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restricting oil to the rocker shaft when putting a mech shaft on a hyd head
https://www.slantsix.org/forum/viewtopic.php?t=66046		 Page 1 of 1
Author:  DadTruck [ Thu Jun 24, 2021 6:19 pm ]
Post subject:  restricting oil to the rocker shaft when putting a mech shaft on a hyd head
Putting this posting in the general engine section to solicit comments and ideas.
This concerns the 68 Barracuda motor, what I call the HI-NA motor.
Last year '87 block and head, with a mechanical valve train, reground OE 87 cam.
Basics: 2.2L pistons, cast crank, K1 rods, ford OS valves, positive valve seals, MS3 Pro fuel and ignition controls, MSD ignition, MPFI, 10.5 compression, 185 psi cranking pressure

The motor has gone through the cam break in, no real miles, an estimate is less than 2 hrs run time on the motor. No real drive time miles. The problem is no matter how lean I get the AF mixture, there is some light blue smoke huffing out the tail pipe and the spark plugs get real black real quick, the plugs get black in minutes of run time.

I am thinking that I maybe overloading the valve seals with oil on the top side of the motor. But this is just a guess. I considered a broken piston ring but all six cylinder are with in 10 psi of each other and all six plugs get black quickly. With the valve cover off I did a visual inspection of the valve seals to make sure I did not crash-crush them due to a clearance issue. They all look fine.

I did not restrict the oil flow to the head as part of the build process, so I am backing into that by using a brass bushing at the rear oil feed rocker arm bolt.
Listed below are photos with clearance information.

Attachments:
File comment: .710 clearance
Hyd shaft and Hyd Rear bolt.jpg
Hyd shaft and Hyd Rear bolt.jpg [ 60.93 KiB | Viewed 2181 times ]
File comment: .645 clearance
Mech shaft and Mech Rear Bolt.jpg
Mech shaft and Mech Rear Bolt.jpg [ 61.22 KiB | Viewed 2181 times ]
File comment: 1.615 clearance
Mech Shaft and Hyd Rear Bolt.jpg
Mech Shaft and Hyd Rear Bolt.jpg [ 62.88 KiB | Viewed 2181 times ]
File comment: .605 clearance
Mech Shaft and Hyd Bolt with Bushing.jpg
Mech Shaft and Hyd Bolt with Bushing.jpg [ 60.81 KiB | Viewed 2181 times ]
Bushing at installed depth.jpg
Bushing at installed depth.jpg [ 55.16 KiB | Viewed 2181 times ]
Author:  DadTruck [ Thu Jun 24, 2021 6:27 pm ]
Post subject:  Re: restricting oil to the rocker shaft when putting a mech shaft on a hyd head
I did some visual observations today looking at oil to the rockers with the mechanical shaft and the hydraulic rear bolt with and with out the bushing. Tomorrow I plan to do another test and get variable data collecting oil that spills out of the head. We shall see how that goes.

I guess my question is: how much oil is needed going to the top end with a mechanical valve train at low and high rpm's? Just a dab will do ya, or a lot? And anyone agree that a lot of oil up top will cause positive valve seals to ingest oil, or is this maybe the rings just have not broke in yet?

thanks
Author:  Rick Covalt [ Thu Jun 24, 2021 6:40 pm ]
Post subject:  Re: restricting oil to the rocker shaft when putting a mech shaft on a hyd head
I wouldn't worry much on a new motor. I'd wait until I got some miles on the engine and put a mileage number to the usage. Also how old is the gas in the tank. Old gas certainly made my truck smoke once I got it running after setting for a year or so.
Author:  slantzilla [ Thu Jun 24, 2021 7:39 pm ]
Post subject:  Re: restricting oil to the rocker shaft when putting a mech shaft on a hyd head
Have you taken it out and put a real good load on it yet? Just running it a few minutes at a time with no real load will kill plugs.
Author:  Killer6 [ Fri Jun 25, 2021 7:54 am ]
Post subject:  Re: restricting oil to the rocker shaft when putting a mech shaft on a hyd head
Step 1)start-up/cam break-in/check for leaks etc.
Step 2)drop in gear & block it up against the brakes hard 4 or 5 times.
If it's burning that much oil after that, something's wrong.
Blue smoke isn't jetting, don't lean it out, that's oil. Double check the oil for fuel contamination, possible leaking fuel pump/excessive fuel pressure/float level too high/needle-seat not sealing.
Because the Slanty pump is "inverted" style, it can leak & run right into the crankcase w*n leaking externally, & I know 1st-hand.....
If the oil pressure is excessive, it can put a lot of oil in the top end, but PC seals shouldn't have a problem handling that,....
Author:  DadTruck [ Fri Jun 25, 2021 5:07 pm ]
Post subject:  Re: restricting oil to the rocker shaft when putting a mech shaft on a hyd head
installed the hydraulic rear rocker shaft with a bushing that reduces the oil passage clearance. My visual observation is that I did not see a difference in the oil flow to the top end. But directionally this seems to be the right thing to do, although certainly the way things are I do not see oil starvation valve train issues in my immediate future :D . I will take the recommendations that I drive the car, break in the motor and re evaluate from there, so that is what I will do. Thanks for the recommendations.

Attachments:
Rear Bolt with Bushing.jpg
Rear Bolt with Bushing.jpg [ 67.62 KiB | Viewed 2097 times ]
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