Bew cam useable in Brm engine?

[craig01b]

I got a note that a BEW cam will work in a brm engine, albeit for economy and not performance.

Any input?

 

[Spiked1Z]

Yes I believe so, look up the thread about cam wear, or search on bew cam and you should find the user (can't remember his handle) that has done this. His theory was the less aggressive ramps on the BEW cam should help with the oiling issues on the stock cam..

 

[BleachedBora]

A large percentage of our customers go with that setup - it's very similar in power to stock, however it is a lot more reliable of a setup.

The BRM is a unique motor to the North American market. The BEW cam is identical to most other 1.9 PD cams found in other VW models around the world. You'll find a BEW cam will work in almost anything from BEW to BRM and BHW....

Cheers!
-BB

 

[dieselpony]

I have this setup in mine, one of Franko6 stage 2 BEW cams. So far, so good, after 3 years and 60k miles.

 

[craig01b]

Thanks folks....

 

[Franko6]

For the greater part, we designed for economy with the PD engine. But it is NOT a stock cam. The stock cam for all PD motors is basically the exact same cam lobe design, which in our opinion is closer to a solid lifter profile then a hydraulic profile. The stock profile is very hard on the cam followers. We redesigned the lobe, chrome-plated the cam journals and the cam bearings.

The injector lobe is the major difference between all of the PD cams and The BRM, with it's additional height, adds more pressure to a design that is already stressed. That is the major reason for the reversion to the BEW cam for most applications. The power obtained from the .010" difference in injector lobe height in the BRM is virtually indistinguishable from the BEW cam, unless your intent is to exceed around 180 hp. Then the BRM is an option.

 

[KERMA]

BRM has additional lift on the fuel lobes, to accommodate post injection. It's the same cam that's used on DPF-equipped PD in Europe. One can only speculate as to why we got a DPF engine without a DPF. Maybe VW was keeping its options open for 2007 then changed its mind.

The additional lift on the injector lobe adds no appreciable stress or pressure. It is not injecting during the post-injection region of the cam (not injecting during those "degrees" of the cam long after TDC). Fuel pressure is determined in part by the slope of the fuel lobe, that is why there's 6 different duration maps in a PD ecu, selected by timing. Different timing selects different "rate of rise" of the slope and therefore different average injection pressure. Using the wrong cam throws off the fuel maps. I guess you could explain away the lower power as "because fuel economy" but lower injection pressure should have exactly the opposite effect through longer injection delay (effectively retarding timing).

the fuel lobes are very different between the BEW ("normal style" PD style cam) and BRM ("DPF style" PD cam) and the fuel maps are very different between BEW and BRM.

they are definitely NOT identical and I would argue not directly interchangeable. But if all you have is a BEW cam, then I suppose you can make do.

 

[James & Son]

If you want to increase the rate of injection you need to increase the rise, to do this you need to advance the injection lobe which increases the average rise rate(advancing the rotation of the cam increases the slope of lobe and injection takes place higher on the lobe effectively injecting the same quantity of fuel in a shorter period of time).

I just reworded what Kerma said so people with a BEW cam in a BRM may find better performance by adjusting torsion. Loosen 3 screws and rotate sprocket counter clockwise to increase rise.

 

[dieselpony]

If you want to increase the rate of injection you need to increase the rise, to do this you need to advance the injection lobe which increases the average rise rate(advancing the rotation of the cam increases the slope of lobe and injection takes place higher on the lobe effectively injecting the same quantity of fuel in a shorter period of time).

I just reworded what Kerma said so people with a BEW cam in a BRM may find better performance by adjusting torsion. Loosen 3 screws and rotate sprocket counter clockwise to increase rise.

So, with the BEW stage 2 cam in my car, would I be better off with a + or - torsion value? I had it at 0.0 for a long while, but now am at +2.0, doing some experiments to try to lessen the large cloud of startup smoke.

My other BRM hardly has any startup smoke, so something seems to be amiss with this one.

 

[James & Son]

You advance or retard torsion and then check fuel mileage or performance, it has nothing to do with start up smoke. If it is black smoke, then do a search and have fun narrowing it down( had to do the same thing).

 

[James & Son]

I decided to verify my own post #8 today.

I had just installed( 2 weeks ago ) a cheap Febi Belstein I bought about a year ago. It was suppose to be a BRM cam but who knows it could be a BEW cam. I set it initially at 0.0 with my locator tools. The cam was definitely laggy especially around 1800 and 2000 rpm.

Normally the turbo with my OEM cam would have a bit of hit( small boost hit) there due to probably the actuator wear (zip tie solution may be in my future). Anyways it was laggy enough that was not noticeable and I could easily( but carefully) pull from 60 kilometers/hr in 5th gear.

I did exactly what I said in my post. I locked the cam with the locate pin and loosened the 3 sprocket bolts and rotated the cam sprocket( not the cam) and crank counter-clockwise 3 degrees using a dial indicator to measure the movement of the sprocket.

It definitely feels BRM like now with the same light throttle response and closer to the stock BRM pull.

Edit:advancing increases the rise of the injection rate and improves pressure of injection as well, but the effect on valves: see quote, an unknown author quote:
Advancing and Retarding:
By advancing the cam, the valves open and close earlier. Duration and overlap remain unchanged. Advancing raises the cylinder pressure (due to earlier valve closing) This improves low end and mid-range torque at the expense of some top-end power. The result is similar to using a shorter-duration cam since the intake valve closing point is more critical than its opening point.

 

[dieselpony]

Well, I tried +2.0 for torsion value for a few weeks and a couple tanks, and my MPGs really went down. It's hard to tell exactly how much because there are so many variables, but I'd say I took a 2-3 mpg hit. I'm now trying -2.5. We'll see how that goes.

 

[James & Son]

Well, I tried +2.0 for torsion value for a few weeks and a couple tanks, and my MPGs really went down. It's hard to tell exactly how much because there are so many variables, but I'd say I took a 2-3 mpg hit. I'm now trying -2.5. We'll see how that goes.

The unknown author could be talking about a gas engine where intake is dominant. If you consider a diesel maybe I want the exhaust valve not to open sooner but later, maybe plus 3 is to much and I am going back to plus 1 degree. I don't have VCDS yet and use a dial indicator. Be interested in your result.

Edit: to get +2 torsion which way did you move the sprocket, counter-clockwise? or clockwise?

Also remember if you have a smoke problem, you should check egr, inter-cooler pipe leaks, vacuum leaks, and then Maf and turbo graphs for proper response.

 

[dieselpony]

The unknown author could be talking about a gas engine where intake is dominant. If you consider a diesel maybe I want the exhaust valve not to open sooner but later, maybe plus 3 is to much and I am going back to plus 1 degree. I don't have VCDS yet and use a dial indicator. Be interested in your result.
Edit: to get +2 torsion which way did you move the sprocket, counter-clockwise? or clockwise?
Also remember if you have a smoke problem, you should check egr, inter-cooler pipe leaks, vacuum leaks, and then Maf and turbo graphs for proper response.

I loosened the 3 bolts that hold the sprocket tight, then turn the center bolt clockwise (timing belt holds the sprocket in place). Center bolt moving clockwise moves torsion to the + side, counter-clockwise to the - side. Very small movements produce large results, so you have to be very careful, as I'm sure you know. I detect a smoother running and starting engine with the -2.5 torsion. I'll try this for a while and see what MPG does.

On the startup smoke, there is definitely a correlation to torsion. With a -2.5, I definitely get what I would call a "cloud" of whitish/grayish smoke on startup, with a warm or cold engine. It goes away within 5 seconds of starting. Car doesn't use oil (well, maybe 1/2 quart per 5,000 miles, but I'd say that's pretty normal). With - torsion, there is less black smoke under heavy acceleration.

EGR is blocked off, Anti-shudder valve butterfly has been removed, and I have not detected any kind of vacuum or boost leaks. There is no excessive turbo shaft play. I run diesel purge every 20k miles when I change the fuel filter, so I don't think the injectors are dirty. Car has 135k miles, and a stage 1+ tune.

 

[James & Son]

Ok, thanks for that. My wife just finished a 274 kilometer round trip yesterday and i was not impressed with the fuel milage based on gage position. Then I realized advancing was opening the exhaust valve sooner which was not a good thing for the exhaust valve temperature and it also having to work to open against more residual pressure in the cylinder.
I retimed my cam and now have gone to -1 torsion and I have a trip coming up and will check mileage.

 

[James & Son]

Ok, thanks for that. My wife just finished a 274 kilometer round trip yesterday and i was not impressed with the fuel milage based on gage position. Then I realized advancing was opening the exhaust valve sooner which was not a good thing for the exhaust valve temperature and it also having to work to open against more residual pressure in the cylinder.

I retimed my cam and now have gone to -1 torsion and I have a trip coming up and will check mileage.