Iron-head 2.8MPFI Turbo Install / 85 Celebrity

[davida1_hiwaay_net]

Ok here's the rest of the turbo repair pictures. The center housing was soaking in EvapoRust overnight. This stuff is exellent. It won't damage or affect anything other than rust. I was skeptical that it would work, seeing how "safe" it claims to be. But it is badass. If you use it as directed (there is a temperature requirement) it really works.
The product:


The result:




And there is no chance of leaving blast media in the housing.

Next the bearings and shaft go back in.


Then the inner part of the thrust bearing journal.


Then the thrust bearing plate. The outer part of the thrust bearing journal is assembled to the cover, ready to go on.


Then that assembly slides in and the snap ring goes in. It's a tapered ring to keep vibration to a minimum. Therefore it must be firmly seated by expanding it and tapping on it. As the o-ring compresses, the ring expands into the groove, locking the cover in place.


Now for the alignment of the parts, for balance reasons. Look at the turbine wheel. See the number "510" between the 2 blades. One slot to the left, there is a round dot cast into the wheel. This aligns to the drill mark on the housing flange. This was the position before teardown.


The compressor end has an "A" logo (for Airesearch). The first blade to the right (viewed normally) lines up with the scribe mark on the housing.


Then the nut goes on, and tightens to the original position, by lining up the scribe marks placed on them earlier. The mark on the compressor wheel is very small to avoid damaging the wheel. I dotted black Sharpie pen over them to help with visibility.


Finished CHRA.


Now to clean the ash and carbon out of the turbine housing. Wire brush wrapped in Scotch Brite works well.


Result:


Install the clamps with antiseize on the bolts. Line up the drill mark and tighten it.


No carbon in there.


Compressor o-ring


This snapring is a tapered ring to compress the o-ring as it wedges into the slot. It's important to expand it forcefully and tap the housings. This will make sure the o-ring is compressed and the housing is fully seated.


Completed turbo!




I forgot to take pictures, but I had to re-drill the actuator bracket mounting holes. They are threaded into the compressor housing. I rotated the housing to give the air hose a less strained alignment with the charge air pipe on the car body. After that, the actuator holes didn't line up. It took a trip to the store to get a M6x1.0 tap set and a 5mm drill bit. But it will be worth it when the car goes back together.

[davida1_hiwaay_net]

I enjoy the how to. Makes me feel like I'm in shop class again. Man if I ever need all this info again there is going to be alot of back tracking. Don't take that the wrong way. I love how this makes you feel more like a part of this build. Much better than a post that just has "rebuilt the turbo today" or "the heads are almost done".

Thanks. I appreciate it. Yes I hope it encourages others to do similar, or at least use the pictures as a reference.

This brings to mind the opposite. I've been on the Internet a long time and you see some interesting characters. There have been seen some very spotty build threads before, where I don't completely beleive the author actually did a build. Not talking about someone who started a build with good intentions, then got in over their head - but a thread only meant to trick people into thinking the poster had abilities they did not. I think of that when I consider saying "rebuilt the tubo" in 3 words. It takes about 2 hours to do this (with proper equipment - longer if you don't have cleaning equipment), and 2 hours of working takes more than 3 words to document!

Years back, I read a series of posts where a member claimed to have built a turbo system, got it working, and it was tuning it.

The extent of the build thread was a few pictures. The first was (from a distance) of an engine on a stand with a turbo crossover pipe and turbo mounted on it. No oil or coolant or air or downpipe connections.

Then there were lots of very close-up pictures of "something" that looked like an engine block with an oil return but you could not tell what sort of engine or what type of car. Looks like he found several different legitimate turbo cars parked in parking lots, laid down on the parking lot and took pictures of the bottom of the engine - with cell phone.

Finally there was a picture of the guy's car with hood up, taken from a low angle (kneeling?) where you could just see the top of a turbocharger to the right of the engine. For all I know it was just sitting there on top of hoses and wiring in the engine bay. It wasn't even straight.

It was supposedly making "300 HP on the dyno." We all know any of these engines that will make 300 wheel HP is a serious piece of machinery and takes a full build through and through, plus transmission work.

Then when people started commenting and expecting to see more of the car and how it was working, as well as the dyno printout, came the sad story of the theft and damage to the car. The car had been stolen and "blown up," and because he could not afford to replace the damaged turbo, so he did a stock rebuild. Yeah. Oh - and the dyno printout was lost by the car theives, too.

Sincerely,
David

[Purple pit]

I enjoy the how to. Makes me feel like I'm in shop class again. Man if I ever need all this info again there is going to be alot of back tracking. Don't take that the wrong way. I love how this makes you feel more like a part of this build. Much better than a post that just has "rebuilt the turbo today" or "the heads are almost done".

[davida1_hiwaay_net]

Turbocharger freshening...

This shares the oiling system with the engine, and surely it took a beating. Also it came from a junkyard and I should have overhauled it the first time anyway probably.


First, off with the compressor housing. That snap ring is a bear to remove. Had to heat the housing area to soften the o-ring and help things get moving. I did not mark the orientation of the housing, because I was not satisfied with it. I will find a new better position when it goes back on the car. The air hose was in an "uncomfortable" position.


I did mark the turbine housing orientation. That one has to be same, or the tubelines won't fit.


CHRA out of the housings. Removal of the turbine housing the first time (during initial turbo system build) was VERY hard, requiring heating and use of hydraulic expanding "duckbill" thingy. This time it just came off normally.


I blasted the impeller and turbine with glass beads before dismantling. There are factory markings on them which were covered in ash. I marked the housin with a very shallow scribe line, and made note of which factory marking lined up with this. This way I can ensure the oritntation of the shaft and compressor wheel is the same. Also marked the shaft nut with a scribe line because it is balanced with the other parts and needs to be torqued to exactly the same position. This is for maintaining the balance of the unit.

This part is critical. The turbo shaft must absolutely not be subject to any side loading. It can not tolerate any bending. The only way to remove the nut is to support the end of the turbine wheel and the nut its self. The housing can NOT be used for any support or leverage during the torquing or removal. Doing so will ruin the turbo. The nut is insanely tight for such a small part.


Impeller off.


This part did not want to come off. I had already plugged the oil ports so that blasting media could not go in the turbo. I just applied air to the oil port after removing the snap ring. It was LOUD and that cover went flying!!!


Shaft out.


The bearings. New and old. You can see the damage caused by the contaminated oil.


New thrust bearing. It's a different design. The original one had a one-piece journal and an open side to the thrust bearing. The new one has a two-piece journal and a 360° thrust bearing.


This is it for today. Parts cleaned up, but the bearing housing is in a chemical bath overnight. I don't want to risk getting blasting media inside it, but the crud in there has to go. So it will have to soak overnight.

Later,
David

[davida1_hiwaay_net]

Block is still at machinist for cam bearings, but I got the heads ready today. The exhaust valves worried me a little, but the light pitting lapped out.

Lapping the valves with grinding paste. It looks like liquid Terminator!


Just used the electric drill and pressed the valve head against the seat with an oiled thumb.


Result was good!


Seats look OK too.


All valves lubed with Sta-Lube and installed. The tape keeps them from falling out by accident.


I use an old drill press to compress the springs. That's just a 3/8 socket extension with a crowfoot oxygen sensor socket.


A rubber plug under the valve head keeps the stem out all the way.


The exhaust valves don't have a valve guide seal, but they have a sheild and an o-ring on the stem.
Press the spring all the way down.


Install the o-ring....


And the wedges....


And done!


The intake valves have a valve guide seal, as well as the o-ring.

Put this protector over the stem, then press a lubricated valve guide seal over the protector. Stop halfway and remove the protector and seal.


Install the spring, then put the protector and seal back on the stem.


Press it in with a socket.


It's in. Now the protector can come out. After that, it's the same as the exhaust valve, with the o-ring and the wedges.


All done.


Still got to get a set of pistons and get them installed on the rods. Waiting on confirmation that the block won't need to be bored out.

[davida1_hiwaay_net]

Nice work! I didn't know that the older engines had piston slap. Thought that was only on the newer ones. My old 3.1 never did it. Still miss that engine, the compression was good even after 200k. Each start was a little cranking and then a boom. The 3100 sputter starts sometimes due to a bad cylinder from piston slap. That thing sounds like someone banging on a tin can with a hammer when it's cold out. You can hear it inside the house.

Maybe I'm wrong about the piston slap on ALL the engines. Shouldn't make "blanket statements" like this! I had a 2.8 carb that had piston slap but it was very very old; as well as probably had no good maintenance from previous owners. Then my 2.8 iron-head turbo motor (the first turbo project I ever did) has bad piston slap. But i did not know what I was doing with tuning, used it w/o intercooler at first and it saw bad detonation. So I've had experiences with this, but my engines were either old or abused.

Yeah. Sputtery starting, crank-and-die, long cold cranking times are common. Blame that on the EPA. To pass the "cold start" emissions requirements, GM tunes the ECM to just give it the BARE MINIMUM fuel to ignite a perfect engine with perfect injectors. When the injectors are old and don't flow exactly as they should and the engine is old and doesn't have perfect compression, and the valves have carbon that traps some of the fuel before it reaches the cylinders - things get a little iffy.

If you have tuning access, select the entire "cranking pulsewidth" table and scale it by 1.1. This works 100% of the time with the MAF 3800 engines. Gives it 10% more fuel to crank. Not knowing the strategy of the ECM on the 3100 I can't say exactly which table to go to. But the ones I have modified this way fire on the second compression stroke every time, as in "ra ra bvoom!.."

The slap was more common on the 3x00 stuff, but usually the mpfi's that ran non syn oil and had long intervals between oil changes and ran hot experienced the slap.

Looking good David! Really considering buying you a plane ticket to take on the stuff I have no time for lol!

'Preciate the compliment. I hope it runs as well as it looks. Honestly it ran fine before the bearing failure, so I'm just hoping for long life out of it. The porting should help though. I surely know the feeling of not having enough time! I have so mmany projects now. Have a 84 Olds Ciera convertible (massive restoration project) that needs engine work. Have a 85 Buick Century Diesel, 2-door car. Engine is apart can't locate parts but trying. Have an 86 Buick GS that I want to build a totally badass 3.8 / 4T80E setup for. Plenty to do and not enough hours in a day!

As for the pistons, the ones from the 3.1 are all scuffed. Also they are not the correct compression ratio for the iron head engine. Gotta get something correct for the application, and having the coating can't hurt!

[1988GTU]

The slap was more common on the 3x00 stuff, but usually the mpfi's that ran non syn oil and had long intervals between oil changes and ran hot experienced the slap.

Looking good David! Really considering buying you a plane ticket to take on the stuff I have no time for lol!

[Purple pit]

Nice work! I didn't know that the older engines had piston slap. Thought that was only on the newer ones. My old 3.1 never did it. Still miss that engine, the compression was good even after 200k. Each start was a little cranking and then a boom. The 3100 sputter starts sometimes due to a bad cylinder from piston slap. That thing sounds like someone banging on a tin can with a hammer when it's cold out. You can hear it inside the house.

[davida1_hiwaay_net]

Back to the engine build - The machinist isn't done with the cam bearings yet. They are really busy! They are installing SBC cam bearings in the block.

I worked on the heads today, porting and cleaning them. I feel as if the iron head engines can benefit quite a lot from simple porting such as gasket-matching the intake ports and blending / smoothing the valve bowls. I didn't spend a long time on this, maybe 2 hours. Did a similar porting job years ago on a carb 2.8 and it made a very noticable difference.

Before:




After:


Also, as suggested I cleaned up and blended the oil drainback channel - removing casting flash and creating a smooth path for oil to return to the block from the valvetrain.





Valves all cleaned up. Will probably take them to the machinist to get them ground, IF they won't clean up by lapping. There is hardly any wear, just some light pitting on the exhaust valves. The intake valves looked unused after polishing.



I've got to order pistons for this. Thinking about these Sealed Power WH562CP hypereutectic coated skirt pistons. I really like the coating on the skirts. Every one of these engines has scuffed pistons and piston slap; and this looks like a way to avoid it.

They are standard for an iron head 3.1 so the compression ratio should be OK for this build.

EDIT: I have ended up with 2 threads on this build, but I want to consolidate it to this thread (This one you're reading now) because there's more info in this one. The engine has been discussed here http://60degreev6.com/forum/showthre...C-Is-it-better also.

[davida1_hiwaay_net]

Ok, here are some picts of the block cleanup and grinding job on the "new" block.

Washed and oiled up a little. Don't like the flash rust getting in it!


Before any grinding. There definately is some flash.


The new bearings are better. They have larger oil holes as well as oil groove on the lower insert. There is quite a bit of metal blocking some of the larger oil hole.


Oil groove design. I like this.


The new and the old.


Hole size comparison.


I drilled the old bearing to the same side as new ones. It will be a pattern for modifying the block, without risking a slip of the grinder and damagin the new ones.


Pattern in the block.


Modification done. Radius and blend the oil passage into the oil groove. Widen the bottom of groove from a V shape to a U shape, and add a "toilet bowl" area to match the larger bearing oil hole.


New bearing matched up prettywell!


This one was the rear main. It was the worst. This is after modifying.


All bearings line up well now.


That gets the oil TO the bearings. NOw to get it back to the sump. The casting flash gone.




I enlarged the 3 return holes which were not too close to the cylinder bores. This should help the oil to get back to the sump instead of getting trapped in the camshaft compartment.


So tomorrow I plan to drill and thread the turbo oil return hole and get the block ready for new cam bearings. I want to have the machine shop REMOVE the old cam bearings so I can inspect and possibly port or blend the main bearing oil feed at that location.

Sincerely,
David

[davida1_hiwaay_net]

Wow those valves were sealed up extra tight. I would have thought there should have been a little leakage.

You thinking about the rainwater getting in? It did get in. There were several cylinders full of water. That's why I wanted to dismantle and clean everything ASAP.

[Purple pit]

Wow those valves were sealed up extra tight. I would have thought there should have been a little leakage.

[davida1_hiwaay_net]

Sorry it's been a while since I posted an update here. I found more problems with the engine, and determined it would be most cost-effective to buy another core engine to use for the rebuild. The camshaft and lifters are damaged, and the oil port alignment problem is present at the cam bearings also. This area is not accessible to the grinder for opening up the misaligned ports. So it was time to find another core.

I went to Pull-A-Part in Birmingham today. It was cold out (by our standards) but I survived!

I found ONE lonely, abused 3.1 engine, with the upper intake manifold missing and the intake runners full of rainwater. It was my only chance, so I tore it down and found it was not rusted yet. Must have been from the rain yesterday. The car was a 91 Cavalier Z24, hit hard in the right rear quarter. Looked well taken care of otherwise, so the engine had a good chance of being usable - other than the water.

I got the engine (less the heads) for the cost of a block only, due to the water issue. Quite a deal considering the condition it ended up being in. The bottom end is near perfect. Two pistons have light scuffing but the crank is perfect, cam and lifters perfect, and there are no obvious defects.

Yes, I cut the seatbelts out of some hapless car and made lifting straps.. That was at the sugestion of the junkyard guy, by the way...


Front cover off. Looks a little varnished but the chain is no where near as stretched as the original one from the 2.8.


Camshaft out. No spalled lobes or scored journals. This is good!


Oil pickup screen is clean.


Comparison of the 3.1 piston (left) with an original 2.8 piston (right). The 3.1 piston is lighter weight. It will not put as much stress on the connecting rods at high RPM's because of less reciprocating mass. The top of the piston has a dish in it to lower the compression ratio. I will have to research it and see what kind of CR this will give. It may require new pistons with different CR.


Crankshaft rod bearing journal. Not a single scratch.


All the parts laid out, sprayed with corrosion inhibiter.

[davida1_hiwaay_net]

X2

The windshield in my car used to leak and from the snow and rain I got left with carpet that had mold and destroyed backing.

Sent from my HTC One X using Tapatalk

Ah yeah - that moldy smell. I hate that! I've found that the pressure washer will remove all traces of mold from carpets, but if the backing is ruined, it's over.

By the way, there's another thread going on for the engine repairs. See http://60degreev6.com/forum/showthread.php/51319

Sincerely,
David

[pocket-rocket]

Excellent, thank you for the link.

X2

The windshield in my car used to leak and from the snow and rain I got left with carpet that had mold and destroyed backing.

Sent from my HTC One X using Tapatalk