Cam bearing Reengineering for PD motors

Frank; Nice write-up and explanation. You filled in many blank pieces of the puzzle and explained it clearly and concisely. Thank you

If concerns exists about start-up wear, a pre-luber should resolve that.

Small drill - high speed

Drilling with a 7/64" drill, start the hole by drilling straight into the bearing cam cap for about 1/16". WARNING! THIS IS A SMALL DIAMETER DRILL PRONE TO BREAKAGE! Work slowly and carefully.

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Work slowly may lead some to turn the drill at low speed. For a 7/64" drill you need around 3000 rpm to get a good cut. The trick is not to press the drill too hard (this is where slowly and carefully come in). Patience is needed along with spare drills if you push too hard .

Franko6

Have you done inspections of the bearings after this mod at some point to see results? Are there pictures? How do you know this changes things as your theroy suggests? It sounds good and reasonable. I may even step back into an 06 if this works well.

Yea. Too bad VW are such weasels. Otherwise they'd offer their opinion. But no, according to them there's no problem, snafu.

Lightflyer1 said:

Franko6

Have you done inspections of the bearings after this mod at some point to see results? Are there pictures? How do you know this changes things as your theroy suggests? It sounds good and reasonable. I may even step back into an 06 if this works well.

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Sticky?

Very nice Frank!

Thanks Frank, i would be ready to purchase a set, when you get there..

I hear you on the projects liosts, I am down to project #295...

Dave, jumped ship too quick??

Mach1 said:

Dave, jumped ship too quick??

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I will PM you.

Franko6
Given some of the devlopment costs and we are still in the Mark I phase of this mod. Have you compiled any costs for the modifications and replacing the Cam? Just want to know how much fun I have to postpone to have this done. This is akin to Russian roulette, worst case find a used head for the Mark II mod or live happily ever after. Currently using Mobil 1 ESP with 2oz ZDDP+

Good idea Frank!

RichOxfordBlue wrote: " Patience is needed along with spare drills if you push too hard ."

Yes, I don't mean slow drill speed. I fast drill, but don't push the drill too hard or it will break.

Also, the drill point should not be as much chisel angle. Most drills are cut with a rake intended for steel. Aluminum drilling should be done with a drill with a 60-70 degree rake angle. It won't dig in as bad or catch when the drill breaks through the bottom of the hole.

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hi frank06 whats your opinion on my PD cam

I need a better pic to really tell, but it looks like you have the typical cam lobe wear on #4. Post up a better pic.

cheers for reply frank.. i was going too remove cam for better inspection. but unsure what is involed???

If I had the cam removed, I wouldn't put the old stuff back there again...

Franko6 said:

Looking at the available room and support, I believe that a thicker and wider bearing shell would be a benefit. Getting custom bearing shells rolled, even at the ridiculous price VAG sells them for is a problem. The setup for boring the oversize shells in not an 'off the shelf' project. I'm still looking into that.

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Frank there is a thread on a V-Rod forum that I belong to. Crank bearing bore is out of round, he's going to bore it bigger and get some bearings made. I asked him for the info on the manufacture, when I get it I can pass it on to you if you would like it.

Frank; Do you have any thoughts about (any of the various aftermarket surface) treating any, or all, of the parts prior to re-install? Help? Hurt? Waste of Money?

I think this approach will yield some more oil where there needs to be some, but the underlying issue is cam loading from the injector.

I wish I had a BRM cyl head and some time, I'd like to machine (line bore) the cam bearing bores 1/4 inch larger in order to place some hard steel backer shells under the stock bearings. I'd also make some billet caps and use studs instead of TTY bolts in that location. It's not THAT much work to improve this crappy design, but the end doesn't justify the means here. Lipstick on a pig, imo..

I also like the idea of surface treating on the bearings and the cam bearing journals.

I'd like to know how much the head is flexing under loads and how much the cam deflects too.

But I also think doing anything to this engine is like a DuPont overhaul of the real issue, and no amount of bearing grinding and slotting or drilling more oil feed holes will do much to help.

Until loads - both belt tension, and injector - block and head flexing, and uneven oiling are addressed, this is a POS design with no hope of improvement worth the effort. Trade it and get a CBEA Common Rail. More power, cleaner, better or equal mileage, quieter, and without the mechanical injection.

Leave this kind of direct injection to the Caterpillar engine folks who know how to make them bulletproof.

Rod Bearing said:

I think this approach will yield some more oil where there needs to be some, but the underlying issue is cam loading from the injector.

I wish I had a BRM cyl head and some time, I'd like to machine (line bore) the cam bearing bores 1/4 inch larger in order to place some hard steel backer shells under the stock bearings. I'd also make some billet caps and use studs instead of TTY bolts in that location. It's not THAT much work to improve this crappy design, but the end doesn't justify the means here. Lipstick on a pig, imo..

I also like the idea of surface treating on the bearings and the cam bearing journals.

I'd like to know how much the head is flexing under loads and how much the cam deflects too.

But I also think doing anything to this engine is like a DuPont overhaul of the real issue, and no amount of bearing grinding and slotting or drilling more oil feed holes will do much to help.

Until loads - both belt tension, and injector - block and head flexing, and uneven oiling are addressed, this is a POS design with no hope of improvement worth the effort. Trade it and get a CBEA Common Rail. More power, cleaner, better or equal mileage, quieter, and without the mechanical injection.

Leave this kind of direct injection to the Caterpillar engine folks who know how to make them bulletproof.

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Rod, I like your stud idea, easy enough to perform...

I already dump the TTY's when I do work, especially the mounts..Of course its up to the customer to make the call..I advise--they decide...

I absolutely agree with the thicker shell. I don't think the head is walking and flexing. I think it's heating... well, I guess in that case, it's walking and flexing... but not from insufficient stiffness...imo.

Rod Bearing said:

I think this approach will yield some more oil where there needs to be some, but the underlying issue is cam loading from the injector.

I wish I had a BRM cyl head and some time, I'd like to machine (line bore) the cam bearing bores 1/4 inch larger in order to place some hard steel backer shells under the stock bearings. I'd also make some billet caps and use studs instead of TTY bolts in that location. It's not THAT much work to improve this crappy design, but the end doesn't justify the means here. Lipstick on a pig, imo..

I also like the idea of surface treating on the bearings and the cam bearing journals.

I'd like to know how much the head is flexing under loads and how much the cam deflects too.

But I also think doing anything to this engine is like a DuPont overhaul of the real issue, and no amount of bearing grinding and slotting or drilling more oil feed holes will do much to help.

Until loads - both belt tension, and injector - block and head flexing, and uneven oiling are addressed, this is a POS design with no hope of improvement worth the effort. Trade it and get a CBEA Common Rail. More power, cleaner, better or equal mileage, quieter, and without the mechanical injection.

Leave this kind of direct injection to the Caterpillar engine folks who know how to make them bulletproof.

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I too agree with the bearing support shells.. I think that alone will solve alot of the bearing problems.

Iam no expert just a though, If the TTY's bolts reach there plastic phase due to long time of constant load. They only strech a couple of thousand of inch, Mabey the bolts reach this state to early in the bolts life do the the heavy load from the injectors and TB creats to much heat. Mabey that heat breaks down the material that bolt made of. Change to studs is a good idea. If you think this is in left feild and I will not get offened.

Here's the info on the bearing manufacture Frank incase you wanted it.


"GMO"
Postal Address:
Gleitlager und Metallverarbeitung GmbH Osterwieck
Ziegeleiweg 3
38835 Osterwieck
Germany
phone: + 49 (0)39421/770-29 and -30
Fax: +49 (0)39421/770-31
Point of contact: Mr Doeppelheuer
http://www.gmo-gleitlager.de/
e-Mail: GMO-Gleitlager@t-online.de

Quote:
...The manufacture is focussed on plain bearings for combustion engines, compressors, pumps, gearings, vehicles, hydraulic systems, transport systems, textile machinery and other applications.

It is a great advantage for our customers that the products can be manufactured in small piece numbers at reasonable prices. This is why it is also possible to manufacture plain bearings for oldtimers. Furthermore, diverse vendor parts for the construction of cars and vehicles as well as for machine building, rotationally symmetric parts, castings and punched parts for your specific applications are manufactured.

Permanent quality checks ensure that all products leaving our company meet highest quality standards. Our company has adopted a quality system according to the standard DIN EN ISO 9001, 8.94....

Frank, what are your thoughts on doing the mod to all the caps, but not the #1 journal on a car that has less than 20k on it and shows no wear yet. (dont want to pull the cam and t-belt etc yet....

Nic, Am I understanding your post correctly that the company you posted is currently manufacturing oversized bearings for PD cams?

nic_a_bod said:

Here's the info on the bearing manufacture Frank incase you wanted it. The company producing the new oversized main bearings is: "GMO".....

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Bob S. said:

Nic, Am I understanding your post correctly that the company you posted is currently manufacturing oversized bearings for PD cams?

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I don't know if they are or have, but they can make them though if they haven't. I will edit the post so people don't get confused, I copied and pasted it from another forum, it's referring to main bearings for a vrod.

oldpoopie said:

Frank, what are your thoughts on doing the mod to all the caps, but not the #1 journal on a car that has less than 20k on it and shows no wear yet. (dont want to pull the cam and t-belt etc yet....

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Justin,

I'm thinking you wouldn't be hurting anything to do a preemptive strike. Actually, the #1 bearing usually shows the least amount of damage in this cam circuit.

While in Marty Bergell's GTG Saturday, I ran the PD bearing cap mod by a lot of people. One person in particular had just gotten an 06 Jetta with a few thousand over 100k. The cam on #3 exhaust had the typical wear patterning.

Because the individual only had a partial timing belt done, the idea of doing the cam mod seemed quite appropriate and to see how it would go, the thought was to do just the cam bearings and bolts with the mod. Let the cam try to sort itself out. I am dubious about the outcome.

Another conversation with Whitebread, Keith Blakemore and sorry, I can't remember the other folks, was to possibly not use the TTY bolts for the camshaft caps. Some people have replace rocker bolts with studs. I'm not sure about that, but one thing is for sure. Not having the TTY bolts would cause less inhibition to get into your cam circuit.

Particularly, to use TTY bolts on the cam caps is quite absurd. Since the cam force is downward onto the cam saddle and not upwards on the cap, I see no reason to use the expensive TTY bolts for the cam. You can make an excuse for the rocker bolts, as the force is upward from the rocker shaft. However, that would be each individual's choice. I expect I will stock an alternative bolt in a 12.9 hardness for the cam and the studs for the rocker shafts.

I'm all for non-TTY bolts and studs.

Could you not eliminate the need for drilling the caps/head by just dremeling a groove from the lower bearing oil slot up towards the 2 o'clock position?