Where to stop?

eddie_1

Veteran Member
Joined
Dec 27, 2004
Location
Hannover, Germany formerly Toronto & NY
TDI
Jetta Wagon 2003 TDI tuned to 170HP, A6 Wagon 2008 TDI 2.7L tuned to 340HP
I think though in light of the meltdown if indeed the FMIC would have helped. With 2.5inch piping it is not only pressure but a sizable amount of air flow vs PSI. I also wanted to mention doing the FMIC now that it is apart but CC had the same thought. It is a trivial addition compared to all the engine rebuild. It seems all this porting could benefit from the FMIC too.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Help Please - What is the torque spec for the ARP Bolts for the Rosten Connecting Rods?

I've searched and I guess it was supposed to come with the rods, but all I got was a ziplock bag with 8 bolts in it.
 

Whitbread

Vendor , w/Business number
Joined
Jan 21, 2007
Location
Johannesburg, MI
TDI
Several
The stretch spec is .0055". If you can get a hold of a rod bolt stretch gauge, the spec if 30 ft/lbs. I highly recommend doing it the right way if at all possible though.
 

Whitbread

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Joined
Jan 21, 2007
Location
Johannesburg, MI
TDI
Several
Ruh-Roh! Welllll, you have a couple options, but I think the easiest would be to have the big end of the rod re-centered .010-.012" up. Grind .006" off cap and the bottom of rod, then re hone it to spec. That should move your CTC measurement up .010-.011". Make sure to check big end rod weights after.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
My used 2 hole head gasket measures 0.068" so I'm assuming that the head gasket thicknesses in the Bentley are "compressed".

If the pistons stick out 0.057" (max) and the head gasket is 0.0673" that gives ~0.010" piston to head clearance vs 0.020-0.023 called out in the Bentley.

Valve Reliefs in the ALH pistons are 0.038" and 0.041" in the PD150's so there is 0.003" there - plus I can sink the valves as deep as I want in the head very easily at this point. They're currently 0.030" out.

Rods are within 0.0005" of each other (ALH vs Rosten's) so that's good.

Wristpin to Top of Piston is within 0.0005" between the ALH and PD150 pistons so that's good.

The block was decked "less than 0.010" (pictures of that to come later, but it's interesting) so that's probably the main cause of the issue.

Thermal expansion of the rod and block should be similar, but the piston will grow disproportionately more being aluminum - will it grow 0.010" in length over the operating temp of the piston? I doubt it since it's only ~1.5" from the wristpin to the top of the piston.

I'm trying to talk myself into using a 3 hole head gasket and sinking the valves to 0.010-0.015" protrusion and not having to alter the rods like Matt suggested. Does anyone know the reason for having a 20-23 thousandths piston to head clearance? Is it for valve to piston clearance (which I can fix by adjusting valve protrusion) or is it for something I'm not accounting for above which would allow the piston and head to touch?
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Wow - 0.025" seems like a lot for rod stretch....not doubting it, but I was thinking it might be more like 0.003"-0.005".

I'm halfway there to calculate it by having the piston motion mapped out - just need the mass of the piston/rings/wristpin/top half of the rod and the crossectional area of the rod.
 

TDIJetta99

Top Post Dawg
Joined
May 17, 2005
Location
Port Jervis, New York, USA
TDI
03... Faster than yours =]
I'd knock .010 off the piston tops... This is a situation where it would have helped to test-assemble everything before having the pistons coated..

Are there any thicker head gaskets available that'll fit an 8V block?

Edit: Looks like the ALH 3 hole is the thickest of the TDI gaskets according to post 9 in this thread http://forums.tdiclub.com/showthread.php?t=273594
 
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Keebler145

Veteran Member
Joined
Jun 29, 2008
Location
Niles, Ohio
TDI
Jetta MKIV 2000, 2003, and MKV 2006 PD DSG
O no fub! This is the very thing I feared when I did mine =( I wouldn't take anything off the top of your pistons, not trying to offend anyone but in the case you had (similar to mine) it's foolish to take material off the place of this piston that failed. You're weakening a piston that you bought to be more durable than the previous.

From the couple of blocks I've worked with the issue seems to always happen when you knock more than ~.0055" off the block.

When I went through the build I got lucky and fell just inside the limit, I let Frank know and he recessed the valves a little deeper as you were already planning to do.

I discussed doing the option Matt suggested before with him too. If you can find a shop to do it, that wouldn't be a bad option. I had the problem of finding a shop and then finding a shop that would do it for a fair price and then someone I would trust. Never found one, but never needed to thankfully.


Edit: Never thought to check mine, are the intake and exhaust valves in the exact same spot/same size for pd/alh pistons? I ask this cause you mention the valve reliefs being deeper, which works so long as they are the same or larger diameter =P
 
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Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I've got one side of piston 4 at 0.057" protrusion - the other side of that same piston is at 0.052".
Piston 1 is 0.046" and 0.047"
Piston 2 is 0.051" and 0.052"
Piston 3 is 0.052" and 0.053"

I'm not sure yet why 1 is so much shorter than the others or why 4 has such different measurements one side to the other - I didn't have time to measure the individual rods and pistons before I had to leave.
 

Keebler145

Veteran Member
Joined
Jun 29, 2008
Location
Niles, Ohio
TDI
Jetta MKIV 2000, 2003, and MKV 2006 PD DSG
were the journals oiled? I don't remember but the Bentley specifies where to measure to keep an accurate measurment. If you measured on the swivel sides the piston could have been leaning in the cylinder and thus higher on one side?
 

TDIJetta99

Top Post Dawg
Joined
May 17, 2005
Location
Port Jervis, New York, USA
TDI
03... Faster than yours =]
.010" won't weaken ASV pistons... They are really thick along the top surface... I might be a little concerned about doing that to stock ALH or 1Z pistons but not the ASV's... the only other options I can think of are to have the rods re-sized (like Whitbread mentioned) or look into a custom head gasket.. Simply deepening the valve pockets doesn't change the relationship of the piston to the cylinder head..

The protrusion measurements should be made inline with the wristpin (left and right sides).. anywhere else will give you inconsistent measurements since the piston can rock back and forth a little in the bore..
 

JFettig

Vendor
Joined
Aug 18, 2010
Location
Blaine, MN
TDI
B5 Passat, 2010 Jetta
The two motors that I have measured protrusion had only .001-.002" difference from piston to piston. Something else causing this huge variation?
 

Keebler145

Veteran Member
Joined
Jun 29, 2008
Location
Niles, Ohio
TDI
Jetta MKIV 2000, 2003, and MKV 2006 PD DSG
.010" won't weaken ASV pistons... They are really thick along the top surface... I might be a little concerned about doing that to stock ALH or 1Z pistons but not the ASV's... the only other options I can think of are to have the rods re-sized (like Whitbread mentioned) or look into a custom head gasket.. Simply deepening the valve pockets doesn't change the relationship of the piston to the cylinder head..

The protrusion measurements should be made inline with the wristpin (left and right sides).. anywhere else will give you inconsistent measurements since the piston can rock back and forth a little in the bore..

for what it's worth he got pd150 pistons not asv.

who makes custom head gaskets?
 

TheOtherFuel

Member
Joined
Jul 23, 2011
Location
Chicago
TDI
'80 Westy Rabbit
I beleive the ASV pistons have a shorter topland to wristpin dimension. Franko6 had me deck the block a bit to accomodate the difference on my build (AHU with rostens/ASV), hate to say it but the ASV's may be your best option here unless you find a custom gasket
 

kiwibru

Veteran Member
Joined
Sep 21, 1999
Location
Distant island in WA. state
TDI
Golf 2-door, 2k Silver. Red RTDI now gone but not forgotten!
So can I conclude from this very interesting thread that if the block and the head had not BOTH been skimmed off this protrusion problem would be a non-issue? What a hassle...I will be watching to see how you end up solving this engineering problem!
Bru
 

TDIJetta99

Top Post Dawg
Joined
May 17, 2005
Location
Port Jervis, New York, USA
TDI
03... Faster than yours =]
So can I conclude from this very interesting thread that if the block and the head had not BOTH been skimmed off this protrusion problem would be a non-issue? What a hassle...I will be watching to see how you end up solving this engineering problem!
Bru
The head has nothing to do with piston protrusion, the issue is with the ever so slightly taller pistons, and skimming the block..
 

TDIJetta99

Top Post Dawg
Joined
May 17, 2005
Location
Port Jervis, New York, USA
TDI
03... Faster than yours =]
for what it's worth he got pd150 pistons not asv.

who makes custom head gaskets?
I must have missed the PD150 piston part. That explains a bit of it.. I think the top thickness is pretty similar, if not a little thicker than the ASV's...

The few PD150 pistons I was playing with and comparing to the ASV and stock ALH pistons were slightly taller from the wristpin to the piston top.. About .015-.020"... I'm willing to bet that's what put it over the edge as far as protrusion.. I'd still knock .010" off the piston tops (including .010" from the valve pockets)... The sucky part is that he already had the pistons coated..

I'm not sure who makes custom head gaskets for the VW's (if anyone even does).. I used to get various assorted thickness gaskets for GM and Ford engines from Summit and Jegs, but they don't seem to list a whole lot for the VW's..
 

Keebler145

Veteran Member
Joined
Jun 29, 2008
Location
Niles, Ohio
TDI
Jetta MKIV 2000, 2003, and MKV 2006 PD DSG
hmmm that's a bummer. I wish you could just waste a ton of money and weld the block higher and then re-machine it down lmao.

At that point I guess finding another block or modding the pistons is the better option. I'm rather intersted to see what the choice is.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
........Wristpin to Top of Piston is within 0.0005" between the ALH and PD150 pistons so that's good.

The block was decked "less than 0.010" (pictures of that to come later, but it's interesting) so that's probably the main cause of the issue........
I measured one of each (not all 4 of each) and they were within 0.0005" of each other from wristpin to top of piston (and that's with the ceramic coating on the PD150 pistons).

Maybe just to eliminate a bunch of measurement variables, I can put one of the old original ALH rods/pistons back in the engine and measure it's protrusion to see if it is indeed the block that is now too short or maybe the crank throws are off - Cylinder 1 is ~0.005" shorter than all the others.

I suppose another option is to go with under sized rod bearings and have the crank offset ground to shorten the stroke (or equal it out)
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Ok - taking a step back away from the short block problems....I did get some productive work done on the cylinder head this weekend.

Reaming the valve guides out started thing off - Goodson TNR-7MM-B


Run though each guide 3 times with plenty of "Reaming Oil" (we need some of this at work when things don't go so well :))



After the reaming is complete - on to seat cutting






No grinding or lapping of the valves - just drop them in after seat cutting and they all hold >0.8 bar vacuum. Plugging the tester with your finger gives 0.9 bar.


The valves were backcut with a 30 degree angle per Alex22's recommendation (he recommended the intake valves only, I did the exhausts as my own decision - there was not much removed). The backcut valve is on the right.


Here's both the intake and exhaust valves. I marked the valve seat with a red sharpie marker and then spun it (by hand) against the valve seat to see where the seat and valve contact. Then I backcut the valve until there was just a little (~0.020") of the line left so as not to reduce the seating area of the valve on the head - you can see the red line remaining on the valve between the back cut area and the seating area
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I temporarly lost the valve seals so didn't go any farther assembling the head, but there's not much left - just install the valves, springs, seals, retainers, keepers and lifters. Sounds like a lot, but goes quick. Fortunately, I found the valve seals, but not until later so I will have to put it together next weekend.

On to the bottom end assembly...Rods and pistons assemble together easily - just lube the wristpin and slide it in the piston and rod. Install the circlip and you're done. Sorry, no pictures of this process.

Once everything is thoroughly cleaned, and then cleaned again, you can begin assembly. I used ATF as an assembly lubricant - it has very good detergent qualities. Due to oily hands, I didn't take any pictures of the piston/rod assembly either, but more on that later.

I decided not to purchase new oil squirters as recommended by someone very early in this thread. Insted I decided to tweek the ALH ones to work. Below is a picture of the mis-match between the ALH oil squirter and the PD150 ARL piston oil gallery


A little adjustment with another very specialized tool...


Here it is aligned - it's a little difficult to see, but the squirter should be moved mostly to the side and just a little toward the center of the bore. You want it to hit the hole when the piston is at the top of the stroke as well as the bottom. Stroke the piston all the way to the top of the bore and eye it to see if you're still on target.




Be careful - they bend easy

I found a good use for the ARP Cosworth Head Studs




I spoke to my friend who took the block and head to get surfaced. He took his camera and took a couple pictures (of which I only have one right now). The block was fixtured up and a pass was made that just touched the top of the block on the edges and high spots on both ends of the block. A second pass was taken ~0.0035" deep and this was the result...


Notice the rings remaining between cylinder 1 and 2 and the depression all the way around cylinder 1? This was not present on any of the other cylinders. It's like the deck by this cylinder was depressed. First thought was that the block was not fixtured level, but the deck cleaned up beyond this part on both the very first and this pass.

A 3rd pass of ~0.0020" cleaned everything up for a total removal of 0.005"-0.006"

[EDIT] Piston Protrusion measurements are inaccurate/not repeatable - see post 243 - however these measurements support what was found in post 243[/EDIT]

The resultant piston protrusion is shown below - measured more/less where the number is written with a depth micrometer "vertically" as shown in the picture on the left and right sides.






 
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Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
This is where I did a dumb dumb...I was putting the pistons in the block with the head surface down and "pulling" the pistons up in the bore with one hand while guiding the rod on to the crank journal with the other. The rod will slide side/side on the wristpin and make it tough to get everything lined up. It was ~12:30 AM and I was getting frustrated and tired and I couldn't get the last piston/rod lined up and installed. I had it twisted in the bore a little so I had to remove the piston/rod and start over. I tapped on the bottom of the rod and there must have been some localized excess gravity right there because that piston came out of the bore so fast, hit the engine stand, then the floor.

Crap!











I filed the deformed areas and said "Crap!" again






Crap!

Moral of the story - no matter how much of a pain it is, put the pistons in from the side or the top.
 

runonbeer

Maintenance EnthusiastVendor
Joined
Apr 15, 2002
Location
Austin, TX/Chapel Hill, NC
TDI
'00 Golf 02M, '10 Golf 02E, '02 UTE 02M
Big bummer about that piston. I had to get 7 stitches last time I did bottom end work (a few weeks ago). Now I have 2 paralell scars on my left hand that are exactly the same distance from eachother as a BEW rod journal width.

Too bad the scar on that piston won't heal. I don't like it.
 

oldpoopie

Vendor
Joined
May 14, 2001
Location
Portland Oregon
TDI
2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
Oh man. Reminds me of when I gave a buddy of mine a brand new set of ASV pistons to machine the valve reliefs with his cnc mill. He jigged it up and set the program. Loaded he first piston and as the mill was moving into position it slammed the bit straight thru the top of the piston. It never had a chance..... 1/2" hole straight thru the bowl to the other side. Glad boraparts had another one I could replace it with. I have a buddy who has a bunch of melted and otherwise messed up pistons on his sales counter. I gave it to him for an addition to the collection.
 

Ben Dur

Veteran Member
Joined
Mar 8, 2010
Location
Pensacola FL
TDI
2000 VW golf tdi
to be honest the piston look alright. we put far worse looking pistons into the autoX experiment and it ran 6500rpm for many miles. its demise was not piston related. although it was an over-square engine and not a diesel.............

I would get it stripped, inspected for fractures and re-coated. or for the peace of mind you could always see about buying a single...

That sucks though. Murphies law, as is always said here "if it can, it will."
 
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