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Hi all I have now decided to return to D-jet after not having too much fun with any of the carb set-ups I have been using. I am hoping to soon be building an 1800cc, which will remain pretty standard. What I was wanting to know before I commit to the build, is there anything I can do to help improve the D-jet set-up, such as, can I increase the CR if so how far, I may have some money for a new cam and lifters, any recommendations? …. it is going into my 74’ 412LS as a daily driver. I have basically got the case the heads and the crank what could I be adding to my shopping list that would work for such a set-up. I have collected two complete D-jet systems from running cars where the body has lost its fight with rot. What components from these systems should I be looking to replace, I have a book that explains how to test most of the main components, but should I be replacing anything outright, such as the injectors? I am sure I will have a few more questions soon, so this will do for now.


Any help is greatly appreciated.

Nick Sparrow

Do a search, there is lots. There are lots of little tweaks taht you can do to the FI. You can get an honest 10 hp with the bone stock motor just by closer balancing of the fuel system tuning. A better ignition...basic pertronix...or almost anything other than the points...better valve sizing, a web cam #73...for injection, with lifters....and a mild port job goes a long way. Compression should be no lower than 8.0 to 8.2:1. Up around 8.6:1 works nice. The d-type responds very negatively to too low of a compression ratio. The fuel mixes poorly. If you remain with the 1.7...a lot can be said about the original domed pistons. They are set up to work with the quench area of that head. They make a noticable difference in the same engine with the same compression using flat top or dish pistons. Better response and more incremental fuel tunability is about all I can describe. With good port work, 100 HP with a 1.7, tuned out is not too hard. Ray