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[grc]

There must be a reason MOCO recently 'upgraded' their previous oil pumps and cam plates to what appears to be a different vendor. 

After changing to Feuling oil pump and Delkron cam plate, my oil pressure now runs at 15-20PSI @  idle and   45-50PSI at highway speeds and the oil temps have decreased. The peace of mind is priceless!  At least in theory, aids the cooling and can increase HP at least a few. To me, the peace of mind is worth it IMHO.
Joe

Joe,

There are a few reasons why H-D upgraded the pump:  increase the scavenging to reduce the amount of oil in the crankcase that contributes to blow-by, the change to "plain" bearings for the cams ('06 Dyna, '07 all other B/Twin), and to address internal pump wear issues. 

Since the older engines don't have plain bearings, they don't need that "upgrade".  And just adding a stronger spring to the bypass valve doesn't address the scavenging issue, and may exacerbate the wear issue when using a stock pump. 

The method you used, with a better quality aftermarket pump, addresses all the issues.   I still don't see a need for the 50⁺ psi at highway speeds on the older Twin Cams, however.  And the excess pressure will use more power, not create it.

Jerry

[GMR-PERFORMANCE]

The idea though that a plain bearing cam plate will work in the HD version is just plain funny. I have replaced over a dozen so far that had egg shaped cam holes. Install a gear drive and have excessive backlash as the cam can move around in the plate.  The cam plate for the 07 with bushings will be done in about two more weeks.

 The stock 07 cam plate does not cut it, just one more item in a long list of items that HD has tried and is not up to the task.  And if HD thinks the stock plate does not need any upgrading why is it that they no offer a billet plate?? 

[Talon]

The idea though that a plain bearing cam plate will work in the HD version is just plain funny. I have replaced over a dozen so far that had egg shaped cam holes. Install a gear drive and have excessive backlash as the cam can move around in the plate.  The cam plate for the 07 with bushings will be done in about two more weeks.

 The stock 07 cam plate does not cut it, just one more item in a long list of items that HD has tried and is not up to the task.  And if HD thinks the stock plate does not need any upgrading why is it that they no offer a billet plate?? 

So is your new plate using old style bearings?
Now Andrews is providing cams to convert to this new style setup for earlier TC motors, with hydraulic tensors using the stock cam plate.

[GMR-PERFORMANCE]

Yes the plate is back to using a bushing as it should have been. You need a bushing in this set up. This is not a cam that is supported like a import.

[djkak]

My humble opinion on the new plain bearing cam plate is that it is a significant upgrade to the components that it replaces. Losing the ball and roller bearings was necessary in order to improve durability. A peripheral benefit was to reduce engine noise which allows Milwaukee to increase exhaust volume. With the spring tensioners out of the picture, the next durability issue would certainly have become the ball bearing for the front cam. These bearings have been somewhat problematic, which is significant when you consider that they are normally replaced with the tensioners and chains. Hopefully the hydraulic tensioner setup will eliminate the periodic servicing of this area in the engine.

I have replaced a small number of failed cam plate ball bearings. While the issue isn’t huge, it can be a very big deal if the failure goes unnoticed for any length of time. I recently replaced a set of cases on a B engine that became damaged as a result of a front cam ball bearing failure. I am very happy to see the ball and roller bearings replaced with a plain bearing in this new setup.

BTW, as long as we are talking about cam plate ball bearings; it is noteworthy to mention that the S&S gear drive (which I am running) requires the substitution of the rear roller bearing to a ball bearing. Although the rear roller bearing will handle greater load, it runs with more clearance which makes more noise with gear drive cams. Being someone that likes to run over with road, I can tell you that my primary long term durability concern with this arrangement is the ball bearings.

Everyone seems happy to lose the ball and roller bearings, but there is an argument over H-D’s chosen material for the plain bearing in the cam plate. The issue becomes more interesting as this specific application enters its third year of Dyna Glide production and second year of full production. My best guess at the moment is that there are probably somewhere around 250,000 of these units in the field, with more being produced every day. The average mileage of these machines continues to climb, but the jury is still out on the long term advantages or disadvantages of the chosen material.

I’m placing my bet with H-D’s choice to run the parent material in the cam plate. Aluminum has proven itself over decades to be a long wearing bearing material, capable of handling high speed and load. The second reason that I like using the parent material is that there is some real potential for the bushing itself to cause a failure. Ask anyone with a Buell or XL with a spun inner cam bushing how much they paid to replace the crankcases.

Assuming that the metallurgical properties of the parent material are adequate for the job; from a manufacturing perspective, using the parent material returns the highest degree of precision and reliability because there are fewer processes and components involved in the manufacturing of the part.

Borrow four bucks from your wife then print this post and take it to starbucks; you know the drill.

djkak

[vagabond6542]

My humble opinion on the new plain bearing cam plate is that it is a significant upgrade to the components that it replaces. Losing the ball and roller bearings was necessary in order to improve durability. A peripheral benefit was to reduce engine noise which allows Milwaukee to increase exhaust volume. With the spring tensioners out of the picture, the next durability issue would certainly have become the ball bearing for the front cam. These bearings have been somewhat problematic, which is significant when you consider that they are normally replaced with the tensioners and chains. Hopefully the hydraulic tensioner setup will eliminate the periodic servicing of this area in the engine.

I have replaced a small number of failed cam plate ball bearings. While the issue isn’t huge, it can be a very big deal if the failure goes unnoticed for any length of time. I recently replaced a set of cases on a B engine that became damaged as a result of a front cam ball bearing failure. I am very happy to see the ball and roller bearings replaced with a plain bearing in this new setup.

BTW, as long as we are talking about cam plate ball bearings; it is noteworthy to mention that the S&S gear drive (which I am running) requires the substitution of the rear roller bearing to a ball bearing. Although the rear roller bearing will handle greater load, it runs with more clearance which makes more noise with gear drive cams. Being someone that likes to run over with road, I can tell you that my primary long term durability concern with this arrangement is the ball bearings.

Everyone seems happy to lose the ball and roller bearings, but there is an argument over H-D’s chosen material for the plain bearing in the cam plate. The issue becomes more interesting as this specific application enters its third year of Dyna Glide production and second year of full production. My best guess at the moment is that there are probably somewhere around 250,000 of these units in the field, with more being produced every day. The average mileage of these machines continues to climb, but the jury is still out on the long term advantages or disadvantages of the chosen material.

I’m placing my bet with H-D’s choice to run the parent material in the cam plate. Aluminum has proven itself over decades to be a long wearing bearing material, capable of handling high speed and load. The second reason that I like using the parent material is that there is some real potential for the bushing itself to cause a failure. Ask anyone with a Buell or XL with a spun inner cam bushing how much they paid to replace the crankcases.

Assuming that the metallurgical properties of the parent material are adequate for the job; from a manufacturing perspective, using the parent material returns the highest degree of precision and reliability because there are fewer processes and components involved in the manufacturing of the part.

Borrow four bucks from your wife then print this post and take it to starbucks; you know the drill.

djkak

DJ,

Wouldn't relying on the parent material become expensive once a cam "wobble" become apparent? There would be a few pieces replaced.

Starbucks lost on the post, brewed my own coffee.

[GMR-PERFORMANCE]

I can see your point and you state it very well.  I think I will go with what I see when I have my hands covered in oil and I can see the specks of aluminum floating around and stuck to my hands. Only to see the same thing we here have seen, R&R has seen as well as many others.  I am not against a plain bearing set up , they work fine in a OHC engine where you have 25 lbs of seat pressure, no flexing of the mounting surface like in a HD. Why do you think S&S went to o-rings on the cam plate?  It was not that they where unable to machine the cam plate flat, or that the case mounting surface was not flat. The amount of distortion that a case goes through. Flex's the cam plate allowing oil to spray inside the cam chest. When that case moves the cast plate flex's and then the cam , starts to wear unevenly. As far as HD trying to make the engine quiet, fine more power to them.  I myself would rather have a engine that I know will go the milage trouble free with a bit more noise than the alternative.

[CVOJOE]

The major advantage of the aftermarket cam plate is mainly that they are "blue-printed" and the tolerances are much better than the original plate. The factory cam plate is a cast unit, and with variations in the casting process, and the dimension tolerances area not always correct. While the spacing between the cams themselves is not so much a major factor for chain-drive cams since the chain and tensioners do compensate for this additional spread or tightness. But, if you're going to spend the money and change over to gear drive cams this setup becomes very important. Gear drive cams require "perfect spacing" from one another in order for the gears to mesh properly and provide proper cam timing as well as wear. These aftermarket (Feuling, Delkron, etc.) cam plates provide this, mainly because they're a billet piece that is machined to exact tolerances each time, instead of being a casting. Also, these cam plates have improved (enlarged) oil passages, for a better flow and volume of oil to the pinion shaft and connecting rod bearings. As I understand the problem, the Harley oil system is a blend of high-pressure low volume and low-pressure high volume in design, and the MOCO oil pump, at least prior to the 'improved' version, was not capable of meeting the design needs. The internal oil jets require oil pressure to open and may not get the needed pressure all the time. In theory at least, when paired with an improved oil pump there is an associated decrease in engine oil temperature and some HP & TQ gains at the rear wheel should be achieved. Feuling claims a documented 3HP & 4FT LBS by using their oil pumps and cam plate. Jury is out on that, but I certainly saw no decrease in my dyno numbers after this upgrade. 

[djkak]

I can see your point and you state it very well.  I think I will go with what I see when I have my hands covered in oil and I can see the specks of aluminum floating around and stuck to my hands. Only to see the same thing we here have seen, R&R has seen as well as many others.  I am not against a plain bearing set up , they work fine in a OHC engine where you have 25 lbs of seat pressure, no flexing of the mounting surface like in a HD. Why do you think S&S went to o-rings on the cam plate?  It was not that they where unable to machine the cam plate flat, or that the case mounting surface was not flat. The amount of distortion that a case goes through. Flex's the cam plate allowing oil to spray inside the cam chest. When that case moves the cast plate flex's and then the cam , starts to wear unevenly. As far as HD trying to make the engine quiet, fine more power to them.  I myself would rather have a engine that I know will go the milage trouble free with a bit more noise than the alternative.

The OHC engine that I was thinking about is the VRod. This machine runs around 65 pounds of seat pressure per valve in stock configuration. The modified VRod heads that Zippers and Tilley’s 1320’s run have heavier springs. My guess is that these configurations have seat pressures running at least 20% higher, somewhere near 80 pounds. With twice the valve count plus a 30% to 40% increase in the average engine speed over the Twin Cam and you have substantial loading of the VRod’s plain aluminum cam bearing.

The diameter of the Twin Cam’s cam bearings is substantially larger than the VRod; although I can’t say for sure about the total surface area per cam. Bottom line is that there are plain bearing valve trains running reliably under substantial loads. It is not at all unreasonable to expect that an aluminum plain bearing could be designed to handle the load of the Twin Cam’s valve train. All that is left now is to stir in some more time and mileage to sort this out. If these new cam bearings are as prone to wear as has been suggested, the cam plate issues should make the 110 head gasket problems look like a non event. As previously posted, my bet is that this cam plate arrangement will substantially improve the long term reliability of this assembly; time will tell.

Regarding the crankcase and camplate flex resulting in oil pressure loss and uneven camshaft wear: One item conspicuously missing from the list of issues related to the overflex of these components is their structural failure. It is my understanding and experience that fatigue and breakage occurs when cast aluminum is exposed to repeated overflex cycles; it is the nature of this material to break when repeatedly overflexed. Cast aluminum is an extremely reliable material when coupled with a rigid design for the intended application.

During normal operation, components are loaded, stressed, heat cycled; they grow, shrink and they move around. The cyclical loading and other stresses are normally accounted for in the design and choice of materials of the components. The bold claim that the crankcase and camplate design is inadequate for the average street machine application seems overstated. The Twin Cam is in its 10th model year of production with no apparent long term structural issues with these components; never mind the relatively diminutive construction of the Twin Cam’s predecessors which ran successfully for many decades under similar loads and conditions.

Let’s assume that for a specific application the projected stress cycle limit of the OEM cam plate is an arbitrary number equivalent to 250,000 miles. The cam plate is replaced in the same application with a structurally heavier piece that will theoretically tolerate cyclical loads equivalent to 350,000 miles; where is the added value? The camplate will reach its service wear limits long before it reaches its structural limitations; these things are going to wear out long before they break.

IMHO, one of the drivers for over engineering a product like this is to differentiate the product from the OEM or other manufacturers. Without the perceived value of a more robust design, the camplate would be much more difficult to market successfully.

When the smoke clears at the end of the day, if one way or the other your needs and expectations have been met, I’m thinking that you have accomplished your mission.

As always, these ramblings are JMHO.

djkak

[rednectum]

bravo!!!! dj, you obviously are an engineer. ramble on!!!!!!!!!!!!!!!!!!!!!!!!!!!

[djkak]

I would be surprised to learn that H-D is willing to share their blueprints with unlicensed aftermarket manufacturers. It is my understanding that a manufacturer attempting to duplicate a component like a cam plate, without the benefit of the Factory blueprint, would have to rely on previously manufactured OEM components as patterns. The problem with this approach is that there is no way to determine how the various points of reference on the pattern parts relate to the Factory blueprint.

The pattern part could have been manufactured anywhere within the plus or minus tolerance range allowed for that specific part; it is even possible for the chosen pattern part to have been manufactured out of tolerance. The pattern part together with each aftermarket manufacturer’s ability to develop a layout from it, become the standard for the aftermarket Blueprint. The aftermarket part is then manufactured to their own plus or minus tolerance. A small tolerance “stack up” could easily result in a manufactured component that falls far outside of the OEM tolerance limits. This and other factors help to explain why aftermarket goodies typically have fitment issues.

A few key reference points on the camplate that would be important to consider would be the center to center distance of the camshafts as well as the center to center distance of the rear cam and gearshaft. Equally important are the reference points on the camplate which index the centerline of each bore in the camplate with the corresponding centerlines in the crankcase. As far as machined tolerances are concerned, it wouldn’t matter one way or the other if the camplate “blank” is cast or billet.

Regarding cam gear drives; the degree of perfection required to run the gear drive cams is relative to S&S’s ability to manufacture “perfect” gears. The last time that I looked, S&S manufactured machine cut gears with three pinion sizes and three secondary cam gear sizes. As I recall the differential between sizes is approximately one onethousandth (0.001”) of pitch diameter.

XL’s, EVO’s and later Shovelheads have seven sizes of precision ground cam and pinion gears with an approximate differential between sizes of two tenthousants (0.0002”) of pitch diameter. This allows for 49 possible combinations in the Big Twins and hundreds of combinations in XL’s to achieve an appropriate running fit. I believe that you can no longer purchase individual sized cam gears for the XL, but must purchase a complete “matched” set.

The attached photos illustrate the difference between the finish of the S&S gear teeth and H-D’s. Remember when looking at the photos that the macro focus magnifies the gears.

Regarding Feuling’s claim of horsepower increase; I believe this claim is based in part on the lower rotating resistance of their oil pumps. Fueling built a display with their pump along side of an OEM pump to demonstrate the low friction design of their pump. Both pumps have a knob on them which allow the gerotors to be rotated by hand.

djkak

[djkak]

Gear photo 2