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Discussion Starter · #1 ·
I was scheduled to work with my engine builder Sat to pull the intake on my 383 that has been having an on going issue (rather puzzling) with smoking and oil consumption (after 2 recent rebuilds). Plan was to measure angles etc of heads and intake surfaces to determine what was going on and to verify that oil was being sucked from the galley (other potential sources of oil consumption were ruled out). However I was researching another potential issue, rocker studs not being sealed that went through to the intake ports (thanks to this board and all those who posted to some of my previous posts). What I figured first that was even if they were not sealed that it would not be a potential source of oil into the combustion chambers. Anyway dropped the car at ths shop thurs, fri the builder pulled and cleaned plugs then proceded to remove rocker studs and what he found was rather interesting:

1. Rocker studs on procomp pc3003 210cc did in fact go through to the intake ports despite procomp's tech support saying they did not (however suspected they did based on other's experiences)
2. When studs removed no sealant was on the threads, also oil coated the threads and inside the hole there was a shelf in the casting that oil sat on.
3. Builder believes that one contributer was the use of "adjustable" guide plates (oval hole vs circular) allowed oil to more easily pass down into the threads by being able to get under the nut by using these oval shaped guide plates.
4. Threads cut in head appeared to be "loose"; basically threads in head cut significantly deeper than the threads of the bolt, allowing more space for oil to work it's way past the rocker studs and into the cylinders.
5. That combination of threads not being sealed, #3, #4 along with positive crankcase pressure in above the rocker studs and a vacuum in the cyliders belwo caused a sort of "capillary" action pulling oil into the combustion chamber causing oil consumption and smoke.

The actual mechanism may not be correct but it APPEARS that all smoking has ceased. I plan on running the car and watching the oil to verify problem has been fixed. Question is if I really needed any of those rebuilds, but I guess I never will now. What a learning experience !!
 

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Discussion Starter · #3 ·
well ya get what ya pay for!
PROCOMP heads just plain suck! and end up costing you more in the long run .
with all the money spent you could have gotten a quality set of Brodix or AFR heads.
I am well aware of the potential issues on these heads. And also know that a lot of people use them w/o a problem. Defineately not my first choice. So you have used these heads first hand ???? Also FYI I did not get what I paid for since they were on the engine when purchased the car and had 50 miles on them.
 

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Glad to see you found a source for the oil consumption problem :cool: . Some will go straight to blaming ProComp, but all aftermarket SBC heads are drilled into the top of the intake ports. I've seen people who didn't know this have problems with oil down around the stud threads in Dart heads, too. Many also have exhaust stud holes that go through to the water jackets, although the PC3003's I have the exhaust holes are blind. My 15 year old Dart Sportsman's exhausts go into water.
 

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Discussion Starter · #5 ·
Glad to see you found a source for the oil consumption problem . Some will go straight to blaming ProComp, but all aftermarket SBC heads are drilled into the top of the intake ports. I've seen people who didn't know this have problems with oil down around the stud threads in Dart heads, too. Many also have exhaust stud holes that go through to the water jackets, although the PC3003's I have the exhaust holes are blind. My 15 year old Dart Sportsman's exhausts go into water.
Sure has been a learning process. Thanks for everyon on this forum with the tons of knowledge. Hopefully this is the end, but makes me wonder how much $, time and heartache I could of saved if this was investigated first :(
 

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The Dart II`s we ran have the studs in the intake ports. All you had to do to verify this was run your finger in the upper corner of the port, when you found a hole you found the stud. The first time I ever noticed this was on 882 heads when I checked the ports on them. I was surprised to find the dart`s had the same design as I thought that this type of ports were not what was wanted. I had read the 882 castings port did not permit a smooth mixture flow in the mid to upper rpm ranges so I wondered why would dart copy the port. I had also read the 882 was the best flowing small block smogger head with the correct porting. When you get conflicting answers like these you tend to not believe everything you read. I hope sealant on the studs takes care of your issue, lord knows you`ve been through enough.
 
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