#381  
Old 11-21-2018, 03:24 PM
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Day 5! Made it back to Atlanta Dragway!






I put a catch bottle on the outlet of my crankcase vacuum pump and it would pick up a bit of oil after a pass. This is even after the oil catch before the vacuum pump.


So then I got the idea to skip the vacuum pump altogether and open up the vent on the oil fill cap and see if the engine would do better with the crankcase fully vented to atmosphere versus just the 3/8th vacuum port, and it put a bit of oil out the vent into the catch bottle. This was not un-expected because my lash adjuster oil pressure regulator returns to the oil fill tube, so any gases going up the tube have a direct shot of oil entering the air stream.


It did okay, but oil pressure was a little wobbly at the end, so I thought I'd add a 1/2 quart of oil and then really wind up the rpms to see if I could crack into the 14's. But it wasn't meant to be. It nosed over very hard at the top end of 2nd, then a bunch of smoke coming out from under the hood, though oil pressure was still good. Turns out it nearly filled the oil catch bottle, then proceeded to oil down the engine bay. Called it the day and week. I finished Drag Week 2018 and the car still ran.





Then a friend of mine in Montana was rolling home with an empty trailer, so we loaded the car up on his trailer so I could fly home with my family.


Then in October I flew up to Montana and picked up the car to finish it's drive home.






Made it home!!



Now, I want to put the rear axle back in my Skylark and put the 8.5" back in. I've decided to buy some upgraded moser axles for the 8.5" and put in the 4.56 gears I have on the shelf. I figure the gears are good until I run about 108mph in the 1/4, depending how well the new engine and head breath. At which point I can decide if I want to go back to the 3.42 gears or buy a 9" rear end with a different ratio. At some point over the winter I'll get the other engine together.

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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #382  
Old 11-21-2018, 07:07 PM
gtospieg gtospieg is offline
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Nice....glad you made it back and sounds like you had a pretty successful trip.....I
like your wheel choice...I have the same wheels on my "67 GTO...looking forward to the new engine, turbo, cam etc.

  #383  
Old 09-04-2023, 12:34 PM
Bzltyr1 Bzltyr1 is offline
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Randall - I have a dual turbocharged OHC6. I am having trouble with crankcase pressure. What did you do to stop oil from leaking from the oil filler tube or wherever?
Thanks.
Brad

  #384  
Old 09-04-2023, 01:40 PM
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Not Randall but think about venting on other side of motor
and blocking off the fill tube.
Youre fighting a battle with crankshaft windage

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  #385  
Old 09-04-2023, 01:44 PM
Bzltyr1 Bzltyr1 is offline
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I have a connection to the inlet side of one of the turbos to pull pressue out of the engine. and a catch can that opens to drain whatever oil is in the can when I shut off the engine.
Completely blocking off the oil fill tube will not cause any other problems?
Thanks for the quick response.

  #386  
Old 10-23-2023, 06:27 PM
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Yup, vent vent vent, and oil control to not take the oil with the venting.

I put a literal rubber stopper in the dip stick tube because the bottom of the tube sits in oil and crank case pressure pushes raw oil straight up the tube.

The oil filler I put a grommeted breather cap on it (sealed up) with a hose going to an oil catch can. You can see I used an expansion plug to seal the side hole as well.


I'll get a picture of it later, but I also took a sheet of tin metal and rolled it up so the ends were about 1/2" apart and dropped it down the oil fill tube, all the way down to the block surface with the 1/2" gap facing outwards. Just so the venting gasses have to change directions a few times and hopefully drop the oil out. I also vent the PCV port straight to the catch can, but I had added extra internal oil baffling around the PCV port to try and catch oil before it left the block.


I just pulled the engine a few weeks ago, as it was mixing water into the oil. Turns out cylinder #3 cracked. I'll make a bigger post later on and hopefully post regular updates.

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  #387  
Old 10-23-2023, 06:49 PM
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I also started monitoring crank case pressure in my data gathering. Mostly to find out when the rings get upset from over revving or such. The rev limiter ALWAYS pressurized the crankcase big time.

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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #388  
Old 10-23-2023, 07:44 PM
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85.6 what units? PSI? Atmospheres?

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  #389  
Old 10-23-2023, 08:36 PM
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Quote:
Originally Posted by Bill Hanlon View Post
85.6 what units? PSI? Atmospheres?
Its kPa.

Crankcase is at 85.6 kPa and the atmospheric pressure is two numbers up at 86.6 kPa, so running 1 kpa more pressure than atmospheric, which is essentially free flowing venting.

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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #390  
Old 11-03-2023, 02:41 PM
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Long over due update. The short version is I ran all of drag week 2018 on 5 cylinders as I found coil #5 wasn't getting power. It explained why it struggled to build boost, why it constantly would run lean despite the plugs showing obvious signs of being too rich, etc. It was a huge diagnostic miss by me in the moment. The turbo certainly muffled the miss sound and and the engine being inline didn't wobble at all.

So sadly I was probably making around 240HP on 5 cylinders and 5-7psi. Once I had that fixed, and got the transmission shift timing right to not hit the rev limiter, the engine came alive. It quit filling the catch can, would bark the tires into second and third, and really lose traction in second as soon as it hit 10psi. I estimate it was making around 350-380hp at 15psi. I popped one head gasket running it up to 20psi and 6,000rpm, which it wasn't happy with. It popped on cylinder 5, which I attribute to the thousands of miles and hits of getting loaded up with fuel but no spark, just hammering the gasket with incompressible fuel. Then eventually the crappy bores in cylinders 3&4 came out of hiding and a long time feature of #3 became a crack and it was time to pull the engine.





Now, as time allows I'll make some posts on getting here

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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #391  
Old 11-03-2023, 03:01 PM
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So soon after figuring out that cylinder #5 wasn't firing, I took it out for some test runs, regularly hitting the rev limiter and overboosting as I was sorting out the transmission shifting programming. Multiple trips to 6,000rpm and 17-20psi of boost until eventually the head gasket let loose on #5. It actually blew out the side of the engine so was a massive cylinder leak to atmosphere, no water!

https://www.youtube.com/shorts/g9lXrICAzOc

https://www.youtube.com/shorts/BWsrUxhPmJc




Cleaned it up and put it back together.


Soon after it started developing a bad vibration. It seemed to only be in 3rd and 4th so I pulled the 4L60e apart, found nothing, changed u-joints, nada, and came to the conclusion the always whinny 4.56 gears must have an issue. I put fresh races, bearings and new set of 3.42 gears in the rear end and the vibration was cured. I found some chatter marks on some of the races and figure the carrier was moving around some causing issues. At some point during the rear gear fixing process my son dumped a quart of gear oil on me while I was under the car and after fighting this vibration for so long, that was a straw that made me walk away from the car for a few months.









In the process it got a new transmission cross member as well.


I always chuckle at the absurdly large exhaust system on this car. I didn't want any post turbo restrictions, lol. 4" from the turbo to rear axle, then 3" over the real axle.

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  #392  
Old 11-03-2023, 03:18 PM
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Then while the car was just sitting, I started poking at the "good" engine sitting on the engine stand in my garage, which I started to assemble over the last few years. Periodically spraying the bores down with WD-40 and rotating the bottom end.

Fresh coat of Pontiac Blue.


Gapping the rings in prep for some boost.


Some Ross forged pistons on SCAT rods.


I had the machine shop fly cut some smaller valve relief's into the flat tops. There are some forged factory style pistons now offered by Ross Pistons.


Bottom end buttoned up. The clearances are on the tight side around 0.0020" but really not much I can do about it unless I want to send the whole crank out for a significant regrind. Got main studs in place. Fun fact, Chevy 230/250/292's use 7/16" bolts and Pontiac 230/250's use 1/2"!


Up top likewise got studs, also 1/2"!


Assembled the professionally ported head with ridiculously expensive Inconel valves. I hope I never crash a valve into a piston.


Then top end bolted down. You'll see some additional hole in the side of the block. I drilled and tapped these to use as oil returns for some oil modifications and the turbo return. This is more or less where it sits today.

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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #393  
Old 11-03-2023, 03:43 PM
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I mention some oil modifications. With my old engine I experienced an oil pressure drop every time it shifted hard into 2nd gear. Even with an extra quart in the pan. And I suspected I was seeing lots of windage as well. One of the designs is the oil return from the head drops right on top of the crankshaft up side swing, so I wanted to see if I could eliminate that as well as put a windage tray in to separate the sump from the crank. Also, since I put main studs in, I lost the oil pickup tube support point off one of the main bolts, so thought, since the oil pump is external, maybe I can run an external oil pick up line too and that way if I have to pull the oil pan in the future, I don't have to fight the oil pickup tube and the windage tray can go front to back!

First step was seeing if an external line was even possible. There are multiple 90 turns in the run from sump to pump, so certainly I could do no worse there. The pump inlet is about 1/2" SQUARE in the accessory drive, so not exactly large. On my mock up block, I drilled a hole in the accessory drive oil pump pickup passage and plugged the pickup in the block.




Then literally stuck a rubber plug with nipple in the oil drain of the pan with a plastic line to test if the pump can actually pull oil over an extra long external line.


It had no problem at all. Fun fact, these engines use HV pump gears with a 30psi spring to keep it alive. I've modified mine a long time ago to run 60 psi and regulate down to ~12psi for the lash adjusters.


So plans were made.


So the finished accessory drive housing here. I've opted to go to a remote oil filter mount so I can feed the main line oil passage directly into the front of the block instead of through the restricted drive housing. Since I was going filter straight to block the return side of the adapter was left open, and this is a perfect place to pull oil from to the lash adjuster galley and turbo feed. This passage will be back filled from the block's main oil galley. You can see the oil pick up fitting is much larger than my test one, so should not have any oil volume concerns.



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The Silver Buick- '77 Skylark coupe w/455, SPX, MegaSquirt 3 & TKO-600 (Drag Week 2011, 2012 & 2015!)

1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #394  
Old 11-03-2023, 03:54 PM
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Then for the oil windage tray, the issue I ran into was with the deep skirt block and shallow oil pan is the crank practically touches the oil pan in stock configuration. So I scanned an oil pan gasket and had a metal fabrication shop cut a 1/2" aluminum spacer out to move the oil pan down a 1/2". This will allow me to add useful volume to the crank, let oil sit further away from the crank, and allow me to insert a windage tray at roughly the original pan location. I'm now at the point I need to install the pickup tube in the oil pan. I have it all mocked up on another engine, with starter in place, etc to put it in the right spot to fit the chassis and keep the starter serviceable.








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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #395  
Old 11-03-2023, 06:19 PM
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So back to the car. I got it on the road after the rear gear swap and went back to testing, but finally got the transmission shifting more or less dialed in and started shifting it at a conservative 5,000rpm as the engine usually seemed to get unhappy after 5,200rpm. I added a crankcase sensor to figure out when the rings were getting unhappy and quickly learned it was the rev-limiter that upset the ring seal the most. Any time it hit spark cuts, rather from rpm or overboost, it would puke oil out all the vents. So with the shifting and rev limiter now under good control, I was still struggling with boost management.



You'll notice in these videos it shifts nice and cleanly right at 5,000rpm but starts kissing the 15psi boost limit I set. I have an adjustable manual boost controller and I was trying to find the sweet spot around 10-12psi, but it seemed very very sensitive to either capped at 7psi or go to the moon.

This video is fairly tame, I let up before it gets into spark cut.
https://www.youtube.com/shorts/BWsrUxhPmJc


Along with boost management, I was trying to find ways to build boost while foot braking. Pretty much found that over 2,000rpm and the tires would break loose no matter what, so retarded the timing by a massive amount to keep power down under 2,000rpm but still try and get some heat into the turbo.

This was -5 timing in my driveway. Ignore the mph, its electrical noise in the VR speed sensor that the 2-step causes.
https://www.youtube.com/shorts/5CsU1qLkH1Q

This was a field test with -10 of timing, and in 2nd gear hit the overboost protection at 15 psi so it started cutting spark.
https://www.youtube.com/shorts/uLhRBNbLiTw

Here's a semi-recent walk around the car before it started consuming water.
https://www.youtube.com/watch?v=CadpRSPHIxs

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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #396  
Old 11-03-2023, 06:22 PM
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I'd take the car out and about.







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1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #397  
Old 11-03-2023, 07:11 PM
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Then one day it started overheating on me, and I came to the conclusion the water level got low and was cavitating the electric pump. I did fix a minor coolant leak on a hose fitting a week or two earlier and thought "well maybe I didn't burp the cooling system as well as I thought I did", and while adding more coolant thought, "I don't really like that my water pump is either ON or OFF, basically comes on at 185F and off at 175F (or at moderate load), so take another shot at speed controlling the water pump. So installed a heavy duty Jeep solid state Fan relay and wired up the water pump to it.

Here's a video of it running. The pump hums a bit under 80%, so I am currently looking for a solution that multiplies the PWM frequency up quite a bit more. But basically it runs slow when cold and as coolant approaches 185F it speeds up, and if the temp drops it slows down. But by this point, I started to notice I likely had more going on with the missing water than a small leak a few weeks earlier.
https://www.youtube.com/shorts/9xNrlGOfaB8

I felt it likely wasn't a head gasket because none of the spark plugs came out clean, and there really wasn't any water coming out of the exhaust (after the morning warm up condensation). But the cam housing to head has a water/oil gasket interface, so I thought I'd start there and change that gasket in case it popped there. The oil was definitely milky at this point. Changing it out though did nothing.



I started to suspect a crack somewhere from the overheating event, even though the measured temperatures never exceeded 220F. I wasn't going to mess with it anymore, it was time to put the good engine in. So I pulled this engine to see if the bottom end would teach me anything about the abuse I gave the engine. Turns out, the crack happened first and caused the low coolant that lead to the overheating. I'll post up engine disassembly later.

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The Silver Buick- '77 Skylark coupe w/455, SPX, MegaSquirt 3 & TKO-600 (Drag Week 2011, 2012 & 2015!)

1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #398  
Old 11-03-2023, 10:31 PM
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Fortunately a few years ago I finally got a decent 20'x40' concrete pad poured in the backyard so all the work goes much smoother than a few years ago on gravel or having to move a bunch of stuff to the garage.







On most the bellhousing bolts I cut a slot in them so I can do most the threading or unthreading with a flat head screwdriver from the front.




Fun fact, Ford FE engine lift brackets found on early 60's FE engines match the cam housing bolt spacing perfectly.


Going to get a good scrubbing and painting.


And all tucked away in my shed.

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The Silver Buick- '77 Skylark coupe w/455, SPX, MegaSquirt 3 & TKO-600 (Drag Week 2011, 2012 & 2015!)

1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #399  
Old 11-03-2023, 11:21 PM
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Started pulling the engine apart.

The head gasket looked good after a year or so. Nothing obvious stood out at this point.


I knew the valve guides leaked so oily valves and chambers didn't surprise me. This was a $250 craigslist engine I re-ringed, bearings and gasketed, with a little home griding on the head and lapping the valves.


Every runner had oil trails like this. I figured detonation would be the ultimate end to the engine, but surprisingly not.


#3 was the only piston top that looked like it may of had some steam cleaning.


And there it is. Cracked. Now cylinders 3 & 4 always had very poor looking bores. I've dingle balled all the cylinders and 3 and 4 never cleaned up and both had spots that fingernails easily caught on. You can see a pock mark in the picture as well, that was there the day I put the engine back together after inspection.


This is cylinder 4. Again, that way since the day I got the engine. This was always meant to be a cheap throw together test engine to try stuff out on and attempt to find some physical limits. I had no idea I'd use for nearly 9 years, lol


The bottom end looked clean despite being milkshaked for a bit.


There were some bits in the oil pickup screen and actually I cut the oil filter open on the last oil change was found a handful of small metal flakes too. So I was expecting some good bearing wear.


Pulled the pistons and actually was quite surprised how well the rod bearings looked after 9 years. ALL of them were shrunk up a bit and fell right off the rod and cap.


Only #2 and #3 showed copper.


Mains all looked reasonable as well.


The crank turned easily and smoothly when the rods were pulled. Makes me tempted to simply re-block the rotating assembly!
https://youtube.com/shorts/LBgQGKt**...DywTeuhIqbv5k3

Top ring of #6 was in two pieces and the top rings on #1 and I think #5 were a little sticky but were still springy and loosened up after I moved them a bit. I've broke ring lands on my Buick from detonation, and I'm not sure that is what happened to #6, and kind of wonder if I managed to break the ring 9 years ago when I installed the piston? The engine always smoked and I never expected peak ring seal with the junky looking bores.


I haven't fully cleaned up the pistons, but on a cursory inspection, all the rods and pistons appear to be in perfect shape. All pistons move freely on the pin, the rods are factory forged pieces, and the dismal 8.3 compression with stock cam likely kept detonation away despite the oil and boost. Things I was looking for and didn't find was significant main bearing damage from the long crank twisting and flexing and much more hammered rod bearings from RPM, boost and possible detonation. The crank isn't even marked, the mains look good. Now I hope its because its a strong setup and not because the rod and main bearing clearances on this engine were loose at 0.0030" giving it the room to flex. I'll find out if my new engine eats bearings from the 0.002" clearance.

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The Silver Buick- '77 Skylark coupe w/455, SPX, MegaSquirt 3 & TKO-600 (Drag Week 2011, 2012 & 2015!)

1969 Firebird with a turbo'd Pontiac L6 controlled by a MegaSquirt 3 and backed with a microsquirt controlled 4L60e and 4.56 gears! (Drag Week 2018!)
  #400  
Old 11-04-2023, 10:42 AM
Cammer-6 Cammer-6 is offline
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thanks for update
glad to see youre back in it.
Reading that #5 coil was MIA is a relief,I was saying to self that
something was a miss(no pun intended)as it just wasnt a strong as I had
envisioned it would be.

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