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Cheap Junk 1971 Build

Posted: Wed Oct 22, 2014 10:44 am
by Clatter
OK, so, turns out that i have been doing this whole "aircooled" thing for a long time now...
And, after a while, seems like i'm kind of getting the hang of it.

So, because there doesn't seem to be a basic "how-to" thread, i'm going to take this one on.

Here will be a build-up showing my shop setup and how "i" do these things.
Any comments/criticism, and tools/tricks are invited.
The idea here is that we all can learn from each other.

Also, part of what makes the T4 so much better than the T1 is that you can re-use OG factory parts.
Here we take this to the extreme; using parts found under a tree.
Not "found under a tree" as a manner of speaking; actually found under a tree.

NOT these types of parts:
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These types of parts:
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The goal here is not to build the ultimate street warrior, but to build a motor that will last a long time, spending as little $$ as possible.
Time doing this is not a consideration, as this type of thing is my idea of fun.

A bus motor is to be built here, because, er, that's what was lying around.

Other things that make this kind of not 'fair' to the new builder, are that i have been scrounging T4 parts for years,
Have a decent array of VW tools,
And a really, really, good friend of mine happens to be a long-time automotive machinist, having built at least 1000 VW motors.

Jim at Napa Carr Parts in Santa Cruz;
He is the king, and not to be questioned.
Any "internet experts" question his methods or abilities, you better have at least 1000 motors under your belt.
Jim actually has several thousand, as his shop was turning out two or three a day for many years.
Give him a call if you are in the SF bay area, and you will not be disappointed.

So, remember, this is Type 4 101; "Building a Bus Motor on the Cheap, so it will Run for a While".
Spending as little as possible...

Also be advised that i am going to drop names and say what these things cost.
No secrets...

This build is NOT on The Samba, because just as soon as i was starting to get the urge to post this there,
Another one of the typical trolls that lurk there decided not to let NO experience keep him from posting advice.
I love the civil discourse found on this site; That, and the users' years of real experience.
Hope Ev doesn't mind my cross-linking pictures... I love his site, save for the mouth-breathing toads.

Anyhow,

The two cranks above came from a Craigslist motor, and my "tree find".
The stuff under a tree was a couple of botched 1.8 914 motors, and the Craigslist one was a 2.0 914 that i bought as a parts lot.
You can get these cranks in this shape for like $20-$30 (or free) depending upon how much time you spend looking.
I consider them free, because i got a bunch of other stuff when this all came along.
Looking at them above, one has water damage (rust), and the other is burnt (purple color).

First thing to do is mic the journals - lucky me, they are both std/std.
Grabbed out that roll-pin with some Channel-Locks..
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Next, i take and sand down the butt. Get that Fat End Flat!!
Everybody has a flat piece of steel with some wet/dry 400 glued down to it, right?
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Here is my vise-mount crank holder.
I copied this directly from Jim.
It's a piece of "C"-channel, with the bottom cut and folded over/welded for strength.
It also has a T1 gland nut welded to the side should i ever digress and build a T1.
This is better than having your engine stand be your crank holder, because in my case, the stand always has an engine on it...! :D
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In order to use the holder above, the flywheel mount bolts need shortened, as the holder is thinner than a flywheel.
Here is another trick, where i made my own "bottom tap" by grinding flutes in an old bolt.
This wouldn't work for seriously damaged threads, but seems to do the trick for chasing out threads on a rusty/gunky crank.
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Here we have a crank in the holder for some polish work.
This is another trick i learned from Jim.
A piece of soft cotton rope works better than synthetic.
Emery cloth in 120 grit is used here because the cranks are in such very bad shape.
Finer grits would be used to polish a decent crank.

Wrap the emery cloth around the journal, and saw it
To:
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And Fro:
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Don't be timid about it, son. Get yer hump on!

This is way better than just shoe-polishing journals with a strip of the cloth.
The rope provides pressure all around the journal.
All of the grit stays wrapped up in the cloth around the journal,
Not on the floor.
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So, that was just for demonstration purposes;
Don't want to be getting grit all over my drill press and body-work supplies... :roll:
Here i got them outside where they belong, and am starting to polish them all up, to see what i actually have here.
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So anyways, stay tuned for to see what these cranks look like, and if they go:
1. Straight into the bin,
2. Off for a grind or polish,
3. Onto finer grits and into some bearings.

Re: Cheap Junk 1971 Build

Posted: Wed Oct 22, 2014 7:56 pm
by Tony Z
Thats a cool trick, thanks.
Keep it coming, I am keen to see how this progresses

Re: Cheap Junk 1971 Build

Posted: Wed Oct 22, 2014 10:34 pm
by Clatter
Tony Z, glad to see someone watching.
Hoping that there would be a person who gets something from this...

The general rule with polishing a crank with emery paper like this, is that if you can feel the damage on the journals with your fingernail,
it's time for at least a polish. (machine polish at a crankshaft place)
Unless you can sand/polish it out... by hand.

Of the two cranks I was trying here, the one that got wet proved to be pretty bad in the thrust area at the back of the crank.
Because this area isn't typically hit by a crankshaft grinder, it might make that crank not worth saving.
After polishing the burned crank, it was all looking pretty good,
until I found this:
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This is smear-age from a burned-up bearing.

Here it is next to an adjacent journal with either rust damage, or, more likely, porosity.
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Now, before you condemn this, be aware that it is quite common.
Pits in the journal surface are most often acceptable.
Just look at how big the oil galley is... That's a big hole in the journal by design.

Here the two cranks are, as polished as i'm going to get them.
Both are damaged beyond what I will be able to get clean by hand.
They have, however, been inspected, and cleaned up well enough that the machinist will be able to inspect easily.
He would be the one who would know if the thrust on the rusty one is damning,
Or if that spun journal on the burned one will clean up with a grind, or polish.

Either way, they have been cleaned, and this is _very_ important, IMHO, to show respect to your machinist.
To expect them to deal with grimy junk from under a tree is an insult.

Anyhow, rant mode off, here I am chasing the crank snout threads with a bottom tap.
These can get buggered easily, and might make the difference between one of these being useable, or not.
(It's pretty close when stuff is junk like this :P )
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I also hooked the bush out of the crank.
Used an old screwdriver shaft I always use as a chisel..
This is a 914/912E part, as the roller bearing is in the flywheel with the 914.
Because we will be using a bus clutch, the bushing comes out, to make way for the roller bearing installed here in the crank.
(But that will be installed very last, after everything is cleaned up and ready)
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So that's it for the crank(s).
They both have been inspected, and are soon to go off to the crank guy.
This will be Schroeder's in Seaside.
He has good prices, if not the cleanest shop around.
He gets $40 to polish a crank.
And, if I'm feeling wealthy, $150 to spin-balance a whole rotating assembly.
For comparison, Ellsworth Brothers over the hill in Mountain View gets $275.
But they are a higher caliber shop, and the balance job would likely reflect this.
Alas, they are no more, and the bay area lost one of, if not THE best automotive machine shop here ever.
:( :(


On to connecting rods...
I keep them in bags soaked in WD-40, as they are already rusty enough!
You can see the different color of the bag on the lower left.
Jim replaced and honed the small-end bushings, and sized the big end on a Sunnen rod machine.
This was a couple years ago, I forgot what it cost. it was reasonable.
What's not shown here is test-fitting the piston pin from the actual pistons to be used.
The 'light hand press' fit was like butter on all four...
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Here is a small tidbit;
I love my wobbly-head ratchet.
Used to be that this was a Snap-On patented design, and cost accordingly.
After 50 years or so, Craftsman can sell them now.
It's like a speed brace and socket handle in one, can't live without it.
This also shows my deep-well 6-pt. socket lightly clearanced to fit the rod bolt.
You have to make sure the socket doesn't hit the rod and mess up your torque reading.
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Filing the obligatory oil-spray groove per "The Bulletin".
This was put out by VW years ago, recommending you do away with the head gaskets and put in base shims instead,
Included advice on upping the piston to cylinder clearance.
Also gave the instructions on how to file a groove for some oil spray to the bottom of the piston..
Make sure to read up! --. https://ratwell.com/mirror/www.dolphins ... hbull.html
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Oh, and always polish up the burrs off of your groove on the old wet/dry.
Any time there are metal parts sliding past each other like this I polish away...
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Also same treatment to the big ends of the rods.
The re-sizing procedure can leave a burr.
Same was done to the rod caps, only with a file.
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Someone used some thread-locker on the bolts.
This got cleaned up with the wire wheel
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Passed a brush through the nuts.
You want them to thread on by hand easily and freely to make sure the threads are still nice,
and not effect your torque reading.
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I had spoken to Jake years ago about upgrading the bolts in my hot bus motor,
It is a copy of his Camper Special,
And he indicated that up-rated bolts aren't needed in that application,
so this junker won't get them.

The rods still need to be balanced, which will come in a future installment.

Re: Cheap Junk 1971 Build

Posted: Wed Oct 22, 2014 11:13 pm
by Clatter
Onwards to the old bump-stick!

One of the motors under the tree had a Web 86 in it!
WhooHoo!!!
After talking with the PO, he said he put it together, but it wasn't "tuneable".
What had happened is that he didn't check the clearance of the cam-to-gear bolts,
and the bolts 'clearanced themselves' by wallowing out the holes in the gear,
and mangling the oil pump and case.
The cam timing got so retarded (in more ways than one! :lol: ) that the motor would barely run.
The PO didn't notice the racket.. God knows what it sounded like. :roll:
I had some pics of it all somewhere, but it wasn't pretty, so I'll hold out on those.
Luckily, the cam itself was un-harmed, and the bolts threads are still tight.
That camshaft material is hard!
Here it is with one of Jake's T1-oil pump-clearanced gears, and the bolts that survived the carnage.
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Unfortunately, it got wet after sitting outside for years, and a lobe got rusty.
I polished it with some more good 'ol emery cloth, but it's still just *barely* feel-able with the fingernail.
After looking at it some more, the damage is on the 'down hill' side of the lobe,
So, fuggit, I'm a gonna run 'er and see what happens!
Nothing a little zinc in the oil can't cure, right?
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A few rusty/pitted lifters got drug out of the stash.
They got a little polish work to get some rust off (See a trend here yet? :roll: ),
And will get sent to Steve Long Racing for the SLR re-grind/parko treatment.
$20 per set! Can't beat that with a rusty cam lobe!
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Er, right?? :oops: :oops:

Re: Cheap Junk 1971 Build

Posted: Wed Oct 22, 2014 11:19 pm
by Tony Z
Clatter wrote:Tony Z, glad to see someone watching.
There is always somebody watching

Re: Cheap Junk 1971 Build

Posted: Thu Oct 23, 2014 12:05 am
by Piledriver
Tony Z wrote:
Clatter wrote:Tony Z, glad to see someone watching.
There is always somebody watching

Indeed :twisted:

Re: Cheap Junk 1971 Build

Posted: Thu Oct 23, 2014 12:15 am
by Clatter
Pee and Ell!
If you want to sound like you know your aircoolers call them P&L...

This is always a time-consuming job that I just can't ever bring myself to do short-cuts on.
Especially if you start with broken, rusty, old Brazilian junk from Craigslist! :P

Dunno if any of you are old enough to remember Cofap cylinders,
But a set of them showed on Crankslist, and I got them for like $60.
Now, the Cofaps were no prize for sure, but, that was the days of Cima/Mahle and KS (from Germany).
Since all we have is AA now, Cofaps don't seem so bad.
My experience with them in the past was that you would find mis-matched sets.
Meaning that the paint marks wouldn't match, and they would be different weights, and sometimes even different sizes.
Since then, I have always been in the habit of marking the P to it's L.
Even though they might be different sizes, they might still be fitted correctly to their specific cylinder, er, liner.
So you would want to keep track of which went with which.
Make sense?
Scribe the inside of the skirt, the crown can get carbon you might not want/need to clean at some later time.
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And the side of the liner.
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This keeps the parts aligned, but doesn't spoil the beauty of your motor on the outside once assembled. 8)

The cylinders went off to my FLAPS (Jim again) for a honing on his honing machine.
This gets me a 'plateau finish' with first a 200-grit stone, then a light touch with a 320-grit (IIRC).
The out-of-round-ness of the cylinder can be seen as a dark 'shadow' where the low spot is hit lightly by the honing stone.
This is the area all along the left side, not the ring stain...
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They were also a tad rusty from sitting.
Plus, it doesn't hurt to have a bit of extra clearance in a bus motor.
Customers never follow proper break-in procedures!

Old habits die hard; have done this forever.
Mark a board with numbers to keep track of which is which.
Also shown is my Craftsman ring expander, and a clearanced cheap 1/2" drive socket extension I use as a drift on wrist pins.
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Got this cheap postal scale at OfficeMax or Staples or one of those.
Good to a gram + or -.
In order to get a bit more accuracy out of it, you can see which number flashes before it settles.
That, or blow a *tiny* puff of air on it, and watch it behave.
For this motor, heck, any balance at all is overkill, right?
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After I weigh everything, rings off, and pins separately, pins and pistons get their weight written on them with a marker.
I'm easily confused and/or distracted, so I make the weight markings as simple and plain and obvious as possible.
Here, there was a few gram variation in pin weights, so the heaviest pins got put with the lightest pistons.
Then, the total weights of piston and pin together get written on them, and the balancing procedure can begin.
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First thing is to remove weight from the heaviest piston, by whittling away at the 'balance pads'.
On these, there is one on the pin boss, and a couple more inside on each side of the skirts, under the pin boss.
I like to use ATF for this - way better than WD-40 or wax or grease or some other cloggy nonsense.
Make sure to mark it, though, as you wouldn't want those chips to find their way into Pops's Chevy.
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'Balance Pads' not providing enough weight reduction?
Pick and Peck at the back of the crown with a drill bit.
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Heaviest and lightest pistons side-by-side;
You can see all tricks were employed to correct the 3-4 odd gram difference between them.
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Check ring gap - all were around .020", which is good considering they were honed.
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Lastly, we fix a broken fin.
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Nothing a little JB Weld can't handle...
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So, after this, we have one thing that is actually _done_(!)

Re: Cheap Junk 1971 Build

Posted: Thu Oct 23, 2014 12:59 am
by mdmax72
Likin this thread. I'm watching and learning. As the saying goes " you learn something new each day"

Re: Cheap Junk 1971 Build

Posted: Mon Oct 27, 2014 7:03 am
by Clatter
One thing I learned early on, is that the fan has to stay indexed correctly to the pulley/ring.
Get that one off, and your timing goes out the window.
Here i mark the thing just for index ASAP.
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Chalk that one up on the "newbie mistakes" list. :roll:

Why even take it apart, you ask?
Well, back years ago i was an A/C tech in Phoenix,
and there was literature included with the chemicals and tools we used to clean off fan coils and whatnot.
Sure, they were trying to sell us something,
but,
their literature showed huge differences in efficiency with dirty vs. clean fins on centrifugal fans.
It made an impression on me.
Only a slight build-up in the 'cupped' area of a fin would reduce the amount of air moved my some huge fraction.
So I always take those apart and clean clean.
Here, we do a shot-peen treatment.
My hope is that the smoothed surface will flow air more easily, and also resist the accumulation of grime.
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The next step above this would be a polish... But i'm not _that_ crazy for these things.

If painting or powder-coating the pulley/ring, make sure it lays flat when drying/baking.
It's really handy, with those holes in it, it hang it up, so watch any lazy-asses you might pay to do this work.
Should the painter/coater hang it up to dry, the balance can be effected.
Because there's not a lot of different places to remove material from these things, this can count.
Another thing, is that if you take your fan apart, set it up so it doesn't run out.
There is a lot of slop in the fan/ring mounting, and it needs set-up on center again to preserve balance.
Here is the fan-centering set-up:
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Just an indicator, on a mag base, on an old oil pump cover, attached to the case.
This allows me to slightly tighten the fan/ring bolts, nudge the ring around until it's concentric, and tighten it down.
Now, it's ready for balance, and will hopefully need as little done as possible...

Kind of 'out of character' for our 1971 Cheap Junker, but, all of this is either work, or cheap, so why not?

P.S.
If there was one broken fin, just break one off on the exact opposite side to get the balance back.
914 race guys have been known to remove fins to reduce HP losses, so no big deal, really.

Re: Cheap Junk 1971 Build

Posted: Mon Oct 27, 2014 7:23 am
by Clatter
Back to Cheap Junk...

Here I am saving a used pressure plate from the junkyard. :lol:
Why even bother saving a used pressure plate?

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Ha! the room got real quiet all of a sudden.. A _German_ pressure plate - That's different.

Us Garbage Parts enthusiasts have had a lively discussion as to the correct treatment for cleaning/saving an old PP.
They are supposedly factory-lubed at the fulcrum points way inside.
Short of dis-assembling, cleaning, and re-assembling (which takes special tools),
There's not a lot to be done with them.
You don't dare tank them, because the lube would be all gone.
It's supposedly a heavy grease type of lube, so a re-oil isn't right.
Even want to be careful with the compressed air blowing the dust all away, so as not to contaminate the lube.

I just gave the shoe a block-sanding with some wet/dry,
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Scrub-brushed all of the dust away,
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And lightly/carefully blew the dust away with some compressed air.
If it was already balanced, i would not have hit it with the air.
(probably shouldn't have anyway).

Here's all of the stuff in the back of Grandma's Volvo ready to go to the crank guy.
I might just do the whole 'balance' thing after all...
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If going to balance, make sure you get all of the bolts and everything.
I grind all of the bolts and get them to weigh exactly the same, so they don't need kept track of.
Don't forget to include the keyway for the fan hub and the roll-pin for the crank.

The flywheel is a whole 'nuther story, and i'll ramble needlessly about that in another installment....

Re: Cheap Junk 1971 Build

Posted: Tue Oct 28, 2014 12:28 am
by Piledriver
Slightly off topic due to the "cheap" aspect of the thread... but IIRC Kennedy can fully rework/repair a used PP for a very reasonable price even vs. new Chinese poop.

They can of course recondition flywheels but shipping those hur$SS... unless they fit in a flat rate box... Hmmm...

And they have to right tools to do it, and can even upgrade it to a stiffer plate at the same time, if the need is there.

Re: Cheap Junk 1971 Build

Posted: Tue Oct 28, 2014 5:04 am
by letterman7
Sold a VW to Corvair flywheel and pressure plate a few months ago and it did fit in a flat rate box - barely! Couldn't complain about the $12 or whatever it was to mail it off. And it arrived just fine.

Re: Cheap Junk 1971 Build

Posted: Tue Oct 28, 2014 6:13 am
by Clatter
Good info there guys.
Fits our theme here perfectly.

Have shipped heads in a flat rate box, too...

I knew Pile would have some stuff to add here,
He has advocated 'recycling' for years! :D

Here we move on to oil pumps.
The OG type 4 pumps are getting scarce, as they are no longer available, and are somewhat of a 'wear' item.
Type 1 pumps can be clearanced, and used with a clearanced cam gear to work on our t4.

If you are lucky, you can find OG pumps that are still serviceable.
Especially in this type of environment...

The best way to tell of an OG pump is still good is to look a the scuffing on the pump body.
_Any_ scuffing on the area where the 'sides' of the gears go means trash has gone through the pump.
Toss those, they're junk. Not even good for a core.
Scuffing on the 'top' and 'bottom' of the gears can be OK.
Here are a couple of pumps with some of this normal wear/scuffing.
Saved these because they looked decent enough for a Junk Revival build..
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The bottom one shows how it was full of water for years,
and they both are worn about the same.
Those 'scuff rings' are feel-able with a fingernail, but only slightly.
If you assemble and torque the pump,
The end-play measures about a thou or two, so they are borderline.
If this was a 'real' motor, you might go through the arduous job of finding an NOS or rebuilt pump.
(Notice I started the sentence with the word "If")

Here is a type 1 Schadek, modified to fit type 4 I got from Jake a few years back.
The back of the pump is milled away, and the drive shaft pressed deeper into the drive gear.
The cover is also notched to clear the case fan mount webs.
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These Brazilian Schadeks are too small on the OD, and do not fit into the case with the proper interference.
Some of the oil is then 'leaked' around the outside of the pump body, and not forced into the oil galleys.
This had been discussed ad nauseum on this fair site, and different things have come up as a partial solution.
Some use the "PBR Method" shimming the OD of the pump.
Others might anodize to gain a few mil, or O-ring the outside of the pump.
My own solution might be to use a bit o' RTV (gasp! :shock: ) on the outside to fill the gap.
This T1 pump is 2mm bigger than the OG pump, and I could see that being just enough to offset any leakage anyway.

I did find one of those old leaky iron boat-anchor Mellings in my stash.
Here it illustrates why you modify your cam gear and watch those bolts.
This is from the motor with the cam gear carnage I mentioned earlier.
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There has supposedly been a guy rebuilding OG pumps in Europe.
Also found this: http://www.evwparts.com/volkswagen/Type4OilPump.html
They are also selling modified t1 pumps at the Type 4 store.

Can't vouch for any of them, however, but throwing it up there your reference.....
Any real-world experience to share is welcome.

I'm throwing the water-damaged one in the Junker here.... :wink:

Re: Cheap Junk 1971 Build

Posted: Tue Oct 28, 2014 7:36 am
by Clatter
Next up, we have the case...

There have been different cases over the years, all basically interchangeable with a few minor mods.
Consensus is that 'the earlier the better', which, with VW's cost-cutting through the 70s, holds true for many things.

Like to have them labeled when they are all in a pile or on the shelf;
Nice to know at a glance which one is the worst! :D
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The obvious things to look for are physical damage from handling, line bore and thrust.
Unlike a type 1, you don't have to look for cracks, or worry about the head studs pulling.

Something to inspect is how the lifters fit in the bores.
With a super-crusty case like this one, first running a bit of scotch-brite through the lifter bores,
and testing fits with a lifter tells a lot.

Other than that, it's common sense.
Follow along, folks, as we get this one ready to go...

We will be installing the galley plug kit from Jake in the pic above.

My favorite way of pulling galley plugs is using a dent puller. Easy.
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Correct tap drill size for our 3/8" NPT is 37/64", as shown on the tap.
The next drill above that is 19/32".
There is a difference here of .015" give or take a few tenths.
IMHO, the bigger bit makes life better.
YMMV, but this is a PITA enough, and the little bit of extra room makes this more fun.
Been doing it this way for years, never had a single leak, *garumph* *garumph*...
Notice we have one tap full-length to start easily,
and another ground short for bottom-tapping use; very important, have to have the bottom tap.
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Check out the cool old square sockets I got years back.
These with the slider break-over bar make short(er) work of this.
The extension helps me 'sight' the tap as it goes in, getting it square(er) to the hole.
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Once we do the two front plugs, (this is why the bottom tap is mandatory)
A trick is to take a small long-shank burr in there and chase out any chips that might be trying to flake off and foul a bearing.
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I won't start a tapping lesson here, but go slowly, use lube, blow things out regularly, and finish up with the slightest turn to clean the threads.
Creep up on your depth, and test-fit until you like it.
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This shot here shows my methodology a bit better.
A mill would of course be WAY better for this, as would a big drill press.
But, alas, we make due, and do it right nonetheless.
I like to put the thing on the ground, and wrangle it like I was tying a steer.
Some put them on a crate or bench. F that.
Pull the head studs, two rear mount studs, and the two long oil cooler studs, and put it on a board, on the ground.
Then sit down on it, between your legs and rassle that little doggie into submission!
It'll try and git away from ya when that drill bit grabs, but hang on and ride 'em like they do in Texas!
Unless you have a big drill with a handle on the side, this will be a lot less fun.
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Here's the three on the back.
Two on front, three on back.

Note - Make sure that if you have an early case, with mechanical pump,
Do NOT remove the galley plug by the pump rod!
There is low pressure there, and you will bugger the brass guide sleeve.
This is the plug to the right in the picture below.
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Here's the long-shank burrs I was talking about earlier.
The long-shankers are from the machinsts supply place,
and the short ones are cheapies form Lowe's or Home Depot or the like.
The difference in quality is palpable.
Seven or Five-flute burrs are technically correct for this (aluminum alloy) material, and would cut faster.
Here, we are just smoothing, and need a lighter cut, so these are chosen.
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Something I can never resist doing - smoothing out the 'window' between the jug holes...
Free power, free fuel, a smoother running engine with fewer pumping losses... win-win-win, right?
OK, so maybe it's miniscule, but here we are with the die-grinder in hand, so....
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I cruise around the case and de-burr anything that might come loose, or skin a knuckle, or impede the oil flowing to the sump.
And, alas, with a crusty, crappy case like this, even though it was tanked already,
There are a bunch of crusty spots to be chiseled clean, before it all gets tanked again.
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Nothing irks me like a "rebuilt motor" from one of these volume engine houses, that still has crap in the corners like this.
Call me anal, but these alloy cases DO cool a bit by radiating heat, and it helps to have them clean.

Here's something that sucks; there were few places where the cylinder seating surface was damaged.
Looks like 'shelf rash' or someone (me) being a caveman handling the case.
This means that we will have to go to get the case decked.
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Now, there is the whole deck/CR issue at hand here, should we deck the case, so it might be prudent to mock up first.
This is a whole other subject, so hold that thought...

Something else to do here is open up the case fill hole.
This is a 914 case, and it will be converted for bus use, so the boss/hole will be put back into use.
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Still have to drill/tap/install a mounting stud for the bus filler tube...

So I scraped gaskets, filed down dings, die-ground burrs and chiseled away grime.
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Got it all basically clean, and ready to go back to Jim for a case deck and final cleaning.

Until next time....

Re: Cheap Junk 1971 Build

Posted: Tue Oct 28, 2014 10:28 am
by Clatter
Because the die-grinder was out, and i was all covered in chips and oil anyhow...

The heads got some love.
These already went to go and see Jim at Napa Carr Parts in Santa Cruz, CA.
He, as always, did a fabulous job on them.
They got flycut/opened up for the 94 cylinders, guides, a plug hole repair, and valve job.
This was a few hundred dollars, (don't remember the exact amount, but a very good price) the biggest investment in the whole motor, and well worth it.
Unless you can get your heads sealed up and right, don't bother with the rest of this stuff.

It would have been far smarter to do this port clean-up work _before_ the valve job, but such is how things are.
Any real porting will have the guides either removed, or if the heads are brand new, pushed out of the port/way.
Real porting would likely involve oversize seats/valves too.

Stock-size valves, as here on these 1.7 bus "J" heads, are well-served by the ports as-cast from the factory.

We are doing here only a _very_ slight clean-up of some flash, and to correct irregularities in the casting.
Am also paying attention to the size of the port underneath the valve seat, to get them the same.
I colored the offending bit of material red with a marker to illustrate what we are going for here.
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You can also see a similar slight ridge in the intake port just under the seat.

Another view of the same ridge:
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See how there's a 'step', as the ridge sticks into the 'bowl' area under the valve seat?
The ridge will get taken away, and the wall of the bowl will flow smoothly into the rest of the port.
This area is NOT to be opened up any more than the ID of the seat.
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Here it is afterwards.
There is an area where the port widens out a bit more than the ID of the seat, shown as a dark line running sideways.
Because the port flows with a constant size above and below this low area, it was left alone.
The urge to open the port up and remove this low area should be avoided, as you would have this area too wide in cross-section.
That would cause a 'slow' spot in the port, and also remove needed material under the seat.
Especially since this is an exhaust port, and the flow is 'out' the port,
The seat sticking into the bowl area would be bad.
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The intake ports got hit very slightly,
only to remove any offending ridges, flash, and core shift,
and to make the ports all as similar in size/volume as possible.

There is a whole world out there with porting cylinder heads, and this really ain't that.
This is just to correct any flaws, and make them as 'correct' as possible.

Another one of my 'silly old man' tricks:
A board with holes drilled to clear the rocker studs and valve tips.
The big holes are for type 4 the small holes are for type 1.
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Now i can set both heads flat on the bench fpr a few operations chamber-side.
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Some of the holes are drilled so the valves won't hit the board when they are seated.
Looking down the guide, the hole in the board lines up.
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I say to Jim:
"Just do a super-quick cheap-o job on these - they are just for a junky sweep-the-floor motor - just the minimum to make them work at all.."
And, like a typical customer - i was lying right to his face.
What that really means is:
"I am going to take super close-up pictures of these and put them on an international website with your name on them"(!)

And, as always, his work is top notch...
Even though it was not needed, i lapped them in a bit to show just how consistent the margins are on these.
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Some may like the exhaust margins a bit wider.
Others disagree.
Because they wear as much as they do in their hard life pushing a bus,
best to remove as little seat surface as practical.
The seating area will get wider on the exhausts all by itself.
(plus a bit more flow, too)

Inevitably, talk turns to performance.
These heads i have here are 1.7 "J" heads from a bus.
1.7 heads are the toughest of the lot, and drop seats less easily than any of the others, reportedly.
My experience has shown this at least.
Heads around these parts always get the "Ghetto Oven Head Test" before i even start deciding what to do with them.
http://www.shoptalkforums.com/viewtopic ... lit=ghetto
Even though these J heads were in a bus, they didn't lose any seats.
Proving, yet again, how tough 1.7 heads are.

The valves and ports are slightly bigger than the 2.0 bus heads, so a slight performance gain over a stock 2.0 bus, BTW..

The guides were worn, but their removal showed their holes still tight, so standard guides went back in.
Now, it's always prudent to replace valves, but, in this case, we are on a budget.
Jim said something that flies in the face of what everyone says on the internet, and it makes sense.
The only time he has ever seen a valve lose a head is if the seat has failed.
Doug Ellsworth mentioned the same thing to me like 15 years ago.
These guys have experience with these motors.
A nice set of un-scuffed, matching, used OG valves was fished from the stash and installed.
Your Mileage May Vary, but it's those nasty old type 1s that have their valve heads fall off.
At least, when the valve seats are still intact....

Opening up chambers is a good way to gain flow.
With my Cheap Junker, we are using dished pistons, and will likely need all the CR we can get.
But,
This diagrams where we -would/might- remove material from our heads IF this was a performance build.
If we were shortening the cylinders, upping the compression, tightening the deck, and increasing the cam duration,
we -might- be inclined to remove material like the (holy grail) 2.0 914 head had.
See below the 914 2.0 for comparison.
Un-shrouding on each side of the plug, and on the plug side of the chamber...
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You can also see where i scribed the inside of the cylinder, should the 1.7 chamber need/get opened up to 94.

Even the 1.8 head is 'relieved' to expose more of the plug.
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If we really had the deck tight, and wanted some more chamber CCs, the non-plug side, while more of a no-no than the plug side, iit -could- get some taken away.
Like this:
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All of this is pure speculation, as i am very unlikely to pay money to chop down a set of cylinders for this particular motor.
Be advised that the AA cylinders are a bit longer than OEM.
Type 4 heads are generally to be fly-cut as little as possible, and it's also a good idea to save case deck meat too, if you can.
So, often, building a stock-stroke motor with a big cam, opened-up chambers, tight deck, and high compression will require shortening the cylinders.
This costs a "lot" of money, and it's hard to find a guy who will do them all exactly the same size.
FWIW.

Here is how i check chamber volume - Anybody remember CDs?
Back in the days of CDs, a spindle of them would come with a plastic blank on top.
That gets cut down to make a CC kit.
Free is free, baby!
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Just like i always hit up my dentist for leftover pick/scraping tools,
A 60cc syringe can often be swiped from the hospital! :D

Hopefully, being old won't have me there too much,
as i already got my 60cc syringe... :wink: