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Dart Iron Eagle Oil Restriction

Keith Rittenberry

Keith Rittenberry

Member
Feb 28, 2016
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Well, I never got an answer on the GM Rocket block (with over 600 views), so I'll change it to a Dart question.

I'm having issues with oil return on an Iron Eagle motor. I run a Dailey external pump returning to a Stef's pan. I currently have no restrictions except for the key-way lifters themselves. Should I run some restriction somewhere to prevent sticking all the oil to the inside bottom of the valve covers? Weaker spring in the oil pump?

It is basically a comp motor that I need to taxi to and from my trailer without a tow vehicle. Any serious help appreciated.

Thanks,

Keith
 
racefab57 said:
If you go to Dart's website there's info on oil restriction there..So Ive heard. Trying to help!! David R.
Click to expand...
Thanks David! I saw the Dart info, but was hoping someone could confirm those restrictor sizes are what's needed, or the restrictions could be refined a little. I have gone away from the external pump and went internal because I was running out of oil (external pump too efficient). I don't think there is any evidence that an internal pump causes enough camshaft deflection to be noticeable anyway. Opinions?

Keith
 
Hello to all. New to this site. The first post I viewed is something I could be of help with. I have engine building experience in all forms of motorsports, but in particular I have had great success with naturally aspirated Iron Eagle engines. Long stroke combinations for SCORE desert racing with multiple Baja 500 and Baja 1000 wins as well as class championships so they are proven to win as well as last.
All of my serious wet sump engines have external oil drains in the cylinder heads. Not fittings high in valve covers but as low as possible, to catch and return the oil before it has a chance to drain into the valley. Bigger is better. -8 minimum. Crankcase windage will obstruct oil return in smaller lines. Port the head casting to direct the oil into the drains before it has a chance to ride the chute into the valley. Welding on drain bungs is most effective but can be drilled and tapped. I open the rear return hole in the valley back by the distributor gear and cover it with a coarse screen. I use large standpipes in other locations to allow the crankcase to breathe but not allow oil to return onto the rotator.
Lifter galley restriction can be done two different ways. Both have worked fine for me. The option Dart prefers is to block the inner 1/4 npt lifter galley plugs closest to the oil pump or inlet. The opposite end of each lifter galley has each inner 1/4 npt plug drilled for your desired restriction. I have had good luck with .090 to .100 holes in each plug when following this method. Your mileage may vary.
A second option is to drill all four inner 1/4 npt plugs to feed the lifter galleys from both ends. A hole size of around .060 to .065 in each of the four plugs has worked well for me. As with anything, your mileage may vary. Restriction will vary depending on pump capacity, oil bleed (clearance), oil return efficiency etc.
Hopefully this will be of some help.
Steve Roehlk
 
stevespeed said:
Hello to all. New to this site. The first post I viewed is something I could be of help with. I have engine building experience in all forms of motorsports, but in particular I have had great success with naturally aspirated Iron Eagle engines. Long stroke combinations for SCORE desert racing with multiple Baja 500 and Baja 1000 wins as well as class championships so they are proven to win as well as last.
All of my serious wet sump engines have external oil drains in the cylinder heads. Not fittings high in valve covers but as low as possible, to catch and return the oil before it has a chance to drain into the valley. Bigger is better. -8 minimum. Crankcase windage will obstruct oil return in smaller lines. Port the head casting to direct the oil into the drains before it has a chance to ride the chute into the valley. Welding on drain bungs is most effective but can be drilled and tapped. I open the rear return hole in the valley back by the distributor gear and cover it with a coarse screen. I use large standpipes in other locations to allow the crankcase to breathe but not allow oil to return onto the rotator.
Lifter galley restriction can be done two different ways. Both have worked fine for me. The option Dart prefers is to block the inner 1/4 npt lifter galley plugs closest to the oil pump or inlet. The opposite end of each lifter galley has each inner 1/4 npt plug drilled for your desired restriction. I have had good luck with .090 to .100 holes in each plug when following this method. Your mileage may vary.
A second option is to drill all four inner 1/4 npt plugs to feed the lifter galleys from both ends. A hole size of around .060 to .065 in each of the four plugs has worked well for me. As with anything, your mileage may vary. Restriction will vary depending on pump capacity, oil bleed (clearance), oil return efficiency etc.
Hopefully this will be of some help.
Steve Roehlk
Click to expand...

Thanks Steve! That's the kind of detail that helps. I have to shutoff at the end of a run and wait for oil to return to the pan before I can continue back to the trailer. It's a pain in the butt that is usually compounded by the ET shack not being able to find my time slip.
 
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