Putting a newer distributor on my 1972 Mercruiser 325

[donwhiteside]

Hi All- I picked up a distributor, with ignition module and what I think is an "anti-knock" module, from a 1996 454 MARK V motor. I would like to install it on my 1972 Mercruiser 325 (427 engine with Thunderbolt 1 ignition system). It looks pretty staight forward in terms of mechanics and mounting (using coil, wires, etc. from newer unit). Question is: can I eliminate the "anti knock" module? Any on-line resources for a wiring diagram for this engine?

Thanks,

Don

 

[Reel Poor]

Re: Putting a newer distributor on my 1972 Mercruiser 325

The distributors are the same, TB IV and V. Just use the TB IV module. You can look here for more information.

http://www.boatfix.com/merc/Servmanl/16/16B4R2.PDF

 

[newport dave]

Re: Putting a newer distributor on my 1972 Mercruiser 325

Assuming what you have is a Thunderbolt V distributor, you should be able to use the distributor, but I would not attempt to use a Thunderbolt V ignition module without a knock sensor and knock module.

You would be much better off finding a Thunderbolt IV module to use. It will work with your distributor, and does not have a knock system.

Dave

 

[Don S]

Re: Putting a newer distributor on my 1972 Mercruiser 325

I'm with Dave. Stick with the TB-IV. Without the knock sensors, the TB-V knock module would not have the proper input and could destroy your engine.

 

[donwhiteside]

Re: Putting a newer distributor on my 1972 Mercruiser 325

OK, thanks guys. Further research (offshoreonly.com) had a pretty good thread on this. Apparently, the TB-V goes to full advance (37 degrees) or full retard without input from the knock sensor. Too much risk for my old boat. Anybody want to buy a TB-V ignition module and knock sensor??