Detroit 12.7 Injector Choice??

Do you have the whole part number?

 

I'm trying to find the answer to this too. PDI tells me their performance camshafts for detroits can work in place of 1681 and 4912. But 1681 uses 18 mm bolt, and 4912 is 20 mm. Any thoughts?

 

If the gear ring is identical and is just a bigger cam bolt...changing the great won't be too bad. Just PTL the front cover, change out that gear. Wouldn't even need to time it if you were careful. If the gear ring is not identical you would have to change every other gear with it...thats gonna be expensive and if you don't get it timed perfect something is gonna break the first time you start it.

 

23625526

 

That's right the issue is you have to disassemble the front cover to change the gear. I was kinda putting that off until next time I replace the bull gear bearing it's not a small job.
Alot easier to just swap a cam that has the same bolt size.

 

A weekend and a couple six packs. What's the problem? Maybe leave out the six packs if you want it back together Monday morning.

 

Ok, but if it's just a size of the hole on the cam gear to put a larger 20mm bolt thru the only thing that matters, what if you just drill a slightly larger hole through a cam gear? This may sound rudimentary, but if it works there would be no need to remove a front plate or change the gear. Although metal shavings from drilling probably would get in the engine.

 

Pull the cam gear access plate. It's just 4 or 5 bolts. Take a peek inside and then think about how good an idea that is.

 

Probably not a good one, lol. But opening a front plate not appealing either right now. Guess I'll go with 4292 cam and 5915 inj. Hopefully should see improvements over 1681-5575 combo I have now. Does anyone have some input/experience with 4292 cams?

 

Actually just read on dieselenginetrader that 4292 and 4912 are exactly the same specs cams, except bolt size, both 500 hp and 81.0 inj height. If that's true then stupid me just wasted lot of time figuring out if 4912 with 20 mm bolt was better, lol