Deck height measurements driving me crazy, Need advice Options

[stugray]

Yes, less than 0.001 between the two.

Stu

[stugray]

Bump!

So the only things I can find say that I need to have the case deck machined, but that doesnt make sense since the tops of the cyls look to be very close (less than 0.001).

Can I have a crank with that much variation?
Mismatched rods?

I want to measure as many things as possible before breaking everything down again.

Stu

[yeahmag]

I would suspect the rods first. You can snake them out without opening the case. It's not fun, but it's doable.

[r_towle]

You need to open up the case and send everything to a machine shop for measurements.

Its not a huge job to open the case again....just take your time and keep track of all the parts.

Get more sealant.

You will sleep better knowing the rods are balanced and the crank has been measured and polished.

Once the case is apart, have them measure the sealing surface where the cylinders meat the case...from a flat surface.

rich

[brant]

I would have a shop check the registers and also for line bore

I believe A LOT of these cases are needing a line bore these days.

brant

[Valy]

Measure the piston travel. If it's as expected (71mm or whatever crank you have) then it's a rod problem. If it's less or more (probably less in your case) then it's a bad crank.

You may also check for play in the bearings. Rotate the crank so the piston is at bottom and then push the piston in the bore. If it goes further down you may have bad bearings, any of them can be the faulty: pin bushing,rod bearings or main bearings.

[yeahmag]

I agree in principal, but there is no reason not to take it one step at a time and pull the rods and have them checked. Personally, I'd tear it down and have the following done:

* Case checked and if necessary line bored
* Deck the registers
* Measure cylinder length
* measure piston crown to pin height
* Blueprint Rods
* Blueprint Crank

But taking out the rods does relegate you to *not* doing any of that, it's just an easily reversible check.

[stugray]

I will go over all of the suggestions above but here are a few comments:

Bearings are all new and stock size.
All journals looked to be in great shape. (measured and inspected).
Entire rotating assy. was already balanced by local machine shop.
Top of cyls measure flat to within .001 with full head torque.
Brand new EMW cyls & flat top pistons.

This is screaming mis-matched rods or bad crank.
I hear that the high perf. crowd have their cranks "indexed" to make sure the stroke is perfectly matched.
With yeahmag's tool I might be able to remove the rods, retorque the cyls and measure to the top of the rod journals at TDC & BTC, but I would be wary of trusting that measurement unless way off....

I have another set of rods, but not sure if they are 1.8L or 2.0L (I have two engines, so spare parts could go with either after years of storage).

I think I will give EMW a call too.

Stu

[r_towle]

Crank was balanced at a shop? then its straight.
Rods balanced and they are stock rods? those should be fine.

Maybe one of the dowel pins was not lined up, but otherwise I would pull all the cylinders and pistons and measure those very carefully.

Then if those check out...and all pin heights are correct...
It must be the case.

rich

[yeahmag]

Actually, the rods can be in balance but different lengths. Typically resizing the large end for a new bearing at the machine shop involves cutting some material off the cap and then honing to round again. You can end up with rods of different lengths after this is done a few times.

[r_towle]

Actually, the rods can be in balance but different lengths. Typically resizing the large end for a new bearing at the machine shop involves cutting some material off the cap and then honing to round again. You can end up with rods of different lengths after this is done a few times.

I would be pretty sore with my machine shop if they gave me back rods of differing lengths after they were re-bushed and balanced.

Its not terribly hard to remove the rods with the case in tact....
Pull all the pistons and cylinders.
Use a socket wrench from the other side while you hole the rod.
Be careful not to drop anything...

BTDT at 2AM on one rod...got it done and won the next day...so I know it can be done.

Rich

[yeahmag]

Agreed, but the one thing I have taken to heart from Jake's rants is that, "Everything is guilty until proven innocent." You end up slightly insane at the end of a build, but that's a relative measurement. ;-)

[stugray]

Crank was balanced at a shop? then its straight.

I would agree that the MAIN journals would need to be straight. But they just put "bob weights" on the rod journals. They dont spin anything to make sure they are straight.
And the shop only balanced the rods, they did not rebush them as they looked perfect. I dont believe they have been measured to verify they all match in length.

Stu

[stugray]

ok, latest update.

I took all four rods off without splitting the case.

They all measured the same from rod journal bearing surface to wrist pin bearing surface to within 0.001.

So I measured the gap from the top of the crank-rod journal to the registers while the crank was at TDC.
I zeroed the depth gauge using yeahmag's plate on cyl #1 and read:
Cyl #2 - 0.000
Cyl #3 - +0.002
Cyl #4 - +0.007

So there is my ~8 thousandths on the deck height on cyl #4.
Now how do I know if it is the crank or the case's fault?

I guess it is time to send them both in for checks.

Who should i contact for a deck height check that could also fix my crank (if that is the problem)?

Stu

[yeahmag]

RIMCO or EMS can do it.

[Valy]

You should have measure the piston travel before taking it out in order to check the crank.

[stugray]

Ok, talked to a two local machine shops who claim to know all about vw & 914 engines and "sunken registers".
The first barely knew what I was talking about and at first said they could fix it, but then said I could just shim it (note to self....)

Second shop: http://racekraftdesign.com/ said they are aware of the "sunken register" problem but rarely see it on the Porsche engines ( I assume they dont work on old worn out engines very much).

Any way, they will measure all the register off of crank centerline and machine them all to match.

So some questions:
What cleans up brand new Curil engine case sealant the best.

Who has the best selection of cylinder shims of varying sizes?
I will probably need more than 0.010 as a minimum.

Where can I get some replacement stock head stud sets?

Stu

[McMark]

Remember that each case half must have matching registers (flat across the two), matching cylinder heights, and matching head registers for proper combustion and oil sealing.

I know you're already aware of that. But I thought I'd remention it just to be safe. (IMG:style_emoticons/default/wink.gif)

[stugray]

Thanks - he said that he would machine all four registers down to the worst case register, #4 is minus 8 thousandths.

However the opposite side seems to be perfect & flat.
If the #1 & 2 side is perfect, is there any reason to machine it down to match #4?

Also - Where can I get replacement head studs?
I cant seem to find any online without buying a full set of ARP studs.

Stu

[ChrisFoley]

...
If the #1 & 2 side is perfect, is there any reason to machine it down to match #4?
...

You can use shims on the 3/4 side to match the 1/2 side instead of machining both case halves.