Aaannnd for the next episode. Got the car together and started up. It was smoking quite a bit of white smoke at first. Which I figured was the leftover coolant burning off. Then the smoke turned blue... I took it up the road and it doesnt seem like it was quite as quick as it was before it blew the HG and I couldnt see the road behind me from all the blue smoke lol sigh. Back to the shop. When I got the car back in the garage oil was dripping out of the tailpipe at the BACK of the car O.o oh boy. So I pulled the downpipe back off and there was oil everywhere. I went to start the car to see if the turbo was blowing oil out of the seal aaaaannnnndddd the BRAND NEW starter **** the bed..... thats when I went inside.
I called up VS Racing and ordered a turbo rebuild kit just in case (99% sure thats the issue). I also am going to send the summit starter back and upgraded to a powermaster high torque starter. That should be here next week sometime because I'm shipping the old starter back today or tomorrow. I'm also going to do another compression test to make sure nothing else is hurt like a ring land that I cant see etc from the HG blowing (maybe it was a boost spike or something weird). Hoping maybe the O2 sensor was causing a false reading from all the oil making the car not seem to go as good.
When I blew the HG originally I had said it blew the heater hose off AND started leaking oil. I couldnt quite figure out the oil part yet. But when I called VS Racing and explained the situation he said something that I overlooked. I told him I blew the head gasket and I understand that if the gasket let pressure into the lifter galley area it could pressurize the crankcase. But no way it would blow pressure up past my oil pump! Being my first turbo build I overlooked a key component. He says "Isn't your turbo DRAIN line a 10AN line back to the oil pan?" >.< well I'll be damned. So it seems that when I blew the head gasket, that 21 or so PSI went back up the drain line and dead headed the already 75psi oil coming from the pump causing all sorts of chaos. Learned something new! Hopefully you guys did as well from todays episode of Duster Devs Nightmare.
Also ordered this to help vent the crankcase, since apparently the factory 3/8s lines from the valve covers aren't sufficient with a boosted motor.
Finally got the new starter in to do some more diagnosing! Putting that new crank case vent in the valve cover showed me something alarming. When I got the car back together last time there was some smoke from the engine bay but I figured it was stuff burning off the headers etc (my PCV is rerouted down to the frame so thats why I thought headers). Well this is what I witnessed after I just pulled the cap off completely.
Soooo I pulled the exhaust all back off and pulled the plugs again for a compression test. The coolant killed my last one so I went and got a cheap one from Advanced Auto. It felt super chintzy putting it in starting with the driver side. Cylinder 1 showed 70psi. Cyliner 3 showed 70psi. Cylinder 5 showed 70psi. "This things f*ckin broken!" Cylinder 7 70psi..... Ah what the hell I'll try the passenger side. Cylinder 2 200psi O.o. Cylinder 4 200 psi. Cylinder 6 200psi. Cylinder 8 200 psi. "hmm maybe it wasnt working right at the beginning" Back to cylinder 1 we go! 70psi..... lol sooo it seems something with the new head gasket did not go well. Which confuses me because theres not much in this world thats easier than bolting an LS head on lol. Idk if one of the dowels messed up holding the head up some. Or the gasket is just faulty. OR if something actually got hurt from blowing the head gasket originally on the other side. Just sucks I wrecked my compression gauge that day so I didnt check the driver side before pulling it apart to know if that was happening before hand too.
I cant imagine I hurt ONLY the driver side rings. But I'm going to pull that head off either tonight or this Saturday and see what I can find.
Also my buddy with a vinyl cutter is now sending me a sticker of this because of all the headgasket and blowby issues lmao it'll go on the rear window in the corner.
Well, I made a tool to be able to check leakdown without having to have the heads on the car. Which was pretty handy. For anyone new to a leakdown test, you plug your compressor into the gauge, zero the gauge, and then attach it to the cylinder you want to be testing. It then will stabilize at whatever % your cylinder is leaking down. For a boosted motor 10-20% is acceptable. Well on the good side WITH the head still on I got 12%. So thats good. On the bad side with my new tool I got 75% leak down lol. Sigh.
So I yanked the motor back out of the car and pulled it apart. The passenger side (good side) all looked as it should. The driver side however presented the issues. The odometer shows 15 miles including dyno time lol. New record for me.
Sooo back to the machine shop the motor goes. I already have the gen 4 rods and I'm going to figure out what pistons I'm going to use.
Holy Cow!! I have never seen a failure like that!! How could something like that happen?! to much boost? related or associated with the head gasket failure?!
Well whats weird is this was the opposite side of the blown head gasket. But idk, I've never done that before to pistons haha. I'm hearing from people that it seems that too much timing will heat the cylinder temps so much and even though the rings were gapped for boost they still butted and broke the ring lands. But I'm not sure.
Dropped the block off at the machine shop today. After Jerry (guy who runs the shop) looked at the pistons and bearings he said it was definitely detonation that killed it from too much timing. Just very odd it was only 1 bank. Hes never seen that before. I'm going to check my flex joint because I've been reading some nightmares about those collapsing. He said the block really should be bored over at this point but then we'll have to pull the cam bearings and basically start over so I'll have a $1500 bill again. Not worth it for a 5.3 when I have a 6.0 up in Vermont I'm going to build this winter. So I ordered some stock 4.8 gen 4 flat top pistons, gave him my gen 4 rods I had ordered and we're just going to slap this block back together sloppy style with some honing and send it until I build the 6.0. He said this will work fine but it may need rings again by 50 or 60k miles because of how much we'll have honed the cylinders. But I'll never put that many miles on this motor since it's going to go into my CJ when the 6.0 goes in this.
Once its back together I'll be back to the dyno, possibly a different dyno.
Dang I’ve missed so much. I’m not getting the updates and I’m following this thread. Stick with it. You’re having the same teething issues anyone has with turbo builds. And it’s exactly why most people don’t finish them. You’ve done well to continually move forward and hopefully you’ve learned from every failure. It’s all worth it in the end when the boost gauge goes to 20 and the dyno needle moves past 800. You’ll get there. And I’m putting money down on the sloppy rebuild making the power. They usually do. Gap them rings WIDE I can’t say it enough.
Holy Cow!! I have never seen a failure like that!! How could something like that happen?! to much boost? related or associated with the head gasket failure?!
Broken rings and broken ring lands are fairly common on forced induction builds unfortunately. It is from too much heat in the rings. And not enough gap. It can be caused by a variety of things; detonation, overboost, timing, octane level, just to name a few. Tuning is very important and the window is small especially for pump gas. It takes a thousand parts working in perfect harmony to get it right, and one small part to fail for it to be catastrophic. It’s all part of the fun.
Yeah I wont give up on it. I've had the car since highschool so giving up isnt an option haha. But I will say its getting awful frustrating not being able to drive it. I started this project April of last year, and its taken way longer than I expected already from little things like this. Which I've built enough custom rigs to know theres always hickups but man this car seems like it doesnt want to be driven haha. Its also frustrating that I dont know how to tune yet. I do all the rest of the work so now having to rely on someone else for the last part is wicked annoying. I'll get it though! I think we're going to go with .008 per inch for the ring gap which puts me just over .030. That should be enough.
Just for sake of comparison I just set the gaps on the drag week 4 cylinder we’re building, (1000 hp goal) on a 3.425 bore we set them at 32 top and 30 second. Gap em wide
Sorry wrong engine. 32 top 30 second was on my turbo V6. The 4 cylinder I set to 28 top and 30 second. The owner over ruled me and closed down the top ring.
I can ask him. I am helping him put this deal together but I am not the final word so to say. We may have differing opinions on a few aspects of the build. With 60psi the goal I’d like to see more top gap and a little larger second. In my opinion he’s setting it up more like a low boost street engine not a big boost race engine and the drag week drive + racing brings in some compromises. But none of us are experts, I for one am always learning. I try to talk to as many people as I can at the track wether they’re running a fuel digger or a turbo Honda. You can learn from them all. My v6 is a street car first and foremost with big hp goals and no drag time. Maybe some road course stuff so it’s set up how I think it should be for that. His is a different animal.
Yeah, thats the Duster. Street car and daily driver over all else and then maybe the drag strip on the weekends here and there along with some autocross stuff.
The hyper pistons in an LS are tough but brittle as glass. If you stick a ring they will break. You've already seen this. I like to know for sure that I’ll never butt the top ring. So I go larger than most people are comfortable with and am willing to give up what little cylinder pressure (if any) I give up to get that reassurance. And I go a little larger on the second to keep from loading the bottom of the top ring and loosing ring seal, knowing my crankcase evac system can deal with it. It’s not rocket science but it is worth doing. The difference in cylinder pressure between 024 gap and 030 gap is negligible and probably not measurable and I know a ring ain’t gonna butt at 030 but I don’t know that at 024. Some guys disagree and I’m ok with that but I snapped a ring land on an expensive big block Chevy and I payed the bill, and won’t do it again.
A couple more updates. Got the new 4.8 pistons to the machine shop yesterday with the gen 4 rods. Also we looked at his piston chart he has from Mahle that says to gap the rings .005 per inch. Thats what he had done which puts me at around .019. I told him that wasnt enough for the boost and beating I'm running. So I told him at LEAST .008 per inch. Basically telling him .030 to .032 for the ring gap. So they should have the bottom end all back together next week with the new bearings and the rings gapped. I've put enough motors together now I have no shame having a machine doing the bottom end on a motor thats getting the **** beat out of it since they have all the correct measuring tools. Where as I have a micrometer, calipers, mag base with a dial indicator and a hammer.... thats about it for precision measuring tools. Hopefully I'll have better luck this go around!
Just in case anyone here didn't know and is pondering LS things, the 4.8 pistons are flat top pistons where a 5.3 are dished. The 4.8 and 5.3 share the same bore where as the 5.3 and the 6.0 share the same stroke. However, the 4.8 uses a different rod length so the wrist pin location hole on the pistons are in the same spot. There for you can put a 4.8 piston in a 5.3 and it makes a 10.3:1 5.3 just like the L33 5.3 (high output) or the LQ9 6.0 is that comes in the Denali.
Got the motor back from the machine last week and finally got some times this weekend to put it together and back in the car! Found part of my oil leak when the crank case was pressurized as well. One of the grommets for the knock sensor basically fell apart. So I got the new ones in today. Hoping to button it up tonight and start it! Also replaced the rear main seal AGAIN just in case. Though I dont think it was leaking.... it was out so I'd be awful mad if it did leak. Worth the $40.
