Which PD crankshaft is the strongest?

[poor_passat]

Hi,

I planning on changing my BKC engine block to a BMM. Which crankshaft is better for high power applications (250-300hp), the BKC, or the BMM? As my knowledge, the BKC is small journal, but it is massive and better then the later BXE/BLS ones. The BMM is big journal, but is it weaker then the older ARL/AHU ones?

The question also stands for the conrods. BKC, BMM, or forged?

Thank you for your time and help!

 

[adamss24]

Hi, I have a caddy in the workshop with a snapped crankshaft, I believe it's a bxe or bls... I got a short block for the crank and indeed the crank is beefier- still small journal/big ends... I will use stock rods and pistons as head has been done a few years ago however this caddy stays stock. If you're planning on running get the larger crank with larger big ends and probably best to get a set of conrods- pd 150 or forged/aftermarket... Make sure they come with right ARP bolts as I knew a few with arp fake bolts that snapped in high power petrol applications...

 

[poor_passat]

Hi, I have a caddy in the workshop with a snapped crankshaft, I believe it's a bxe or bls... I got a short block for the crank and indeed the crank is beefier- still small journal/big ends... I will use stock rods and pistons as head has been done a few years ago however this caddy stays stock. If you're planning on running get the larger crank with larger big ends and probably best to get a set of conrods- pd 150 or forged/aftermarket... Make sure they come with right ARP bolts as I knew a few with arp fake bolts that snapped in high power petrol applications...

Hi!
Thank you for the input! My recent informations show that I will need a ARL/AHU crankshaft even if I get a 2.0 engine. I will not buy ARP bolts though, as the 12.9 ARL stock bolt seems to be more than enough for 300hp.

 

[adamss24]

I meant to get ARP rod bolts if you’re running high pcp, however pd150 rod bolts are plenty strong enough...

 

[adamss24]

Definitely upgrade head bolts though, I feel 12.9 ARL head bolts are not sufficient, I have head lift in my mk2 with gtb2260vk turbo and very aggressive tune...

 

[poor_passat]

I meant to get ARP rod bolts if you’re running high pcp, however pd150 rod bolts are plenty strong enough...

Sorry, what is PCP?

 

[adamss24]

Peak Cylinder Pressure...

 

[poor_passat]

Peak Cylinder Pressure...

Thanks I'm not sure what is high, but I'm gonna consider ordering a set of arp for the engine.

 

[adamss24]

PCP is a multiplication of boost with aggressive SOI and EOI... Basically as you advance timing and inject early, the cylinder pleasures increase massively which puts a lot of strain on head gasket and head bolts. You find out that boost hoses go hard and coolant spills from coolant header safety valve. In severe cases, coolant goes dark/ murky ! That's why going larger turbos and nozzles is beneficial as keeping injection windows as short as possible without detrimental fuel atomization drop...thus keeps EGT low as well and contributes to engine longevity at the same time ! I am however impressed how much abuse the pd130/150 engine can take, I am trying hard to break it so I can rebuild stronger but it doesn't want to let go !

 

[poor_passat]

I'm not the one tuning the ECU, but is a stock ECU and gtd2060 turbo, BJ injectors. Before I ran 2.0 bars of boost and it produced circ. 220HP. I had no issue with head lift, even with stock 10.9 bolts. Right now what I'm building, is a 2.0 block, so I might get away with 2.0-2.2 boost and more HP than previously, without increasing the stress on the engine significantly. They say 2.5 bar is achieveable with the 2060, but I'm not sure my injectros would put up with that without too long injection timing.

 

[poor_passat]

I was reading trough the forum today, and I'm really confused about using ARP head studs. Some ppl say, if I use ARPs, I should make the machine shop use a specificly designed torque plate while honing the cylinders, and surfacing the block. I'm not even sure, that they have a torque plate, but I hope On the other hand high power figures were achieved without ARP bolts, but I might want to buy oversized nozzles for that purpose, to optimal timing. I would not ask for agressive tune by the way, couse I'm need a reliable engine, for daily use.

 

[adamss24]

Having an aggressive tune isn't as bad as it seems, I use my cars for commuting 120-150 km daily from and to work, it's not funny if it breaks down in the middle of nowhere ! I have a host of gauges to keep tabs on the running of the engine: EGT, oil pressure, oil temp and bost ! Also mechanical sympathy plays a big, big role as knowing how to listen to sounds is a lifesaver however building the engine tough from the onset is the wisest approach !

 

[poor_passat]

But it is certainly not helping reliability. Again, I'm not really convinced, that ARP bolts are the way to go.

 

[MukGyver]

I have head lift in my mk2 with gtb2260vk turbo and very aggressive tune...

what are the indicators of head lift. Is one of them loss of some torque on the head bolts from bolt stretch? just curious how you guys know. thanks

 

[adamss24]

Having an aggressive tune isn't as bad as it seems, I use my cars for commuting 120-150 km daily from and to work, it's not funny if it breaks down in the middle of nowhere ! I have a host of gauges to keep tabs on the running of the engine: EGT, oil pressure, oil temp and bost ! Also mechanical sympathy plays a big, big role as knowing how to listen to sounds is a lifesaver however building the engine tough from the onset is the wisest approach !

 

[adamss24]

what are the indicators of head lift. Is one of them loss of some torque on the head bolts from bolt stretch? just curious how you guys know. thanks

I get hard coolant hoses and coolant spilling from header tank...

 

[Franko6]

I think when the trend to go from the 50.6 journal size to 53.7, and the pistons went from 79.44 to 80.96, then they also had a rather remarkable drop in CR, it sounds very plain to me, that the larger engine is aided by the larger rod journals.

When talking about rod bolts letting loose, I know that well, from past experience in big block V8 builds. That is why when designing the connecting rod, the use of 3/8" ARP, with the asymmetric bolt design was important. Yes, I hear it said, 'Go Big or go home.' A 3/8" bolt fits, so why not use it? Asymmetric bolts will cause greater thread contact throughout the rod cap's threads, for more even loading. It won't solve all the problems, but it sure takes care of that one.

 

[poor_passat]

I think when the trend to go from the 50.6 journal size to 53.7, and the pistons went from 79.44 to 80.96, then they also had a rather remarkable drop in CR, it sounds very plain to me, that the larger engine is aided by the larger rod journals.

When talking about rod bolts letting loose, I know that well, from past experience in big block V8 builds. That is why when designing the connecting rod, the use of 3/8" ARP, with the asymmetric bolt design was important. Yes, I hear it said, 'Go Big or go home.' A 3/8" bolt fits, so why not use it? Asymmetric bolts will cause greater thread contact throughout the rod cap's threads, for more even loading. It won't solve all the problems, but it sure takes care of that one.

Well big journal engines to my knowledge were all reduced CR, but in order to withstand higher boost. I went with ARL crankshaft, big journal both but more robust design then the BMM.

Also went with factory rods, no one really changing them, they seem to withstand reasonable boost, if the cylinders are not melting, they should be fine. Or at least that is what I heard.

 

[Franko6]

I prefer conventional rods instead of cracked rods. My opinion is that the reason many changes have been made, like cracked rods, is the bean counters are building your car. Cracked rods are 30% cheaper to produce. I-beams are also cheaper to produce.

When you 'pull out the stops' and make no excuses rods, what I think we have done is make a superior product. So, if someone applies 'unreasonable boost', at least I know the rod is going to make it. Estimate for top hp on our rod is 450. I think that will cover most situations. Or as we put it, "Built for a Battleship; Installed in a dinghy."

There have been two rods damaged by customers. The reason was the pistons on two engines split in two from runaway injectors and the top of the wrist pin rod end was flame cut. Although the rod was still structurally sound, we didn't think using it like that was a good idea.

The ARL and the BHW engines we pull cranks from are similar. 53.7mm rod journal. The difference is the thickness of the bearing shell. Not much, but I'm sure the crank was made with purpose.

 

[poor_passat]

I prefer conventional rods instead of cracked rods. My opinion is that the reason many changes have been made, like cracked rods, is the bean counters are building your car. Cracked rods are 30% cheaper to produce. I-beams are also cheaper to produce.

When you 'pull out the stops' and make no excuses rods, what I think we have done is make a superior product. So, if someone applies 'unreasonable boost', at least I know the rod is going to make it. Estimate for top hp on our rod is 450. I think that will cover most situations. Or as we put it, "Built for a Battleship; Installed in a dinghy."

There have been two rods damaged by customers. The reason was the pistons on two engines split in two from runaway injectors and the top of the wrist pin rod end was flame cut. Although the rod was still structurally sound, we didn't think using it like that was a good idea.

The ARL and the BHW engines we pull cranks from are similar. 53.7mm rod journal. The difference is the thickness of the bearing shell. Not much, but I'm sure the crank was made with purpose.

So you are saying, that ARL cranks and stock rods are a good choice?

 

[Franko6]

What I said is the cracked rods are cheaper. If the ARL crank has the 53.7main bearings, that's fine, as long as it has the proper setup for your crank sensor.

I know in the past I've been given some grief for my opinion. I prefer conventionally built rods. That is going to continue to be my opinion.

 

[poor_passat]

What I said is the cracked rods are cheaper. If the ARL crank has the 53.7main bearings, that's fine, as long as it has the proper setup for your crank sensor.

I know in the past I've been given some grief for my opinion. I prefer conventionally built rods. That is going to continue to be my opinion.

I have no information on if the rods are cracked or not. The question is, are they bulletproof? Indeed the ARL crank is 53.7, and the crank sensor will need to be fit on the outside of the block, not like in the ARL, but it's no problem.

 

[Franko6]

In order to make 'bullet-proof', we use our 53.7mm H-beam rods, 4340 material, conventionally built, with sputtered rod bearings. The rods have what some might think are oversize rod bolts, 3/8" 2000 series, made by ARP and are asymmetric, which is way cool for the aficionado. We have some interesting selections for the sputtered bearings that fit just about any of the rod journals for TDI's from '96 forward.

For the ALH we use a crank similar to our BHW, which has the 53.7mm rod journals and change out the crank sensor wheel. The later common rail version cranks, with rear main seal crank sensors, they can be adapted by either cutting a hole for the hall's sensor wiring, like in the BEW and BHW engines. I believe tuners know their way around that issue; going from crank sensor wheels to main seal sensors.

The pistons are usually the 80.96mm versions like the BHW, BMM, etc., although we do like 79.46mm ARL's; both choices are oil galley ported, keystone wrist pin, and have CR drops of 18.25 and if you go big, Crafters, 16.8. Be careful to check wall depth is no less than .200", especially when using the 81mm or 81.5 O.S. pistons. Some blocks should not be bored to 81mm. If I could get the EA288 wrist pins, I'd go for them, but Nural will not sell those nitrided wrist pins separate from the piston itself... ratz! I keep trying to find a good nitrided pin or someone who will make them for less than a small fortune. The extra slippery on the pins makes everything just a little bit better. As I am used to saying, everything is incremental.

Funny story... My rod designer had someone come to him with nitrided wrist pins, but it was the gold colored nitride, WHICH IS ABRASIVE!! That's great for things like drill bits and cutting tools. Before the engine got warmed up, the pins ate through the piston bushings.

Any 'bullet-proof' goes away when you install things like GTB 2260 or compound turbos, .360 Gibonta nozzles and 6,000 rpm tunes. Add that all together and you are going like a bat out of hell, which is fun, but has the life-expectancy of a barn fly.

And that is all I have to say about that...

 

[poor_passat]

Well, That might be more then I'm looking for, that is a race engine, I'm building a road car engine. My redline is just fine at near factory, power figures should be held within normal driving conditions. By bulletproof I mean long time reliabily at 2.0-2.5bar 250 Hp (gtd2060). This is a BMM engine, with the rear main seal crank sensors, and all the features you have listed.

So far many people have said, that factory rods are not failing if you don't melt the pistons (by failed injectros or really agressive timing). So I didn't buy H-beam rods, but if that should be a concern, I might not push it even that far.

 

[Franko6]

I really don't know how far the PD I-beams can be pushed. Don't really want to find out, as I think just because the manufacturing process is made by cracking the cap off of the rod, that makes be suspicious of the material. Yes, I know the cracking is done under extreme cold, which makes the material even more brittle. I wonder what happens with CrNiMO rods if you were to try cracking them. Would it work or would the material bend? That is the whole point of the 4340 H-beams; toughness.

When the European builders say 'only 250hp', and say that's not a race engine, I wonder what world they are living in. To get a 1 horsepower per pound of engine is A RACE ENGINE. When you can spin the wheels by just stomping the pedal in 4th gear (and sometimes 5th), that's a race engine. And I do not mean just because the same block that initially made 90 hp is now 110, 130, 150, 170hp, so, 2x hp does not mean you can double 170! At least not reliably. 340hp is for the weekend track star.

I'd also mention the Tiguan engine, 2.0 that has dual turbo, 240hp. Just because VW built it with that hp, does not mean it was intended to last. I've got a video of some of those engine's cylinder heads completely worn out at 80,000 km. That is not my idea of a competently built engine. It's the Anti-bulletproof engine. The high pressure fuel pump lobe has an inspection interval of 20,000 miles. So, every time you change your air filter, you have to inspect a crucial engine component?? You've got to be kidding! I think I could build another impressive improvement, just on that POS part.

I have to admit, going back to 1996, the TDI crank has tremendous appeal for me. It's journals look to me as big as the 289 Ford small block, which we felt we were making a monster engine when it had 300 hp from what is approximately a 3.9 liter engine. Sure, I'm talking gasoline and technology from the 60's, but that engine is almost double the displacement compared to the 2.0 TDI. (Oh, by the way, that 289 ended up being a stroker.. 302, reverse logic in today's world...) and then you expect to do more power from 1/2 the volume and not call it a race engine, there is a conclusion that is easy to reach. Life expectancy goes in the toilet.

It was one of the standards, even way back then, to build with the H-beam. But most people do not know or understand, bean-counters (accountants) are building your engine. Why I-beams? They are cheaper to stamp out in a forge. BANG! BANG! BANG! your done... Why Cracked Rods? Cracked rods are 30% cheaper to build. Why H-beams? Strength and torsional stability. I'd go head to head with any I-beam, because we built our rod to be 'bulletproof'. Bulletproof and cheap are not synonyms.

I know there is more capability from the 2.0 blocks, but only with a lot of determined care in building and a lot of thought to make that 'bullet proof'.

Some are gamblers and like to talk about the successful runs of luck. Problem is, whenever I have blown up an engine, it's wasn't 'bad luck'. It was R & D, testing the raw edge and learning the hard lessons.

So, if your attempt is to build structurally sound, the best thing is to build overkill or detune to safe levels. 2 of the 1.6 IDIs I owned managed to make 1.2 million miles (nearly 2,000,000km) between them. Neither one had 60 hp, and the only thing they could pass was a gas station. But you couldn't kill them. When I finally sold them, both engines, were still running and capable of nearly 60mpg. I just got sick of looking at them. Heh... I'd rather have my 165hp Passat 2.0 PD's comfort and power... not too much extra, but very sustainable for a lot of miles.

 

[adamss24]

Durable Engines nowadays are built of really tough parts: Carbon Graphite Iron for better granular structure, forged cranks, tough rods and sputter bearings. Take 2.0 CR engine for example, the bottom end is stout with strengthening ribs and can take 350 Bhp before touching the bottom end, one is limited by the injection and engine management system- its not that simple to make good/better flowing nozzles than factory !
The BMW 3.0 tdi is also breaking records as an "all alloy" engine block and is known to do 600bhp on straight fuel/no steroids ! Manufacturers are pushing the envelope but it costs the end user trough limited reliability !
The 240bhp passat engine also features brilliant head flow capabilities from the drawing board: it's hard to improve further when stakes are raised so high ! Also injection system is boasting 2500-2600 Bar of pressure- you can cut some metals easily with that high pressures so erosion is pronounced !
The only reason we can get 350 bhp from a pd engine is because the accountants didn't have the last say In the engine development and the bottom ends were built as designed. Later on vw did skimp on build quality: take 1.9 tdi engines that break cranks or rods that seize due to lack of wrist pin bronze bush ad break free trough the block...had a few like that in the workshop lately and in stock form-no tuning and under 250k km !
Also gearboxes are not able to survive the kind of torque abuse these engines output but every once in a while manufacturers do release a gearbox which can take a lot of pounding and then some: see hp8 gearbox, some dsg and the 01m 6 speed box... One has to realize that building competitive cars in today's market means lowering quality to the point that it becames too fragile or just about good enough for 100k ! Costs matter...

 

[poor_passat]

I really don't know how far the PD I-beams can be pushed. Don't really want to find out, as I think just because the manufacturing process is made by cracking the cap off of the rod, that makes be suspicious of the material. Yes, I know the cracking is done under extreme cold, which makes the material even more brittle. I wonder what happens with CrNiMO rods if you were to try cracking them. Would it work or would the material bend? That is the whole point of the 4340 H-beams; toughness.

When the European builders say 'only 250hp', and say that's not a race engine, I wonder what world they are living in. To get a 1 horsepower per pound of engine is A RACE ENGINE. When you can spin the wheels by just stomping the pedal in 4th gear (and sometimes 5th), that's a race engine. And I do not mean just because the same block that initially made 90 hp is now 110, 130, 150, 170hp, so, 2x hp does not mean you can double 170! At least not reliably. 340hp is for the weekend track star.

I'd also mention the Tiguan engine, 2.0 that has dual turbo, 240hp. Just because VW built it with that hp, does not mean it was intended to last. I've got a video of some of those engine's cylinder heads completely worn out at 80,000 km. That is not my idea of a competently built engine. It's the Anti-bulletproof engine. The high pressure fuel pump lobe has an inspection interval of 20,000 miles. So, every time you change your air filter, you have to inspect a crucial engine component?? You've got to be kidding! I think I could build another impressive improvement, just on that POS part.

I have to admit, going back to 1996, the TDI crank has tremendous appeal for me. It's journals look to me as big as the 289 Ford small block, which we felt we were making a monster engine when it had 300 hp from what is approximately a 3.9 liter engine. Sure, I'm talking gasoline and technology from the 60's, but that engine is almost double the displacement compared to the 2.0 TDI. (Oh, by the way, that 289 ended up being a stroker.. 302, reverse logic in today's world...) and then you expect to do more power from 1/2 the volume and not call it a race engine, there is a conclusion that is easy to reach. Life expectancy goes in the toilet.

It was one of the standards, even way back then, to build with the H-beam. But most people do not know or understand, bean-counters (accountants) are building your engine. Why I-beams? They are cheaper to stamp out in a forge. BANG! BANG! BANG! your done... Why Cracked Rods? Cracked rods are 30% cheaper to build. Why H-beams? Strength and torsional stability. I'd go head to head with any I-beam, because we built our rod to be 'bulletproof'. Bulletproof and cheap are not synonyms.

I know there is more capability from the 2.0 blocks, but only with a lot of determined care in building and a lot of thought to make that 'bullet proof'.

Some are gamblers and like to talk about the successful runs of luck. Problem is, whenever I have blown up an engine, it's wasn't 'bad luck'. It was R & D, testing the raw edge and learning the hard lessons.

So, if your attempt is to build structurally sound, the best thing is to build overkill or detune to safe levels. 2 of the 1.6 IDIs I owned managed to make 1.2 million miles (nearly 2,000,000km) between them. Neither one had 60 hp, and the only thing they could pass was a gas station. But you couldn't kill them. When I finally sold them, both engines, were still running and capable of nearly 60mpg. I just got sick of looking at them. Heh... I'd rather have my 165hp Passat 2.0 PD's comfort and power... not too much extra, but very sustainable for a lot of miles.

Well really nice summary on the matter, and of course you are making a good point about what being bulletproof is. I ran my stock BKC engine on 220HP for 60k kms, and it held up fine, but did get increased wear, looking like a 500k km engine at the end (it ran 380k km total).
But the million mile club is not what building engine (at home for myself) is about, and of course my financial opportunities are not endless. I don't want bent rods, cracked shafts, and melted pistons, but I also do not want to have a 60hp SDI.

What I meant by "bulletproof" is being better that the one-weekend drag engines, or the racer boy "it can handle 4 bars of boost just fine" attitude, and driving safely around for 50k-100k kms and no being in constant fear of blowing my engine. Here in the eastern side of Europe, PD tuning is a big turbo and a map. Or a large turbo, huge nozzles, a cooler and an agressive tune. I'm trying to be better than that, with reasonable modifications, for "reasonable" power, for having that smile on my face and not the fear in my heart

Maybe I'm staying at the 220Hp tune for now, and I will consider some H-beam rods before stepping the game. Thanks for the answers so far guys But I would be really interested in all the aspects of "determined care". Around here that doesn't seem to be the trend.

 

[Franko6]

We have taken many people from the category of 'I blew it up again!' to sustainability. As a matter of fact, any engine driven to excess will not do well. I think you can take a stock BMM engine against a stock manual transmission and make pieces out of the tranny.

On the other hand, we have built some 220hp motors that could get 52mpg (That is miles to American Gallons. Imperial, Liters, Km, do your own comparison, but it's very good!)

I think a 180hp engine is a lot of fun, doesn't require insane upgrades, is within the budget of most TDI'ers and we build a lot of them. If I build to 250hp, it has a girdle, large cam, ported head, ceramic coated pistons, exhaust runners, cylinder head and valves, galley cooled pistons, with a maximum 18.25:1 CR (but probably much lower), keystone rods and wrist pins, a BHW crank ( I believe your 2.0 engine already has the 53.7mm rod journals), with the main shells; 6 slotted, 4 solid ('extra' slotted goes in #4 main bearing cap), Sputtered rod bearings, diamond impregnated piston rings and our Molnar H-beam rods, (I made those to remove me from all the drama of 'the other guys who say they make rods'). That's just the engine, Valve cover to oil pan. Haven't discussed the turbo, although the GTB's are nice. BMM are PD's, so I haven't talked pumps for engine or fuel tank lift pumps, or a variety of injectors, water injection, intake or exhaust manifolds, clutches.. building big has it's rewards, but done well, it is not cheap. But neither is under-building an engine, only to blow it up. That can get very expensive.

https://forums.tdiclub.com/index.php?media/runaway-turbo-blown-3-rod.142192/full

 

[adamss24]

Just my 2 cents, I have a mk2 golf with a pd150 engine in it, I ran it with AL injectors, gtb2260vk turbo and insane degrees of advance, the car is an animal and I am trying really hard to blow the engine in order to build it stronger ! I have bought a 2.0 sdi cam and new bearings + Ina dlc coated hydro lifters and I have +160% Firad nozzles to go on + a choice of hybrid gtb2260vk an vklr's with different 6+6 blade compressors and larger AMG turbine wheels... I would say build it the best you can and don't worry, you won't break the engine easily if you have a host of gauges to keep tabs on the proper functioning of the engine and mechanical sympathy !

 

[Franko6]

adamss,

I like your enthusiasm. Not many of my people want to play chicken with their engine. That is odd, the AL coded injectors. We found the BE were also a larger piston inside the injector. More fuel, but I was of the understanding the AB and BE and BC? versions were all the bigger ones. There aren't many of those over on this side of the pond. I thought with the 1043's, they were about 220-230hp. I didn't mention it here, but my single biggest problem with the PD's is injector bore cracks. Big power and your head cracks to the injector seal.

I have to agree, lack of gauges will leave you on the side of the road. Oil pressure, temperature, Water temp (don't believe the cluster's water temp gauge), and although boost seems an important gauge to some, not to me. Once you see it on the VCDS, what more do you need to know? You probably can tell when it's boosting... push the go button.

I'll warn you in advance. It's not a gasser. Advance will heat up the engine.

The INA cam followers are NITRIDED, not DLC coated. You have to use them or you're going to hole them out almost instantly. The one thing I personally have never done is make the kind of hole that the link shows. Impressive!