Dan Stokes
New member
- Joined
- Feb 21, 2017
- Location
- Wilmington, NC
I know that making Volvo tachs work with V8s and other odd applications has been discussed on here before but I have a weird situation and, I think, a different solution.
You may recall that the BluePrint 347 SBF that I'm putting in an '83 245 came from BP with an EZ-EFI and a full MSD ignition including their billet distributor. The tach SNAFU comes from the fact the tach wire from the MSD has to go, unimpeded, to the EZ-EFI as it's speed signal. If I "T" into that tach wire the tach begins to work for a second but the engine promptly shuts off just like you switched the key off. A call to EZ-EFI (now a part of Comp Cams) confirmed that that wire can't be messed with. Curses. After trying several things I found that Dakota Digital makes a universal tach adaptor that allows virtually any tach to work with any pulse train input. It can be adjusted for any number of cylinders from 1 to 16 and pretty much anything that pulses, even (with an adaptor) the alternator (might help in a Diesel swap). The only tricky part might be calibrating it to something but the EZ-EFI has a hand held tuner that has an RPM readout so I can make the 2 agree and I'm in tall cotton.
I may be able to take a pulse from one of the EFI injectors or maybe even take the tach signal as it would use no power (the universal tach adaptor is powered independently), just the pulse. I have it hooked up in a test configuration and I'll get back to y'all and let you know how it works out. The adaptor is about $80 so not cheap but it might solve an issue for one of you.
Dan
You may recall that the BluePrint 347 SBF that I'm putting in an '83 245 came from BP with an EZ-EFI and a full MSD ignition including their billet distributor. The tach SNAFU comes from the fact the tach wire from the MSD has to go, unimpeded, to the EZ-EFI as it's speed signal. If I "T" into that tach wire the tach begins to work for a second but the engine promptly shuts off just like you switched the key off. A call to EZ-EFI (now a part of Comp Cams) confirmed that that wire can't be messed with. Curses. After trying several things I found that Dakota Digital makes a universal tach adaptor that allows virtually any tach to work with any pulse train input. It can be adjusted for any number of cylinders from 1 to 16 and pretty much anything that pulses, even (with an adaptor) the alternator (might help in a Diesel swap). The only tricky part might be calibrating it to something but the EZ-EFI has a hand held tuner that has an RPM readout so I can make the 2 agree and I'm in tall cotton.
I may be able to take a pulse from one of the EFI injectors or maybe even take the tach signal as it would use no power (the universal tach adaptor is powered independently), just the pulse. I have it hooked up in a test configuration and I'll get back to y'all and let you know how it works out. The adaptor is about $80 so not cheap but it might solve an issue for one of you.
Dan