Andrew's DiySB Rebuild

[heiche]

Your bird drawing is especially nice.

[StkmltS]

She tried really hard on that one. She'll be happy to hear that other people can tell it's a bird.

Watching her draw a fish was entertaining. She drew the body and then paused when she couldn't figure out how a fish's head attaches to it's body.

[birkhoff]

The rubber strip is in there. There's pressure (compression) on that strip on the top and closer to the block, just not at the bottom.

 

If I recall there is a bit of leeway in positioning the water pump on the block (in contrast to the oil pump, which is dowel pinned). By a little judicious adjustment before snugging the water pump down, you can get both seals to contact.

 

I don't anticipate this will be a problem for you. You could always put a daub of black RTV along the gap in order to ensure a dust-tight seal for the timing gear. Or not.

[birkhoff]

Super hero status: this weekend

Reality: 2 more weekends

Feels like: never

 

Sent from inner space.

 

Don't bust yourself up over the timeline. You have more ahead of you than behind, but you are making amazing progress!

 

The trick (as I think you have found) is to work systematically and with concentration. Having to back up and redo things is a schedule killer.

 

I call dibs on the princess chair. Looks like a perfect place to take a break and regroup when something seem not quite right and needs thinking through!

[StkmltS]

I'm pretty sure I just got a little bit of brake clean in my coffee

[BarManBean]

At some point in your build could you take pictures of #1 at TDC and the placement of the pistons in the other cylinders before you put the heads on.

 

If you'e read a few of the other threads, it might be nice to have real pictures.

 

Byron, here's what I have found.

 

If #1 is at TDC (combustion), then #3 is opposite and sitting at BDC starting it's compression stroke. #2 is at TDC starting intake stroke and #4 is at BDC starting exhaust stroke.

 

Clear as mud? It is for me!

[birkhoff]

Huh? Now I'm confused. If you exchange #2 and #4 in your description, then I'm back to my happy place.

 

Look at a picture of the subi crankshaft. #1 and #4 are grouped together, as are #2 and #3, 180 degrees offset from the first pair. So if #1 is at TDC then so is #4 and #2 and #3 are at BDC.

 

Firing order is therefore 1-3-4-2 with 180 degrees of crankshaft angle between each ignition event. Theoretically it could also be 1-2-4-3 but there are probably some harmonic reasons that is not desirable.

[StkmltS]

Pics to fuel the discussion

 

#1 and #2 are at TDC

#3 and #4 are at BDC

 

It's a "boxer" engine because each journal has its own rod, and opposing pistons appear to be boxing each other. Compared to a flat-plane crank; each crank journal is shared by two rods with their pistons moving in opposing directions.

Edited August 31, 2016 by StkmltS
pics uploaded to server

[StkmltS]

Heads are cleaned, valves installed, and everything cleaned again.

Edited August 31, 2016 by StkmltS
pic uploaded to server

[StkmltS]

With a little bit of 30-60-90 (ft/lbs) and some help from Joe Cocker's friends the shortblock becomes a longblock. Damn it feels good to be a gangsta.

 

For reference: when the key in the crank snout is straight up all pistons are mid-cylinder. When the key is at 90°, pistons #1 and #2 are at TDC.

 

For those paying extra close attention: I did install the four straight pins back into the block before putting the heads on.

Edited August 31, 2016 by StkmltS
pic uploaded to server

[birkhoff]

Huh? Now I'm confused. If you exchange #2 and #4 in your description, then I'm back to my happy place.

 

Look at a picture of the subi crankshaft. #1 and #4 are grouped together, as are #2 and #3, 180 degrees offset from the first pair. So if #1 is at TDC then so is #4 and #2 and #3 are at BDC.

 

Firing order is therefore 1-3-4-2 with 180 degrees of crankshaft angle between each ignition event. Theoretically it could also be 1-2-4-3 but there are probably some harmonic reasons that is not desirable.

 

My bad. You guys are absolutely correct. Firing order is indeed 1-3-2-4 but #1 and #2 are at TDC at the same time, whilst 3 and 4 are at BDC as the pictures clearly show. Thanks BMB and Stkmlts for this. I know you have been thinking a lot about this point, and you got it right the first time!

 

The thing that is not obvious from looking only at the crank is that rods in paired journals are pointing in different directions once in the block. Eg, #2 and #3 which are paired on the crank, lead to cylinders on different sides of the engine!

[xt2005bonbon]

Looks like a brand new engine!

[Max Capacity]

My bad. You guys are absolutely correct. Firing order is indeed 1-3-2-4 but #1 and #2 are at TDC at the same time, whilst 3 and 4 are at BDC as the pictures clearly show. Thanks BMB and Stkmlts for this. I know you have been thinking a lot about this point, and you got it right the first time!

 

The thing that is not obvious from looking only at the crank is that rods in paired journals are pointing in different directions once in the block. Eg, #2 and #3 which are paired on the crank, lead to cylinders on different sides of the engine!

 

Technically, when #1 is at TDC, I'm thinking #2 is not on the same stroke, but 180* out (or is it 90* out ?). Only one piston is at TDC (on the compression stroke) at a time. I believe that #2 would be ready to suck in the intake charge, while #3 is at bottom ready to come up and compress the charge for firing, and #4 is at bottom ready to push out the exhaust gas. Is that right ?

[StkmltS]

Looks like a brand new engine!

I still have a few more items to purchase and add into my spreadsheet, but as of today my total spent is "only" $3,576.25. Not too bad considering that includes having my VF40 rebuilt/converted.

 

Tonight I'll do a leak-down test to make sure the heads and pistons are sealing the way they should. I probably should track down a compression tester and check that too. There won't be a more convenient time than now.

 

While we're on the topic of a running motor... does anyone want to take a stab at guessing the observable long-term consequences of what I did to cylinder "F"?

 

I'll start

Leak-down : 2-4% more than the others.

Compression : 2-4% less than the others.

Noise : slight piston slap on cold mornings, maybe even on every cold start.

Oil consumption : 0.5-1 qt per 3k miles (no noticeable smoke).

[BarManBean]

MaxCap, that's correct AFAIK. Simply put:

 

#1 is at TDC (starting combustion)

#2 is at TDC (starting intake)

#3 is at BDC (starting compression)

#4 is at BDC (starting exhaust)

 

Then #3 fires next and everything moves on as appropriate. So...

 

#3 is at TDC (starting combustion)

#4 is at TDC (starting intake)

#2 is at BDC (starting compression)

#1 is at BDC (starting exhaust)

 

#2 is at TDC (starting combustion)

#1 is at TDC (starting intake)

#4 is at BDC (starting compression)

#3 is at BDC (starting exhaust)

 

#4 is at TDC (starting combustion)

#3 is at TDC (starting intake)

#1 is at BDC (starting compression)

#2 is at BDC (starting exhaust)

Edited August 24, 2016 by BarManBean

[StkmltS]

Technically, when #1 is at TDC, I'm thinking #2 is not on the same stroke, but 180* out (or is it 90* out ?). Only one piston is at TDC (on the compression stroke) at a time. I believe that #2 would be ready to suck in the intake charge, while #3 is at bottom ready to come up and compress the charge for firing, and #4 is at bottom ready to push out the exhaust gas. Is that right ?

 

Correct. Two pistons are at TDC at the same time, but on diff'rent strokes.

 

When #1 is on the combustion stroke #2 is on the intake, #3 is on the compression, and #4 is on the exhaust.

 

edit: beat me to it.

[Max Capacity]

BMB, thanks.

 

Just to be sure, you can't set the valve's on #2 until it is at TDC on the compression stroke, at the 3rd set of numbers in your post.

 

If you set them when your doing #1 @ TDC you will be off. At least that's how I was taught back in the 1975 when I rebuilt my V8.

[StkmltS]

My mind is exploding right now. A violent, painful, yet slow explosion.

Explosion order: comprehension, thoughts, understanding, mind.

[FJuan]

My mind is exploding right now. A violent, painful, yet slow explosion.

Explosion order: comprehension, thoughts, understanding, mind.

 

Take a deep breath, pick up a piece of chalk, and draw a happy place.

[StkmltS]

I've gotten very little done to the motor in the past couple days, but what has gotten done looks pretty cool.

 

Tomorrow I'll be putting about 8 hours into the motor.

Edited August 31, 2016 by StkmltS
pic uploaded to server

[xt2005bonbon]

Looks very nice.

[StkmltS]

Off the top of your heads... do any of you guys remember how much of a difference there is in the valve lash with the timing belt off vs timing belt on? I want to say it's like 0.001" to 0.002" tighter with the TB on. I know its in thread somewhere but I don't want to search for it right now

 

I measured my lash with the TB on but forgot to measure it again after I took off the TB.

[xt2005bonbon]

That's what I found with the 05 for #2:

 

Here are the clearance measurements with the timing belt on vs. off. I only posted measurements for cylinder 2 since it was the only that had different clearances.

So from what I understand, once I install the new buckets, the clearance should be larger than expected for cylinder 2 with the timing belt off. But once I put it on, the clearance should be fine. We shall see.

 

http://legacygt.com/forums/attachment.php?attachmentid=211748&d=1435630541

[xt2005bonbon]

Let me quote that too from our good friend Heiche:

 

fyi - not sure if it matters or not, but when i did "my" method, with the TB off and engine on a stand, i would simply press the camshaft down (towards the center of the engine) in the area of the valve being measured with the heel of my hand while taking measurements. It definitely made a difference in the measurements - perhaps the same difference observed with TB on vs off.

[StkmltS]

So much for having an easy time with the buckets. Yikes!

 

Valve lash on 8/27/16 post-rebuild (all valves are new) without the timing belt installed, no re-arranging or grinding (yet):

Intake

Cyl 1, 11-front (0.0015"), 12-rear (0")

Cyl 2, 21-front (0"), 22-rear (0")

Cyl 3, 31-front (0"), 32-rear (0")

Cyl 4, 41-front (0"), 32-rear (0")

Exhaust

Cyl 1, 13-front (0.014"), 14-rear (0.004")

Cyl 2, 23-front (0.0155"), 24-rear (0.0155")

Cyl 3, 33-front (0.010"), 34-rear (0.012")

Cyl 4, 43-front (0.012"), 44-rear (0.011")

 

Now if you'll excuse me, I have some rocket science to perform.