Hamilton 12V head, anyone use on a DD and have economy results?

kawi600

kawi600

got Coal for Christmas
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Jun 9, 2008
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Ive got a truck thats had economy issues ever since I did the head and cam. My -guess- is that Ive somehow lost intake swirl (unshrouded valves by decking the head, as well as lost compression so the fuel isnt really igniting completely until Im really on the skinny pedal and the heat builds. It perpetually smokes at low RPM and idle. 8mpg city hand-calculated right now. Brand new trans buildup with low stall converter. Last compression check was 360psi on all cyls.
From what I understand part of the reason the stock head is so restrictive is that its designed to direct the air in a pattern rather than optimize for volume.
Ive read Zach's posts about the Hamilton head and still am not really sure if its going to help or hurt low-load MPG. Im sure it will scream on the top end, no doubts there. Unfortunately this truck doubles as my DD.
Has anyone used the hamilton head on a DD and taken note of city MPG?
 
I don't think changing your head will fix your mileage problem. If you are getting only 8 mpg I would do a fuel pressure check and make sure you are feeding the p pump with enough fuel and also have your injectors pop tested to make sure they are clean and popping right, also double check your timing.
 
Sounds like more of a pump/afc/dv/injec issue.
 
I would go through those injectors first, then if thats not it work your way to the pump. Your head is not your issue.
 
Freshly benched 215 PPump at near stock settings, fairly mild injectors. right now 7x.010 148* 275BAR from weston. Ive been down that road already it all looks good. At this point there isnt a whole lot left to try except the head.
 
Cam was recently replaced after it failed due to low zinc content in the oil. I doubt its mistimed. Maybe 5k on the new one?
Fuel pressure is 25psi at idle, 30-ish at WOT. EGT is around 1300 at WOT.
Truck is going in the shop later this month Im going to get a leak-down check done. Maybe back off on the fueling a little.
 
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It hazes pretty bad at idle even when warm.. thats not controlled by the AFC.
Its set a little on the heavy side but when I drive like grandma and it doesnt change economy or smoke somethings up. AFC just limits travel like a light foot would.
 
Stock gasket or thicker? I wonder if your injectors aren't sitting in the cylinders at the proper depth. Just throwing out ideas.
 
I'm sure this head was not designed for a DD.
When I looked at the aftermarket head, the first thing I thought was, where is the swirl? From what I understand it will swirl, but higher in the RPM range.
 
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yeah my first guess is its not DD friendly, just want to be sure since I do want to get a new head on this truck with the exhaust ported anyhow. cut valve seats, etc. You never know though, It might be that the head + cam combo works out pretty good?
Everything I read in my couple hours of searching seems to imply swirl is real important on a diesel for economy at part-throttle. I wonder if propane could do the same thing, igniting the fuel thats sprayed into colder pockets of compressed, slow air.
I have 148* injectors with .6mm copper shims. I think the depth is ok. Timing is at 18* but Ive tried 15 - 20 without much difference except a change in how hard it is to start and where the peak power is. Still hazes and guzzles fuel.
Another variable might be the pump versus the piston bowl.. did they make different bowl sizes in the 160 and 215 motors?
Maybe I did better on my tweaked 160hp pump 5 years ago?
 
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