Yikes! I bought a '74 Super!!

[vamram]

Engine problems. I have the long block put together and was adjusting the valves this morning, hoping to get the block outside and begin re-assembly of the external bits - tin, intake, etc. But I was only able to adjust 7/8 valves. The #1 Intake valve can't be adjusted, there's no room at all, even removing the adjusting screw. I removed the rocker, and checked the pushrods. They're not bent, and are the same size. And they're centered on the lifter seat/lobe, not sure what it's called - the cup the rod goes into.

In this pic, the intake rod appears to be sticking out farther than the exhaust.

Here's the engine turning so you can see the movement of the #1 valves.

Link


What could cause this? If I had misaligned the cam and crank gear dots, i would have issues adjusting all of the valves. Just the #1 intake has a problem. The thought of disassembling the case again is *not* appealing. Is it possible that all I need are rocker shims on the #1 side of the rocker shaft?
_________________
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'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
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Save the Supers!!

[VW_Jimbo]

Pull the head and check the valve seats. Is that one sunk?

How about the lengths of the pushrods? Equal to the others?

Does the other side have the same problem? #3 shares the same lobes.
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[vamram]

Jimbo, 7/8 valves were fine, including both on #3. Btw, I think these are vw/factory pushrods, all straight and the same length.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[VW_Jimbo]

Then you NEED to remove the head and check the valve seat! Sounds like it sank into the head. VW had this problem in the late 70s with sunken exhaust valves on number 3. My own parents lost an engine in their 73SB going 55 down the freeway! I was all of 10 when that happened. My Dad pulled it all apart and the neighbor across the street rebuilt the engine for him! That’s about when my mind switch from Legos to engines!!!! Same building with pieces but more fun with starting it!!!!!
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[vamram]

But Jimbo - this is a brand new head, not a factory original. Is that the only other possible explanation??
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[VW_Jimbo]

[vamram]

I'm pulling the head during lunch and will report back...I almost wish it to be a dropped seat so that I don't need to bust open the case again.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[raydog]

If the valve height and pushrods all check out, then before disassembling or pulling the head, I would swap the rockers on #1 just to see if there is some weird difference. At least that way you are eliminating that possibility before doing unnecessary work.
_________________
Come on, It's not rocket science. KISS

[VW_Jimbo]

[vamram]

Sorry Raydog, I only just now saw your suggestion about the rockers - after I pulled the head. I don't see any problems w/the head. Both sets of valves look exactly the same. Raydog, when you say swap the rockers, you mean a single rocker arm, not the 1&2 for the 3&4 assemblies, right? [EDIT] What about using shims for he rocker base? Or am I looking at sending the head back to have the step "fixed"?

_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[VW_Jimbo]

[raydog]

There you go, Jimbo's suggestion is even better. Just swap the entire rocker assembly from 3/4 side and see how things fit. This beats taking the 1/2 rocker assembly apart, and quicker. Don't go the shimming route, there is something off. Solve the problem rather than putting a Band Aid on it.
_________________
Come on, It's not rocket science. KISS

[vamram]

Ron from carcraft (where I bought the heads) suggested swapping heads as well. I'll. Do the rockers first.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[VW_Jimbo]

Ah, Carcraft......

Hope the heads are good! I have seen the refund policy. Not good.

Fingers crossed for ya!
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[vamram]

Well he did replace one of the pistons that had a pin that wouldn't go in, so I'm betting on the positive side with him.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[vamram]

I swapped the rocker arms. The problem stayed w/the #1 intake, did not follow the rocker assembly to the 3-4 side. 3 adjusts fine. Bummer...I was hoping it went w/the rocker.

Tomorrow... I'll swap the heads.

In terms of deck height - I'm not sure how to measure that so don't know it.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[VW_Jimbo]

[raydog]

Those valves do look like they are sitting a little low in their seats. Here is a pic from the gallery to compare.

I just looked at the original pics, and see that he also has run out of adjustment on the other valves too. The adjusters are backed all the way out. Is the other side like that too? Other than the valves sitting low, which is working against him, I am beginning to think you are going to have to work on your valve train geometry. Shimming the rockers probably isn't going to be enough. You may want to consider getting shorter or cut to fit pushrods.

So regardless of the one intake valve, you have no adjustment left on the others as the motor breaks in.

_________________
Come on, It's not rocket science. KISS

[vamram]

Raydog, i think that may be an illusion from the bad lighting in my basement and crappy smartphone camera. I have the head off and the valves don't look sunk compared to your picture. Also, w/the head off the tips of the stem are all even w/the a straight-edge laying across them, no one valve sticks out further than another.

I will be trying my hand at calculating the compression, deckheight, etc. But it's going to have to wait until next week as I'll be out of town in Berkeley CA for the next week or so starting tonight.

Víctor
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[vamram]

Ok, so as I pack my bags I couldn't resist. I tried my hand at the deck height and such calculation.

I got 41 ml of Smart Balance under the modified CD, which is tight flush up against the ....what's it called...step? Anyway, it's flush against the sides and tight down against the edge/top of the chamber.

And I got 12.8CCs of volume for the piston top/cylinder top space. I measured 87.95mm & 2.12mm depth from the top of the cylinder to the piston head. But I must be calculating something wrong. When I plug the numbers in to the CB calculator I get a compression ratio of 2.6...that ain't right. Displacement is correct...these are 88mm w/a factory 69mm crank. Maybe my deck height figure is wrong?

_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!