Short Block Rebuild Qs

[PwrWgn]

I'm tearing down a 2.7T soon with the intention to do a basic deglaze/hone, re-ring, and perhaps rods.

Looking for advice on a few things:

1) Main bearing clearance checks and main bolts. A machinist/engine builder who I've used a couple times, and who is familiar w/ these motors, has told me that in order to properly check the main bearing clearances I will basically need to sacrifice an entire set of main bolts. In his words, we would need to install the new bearings, torque-to-yield a new set of bolts, remove it all to check the plastigauge, then (assuming clearances are good) reinstall everything with another new set of main bolts. This sounds insane to me. Those of you who have not used studs know that the Original main bolts are very expensive and some are hard to source. This procedure would cost $500+ in main bolts alone.

Unfortunately the Audi service literature does not provide any torque guidance when measuring main bearing clearance on the APB/BEL. The ASJ/AZR book does specify a lower torque for checking main bearing clearances (that does not yield the bolts), but that is of course an RS4 engine and crank/mains are different - but perhaps bolts and bearings are the same.

I'm curious about the torque factory main studs that supposedly do not require oil pan/pump mods - but this is definitely overkill for my needs.

2) Main & rod bearings. This same engine builder says that he has seen lots of variation in Glyco bearing quality. I was planning to use Kolbenschmidt bearings (avail on eBay), but has anyone had bad clearance checks with the Glycos?

3) Piston Rings. Anyone have a flavor they recommend? I prefer Mahle if given the option, but have heard of counterfeits and so hesistant. Seems like Goetze is the most common.

4) Engine block paint. I plan to refinish the block with a basic black semi-gloss or gloss paint. Does anyone have a recommendation for paint that has worked well for them before? Is primer a good idea?
I'm looking at using the following (a little pricey but don't need much): https://www.eastwood.com/2k-aerospra...oss-black.html


Thanks in advance for any info.

[wstpride92]

I used the Torque factory main studs for my build and they seemed to work great. I haven't put the pan on yet but there shouldn't be any clearance issues.As for painting the block.I used the POR15 engine enamel paint. It gives the engine a very high gloss. Looks good, hopefully it last a while. You can look at my build thread to see some pics. I still have a ways to go though.

[JustManson]

Perfect timing.

I’m in the same boat and completely green to this type of work.

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[CELison]

1. I would just get studs and be done with it. No line hone needed. Then when you blow this motor up you can reuse them.

2. Never had any issue or heard of any issues with Gylco

3. I used Goetze in my last motor and Mahle in this one. Neither burned oil and both had/have great compression.

4. Can’t speak to this, mine had flawless oem black paint since the motor sat for almost 15 years in a shop.

[Silverex]

1) I used my old TTY main bolts for checking clearances then used new TTY hardware for final assembly. If your machinist is using a plastic gauge to check clearances I would find another shop, dial bore gauge and a mic is the correct way.

2) I used glyco rod and main bearings and there was very very little variation in the bearings. Actually wouldn’t have mind to have a few with more variations so I could mix and match bearings to get my desired clearances

3) I used the grant rings gapped on larger side and burn no oil 40k/3yrs later with great compression

4) Dont worry as much with what engine paint you use as much as the prep. I spent a lot of time with wire brushes, power washer, then final clean with acetone and went to town with some auto parts engine spray paint and it’s held up pretty well.

I got a decent amount of pictures of my engine assembly in my build thread if you have any questions feel free to Dm me.

[ss4]

-The Torque-Factory main studs are cheaper than stock and have zero fitment issues. Can be used multiple times (torqued and re-torqued). Your engine builder is technically correct about the stock hardware as crazy as it sounds since the factory main hardware is single use, just like the head bolts.
-I used all Glyco brand bearings and Goetze rings on stock pistons with Maxpeeding rods
Very light “cleanup” hone and had the mains checked and align honed with the new main studs.
-I used a basic rattle can engine block paint but like others mentioned, make sure it’s clean and the paint will stick good.

[PwrWgn]

Thanks all for the responses. Valuable info.

Things are continuing to come together (apart, really) for the block rebuild. I tore it all the way down and left it at the machinist for a hot tank and inspection. They have a Magnaflux rig there so I figured what the heck - but I can't imagine them finding any real problems as it's a ~130k mileage block from an 05 Allroad.

Questions again:

1) Assuming the block looks good I intend to have them do a basic brush hone or "de-glaze" on the cylinders. I assume this is standard procedure? I want to keep bore stock with original pistons.

+ a couple go-backs on my questions from earlier:

2) Glad to hear I don't need to throw a whole set of new TTY bolts away. I may go for studs, but I honestly don't want or plan to make crazy power with this engine. I'd really like to just have a healthy bottom end that can handle K04s on pump gas (which we only get 92 up here anyways). This is the same setup I've run for years now on the stock bottom end and find that power level very suitable.

Regarding bearing measurements and clearances: Is Plasti-gage really all that bad? I've been looking at a couple different links (here and here) and it seems like the "performance" or "blueprinted" engine route would be to use a dial bore gauge and then mix and match bearings to get desired clearances. The problem with that approach is that the bearings all come in a set (STD size) and I really can't purchase individual bearings up/down sized for this engine like it's a SBC or something. So although I do believe it may be possible to mix/match bearings within a given set - has anyone actually gone to that extent when putting their 2.7T block back together?

Further - is the recommendation to use a dial-bore gauge and mix/matching bearings on both Rod and Main bearings?

3) One final question: I'm on the fence about upgraded rods. It seems like a no-brainer or "while you're in there" type item, even if my initial plans are just to stick with K04s. If I DO stick with the stock rods, I assume they would need new bolts, but would they also need new bushings to be installed? The fit seems pretty good, but this is a one-time thing and I'm not going to tear it all down later because I need to re-bush my stock rods.

Seems like having to buy new stock bolts and re-bush the rods would tip the scales towards just pushing forward with upgraded rods...even if that would require re-balancing of everything.

Thanks!

[Silverex]

Plastic gauge just arnt that accurate and I don’t know of any machine shop that uses it for measurements. They are really for the DIY guy in his garage so if your machinist doesn’t have a decent dial bore gauge find another. Other than having more accuracy the dial bore gauge is also used to make sure the journals and bores aren’t out of round, have tapered, etc. which isn’t possible to check with plastic gauge.

The standard Glycol bearings do have a slight variation so you might swap some shells to hit your specs.

IMO I’d definitely throw some rods in there while it’s apart won’t be much more that getting new bolts/bushings

[CELison]

For sure toss rods in it. Guys have done rods only and had them run great for 10s of thousands of miles at high power levels. No machining, no new rings, sometimes no new bearings.

[Silverex]

For sure toss rods in it. Guys have done rods only and had them run great for 10s of thousands of miles at high power levels. No machining, no new rings, sometimes no new bearings.

I know guys have reused the main bearings and ring but reusing the rod bearings in new rods seems sketchy to me….guys have really done that with longevity?

[CELison]

I know guys have reused the main bearings and ring but reusing the rod bearings in new rods seems sketchy to me….guys have really done that with longevity?

eh, maybe they tossed new rod bearings in and just kept the mains since they never had to take the crank out. That being said, these are b5s, so I'm sure guys have re-used rod bearings.

[PwrWgn]

Seeking some more wisdom:

1) Block coolant feeds 035103111B. Anyone remove and replace these? Purchase new? If either yes, how did you install them? I recall a Phillip Kaess vid where his former engine builder installed these with some type of sealant, like RTV or something. I don't recall any info on these in the service literature. May seem silly to bother, but when you've literally removed every other piece from the block it does beg to question why not go all the way. Similar question for the N0119034 plugs (kind of like freeze/core plugs in several places on the block).

Note I've had the block hot tanked and honed now, so I figure any former sealants would be compromised by now.

2) Balancing. I'm ordering new rods and wondering if any others have had balancing done on these rotating assemblies could share their experience. Hopefully pretty simple process.

3) Does anyone know why the 2.7T has 2 different rod bearing parts? 078105701JGLB vs 078105701NGLB, I noticed the upper (JGLB) is a lighter shade than the lower, I assume this is because it is under greater pressures and has an extra coating. I also noticed that the uppers are VERY affordable from Audi directly right now, like $10 each so ~$100 for a full set of OE rod bearings. To that end, would anyone see an issue with using only uppers in a build since they are on super sale? Lowers are still your typical Audi BS prices ($50+ per shell). I assume they are symmetrical because aftermarket sets (Glyco, KS, etc) do not distinguish between upper and lower.

Note I've ordered up a set of rod, main, and thrust bearings from the following site: https://www.cs-parts.de/Audi. Shipping took about 2 weeks, but they have a GREAT selection of quality brands for 2.7 engine parts. I was looking for Kolbenschmidt bearings specifically (don't ask me why, just wanted to try them).

I think that's all for now, assembly is starting pretty soon so I'll see if I can share some pictures of the process.

Thanks.

[Silverex]

Seeking some more wisdom:

1) Block coolant feeds 035103111B. Anyone remove and replace these? Purchase new? If either yes, how did you install them? I recall a Phillip Kaess vid where his former engine builder installed these with some type of sealant, like RTV or something. I don't recall any info on these in the service literature. May seem silly to bother, but when you've literally removed every other piece from the block it does beg to question why not go all the way. Similar question for the N0119034 plugs (kind of like freeze/core plugs in several places on the block).

Note I've had the block hot tanked and honed now, so I figure any former sealants would be compromised by now.

2) Balancing. I'm ordering new rods and wondering if any others have had balancing done on these rotating assemblies could share their experience. Hopefully pretty simple process.

3) Does anyone know why the 2.7T has 2 different rod bearing parts? 078105701JGLB vs 078105701NGLB, I noticed the upper (JGLB) is a lighter shade than the lower, I assume this is because it is under greater pressures and has an extra coating. I also noticed that the uppers are VERY affordable from Audi directly right now, like $10 each so ~$100 for a full set of OE rod bearings. To that end, would anyone see an issue with using only uppers in a build since they are on super sale? Lowers are still your typical Audi BS prices ($50+ per shell). I assume they are symmetrical because aftermarket sets (Glyco, KS, etc) do not distinguish between upper and lower.

Note I've ordered up a set of rod, main, and thrust bearings from the following site: https://www.cs-parts.de/Audi. Shipping took about 2 weeks, but they have a GREAT selection of quality brands for 2.7 engine parts. I was looking for Kolbenschmidt bearings specifically (don't ask me why, just wanted to try them).

I think that's all for now, assembly is starting pretty soon so I'll see if I can share some pictures of the process.

Thanks.

1) I was thinking of pulling them also, but ended up leaving the block coolant feeds in. The freeze plugs in heads i replaced since I mixed the heads up. One of them I kinda messed up the install and had a very slight leak. When I replaced that one I used alil rtv around it and have had no issues since.

2) had mine balance and very straight forward process, dropped everything off at machine shop and picked up when finished

3) Rod bearings are symmetrical. Per Audi the uppers are a 2-material bearing and bottoms are 3-material for higher load capacity. I assume it’s just a coating difference also.

No first hand experience but kolbenschmidt bearings do look nice and seem to have a good rep. That site is great!!! One thing they had I’ve never seen before was a full gasket kit for these engines.....also looks like it includes a gaskets for upper oil pan

[PwrWgn]

1) I was thinking of pulling them also, but ended up leaving the block coolant feeds in. The freeze plugs in heads i replaced since I mixed the heads up. One of them I kinda messed up the install and had a very slight leak. When I replaced that one I used alil rtv around it and have had no issues since.

2) had mine balance and very straight forward process, dropped everything off at machine shop and picked up when finished

3) Rod bearings are symmetrical. Per Audi the uppers are a 2-material bearing and bottoms are 3-material for higher load capacity. I assume it’s just a coating difference also.

No first hand experience but kolbenschmidt bearings do look nice and seem to have a good rep. That site is great!!! One thing they had I’ve never seen before was a full gasket kit for these engines.....also looks like it includes a gaskets for upper oil pan

Thanks for the responses.

I'll note that the UPPER rod bearings are the parts that should see the most force in the engine. It is interesting that they use a 2-material bearing at this location, I suppose it can somehow handle more abuse (higher loads) than the 3-material bearing.

Yea neat website especially certain things on there (like valve guides and KS or Mahle piston rings) that I haven't been able to find anywhere else.

[RMode]

Bi metal bearings are often used by OEM's because they are a bit more forgiving to machining intolerances of the parts they interact with, and can help push out debris, so the filter can do it's job better. This let's them use the bearings to arrive at the proper oil clearance, rather than the machining of the parts. They are ultimately harder than Tri's. Tri metal is less forgiving in this way for typical street applications. They are really designed by the OE's ultimately to have an infinite service life so long as oil change intervals are kept and the right spec oil is being used. Then you get into the great equalizer of all performance areas - bi's are cheaper to make than tri's

Trimetal is also not meant to be a one set, one time type thing - meaning at some point much sooner than bi metal, they wear down, and get replaced.

[heindls4]

I know this is super old but hoping to get a question answered. I just installed new bearings with new thrust washers. I did everything to spec and it feels great, no play and spins beautifully. I am about to install the rods and pistons notice the thrust washer has some movement and I am not sure if this is normal or not. I cannot find any information anywhere but my guess is once its fully assembled the bearing will be tight but I am not sure trying to confirm now rather than later.