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Sherlock9C1 builds a wagon

12971 Views 144 Replies 16 Participants Last post by  MWP
[editor's note, I'm migrating this over from GMLongRoof forum, so some of this may be repetitive from my Impala build thread]

Hey guys, it's about time I posted up my wagon project. I've owned B-bodies since 2003, but in late 2013 my fourth Roadmaster wagon sadly caught fire a week after I bought it and was a total loss. I had just moved 1000 miles south and with a new job, three young kids and a whole new city, I needed to simplify. So I sold all three of my B-bodies and just drove minivans for 5 years.

My dad suddenly passed away in fall 2017 and the next summer I ended up inheriting his '96 Impala SS (Dark Cherry, the car I always wanted). It was drivable but needed a lot of work. I was going to sell it, but shortly after I got it to my house the buyer flaked out, so I just drove it and remembered why these cars are so fun (especially compared to minivans!). My wife and I decided to sell one minivan and make the SS my daily driver (which you can do in the Southern US), so I started disassembling it to restore. (That build is over here).

Four months later, while looking for parts, I located a 96 Roadmaster wagon project about 2 hours north of me. The owner had started to build it but hit some snags and health problems and it had been sitting partially disassembled for two years. I figured SURELY he'd be willing to sell some parts from his stash, but no, he said he wanted to sell the whole thing together, and he made me an extremely compelling offer. So I did what any self-respecting guy would do, I told him I'd talk to my wife and call him back.

We talked it over and decided to go ahead and take a good hard look at the wagon. It was dirty and neglected, but other than a hellacious battery acid leak and an unfortunate rainwater accumulation in the left rear quarter, it was rust free and in very good condition.

So we loaded it up with parts, loaded my minivan full of parts, strapped down the powdercoated rear axle and the 383 he had acquired for it (on a specially designed radial transport fixture) and he trailered it to my house.

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Glad I caught up on this - ready for Daytona next spring?

@Brokecello I'm taking my time. 2022 ISSCA Nats in Memphis, TN is my aim. Time to disassemble the block as I've got some plans for it. Step one, use the Kent Moore LT1 tool to pull the water pump drive.
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There's some fantastic engine building books out there. I found these on Ebay; worth every penny.
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One of the things they talked about was oil control. The biggest cause of oil-related engine damage is loss of oil pressure. Having been around the GM B-body community since 2004, this was one of my biggest fears keeping me from opening up my stock engine. So many stories of hurt motors. That's part of why I got so suspicious when I saw that high volume oil pump. Reher-Morrison has a fantastic series of free tech talks on their website in which they talk about how oil behaves inside an engine. Their book goes into more detail. The first thing I did after disassembling the motor was to grind the front and rear block drains for easier flow.
Front, before:
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Front, after. A much easier path for oil to return.
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Rear: before.
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Rear: after. It's not ski-jump smooth but it'll work. BTW, notice the differing chamfers on the lifter bores. Interesting.
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I also drilled out and threaded the oil drains next to the lifter bores for some brass tube. This will allow the crankcase to breathe but keep oil from dripping down onto the crankshaft. This oil is necessary for flat-tappet cams but not for roller cams. This has a lot more effect at higher RPM, and I plan to end the party at 6000rpm, but hey, it's my motor, and if 1slow96 can have 29 gauges and 18 oil filters on his car, then I can install brass breather tubes in my lifter valley. It did take a really long time and would not have happened without cutting fluid. Cast iron is tough stuff.
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If you haven't seen Karl Ellwein's fantastic website or subscribed to his budding youtube channel, you ought to. I've spent hours poring over his builds, looking at compression ratios, cam specs, air fuel ratios and torque curves before I bought this engine. Just a wealth of knowledge and experience. Anyway, one thing he points out is to check the head gaskets and make sure all the holes line up. Sure enough... the left front oil drain.. it's blocked from the factory!

Side note: just below that blocked area is the main coolant feed to the cylinder head. The short side radius of that turn really could use some radiusing, so that's what I did. Impossible to photograph, but it'll help reduce coolant turbulence and pressure drop as it first enters the motor.
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Here's the material to remove:
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There, now oil can drain.
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This probably doesn't gain much at 6000rpm, but another recommendation of the books was to port the crankcase. I put a small radius on the upper edges of all the main webs.

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Once all this grinding was done, it was time to clean the block. So I took out all the galley plugs... well, except for the one that stripped.
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So, I started drilling.
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After lots of drilling, time for the extractor:
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Success. Man these extractors are so brittle. You really have to be careful with them. But, I got it out.
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One last thing before cleaning: porting the oil filter area of the block. Radius the main area, and the supply and return holes. It's surprisingly tricky to get into these areas, so it's not majestic, but it's better than stock.
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Rear main bearing cap where the oil pump bolts to. This is a non-negotiable in my opinion. I get why the factory didn't do it, but man what a horrendous turn to negotiate in stock form.
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Time to clean the block. Every passageway has to be completely clean. Whatever's leftover goes right to the bearings when you start pumping oil through it. BTW, this is also why you should NOT pre-fill your oil filter during oil changes, unless you know that the oil you're pouring into the center of the filter is absolutely clean. Whatever you pour in the center of the filter is going straight to the bearings without being filtered.
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After a thorough drying with a leaf blower and compressed air, I coated the whole motor with WD40 to prevent corrosion.
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And in a bag it sat for several months as I spent my time, energy and priorities on other things. I ordered several sets of crankshaft and rod bearings, and finally needed some mental floss, so I went out and measured the main journals with an inside micrometer compared against a traditional outside micrometer. Perhaps the line hone wasn't done right?
Admittedly this is far more time consuming and less repeatable than a dial bore gauge, but I measured the front and rear of every block journal to check for taper.
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There's quite a knack to this that's hard to explain with words. Not shown is the vintage Starrett outside micrometer I used to determine actual journal diameter. If I was doing more than one motor, I'd definitely buy a dial bore gauge.
I did measure journal #1 at two additional angles and found little difference. It was also late and I was tired, so I stopped there. To eliminate confirmation bias, I didn't look up the spec until after I had measured everything. It was 2.6410". #2, #5 and somewhat #3 appeared on the tight side. Only #1 was actually to spec. So perhaps the journals are smaller than stock, added to the -0.001" bearings is what caused the wear? But this is my measurements here using a dodgy method, so let's let plastigage be the final judge.
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Just to see what the bearing clearances currently were, a veteran racer/engine builder came over to help reassemble everything. These bearing shells and their respective block surfaces were carefully cleaned before the shells were pressed back into their places.
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He thought it odd that the bearing shells all sat slightly high in the lower caps.
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And they were all below flush in the block.
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Also note that the rear oil hole is not fully lined up with the oil feed. I'll be fixing this before final assembly.
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We laid down plastigage on the top of all the main bearing journals (with the existing 0.001" undersize bearings in them).
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Then torqued all fasteners to the torque specs the builder had engraved on the side of the pan rail.
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Then we removed each cap one by one.
#1 cap: between 2 and 3 thousandths:
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#2: over 0.002", but less than 0.003". I thought for sure that this was going to be the tight one.
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#3: more than 0.002" clearance.
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#4: I got a little mixed up in the photos, but I remember that it measured out the same as 1, 2 and 3.

#5: this one showed tight, around 0.0018" ish clearance.
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Definitely less than 0.002".
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Once this was all done, we took the main caps off, cleaned off the plastigage with PB Blaster (this is a genius trick by my engine builder friend), then lifted the crankshaft up, oiled the bearings, set it back down and tightened them one by one, spinning it by hand each time to see if anything had changed. Only the thrust bearing was making any sound (we had forgotten to oil the thrust surfaces). There was no change as we tightened each cap, and the crankshaft spun freely. So, we'll replace #1-#4 with the same 0.001" undersize bearings, and a standard size #5 bearing. In my next post I'll talk about ring gap and connecting rod bearings.
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With all the bearing crush in the caps, it would be interesting to know the crank centerline to cam centerline.
It is what it is but your description sort of suggests they had a "time" with the billet caps and took a lot out of the block.
The dull peen lines at the rear cap line show they were working at it to either move it or snug it up.
As long as the housings are round , striaght, and to size , not the end of the world .
But if they did bury the crank you might be searching for a tighter chain assembly.
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But if they did bury the crank you might be searching for a tighter chain assembly.
@95wagon you mean an oversize crank gear?
Your machinist certainly knows all this.
Before some were marketed as " for align honed blocks" it was luck of the draw. Some sets were tighter than others .
In the case of the GMPP Extreme duty which Cloyes made for them they were typically loose.
An engineer at Cloyes told me it was GMs spec.
They had crank gears that were technicaly out of spec large that helped .
He sent me one .
With no data to back it up , I believe the timing sets that are speced for align honed blocks are nothing more than over spec gears and or under spec chains put together.

Aftermarket cap install can go astray pretty fast if care is not taken. I have been very lucky with a few I have had done localy
I drive my machinist a little crazy with block preheating and main bore finishing with the engine block position to try and never favor the block over the cap because of hone weight.

Your #5 , you know you can use 1/2 a -.001 and 1/2 a std shell ?

I never compare the actual dias of bearing and journal as in write both numbers down and than subtract.
I just read the difference directly.

As in ,adjust outside mic to crank
Adjust inside mic to bearing in housing.
Look at number on inside mic.
Note exactly the amount I adjust it to fit the outside mic.
That is the clearance.
Same but easier with bore gauge
Zero bore gauge in adjusted outside mic
Fit in bearing, read exact clearance directly .

As always , the above is just my opinion
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I knew about mixing and matching bearing shells, but GM specs the #5 bearing as the biggest of them all, so adding a whole 0.001 to that would actually get it around .0025." But if I were to mix, tighter one goes on the load side, correct?

Totally agree with your direct measurement technique. While plastigage is pretty fool-proof, I'm not great at estimating anything between 0.002 and 0.003 with it so I'd rather get a solid measurement. I think I'm just going to buy a dial bore gauge over the holidays and do it that way; using inside micrometers is a tricky (and slow) business.
I'm not great at estimating anything between 0.002 and 0.003 with it
" fool proof"

I might use one of those words with plastiguage.
Too many possible factors to alter the reading.
I have some here , should look in the package. Probably dust after 35 + years.
Plastigage , to me, comes under the heading of BETTER THAN NOTHING.
Standard mics , easy to see .00025 and guess .0001 ( 1/4 and 1/10)
Digital bore guage is quite nice and you have a tracer to watch the sweep.
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