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Old 03-30-2011, 11:33 AM
myk myk is offline
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Join Date: Jan 31, 2011
Location: Kent, WA
Posts: 82
Quote:
Originally Posted by tgreese
Some questions about your choices of components, if I may.

The tooth wheel seems like a lot of extra complexity when you already have a spark signal from the Motorcraft distributor. You could follow the 7-pin approach described here http://www.megamanual.com/ms2/GM_7pinHEI.htm or even use the on-board single coil spark provision on the 3.0 board.

It's all about accuracy, the ECU uses a prediction algorithm to determine when to fire the coils based on feedback from the RPM sensor. The more teeth you have the better it can determine when to do this. With the cam moving half the speed as the crank and the motorcraft dizzy only having 8 vanes, the crank wheel setup I have gives the ECU 12 times as much data per cycle to predict the spark which leads to greater timing accuracy. Also with taking the RPM signal from the distributor you introduce all the slop of the crank to cam gears/chain as well as the cam to distributor gears, the timing will also start to drift over time as the cam chain wears. So yes it is was a bit more work but well worth the benefits imho, if you were to go look at any newer car/truck you would be hard pressed to find one without a crank trigger setup for all these reasons.

Quote:
Originally Posted by tgreese
What advantage does the Walbro pump have over, say, the Airtex E200 http://www.rockauto.com/catalog/moreinfo.php?pk=59606 and is somewhat cheaper?

I presume you will mount the Walbro pump lower than the lowest tank level, to avoid loss of pump prime?

I'm not familiar with the Airtex pump, however the Walbro pump is a very proven pump and will support future growth if I need it (higher HP, MPFI, etc.) the price seemed reasonable, I got it for ~100 with the mounts and end fittings.

I will mount it in the frame rail as low as possible and as close to the tank as possible. That's about the only option I can see that I have.

Mike

Last edited by myk : 03-30-2011 at 11:40 AM.
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