AAZ metal HG on a 1.6td

[phaetonv10]

Hi guys.

I am collecting all bit before i start my engine rebuild. I am looking to build a 1.6td turned up to "11"  .

I have got SB Nozzles, ARP Head Studs, and a AAZ HG. What I want to ask is, What do i do with the extra HG holes??? Do i leave them as it is and simply tighten the Head bolts or should I be looking to drill the extra holes in the head and Block??? 

Other than that I am completely rebuilding the bottom end as well, with new pistons, main bearings, etc....Just need a bit of guidance on the HG bit right now.

Also, when rebuilding the head, should I look to port and polish the head as well???

After the Head and bottom end are done, I would move on to the IP.

Considering I live in Pakistan, and VW's are extremely rare here, sourcing parts in the biggest pain. So i would need all the help I can get on the technical stuff here.

Thanks

[burn_your_money]

Definitely port, I don't think the polish is very important on a diesel.

[RabbitJockey]

polishing is not important at all, the only thing it helps is to prevent soot deposits in exhaust ports.

[libbydiesel]

Is your engine the solid or hydro lifter version?

[carrizog60]

i have done metal headgasket on a solid lifter engine.
had to cap a hole and then drilled the water ones in the block,water chanels were spot on.

[R.O.R-2.0]

polishing is not important at all, the only thing it helps is to prevent soot deposits in exhaust ports.

you want a slightly rough finish.. not a mirror surface..

[phaetonv10]

GUYS.....

Thanks for the replies.

My engine is hydraulic lifters.... MF engine code.

And as far as i understand, the HG would be a bolt on except for the extra water holes....

Can anyone guide me on how to get the extra holes drilled in the head and block???

[rabbit_tdi]

On every 1.6 NA and TD I own the headgasket eventually started leaking; these were the original factory gaskets, and so were 15 to 20 years old.  All of these engines used 12 mm torque-to-yield (TTY) bolts.  It is my opinion that the TTY bolts continued to yield over the many years, until eventually the clamping load on the gasket was no longer enough to resist the peak cylinder pressure during combustion.

My fix for the problem was to use stronger-than-stock allen bolts bought from the local bolt supplier.  I reassembled the engine with a stock type head gasket of the same thickness as the original, and torqued the new bolts up to just below the yield limit of the bolt.  Since the repairs, I have been using these engines for many miles and years with no trouble.  The TD engine has a moderately increased fueling rate, and commonly sees 18 psi boost.

I imagine that your ARP head studs are able to do an even better job than the bolts I bought.  :-)

[theman53]

GUYS.....

Thanks for the replies.

My engine is hydraulic lifters.... MF engine code.

And as far as i understand, the HG would be a bolt on except for the extra water holes....

Can anyone guide me on how to get the extra holes drilled in the head and block???

Search. My build thread even has it, but I had a mechanical lifter MF engine and a lot more work.

The AAZ metal hg will fit an older 1.6L hydraulic block and head with no mods at all. If you want you can add the extra cooling holes in the head and the block. It is about an 1/8" drill bit and taping your gasket down onto the surface and using it as a template.

[burn_your_money]

You don't "need" to drill the extra holes. If you feel it is necessary though, then do it. It's probably not a bad idea to do it.

[carrizog60]

On every 1.6 NA and TD I own the headgasket eventually started leaking; these were the original factory gaskets, and so were 15 to 20 years old.  All of these engines used 12 mm torque-to-yield (TTY) bolts.  It is my opinion that the TTY bolts continued to yield over the many years, until eventually the clamping load on the gasket was no longer enough to resist the peak cylinder pressure during combustion.

My fix for the problem was to use stronger-than-stock allen bolts bought from the local bolt supplier.  I reassembled the engine with a stock type head gasket of the same thickness as the original, and torqued the new bolts up to just below the yield limit of the bolt.  Since the repairs, I have been using these engines for many miles and years with no trouble.  The TD engine has a moderately increased fueling rate, and commonly sees 18 psi boost.

I imagine that your ARP head studs are able to do an even better job than the bolts I bought.  :-)

how did you know what was the torque value for those bolts?

[rabbit_tdi]

The fellow that sold me the bolts was willing to look the torque value up in the information supplied by the manufacturer, and he gave me a photocopy.  :-)

At the cost of destroying a bolt, the torque at yield can be determined experimentally.  Get a short piece of pipe, at least two hard flat washers, and a nut; all to fit the bolt.  Make the ends of the pipe parallel to each other, and at least close to perpendicular to the centerline of the pipe.  Make the ends of the bolt parallel to each other, and perpendicular to the centerline of the bolt.  Put engine oil under the head of the bolt, on the washers, the bolt threads, and the nut.  Put one washer on the bolt, put on the pipe, put on the other washer, and put on the nut.  Hopefully, the nut will be mid-range of the threads on the bolt; if not, add washers or shorten the pipe.

Using calipers or a micrometer, measure and record the original length of the bolt.  Then, torque the bolt to some reasonably low value, then untighten it, and measure and record the length again.  Re-oil the bolt and repeat with a torque that is 5 ftlb higher.  Repeat...  At low values of torque it will be noticed that the relaxed lengths are all essentially the same.  As the torque is increased in stages, eventually it will be noticed that the relaxed length is longer than it used to be; that torque is just over the yield point of that particular bolt.

You may wish to repeat with another bolt or two, in order to see what the repeatability is.  :-)

When you are done making measurements with those bolts be sure to mark them as scrap, because they have been tightened beyond yielding.  (For instance, grind a flat on the threads to mark it, and put the bolt in your toolbox to later use as a drift punch, or something.)

Note!  The torque value you will have determined is for oiled bolts.  When you install the bolts into the engine, the bolt head and threads MUST have oil on them.  Otherwise, you will not achieve the gasket clamping load that you are expecting.  Of course, do not put too much oil in the bolt hole in the block; if in doubt, use compressed air or suction to remove the excess oil.  Use ordinary engine oil; do not use any lubricant that has an 'extreme pressure additive' in it.

[Tightening a dry bolt to a high torque usually galls the threads (in addition to not delivering the expected clamping load).  Personally, I would not want to risk galling the threads of my block nor of my bolts.]

[wolf_walker]

I too have had chronically weeping (oil, external) HG's on pretty much every VW-D motor I have ever seen or owned.
Near as I can tell it's just the nature of them, they go for ages that way, it's messy and ugly but not terminal.

Few years ago I had occasion to put a headgasket on a 1.6 hyd head motor that had a ton of miles on it and was finally
leaking objectionably externally, drivers side rear of head.
This was the first head gasket I've ever had to replace on a VW-D in probably about a million miles now across
three motors in fifteen years or so.
I used an AAZ MLS gasket of the appropriate thickness, coated it with spray copper sealant, did not have
the head or block machined but cleaned them with scothbrite, brake cleaner and a plastic scraper.
Standard TTY head bolts.
I did almost 50K miles on it with no leaking or other problems, hard NA miles on a well worn motor.
Take that for what it's worth.  It's still driving today to my knowledge, I'd be inclined to do the same with
the possible exception of using ARP studs next time.
Also FWIW, my 140K-ish AAZ shows signs of the same sort of weeping just starting, as have several TDI's both
PD and older versions I've worked on.  I believe at this point it's just something that happens after a certain
mileage with stock parts and assembly methods.

[745 turbogreasel]

Using calipers or a micrometer, measure and record the original length of the bolt.  Then, torque the bolt to some reasonably low value, then untighten it, and measure and record the length again.  Re-oil the bolt and repeat with a torque that is 5 ftlb higher.  Repeat...  At low values of torque it will be noticed that the relaxed lengths are all essentially the same.  As the torque is increased in stages, eventually it will be noticed that the relaxed length is longer than it used to be; that torque is just over the yield point of that particular bolt.

Doing it in stages will alter the final result,  the install procedure says  do it in one swing for a reason.

[rabbit_tdi]

Definitely, when installing the head and torquing the bolts, do it in one continuous swing.

The paragraph you quoted, is where I was describing a test procedure to be done on the workbench!  After which the bolts are scrap.