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JustBuggy
Samba Member
Joined: August 01, 2010
Posts: 849
Location: SF Bay Area, Ca.
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 Posted: Sat Apr 30, 2011 6:46 pm Post subject: '76 2.0L fuel injected, can it run on an aftermarket CPU? |
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I'm posting this here as it was recommended (from the bus forum) because T4 engines were originally in the 411/412 before they went into busses.
The '76 2.0L fuel injected bus engine that I got as a replacement engine for my WORE OUT SP1500 has everything still attached to it. It has all of the intake, fuel injectors, wiring harness, just about everything except for the stock EFI brain.
I was thinking about a rebuild for the 2.0 and adding a mild cam and small turbo. My question is, will a Megasquirt EFI system work using the stock injectors? How would I know if the stock injectors are hi or low impedence?
I'd also like to go with a slightly warmer cam than stock and in the future add a turbo. Any cam recommendations? |
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dawie
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Joined: July 27, 2008
Posts: 217
Location: Cape Town, South Africa
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Sun May 01, 2011 10:55 am Post subject: Re: '76 2.0L fuel injected, can it run on an aftermarket CPU |
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| JustBuggy wrote: |
I'm posting this here as it was recommended (from the bus forum) because T4 engines were originally in the 411/412 before they went into busses.
The '76 2.0L fuel injected bus engine that I got as a replacement engine for my WORE OUT SP1500 has everything still attached to it. It has all of the intake, fuel injectors, wiring harness, just about everything except for the stock EFI brain.
I was thinking about a rebuild for the 2.0 and adding a mild cam and small turbo. My question is, will a Megasquirt EFI system work using the stock injectors? How would I know if the stock injectors are hi or low impedence?
I'd also like to go with a slightly warmer cam than stock and in the future add a turbo. Any cam recommendations? |
You simply measure the injectors with an ohmeter across both contacts. Low impedance injectors are typically below 5 ohms. High impedance injectors are about 10 and above.
Injectors are pretty expendable. If they sit for long periods of time they can very well be bad due to rust or varnish. Also selecting injector flow rates with at turbo in mind are pretty specific to the application. They are not really a big part of the cost. I would plan to get new ones.
The intake and throttle body system should work. The original L-jet will have problems with a turbo because of its metering flap. Not saying it cannot be done....but the turbo is going to flow more air than the original flap did. MS with a hotwire or MAP or both would be good.
You will probably need a different fuel pressuer regulator with a turbo. Ray |
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JustBuggy
Samba Member
Joined: August 01, 2010
Posts: 849
Location: SF Bay Area, Ca.
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| Posted: Sun May 01, 2011 11:22 am Post subject: |
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I'll be buying another throttle body, fuel regulator, and pump as mine are not there.
I will do a test on these injectors to see if they work at all, at least for now.
In regards to the turbo was hoping to get the engine installed and running ASAP with everything I already have. Later on I can add the turbo.
Thanks Ray! |
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raygreenwood
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Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Mon May 02, 2011 6:50 am Post subject: |
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I'm not a turbo expert....but I will say this. The type 4 engine in general for use other than for a bus....does not do very well with low compression. It runs hot, has a large deck and is pretty inefficient with regard to heat usage. It also will run pretty low hp numbers.
The issue is that to run a turbo you need moderatley low compression.
So setting it up for a turbo now and not running it that way is not a great method. It also begs the question as to why....other than for fun and it sounds snazzy....you need a turbo? If this is going in the laser 917, you could build this engine out to a stockish 914 spec 2.0 (improved of course) and get an honest 110 hp. Or you could build a Raby style 2056....and end up with 135 to 150 hp.....which would move that laser 917 0-60 in about 6-8 seconds.....all without the engineering hassles of the turbo. Ray |
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JustBuggy
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Joined: August 01, 2010
Posts: 849
Location: SF Bay Area, Ca.
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| Posted: Thu May 12, 2011 5:40 am Post subject: |
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| raygreenwood wrote: |
I'm not a turbo expert....but I will say this. The type 4 engine in general for use other than for a bus....does not do very well with low compression. It runs hot, has a large deck and is pretty inefficient with regard to heat usage. It also will run pretty low hp numbers.
The issue is that to run a turbo you need moderatley low compression...... |
This is NOT going into a bus and the compression will be at 8:1 CR. I'm sourcing out a set of 914 heads as my understanding from reading here and UAC says these help combustion considerably. It'll also be getting an aftermarket cam.
Is this in danger of overheating? It's not that I lugg it around and the car has no A/C so on the very hot days gets used very little.
The reason it's planned as a turbo but going in initially as NA is I NEED to get this tired old 1500 SP engine out and put it out of it's misery. It's such a DOG right now and burns oil at an alarming rate. It's almost an embarassment to drive. Getting all of the turbo plumbing fabricated is going to take too darned long! |
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raygreenwood
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Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
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| Posted: Thu May 12, 2011 2:45 pm Post subject: |
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| JustBuggy wrote: |
| raygreenwood wrote: |
I'm not a turbo expert....but I will say this. The type 4 engine in general for use other than for a bus....does not do very well with low compression. It runs hot, has a large deck and is pretty inefficient with regard to heat usage. It also will run pretty low hp numbers.
The issue is that to run a turbo you need moderatley low compression...... |
This is NOT going into a bus and the compression will be at 8:1 CR. I'm sourcing out a set of 914 heads as my understanding from reading here and UAC says these help combustion considerably. It'll also be getting an aftermarket cam.
Is this in danger of overheating? It's not that I lugg it around and the car has no A/C so on the very hot days gets used very little.
The reason it's planned as a turbo but going in initially as NA is I NEED to get this tired old 1500 SP engine out and put it out of it's misery. It's such a DOG right now and burns oil at an alarming rate. It's almost an embarassment to drive. Getting all of the turbo plumbing fabricated is going to take too darned long! |
Only the 2.0L 914 specific heads give improvements....not the 2.0L bus heads (totally different casting).
And....the 914 2.0L heads will not be worth the investment. They were the most prone to cracking of all of the type 4 heads. From reading notes from Jake and HAM...and also seeing a handful in shops that I know of...virtually all 914 2.0 heads will require extensive welding, re-tempering, new seats, hand reshaping after welding etc. Plus....a god set of core heads can run you $500 to start with...and another $1500+ to fix.
You would be much better off to spend the money with Jake or Len Hoffman at HAM inc....to buy a brand new set of heads that are set up exactly like a 914 2.0 head (better plug angle, 42 x 36 valves, specific combustion chamber volume etc.). Then you get full lifespan and better performance than the original 2.0 914 heads.
8.1 compression should be fine with a mild turbo. Personally I would set it up for 8.5:1 or slightly better for NA use. It will run much better, and cooler ...and with less spark advance. Then when you are ready for a turbo.....you can either put in acopper head gasket to increase deck and lower compression...or have some port work done to increase chamber volume. Either way its only a heads off reqork...everything else stays together.
But....dude...in that light car...and being used to the limited output of a 1500.....you are going to find the torque and HP of even a NA 2.0L built with modern camshaft and good compression...to be light years quicker and faster than the 1500. I'm betting you will forget about the turbo about a month after you start driving the NA engine.  Ray |
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JustBuggy
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Joined: August 01, 2010
Posts: 849
Location: SF Bay Area, Ca.
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| Posted: Thu May 12, 2011 5:48 pm Post subject: |
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| raygreenwood wrote: |
.........
But....dude...in that light car...and being used to the limited output of a 1500.....you are going to find the torque and HP of even a NA 2.0L built with modern camshaft and good compression...to be light years quicker and faster than the 1500. I'm betting you will forget about the turbo about a month after you start driving the NA engine. Ray |
I know it'll be better, but I'm pretty set in my ways and it will get a turbo as soon as I can get the time to build the pipework.
I'm not a stranger to turbos having built a couple of T-engines already. However I do want everything in place to make a good combo into a lion.
Thanks Ray! |
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