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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: MikkiJayne on August 30, 2007, 04:26:45 am

Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on August 30, 2007, 04:26:45 am
Hi everyone,

Well I'm about to undertake a total rebuild of my AHU after pulling the crank to fix the pulley wobble and discovering the bearings were worn out.

So the plan at the moment is to fit .216 nozzles (from dieselvw.com), ARP studs, and standard rings.

I'm wondering if there is anything else I could / should do while it's in bits? I'm aiming for 180-200bhp and 300-350lb/ft long term.

Oh, and should I do anything to the injection pump at 146K miles? It was running fine before, and isn't leaking so I'm inclined to leave that well alone  :wink:

Any suggestions welcome  :)

Mikki x
Title: Rebuilding AHU - any tips for power or longevity?
Post by: jtanguay on August 30, 2007, 01:02:34 pm
get some total seal rings.  i've installed them on my tdi block.  hillfolk'r and andy2 have them and they report NO blowby!!!  very good if you want to run high boost levels to reach your HP goal.

of course std rings will last you a year or so before the ring gap increases enough to give you significant blowby, but why settle for that when you can go near zero blowby for a full 100-200'000km? :)

a bit pricey after the whole UPS customs ordeal, but i'm sure it will pay off in the long run.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on August 30, 2007, 01:15:21 pm
Mmm I was contemplating them, but have had mixed reports from other users of them, particularly relating to them being difficult to bed in.

My block will be professionally honed, and will be going in a daily driver so I need something that will settle very quickly. Is there any special requirement for honing for these rings?

Cost is an issue too - they aren't cheap over here!

Thanks,

Mikki x
Title: Rebuilding AHU - any tips for power or longevity?
Post by: jtanguay on August 31, 2007, 01:33:36 pm
Quote from: "MikkiJayne"
Mmm I was contemplating them, but have had mixed reports from other users of them, particularly relating to them being difficult to bed in.

My block will be professionally honed, and will be going in a daily driver so I need something that will settle very quickly. Is there any special requirement for honing for these rings?

Cost is an issue too - they aren't cheap over here!

Thanks,

Mikki x


pretty sure honing procedure is the same.  but you should buy their quickseat dry lube.  makes the cyl walls turn green... helps the rings seat fairly quickly.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on September 03, 2007, 09:16:36 am
No other suggestions?
Title: Rebuilding AHU - any tips for power or longevity?
Post by: jtanguay on September 03, 2007, 12:29:02 pm
so you're saying you had the crank wobble on an AHU?  that seems very odd... the alternator should be one way, to reduce the shock load on the crank.  check and make sure that your alternator has the one way pulley.
if it doesn't, then put that on your buy list.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on September 03, 2007, 02:01:52 pm
The engine didn't come with an alternator so I have no idea what it had originally. A one way pulley is on my shopping list tho.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on September 11, 2007, 03:25:14 pm
Back up again...

Does anyone have any recommendations on where to get ARP studs and Total Seal rings in the US please? They're too damn expensive here so I'll buy 'em in the US and have a friend ship 'em over  :wink:

Thanks!
Title: Rebuilding AHU - any tips for power or longevity?
Post by: Slave2School on September 11, 2007, 03:53:43 pm
summit racing sells studs as well (ford cosworth kit is installed in my car).
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on September 11, 2007, 04:36:59 pm
Got 'em thanks  :D

Less in $ than in £! We get ripped off for everything  :mad:
Title: Rebuilding AHU - any tips for power or longevity?
Post by: hillfolk'r on September 11, 2007, 05:28:21 pm
Quote from: "MikkiJayne"
No other suggestions?

yea....when i got my "total seal" rings,they werent  made by total seal

they had me buy oem(goetze) rings and send them to total seal to be modified into gapless(they were impressed by the oem quality,and figured why mess with a good thing)

it cost about 20$ a hole to mod the rings,and yea use their dry film lube on the cyls(cost shipped was 125$ to mod the rings,and extra goodies,this is on top of the cost of the oem rings)

when you fire it up,let it idle long enough to get oil psi,then hold the revs at 1500-2000 rpms,every once in a while blipping the throttle hard up to 3000 to load+seat the rings
let it run about 15 mins like this,then get it out+drive it

dont sit there running it more than needed,without loading it by driving
my bores measured out good,i used a "dingleberry" hone (approx 280-320grit) and got a nice crosshatch
try practicing  on an old block if you can
i found that my 18v dewalt on low,and moving up+down 1 complete stroke a second gave me a nice crosshatch
im also running kermas race 520s
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on September 12, 2007, 03:30:10 am
Interesting...

I found the rings listed on their website part number S9205 (can't link to it but you can search on the part number), and also found that number on Summit as TSR-S9205 for $117. There's nothing saying they need a donor ring to make them  :?

I'm planning on buying the full set from Techtonics. I don't know what make they are but I assume they'll be pretty good from them. I was just expecting to throw the 2nd ring away if I get the Total Seals as well...

I'm getting the block profesionally honed by an engine shop, although from your description their tool sounds like the same thing you used.

Edit: I just spoke to Total Seal's main distributor in the UK and in fact they supply a full set of rings with gapless 2nd, rather than just the 2nd as I was expecting. It is also common for them to modify existing rings when the rings are already supplied with new pistons which makes sense.
Price for a full set is only £70 ($140) which is much more reasonable than I expected, and only £30 ($60) more than the standard ring set I was going to get from TT.
Very pleased  :D

Mikki x
Title: Rebuilding AHU - any tips for power or longevity?
Post by: Bojje on November 06, 2007, 04:47:12 am
I've heard that the ARP studs should be avoided on TDI's because the head lifts according to people on tdiclub.com

Stock studs work great. One dude's running stock studs and 258 bhp without any problems.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: jtanguay on November 06, 2007, 01:12:35 pm
Quote from: "Bojje"
I've heard that the ARP studs should be avoided on TDI's because the head lifts according to people on tdiclub.com

Stock studs work great. One dude's running stock studs and 258 bhp without any problems.


well if the heads lift, wouldn't that give a good hg leak?
Title: Rebuilding AHU - any tips for power or longevity?
Post by: Bojje on November 06, 2007, 01:19:09 pm
Quote from: "jtanguay"
Quote from: "Bojje"
I've heard that the ARP studs should be avoided on TDI's because the head lifts according to people on tdiclub.com

Stock studs work great. One dude's running stock studs and 258 bhp without any problems.


well if the heads lift, wouldn't that give a good hg leak?


Well that's why he should avoid them...

I have no personal experince of the studs on TDI engines, but that's what I've read on tdiclub.com. The stock ones seem to work well to so there's no idea changing them.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: jtanguay on November 06, 2007, 01:24:35 pm
Quote from: "Bojje"
Quote from: "jtanguay"
Quote from: "Bojje"
I've heard that the ARP studs should be avoided on TDI's because the head lifts according to people on tdiclub.com

Stock studs work great. One dude's running stock studs and 258 bhp without any problems.


well if the heads lift, wouldn't that give a good hg leak?


Well that's why he should avoid them...

I have no personal experince of the studs on TDI engines, but that's what I've read on tdiclub.com. The stock ones seem to work well to so there's no idea changing them.


i don't get it... if the head is lifting, then there would be a hg leak.  if the head doesn't lift, then no hg leak right?  with the studs there would be no hg leak since the head wouldn't lift?

now if you're talking about some distortion (allowing the head to flex, etc but holding the pressures) and that the studs do not allow this distortion which could lead to head cracking, then that sort of makes sense.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on November 06, 2007, 01:45:23 pm
I read a thread on here or TDIclub where a bunch of people running ARP studs were reporting improved mpg and were very pleased with them. The installation procedure is quite different for the studs compared to stock bolts - maybe people aren't torquing the studs properly?

I like the idea of reusable studs since I will be tinkering with this engine a lot when I get in to it. I also don't fancy paying stealership prices for bolts every time I take it apart! Two sets of bolts is more than one set of ARP studs  :shock:

Mikki x
Title: Rebuilding AHU - any tips for power or longevity?
Post by: RabbitGTDguy on November 06, 2007, 03:02:37 pm
Quote from: "Bojje"
I've heard that the ARP studs should be avoided on TDI's because the head lifts according to people on tdiclub.com


I'd be interested in reading that and also seeing how those people went through the installation procedure for the studs as well. Studs have been tested by time (not to mention the advances in metalugy and fastener technology) and are significantly better than stock. Studs actually by design would elmiinate head lift and prevent HG failure...especially under modified levels (such as more fuel, boost, etc.). Stock will do the opposite, as they are designed to stretch

Quote from: "Bojje"
Stock studs work great. One dude's running stock studs and 258 bhp without any problems.

Stock TDI motors...not a one that I can think of have "studs" as mentioned here. Stock TDI motors run head bolts...not studs. I might have to venture over to TDIclub and search out information on the above. Its weird...every motor that I have had with stock factory "stretch" bolts has eaten a headgasket...every time since I've had that happen (believe it was twice), I always build with studs now and have NEVER had a headgasket go.

Joe
Title: Rebuilding AHU - any tips for power or longevity?
Post by: jtanguay on November 06, 2007, 10:22:50 pm
good to hear some positives about studs... starting to make me question my decision of using studs   :o
Title: Rebuilding AHU - any tips for power or longevity?
Post by: Bojje on November 07, 2007, 06:55:42 am
Quote from: "jtanguay"
good to hear some positives about studs... starting to make me question my decision of using studs   :o


Well i guess the other ones are right, I'm probably wrong. I've mixed up something I think.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: Bojje on November 09, 2007, 01:25:57 pm
"There was a discussion about head bolts (e.g. ARP, Raceware) at tdiclub.com and a handful of owners saw headgasket leaks after only tens of thousand KMs or miles. And many of these TDIs are not big-power ones either. It could be that they neglected to inspect & re-tighten the head bolts after every xxx km, but some of them are quite experienced TDI mechanics."
Title: Rebuilding AHU - any tips for power or longevity?
Post by: MikkiJayne on November 09, 2007, 01:37:46 pm
Mm I saw that too. Interesting that the two forums have completely differing opinions on this.
Title: Rebuilding AHU - any tips for power or longevity?
Post by: RabbitGTDguy on November 09, 2007, 04:09:47 pm
very interesting...

I can cite several good reference sources stating how much better studs are vs. bolts at "keeping things together" and preventing the "lift" that these TDIClub members are citing.

Once ref. I can think of off the top of my head...and I believe a pretty close to direct quote...lol...Corky Bells book on building/design of turbocharged system entitled "Maximum Boost".

"Studs are a engineers choice, bolts are an accountants..."

Or something very close to along those lines. Just count the number of people that have gone farther away from even just head bolts and installed not only head studs...but also studs for mains as well.
As much as their may be some "negative" opinions on TDIClub regarding studs...I can gurantee you that a good number of the people that I know on this and the other side of the pond...every one is using studs...and some have even gone the next step attacking the bottom end hardware (though...more so than head studs...there are some REALLY horrible stories about the use of aftermarket *ARP* and similar rod hardware in both the gasser and diesel world).

I'll stand by what I say...
my 1.6 IDI TD formerly in the GTD...very nicely built...well fueled, some may remember the homemade propane injection (boost sensitive).... NEVER replaced a head gasket with studs installed...

I had two head gaskets on plain old NA motors go with stock hardware... both were 12mm heads (12mm head either IDI or TDI use the same size head bolts). Thats no boost...mildly tweaked fueling on one...nothing but stock on the other.

Same goes on the mTDI now ...no issues.

Importance moves to making sure they are installed correctly and "retorqued" as per the instructions...
Of course one huge nice thing as well on TDI's is the use of the metal headgasket vs. the fiber headgasket on the 1.6's...though many choose the route of the 1.9 AAZ metal gasket to solve that problem as well.

I'll have to look around on TDIClub and see these comments... haven't visited much lately as there hasn't been much interesting going on there (waiting anxiously for the intake manifold shoot-out between PP's manifold, Kerma's (long or short...still to be decided?), and the stock PD and ALH manifolds)...

Joe
Title: Rebuilding AHU - any tips for power or longevity?
Post by: RabbitGTDguy on November 10, 2007, 04:38:11 am
Just to update...

The particular thread "to head stud or not to head stud" over at TDIclub  at http://forums.tdiclub.com/showthread.php?t=194804 doesn't discuss how "head studs" cause gasket failure or "head lift"...

Rather...it suggests that it may be better to leave stock bolts in to PREVENT rod failure by ALLOWING head lift... i.e. the head gasket will go and save the rods. Supposedly, the lesser of 2 evils...

I could go on with that for a while...but I have class this morning, need to do some reading...

Joe