooling and the anti-knock. It's definitely not for an anti-freeze. The only reason most people run water is because it makes the methanol non-flammable for shipping purposes. Boost juice, Snow Performances meth mix, is 51% water for that reason. The more alcohol you run the higher your octane and cooling effect will be. Drag cars running alcohol don't need cooling systems because of the cooling effect of the fuel. That's not to say water isn't helping but it's help is during the combustion process. It keeps combustion temps down. The phase change from liquid to gas sucks up a lot of energy and hence the flame temp is kept down. It's effect is not nearly as pronounced as the alcohol though.


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