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-   -   EST/FI swap to carb (http://www.hotrodders.com/forum/est-fi-swap-carb-222562.html)

garbage pikker 08-05-2012 10:28 AM

EST/FI swap to carb
 
Okay, same question, just asked more differently. I have put as EST style dizzy on a SBC with a carb. The motor has no vacuum ports, none on the carb, none on the manifold, no pcv. it has no computer. It wont advance past the standard bypass mode, cause nothing is telling it to. Is there any way I can add a computer, either aftermarket or OEM that will get me some more advance?

DoubleVision 08-05-2012 09:57 PM

I'm kind of confused here. Why not just install a HEI with mechanical advance? You say your running a carb but it has no vacuum ports? What kind of carb is it?

garbage pikker 08-06-2012 10:09 PM

Quadrajet, in a boat. I put in an est from a early 90's chevy. Because it is in a boat, and boat engines are always under a load, they never will make any vacuum. I was hoping that there was an aftermarket computer solution where i could install a knock sensor but not the EFI. then I learned that in bypass mode this dist has only 1 advance- to about 12 btdc. I did not know that I could get an HEI that was a mechanical only. WHat year did this come on? I would post in boat forums but those guys have too much money and usually just buy their way out!

DoubleVision 08-07-2012 02:25 AM

1 Attachment(s)
The old school HEI's that came in millions of passenger cars and trucks from 75 to the early 80's. In the 80's they started to come with CCC computer control. However the units before that had a vacuum and mechanical advance. You can drop one of these right in no problem. Since the carb has no vacuum you can bypass the vacuum advance and since boats are mostly used at mid to wide open throttle the mechanical advance is all you need.
I just converted my TBI truck over to a carb and I removed the computer control distributor and installed a standard HEI with vacuum and mechanical advance.

Silver Surfer 08-07-2012 11:50 AM

You can get a used q-jet with vacuum ports, designed for street use on Craigslist cheaper than you could cobble in some sort of weird computer.

garbage pikker 08-07-2012 02:35 PM

Quote:

Originally Posted by Silver Surfer (Post 1580929)
You can get a used q-jet with vacuum ports, designed for street use on Craigslist cheaper than you could cobble in some sort of weird computer.

As far as the HEI goes, I have thought of that and actually have one ready to go-boat engines are the same engines that are in cars and trucks, same with the manifolds (well the intake at least-exhaust has a water jacket on it to keep it cool) so I cant get ported vacum, cause the carb simply doesnt have the bosses drilled but I can just remove a plug outta the intake and pull the vacuum offa that. Id switch the carbs but the DNR will pull you over and look for the "marine exemption" tags and stamps-the one on the dizzy is on the bottom so I am not worried but it is stamped right on the side of the carb.

Now comes the next question, and I have no experience in the rev limiter dept, so bear with me on this one. This particular outdrive needs the motor to "stutter" a little bit when going from drive to neutral. Now the shift cable has this little system that if the cable is under tension (like when you are trying to get from drive to neutral and it wont release) it senses the tension and throws a switch until the tension is off. I can either take this switch to a ground, or to a + source, or whatever. I have heard myths of there being a module that will sit in this dizzy, and will advance incrementally and then to activate the shift stutter thingie they just hook +12v to the switch and connect that to the 0 degree jumper so that at idle, when the drive is pushed into neutral and it needs a little shake it will send the dizzy to 0 degrees, dip the revs and the drive will slip out of gear. SO



OK

Is there a way to get an aftermarket rev limiter and have it drop a cyl or 2 and tie it to the switch so that when the switch activates, it drops a cyl or 2 until the switch senses that the pressure is off and turns it off. This is a microswitch, so I could change it out to be on when the pressure is on, OR have it so that the switch is off when the pressure is on. Right now, when coming in to the dock, I have to shut the engine off to get from drive to neutral. Will a rev limiter or a stutter box allow itself to be "tripped" when the motor is at idle? Again, i would ask in a boating forum, but those guys tend to buy their way out of their problems, and seeing as I call myself the garbage pikker I like to tinker and figure it out.

LATECH 08-07-2012 02:38 PM

Just get the correct 5 pin module, and install it in the dizzy. Hook the 5th pin of the module to the ground source or 12 v + depending on which module you have.
For the seven and eight pin modules you have to have a computer to modify the ignition signal when the advanced is activated by the 5 volt source.
I would look real hard at a 5 pin module. Use the one that retards the timing when the "R" tgerminal is grounded. You could hook that to you "bump" switch on the control.
One of the 3 types of 5 pin modules retarded timing when grounded, another retards timing when a voltage is applied, the third ( the one for ESS which you dont want) needs a computer modified signal to control timing, like the 7 and 8 pin modules.
That is why I suggested to get the 5 pin.


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