1978 231 turbo 6 build

[techg8]

Here is my build thread for my 78 231 turbo engine.

I had been considering purchasing a Gbody regal to drop it in or maybe dropping it in my 83 Cutlass (original thread here http://www.turbobuick.com/forums/threads/adding-78-9-turbo-setup-to-1987-231-v6-in-a-regal.407038/). Still undecided as far as which vehicle, but I am going to proceed with the engine build.

Its going to be a re-ring with new bearings all around.
Edelbrock camshaft and lifters.

As of now I have it all disassembled and cleaned.

I got a start on the heads - cleaned up the valves and hand lapped them in the valveseats.

I decided while the valves were out to do a little home porting to try to let the engine breathe better.


I also decided to plug up the heat crossover passages to try to keep the intake nice and cool. Each head needed one 3/4" plug, one 19/32" plug and two smaller ones, - I forget the small size. You can see all four in the pic.


Now I am working on cleaning up the timing cover, water pump and oil pump.

Waiting on a gasket kit with valvestem seals to finish head assembly.

I still need to clean out the block oil passages and install new cam bearings.

 

[mat231v6]

not a edeljunk cam... charlie swears by it but at least for me, i had issues with that cam. then again i have really bad luck...
so, don't take my issues to heart....

 

[turbokinetic]

Glad to see your engine project moving along. Subscribed!

 

[techg8]

I received my gasket kit so I installed intake valve stem seals and finished assembling the heads. One thing I noticed.....the intake valve springs do not have inner coils and the exhaust valve springs do. I suppose maybe thats because only the intake valves get the stem seals.

I honed the cylinders with a ball hone and wiped them down with PB blaster.

I went on to the timing cover next, resurfaced the oil pump contact faces and reassembled the pump with a tight endplay and a quick lube of oil. I had considered oiling system modifications like is common on Buick 350 and 455 performance builds, but decided not to go that deep. Stock passages will have to be fine. Completed the cover by bolting on the Water pump with a gasket and some sealant just to be sure.

I got out the set of engine brushes and scrubbed and rinsed the block's oil galleys and passages clean. There was a lot of gunk and junk still in there, I am glad I took the time to brush and power rinse them out.

I am waiting on a kit of cam bearings and freeze plugs. When I get those I can begin the assembly and I will post pics.

In the meantime I will assemble the rings to the pistons, get them ready for assembly.

 

[turbokinetic]

Yeah, cleaning the oil galleries is critical. We had a rebuilt engine at work to fail the crank and main bearings because of some debris in the oiling system. Not pretty!

Don't forget when you get ready to build the engine, wash the cylinder bores with waterbased soap first. Then wipe them with oil. There is no way that a petroleum based cleaner like PB B'Laster will remove hone abrasive from the crosshatch. For some reason water-based soaps will get it. Once you can wipe it with a white rag soaked with oil, and get no grey color of metal or abrasive, it's good!

I had cam bearings professionally installed by a machine shop, and they left some chips and shavings of metal where the bearings got 'shaved' as they went in the block. I was able to get them out with bore brushes and a very powerful pressure washer. That could have ruined the engine!

 

[techg8]

After cleaning the oil pan I noticed that there were a few pinholes in the bottom. The bottom of the pan was rough enough that I didnt want to try weldong the holes shut or replacing the bottom of the pan. I dont want to sepnd $ on a new pan unless I have to so I took some Metalset epoxy and pasted the bottom of the pan to seal it up. We will see how it holds up.


I cleaned and painted a few brackets etc


And I disassembled the frozen turbo. It was just gunked and carboned up is all, I was careful on disassembly and worked it free with no damage. Are there any modifications I should consider at this point since I have it apart?

 

[turbokinetic]

As for the turbo, you should do a few things to it before it goes back together.

You can get a T3 turbo bearing kit on eBay. It will have the two journal bearings, and a thrust plate plus all the seals. Make sure you specify this turbo has a CARBON / MECHANICAL SEAL because most of the newer ones have no actual seal, only a dynamic slinger. Because yours has to deal with high vacuum when the throttle is closed, you need the sealed type. The other will allow oil to suck into the engine around the shaft.

EDIT: This MAY be what you need but verify it http://www.ebay.com/itm/390770774219

ALL the deposits need to be removed from the rotating parts. Ideal situation is a glass bead blast cabinet. If you don't have that, there may be cleaning solutions that will work. I've always used the blast cabinet.

I'm assuming you marked the relationship of the rotating parts, to preserve the balance. If not, you can send the wheels, shaft, nut, and thrust journal off to be balanced if you wish.

The bearing housing should be cleaned very clean. This is where oil will dry up and clog the system. Clean it good and give it a fresh start!

I posted some pictures of freshening up a turbo. Have you looked at those?

Next, you should test the wastegate actuator. Make sure the flapper valve will move freely. Assemble the housings of the turbo so that the actuator can connect to the bypass flapper, because you don't want to pressurize the actuator if the rod is not restrained from over-extending. You'll need a hand pump with a gauge that reads to 10 or 15 PSI. I would recommend NOT using shop air. Pump the actuator up, watching the rod extend. As soon as the rod hits the full open position and stops, you can watch the gauge and make sure it holds pressure. If the gauge will not hold pressure, or the rod won't extend at all - you need a new actuator.

If the actuator is bad, it will allow the turbo to overboost and overspeed and can really cause problems.

Sincerely,
David

 

[techg8]

I have got an ultrasonice cleaner and a beadblast cabinet with fine beads. I was planning on doing both to the parts.

I hate to admit that I didnt think of the balance issue when disassembling the turbo parts.

Why on earth would one make a balance critical assembly like that without a keyway of some sort?

 

[turbokinetic]

Sounds like you've got all the equipment you need to do the job right!

There is no keyway because it would cause balance problems, and the shaft is under a tremendous tension due to the extreme tightness of the nut. A keyway would weaken it.

Some of the eBay sellers of turbo kits offer balancing service which is very reasonable. One of them offers FREE balancing with purchase of bearing kit.

 

[turbokinetic]

This is a different turbo but it may give an idea about the balance marks:
http://www.turbobuick.com/forums/threads/garrett-t28-home-rebuild.408867/

 

[charlief1]

Why on earth would one make a balance critical assembly like that without a keyway of some sort?

The insides spin over 100K rpm on a regular basis and if you put a keyway in it that would make the shaft weaker. Can you imagine how much stress is on that little shaft and removing just 20% near one of the wheels? As far as fixing or modding it PM bison or junkbrick on the board and they should be able to help you.

 

[techg8]

Thanks for the replies.

I have got a running, operational stock 78 turbo setup on that oddfire dauntless 225 I have. I will likely install that one to get the engine fired up and running, then proceed with a proper turbo rebuild/mod project on the now-disassembled turbo setup.

Let me ask though, because I havent rebuilt a turbo before - what is the worst case scenario if I was to reassemble the turbo without regard to the balance and indexing the impeller etc? Catastrophic failure and parts flying, or just a noisy turbo that wears out its bearings quickly?

 

[turbokinetic]

The most likely outcome will be... the turbo works fine but does not last as long as it should. The life reduction could be negligible or it could be severe. If the turbo is noisy then you know it's definitely not happy.

If the imbalance is severe, the turbo will fail immediately. The shaft will flex, the impeller will rub, and the bearings will be ruined.

A bad wastegate actuator is more likely to cause flying parts.

 

[b4black]

I take a rotary tool to the turbine outlet (elbow) and open it up as much as possible.

Also, the oil return line you have is the early style that uses a funnel like grommet, which is diffiuclt to find new. I would change to the flexible tube.

1978/79 used a rigid drain line that rested into the "hose" fitting. In 1980/83, Buick went to a flexible drain line that fit into a traditional grommet (like a PCV grommet, but bigger). If you can't locate the hose fitting, you might be able to find the flex drain line and grommet at a turbo shop. It's an improved design that should work better (easier installation). Here the GM part numbers:
1978/79 Drain line (connector) - 1260602
1978/79 Drain hose - 1260599
1980/83 Drain line - 25504159
1980/83 Drain grommet - 25504235

 

[techg8]

Some more basic progress. I got it built to where I am ready to put on the oil pan and intake and valve covers.
(I installed new pushrods and bolted down the rockers after this pic)

I did have to fabricate a replacement spring for the cam nose because the stock one broke.


I also noticed that the bypass valve of the oil pickup screen was broken off. So I fished the broken piece out of the pickup and used some aerospace epoxy to affix a penny ove the hole in the screen. So I have no bypass, but its better than an open hole.



I had to go back and re-do the timing cover install because once I put it on I realized that I had forgotten to plug the front of the lifter oil galleys. Good thing I caught that!

I also realized that I had new Comp valvesprings, retainers and locks to go with the camshaft so I installed them before bolting the heads down.

Before I install the intake, whats the best way to clean out hard carbon from the runners?

 

[techg8]

I take a rotary tool to the turbine outlet (elbow) and open it up as much as possible.

Also, the oil return line you have is the early style that uses a funnel like grommet, which is diffiuclt to find new. I would change to the flexible tube.

Thanks for the tip on the drain.

As for the turbo outlet, I have a 2.25" ID exhaust donut. Are you talking about opening that up, or do you mean youclean up the inside of the elbow for better flow characteristics?

 

[b4black]

Inside of the elbow. There a lot of extra metal in there. Not sure if it makes a significant difference or not, but it's easy to do.

 

[techg8]

 

[MeanBuicks]

Ah yes, that '70s GM light blue. Looking good!

 

[techg8]

I pulled the starter and running turbo off the Oddfire 225. Looking at that engine, there are lots of parts that look similar to the 78 231. I was going to give the 225 away to a jeep guy but maybe I should hang onto it for parts, just in case.


Today I also went thru my pile o turbo parts. I actually had three 78 pass side exh manifolds (one without a crack).


Also, I took a look at the three Turbo Control Centers I found. two have number 1894485, and the third has number 16005520. I will have to look the numbers up and see what it means.


I have also got maybe three of the orange air intake setups, and one of the chrome carb hats (83 I think?)