Building the World's Fastest Duke!!! (Page 2/2)
Brivander DEC 08, 07:41 AM

quote
Originally posted by Patrick:

IMO, you're throwing your money away running Premium gas on a duke. Premium gas is for engines with higher compression and/or are boosted. Yes, I understand you've advanced the ignition timing beyond factory specs. So have I on my '84, and I run it on Regular gas after timing it old school by "ear". That involves advancing the timing a bit, flooring it while doing 30 mph in 4th gear while going up a slight incline, and listening for a "rattle". Keep advancing the timing bit by bit until you eventually hear the "rattle"... then back it off a little. If you ever hear it "rattle" again, back it off some more. I've found by advancing the timing in this manner, the gas mileage and acceleration improve, but the idle quality may suffer... and so do the smog test readings, so be forewarned.



100% agree with you, on all of it.

The premium was more of a caution, and only about 5 gallons. I'll probably back off to mid-grade and then to regular if no detonation happens. Also keep in mind this is a toy car for me and won't get driven often, definitely NOT a daily driver. A few extra bucks a year won't affect my budget. The car isn't "mine", the wife has always wanted one and she finally talked me into one. I just got the task of making if perfect. I need some time so I can finish polish it and ceramic coat the thing.

No smog tests in Michigan, though

[This message has been edited by Brivander (edited 12-08-2021).]

pmbrunelle DEC 08, 07:49 AM
Besides the knock resistance, check in your area if the ordinary gasoline has ethanol or not.

If the premium is ethanol-free, it may take longer to go stale. This factor may matter if you don't drive the car often.
Brivander DEC 08, 08:46 AM

quote
Originally posted by pmbrunelle:

Besides the knock resistance, check in your area if the ordinary gasoline has ethanol or not.

If the premium is ethanol-free, it may take longer to go stale. This factor may matter if you don't drive the car often.



Ordinary gas absolutely has ethanol here, but rec fuel is easy to get around me because of all the boaters. Anything I own that gets stored for very long gets rec fuel.
RichLo1 DEC 08, 09:51 AM
You dont have to tear apart your engine for this, new higher ratio rocker arms.
Brivander DEC 08, 11:33 AM

quote
Originally posted by RichLo1:

You dont have to tear apart your engine for this, new higher ratio rocker arms.



Aren't they aleady 1.75? I would be scared to do more than that with a flat tappet cam.

[This message has been edited by Brivander (edited 12-08-2021).]

theogre DEC 08, 07:56 PM
Make sure you have roller or flat cam setup.

Unless you already took cam cover off... measure push rods.
See my Cave, Duke Quick Ref

You can't trust whatever book for year of car because many Dukes was replaced under Recall or Warranty work.
Others replace by 3rd parties using whatever available or thru Jasper etc. rebuilds.
Dennis LaGrua DEC 13, 09:45 AM
As mentioned bolt on mods for the Duke were discontinued years ago. At one time even Hooker made headers for that engine. IMO, unless you are willing to do some extensive and costly mods you cant do that much. Many years back a guy by the name of Ira Crummy claims to have built a 120 HP Duke. Some of his tips are listed on his website:
Iron Duke Resource site

[This message has been edited by Dennis LaGrua (edited 12-13-2021).]

Brivander DEC 13, 10:02 PM

quote
Originally posted by Dennis LaGrua:

As mentioned bolt on mods for the Duke were discontinued years ago. At one time even Hooker made headers for that engine. IMO, unless you are willing to do some extensive and costly mods you cant do that much. Many years back a guy by the name of Ira Crummy claims to have built a 120 HP Duke. Some of his tips are listed on his website:
Iron Duke Resource site





I am not willing to do anything that isn't relatively simple. I'd say we are about done here. Getting it running 100% was really the key.
edfiero DEC 27, 09:37 AM
Like you I advanced the timing on my Duke for a bit more pep.
Also I installed a block off plate on the EGR valve. This seemed to make her a bit more lively as well.

Otherwise, just keep the car stock and enjoy it as is..