Engine (mild) overhaul

So the engine got mostly stripped to see whats going on with it. 

Seems like a perfect storm happened all at once.

Findings are:

1)  even with still having decent compression, the cylinder walls are smooth with no hatching and the rings are tired and gave up without breaking. Maybe sticking rings.

(probably should have done this while head was being changed)

cyl 1

cyl2

cyl 3

cyl 4

2)  "rebuilt" head from sports car warehouse leaks like a seive from exhausts.  Have to lap valves

3)  Measured pistons at top and middle- 3.15 top (stock size) and average 3.12 at wrist pin.    New ones are needed.   

BTW define terminology before ordering a set of pistons.

My version of a set of pistons is enough to do a complete engine. I asked Modernengine if this was a set for the MGB.  He says yes so I buy "them"

So I get one piston with rings for about $100.

 Ebay guy from California states a set is one piston with rings.  

I didn't know if I was wrong so I asked people at lowes and the USPS if they would call that a "set"

They all answered "no"  So suck on that Modernengine.  It's on its way back.

4)  pushrods 5 and 8 were ever so slightly bent.  -both exhaust btw.

5)  the bearings look really good, but a new set (my version) will be ordered.

I bought a honing brush for $37, ($89 at oreilly- really?!?!?) lapping tools and paste, ring expanders, ring compressor, and a bore measuring kit that won't show til after Thanksgiving.

I'll be done by then so it doesn't matter.

Cylinder 4 with the first suggested reverse hone to break the glazing.  What a difference.

   

You can see the honing marks in cylinders 2,3,4.  VS 1 that is oil soaked and black.

The drill I have was set to the lowest speed to initially find how fast the brush needed to be moving.

Turns out that that speed and counting 1 second for entry and exit of the bore came out to the ideal 25-30* hatching .

I started out with a 10 count and checked.  The glazing was gone and a pattern was forming.

I went back and gave them a 30 count (30 strokes) , this was enough for cylinder 4 and 1, 

2 and 3 took a little extra to get rid of the piston ring high and low points.
Needed: 
AFAIK
head and rocker studs, nuts, washers
all copper head gasket
pistons
bearings for rods

I'll find something after placing the order I'm sure.

Mgb engine brexit

Welp.  I was driving around , everything going perfectly, when there was a clattering from the engine compartment.  Sounded like slapping a belt across a flat surface.
  That happened a couple times then the engine lost about 76 horsepower and died on the side of the road.
Thinking the fan belt came off, i popped the hood. Everything was where it should be.   Got it restarted running  rough. Not enough to pull itself in 1st gear.
  Called a buddy for a tow.

Excellent mpgs.  V8 power!

Note the pushrod vs rocker orientation.  After putting it back in place the valves were re gapped.  Couldn't get it running right without gas straight into the carbs, and it wont idle.
  Soooo the head gas to come off. To see whats up.

Much has transpired since last post & mpg update

The top is on.
It came with a guide chalk line already on it for the front of the frame.
After affixing the rear of the top the front middle was pulled taught, not drum tight, this left about an inch between their mark and the frames lip.

This is the link i used for guidelines.

http://www.wmbgbrit.com/install_new_top_mgb.htm

It is an ez on brand from the Carolinas, It fits nicely except the 2 snaps next to the top frame hinge behind the door.  One is stretchable at 1/2"off, the other is not at 3/4".
After 2 weeks on, and several Texas heat cycles, that one snap still cannot be stretched to the frame hinge without popping off.  The extra vinyl from the top was made into a double sided snap spacer.
Btw the zippered rear window is worth the extra $20.
It streches some when driving, but becomes taught again soon after.
After a couple of monsoons, there have been no leaks from anywhere.


--------------UPDATE 9-28-2016

-Fall has arrived in Texas. All 2 weeks of it.
- Cool, dewey mornings and warm afternoons.
-After driving with the top up I found that the fresh air flap behind the radio flows better air at the footwells if it is in the first or second position.
-With the top up you can distinguish what song is on the radio at highway speeds.
-The center dash vents blow a hellish amount of air with just the wing window cracked open
-Also found that my gearstick doesn't buzz if the shifter knob is removed.  Can't tell why. Going to try to pour some caulk down it before screwing it on and see if that stops it.
-Had to adjust the toe in a bit there was some feathering on the inside of the fronts.  May need another 1/2 turn in.
-Doral tires are wearing nicely, are quiet, and predictable around corners.
-The latest mpg was 26.2 with moderate throttle driving after starting fresh and re-tuning the carbs.
High was 27s with them leaned some,
-I found that the odometer ran 0.1 miles high according to highway markers.
 Not bad for a 44 year old pushrod 4 banger with dual carbs.
-I'm thinking an electronic 45d distributor is in the works.  When that transpires- you'll be notified.

Transmission " how to" assembly guide

There just wasn't a lot out there on how to guides for this- so here's my version


(With assembled 1st input/2nd layshaft /3rd output motion shaft)
This is where the transmission is having parts replaced, but not affecting tolerances...
The only parts replaced were the 3rd synchro ring and input shaft...

1>Clean cases- lots of crud accumulated in the tail housing especially

2>Put 2nd motion shaft (laygear) in case with biggest toothed gear side forward, do not try to
    insert shaft yet

3>Insert 3rd motion (output) shaft assembly in without 3/4 synchronizer assy on it. 

4>Line up rear bearing hub with the round locating disk at the 10:00 position looking at rear of the case.

5>Gently tap in bearing hub with soft hammer until tip of 3rd shaft is in blank space of laygear,  then slide 3/4 synchronizer assembly on shaft and tap bearing hub in the rest of the way flush to the back of the case.

6>4th gear synchronizer will try to fall off. Make sure synchronizer outer blocks are inserted into synchro assembly.

7>Insert needle roller bearing in 1st motion (input) shaft cup or on snout of 3rd motion shaft.  I apply some bearing grease for startup lubrication.

8>Insert 1st motion (input) shaft til over 3rds snout.
 It will not go in if laygear is pinned in place or if synchro rings outer blocks are not in the assembly!
  Slide in until circlip on bearing reaches housing.

9>There are 2 oiling spacers with grooves on them that go on either side of the layshaft. Big one up front, small to the rear. Insert these (I used a telescoping magnet) then use a smaller diameter rod to line up with layshaft to the other gears

10>Attempt to insert layshaft pin while not fumbling oiling spacers and pushing out roller bearings. The layshaft pins notched end goes towards the front with the notched side "up" (look at the front cover- you will see)

11>If you succeed in that, then the front oil cover /clutch arm holder and
big bearing spacer shim can go on. 

>>Make sure transmission can spin without binding.

12>At the tailshaft there is a large bearing spacer shim against the bearing hub on mine.

13>The speedo gear goes over a tiny half round key in the shaft. No key= no speedo.

14>A distance tube goes over the output shaft. Flanged side to the back.
Shims separate the end of the distance tube from the tailshaft bearing on mine

15>The reverse gear is placed in the case with fork notch to the front,  pin is inserted from the rear of the case with indent to the front.  This notch accepts a bolt with a pointed tip to hold it in position.

16>The 3 shift forks are placed in the appropriate holes from the rear. Make sure the rear fork bolts are wired. 
If they get mixed up, you can set the forked side on the table and look at the indentions
in the shafts.  This is determined by how far they have to go into the transmission.

The order of shaft holes from the table is
lowest = reverse shaft
middle= 1/2 shaft
highest= 3/4 shaft

17>Do not put in the shift rod pills yet, they will fall into the hole and cause problems. Do them last.

18>Place the 1/2 bronze fork (has 2 holes in it) over 1/2 synchronizer and slide the rod through- lining up the notch with the bolt hole in the fork.

19>Place 3/4 bronze shifter fork on 3/4 synchronizer and slide rod through- line up hole

20>Place reverse shifter fork over reverse and slide rod through- line up hole

21>Insert shift rod bolts, nuts, washers (DON'T drop any!) through shift forks into shaft.

should look like this afterwards...

22>The shift rod forks kind of nest together with reverse running over the top of the rest.

23> Bolt the rear housing to the main case- being careful not to disturb shims and keeping shift rods from being bound up.  The shift fork selector needs to stay towards the reverse plunger. Then its selector paddle goes between the forks afterwards.

24>Shift interlock 

 goes around the rear tabs of the shifter forks and envelops the selector paddle to keep it inline with the selector forks. (keeps it from falling away)  Its mounting plate fits into the indent of the housing.

Interlock is the mowog piece 

25> Install shift tower, plastic bushing should snap in to lower shift cup.  6 bolts- 4 long, 2 short. Check shifting action with screwdriver into upper shifter cup.

26>Insert 3 shift pills rounded side down into top left of case with springs and bolts following them.

27>Seal up side plate, re - check all bolts- is the drain bolt in??  11/16"

>>If everything shifts and turns good,
Replace rear transmission seal while you're at it then put on the 1 5/16" tail nut to torque specs.

About 3 qts of oil and you're ready to go...check the dipstick
------------------------------------------------------------------------------------------------------

It's a 3 synchro- but close enough...

OY! Vat a day! watch for parts store seals...

Got the gearbox back together.  Everything seemed right, not many leftover parts..so we're good. Lol

The nice "new" transmission was bolted to the engine and filled to capacity. 3 US qts from empty.
Engine took 4.5. Blew out oil cooler prior to refill and trying Castrol gtx 20-50 per popular request.

Note: o'reilly and autozone tried selling a rear transmission output seal for the mgb that is NOT right ! It may be for a overdrive- but not the 68-80 4 speed.
 473234 p/n

Autozone on the left, one that works to the right.

Not enough hands for pics during the install, will try a transmission write up though.
At 103* I was racing the heat.

The only other vehicle that is as easy to pull and fit a drivetrain into is a jeep cj.  Simplistic and robust!
Anyway... in a mere 4.5 hours.. the car went from many many pieces to a working, very nicely shifting , better accelerating machine.  Just seems zippier. Especially 2500 rpms up. Probably the fact the valves are opening and closing like they're supposed to

And as soon as the last bolt was turned clouds and rain (first time in 2 weeks) started rolling in.  And the temperature dropped 13*.  Lucky me.

The transmission at a glance and other problems v2.1

So since 3rd gear ground when being shifted moderately hard, the teardown begins.

Bam, torn down.


Shift rods and gears, blah blah blah

 Springs from shift 3/4 shift collar and balls went flying.
There are thicker springs and "pills" for the shift rods themselves on the left upper side under the bolts, dont confuse the 2 types.



Offending culprit just like Byron said .
It cracked through the thick portion.

Oh- and there's another problem! The first motion shaft is shot! "new" one on the way...

That little piece on the right is supposed to be attached to the piece on the left.  It was in the tail of the box!

V2 update:

Good news, after ordering a new batch, I found my synchronizer ball that went flying.  While torquing the engine head it rolled from under the dolly. Figures.

Instead of chasing it and loosing it again I came up with an idea so astounding, so revolutionary, that it should be patented.

First -
get a laundry basket lined with towels. Work in this zone so your balls wont go anywhere.
Second-
 put the springs and balls in the synchronizer- when they go flying again, you'll thank yourself.
Third -
put a large hose clamp around them
Fourth -
inset assembly partially into hub
Fifth-
Whack center hub with soft blow hammer and if everything goes right- you're done!

balls go into cavity with springs- then go flying everywhere!

patent pending , all rights reserved, TM etc... etc....

Rocker shaft rebuild

So instead of 11 to 20 per rocker arm the originals got new bushings.
Its not hard, just time consuming.
  The old bushings get pressed out with a vice and 2 sockets. I used a 3/4- 1/2" drive and a 1/2- 3/8" drive as a pusher.

Heres the fun part- the new ones get pressed in with seam "up".
Done right? Feeling accomplished??

Next take out the adjusting screws
And grind off the rivet head.
Someone said they punched the rivet through- I'd like to see how they did that.

Drill both oil weep holes through the bushing using the rivet hole through to the inner oil port and the upper side hole as a guide.

Done- right?  The official reamer size you need is .6255.
 Why .0005 was needed i dont know.
So the .625 cared for drill bit was chucked up, table vice set up for distance. And with a moderate speed and lots of oil...

After the part was deemed perpendicular to the bit it was drilled.

Then tested on the new rocker shaft. They went on  but took some effort to slide on the shaft.

I ran them on the bit by hand 3 more revolutions at the top of the fluting. 

This gave them a machined match feel to each.

I ran the small oil port bit back through to open the ports again.  Then clean all the bronze shavings off.

The old grooved shaft vs the new setup.
I filled the shaft with oil prior to installing on the new head.
Note the original shaft- rear side (left) worn terribly, front (right) that got little oil in good shape.  Weird.