SourKraut412 Posted December 30, 2015 Share Posted December 30, 2015 Did some searching on this and found conflicting information on compatibility of ND & Hitachi distributors. My 86 Brat is of course Hitachi, but the distributor is going out - play in the shaft. I found a good ND disty at a junkyard. I read that you need a ND coil to use a ND disty and vice versa with Hitachi. I also read that you could use a Hitachi coil with a ND disty, but not the other way around (i.e. Hitachi disty with ND coil = no good). What is correct? Are there any other parts needed to swap to the ND disty besides maybe a coil? Link to comment Share on other sites More sharing options...
turbosubarubrat Posted December 31, 2015 Share Posted December 31, 2015 People swap to the ND to get better spark from what i have read or put in 2 ignition modules in them for better performance. The stock coils are all pretty much the same besides lengths from what i have noticed. I've swapped the 2 brands together and never have had a problem. You could upgrade to a accel super stack or a msd coil if you want a stronger spark. 1 Link to comment Share on other sites More sharing options...
SourKraut412 Posted January 3, 2016 Author Share Posted January 3, 2016 Got a new cap and rotor for the ND disty from a local parts store. It was identical to the one I just picked up for the Hitachi disty, same part number and everything. The rotor was correct though. Isn't the ND cap different from the Hitachi? Link to comment Share on other sites More sharing options...
ferox Posted January 4, 2016 Share Posted January 4, 2016 Got a new cap and rotor for the ND disty from a local parts store. It was identical to the one I just picked up for the Hitachi disty, same part number and everything. The rotor was correct though. Isn't the ND cap different from the Hitachi? Yes the cap and rotors are different, and technically an ND disty will work better with the coil it was designed for. They do have different ohm ratings. The part numbers for the hitachi and ND distys should be different. There isn't any real difference in power between the two units. They just accelerate differently for the most part. I prefer the Hitachi myself. Link to comment Share on other sites More sharing options...
ferox Posted January 4, 2016 Share Posted January 4, 2016 Not that you asked, but I have noticed over the years (and I could just be making this up) that the ND disty seems to tolerate the ignition timing being advanced 1-2 degrees more than the Hitachi in general. But if that is true, then it would seem to indicate that the Hitachi produces a more rapid fuel deflagration rate which would imply a stronger more effective spark (an oversimplification for sure). Said another way, if the ND allows the timing to be more advanced, implying that the spark initially ignites less fuel (reducing the deflagration rate), then it simulates burning a slightly higher octane rated fuel. I've always seemed to get 1-2 more mpgs with a timing-advanced ND system too, but I still prefer the Hitachi. I would posit that the perceived performance enhancement from the ND disty may not necessarily be from a stronger spark per se, but rather the distys effect on the timing and deflagration rate. This also means that if you want the ND performance (as yet unproven scientifically), then you have to be able to advance it the 1-2 degrees more than the Hitachi, especially if you're running a Weber. The ability to do that is highly affected by the individual EA81 engine. Some will take a lot of timing advance and some will hardly take any. So my point is, if you are able to advance the timing to 10* or more, then you may be able to get some advantage out of the ND over the Hitachi. But if your engine won't do that and your settings are close to what the Hitachi would take, then you will probably experience less perceived power with the ND and will notice it most on hills. I'm not trying to present this as fact so much as testimonial and thought experiment. I have also found a much higher percentage of worn out ND distys than Hitachis in the yards. Link to comment Share on other sites More sharing options...
SourKraut412 Posted January 5, 2016 Author Share Posted January 5, 2016 That is all good info and something I will look out for as I switch between the two. The only reason I am switching is because I found a ND disty at local salvage yard that was in good shape. My Hitachi has close to a mm of play in the shaft and is suspected to be the reason for some weird issues I had been experiencing. My plan is to use the ND until I eventually get the Hitachi rebuilt by Philbin. I prefer to keep things as close to stock as possible unless I'm getting significant gains in power or fuel economy, but it never hurts to have spare parts. On the 3rd attempt, I got the correct cap for the ND disty at the parts store. The ND disty from the yard was off a 86 XT with FWD and NA. They kept giving me parts for a Hitachi, but I thought from what I've read the XTs with those features didn't come stock with a Hitachi. It wasn't until I just told them to look up the ND part number for the Brat that they could find the ND cap. Not sure why that was such a pain to get, but I'm starting to think that's the norm with these weird old rigs. Link to comment Share on other sites More sharing options...
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