Any update on the cam situation?

[1bluemcm]

People are dreaming / wishful thinking and I don’t actually think being serious. There is no way the geometry is accurate and it’s not even suitable for CNC. The rockers from schrick and catcams are expensive for a reason and it’s not because they are trying to rip you off. you just aren't going to make significantly cheaper ones that are actually any good. I have seen at least half a dozen different aftermarket rocker designs for various bmw engines they end up being expensive if they work longer kms and all have some kind issue/flaw

The Schrick units appear to be similar to OE in that they appear to be cast followed by machining and some coating or hardening process. No two ways about it, it's an expensive endeavor from design to metallurgy, foundry QC, machine shop QC, there is a lot to it.

[terra]

I have to ask. Have you even seen the model that were talking about? It's very good but some dimensions on the block and crank are incorrect which makes me suspicious.

This is not a complicated part to recreate CAD for by measuring an OE part. 3D printing is a good tool that can be used to validate everything as well.

Getting the correct finish and hardness on critical surfaces will be the more difficult task.

If I remember right that model was part of some Italian engineering student’s thesis project. It’s overall impressive, but should not be considered equivalent to BMW’s original cad files

[George Hill]

I just want to 3d print some correct looking parts to make as desk decoration, lol

[digger]

I have to ask. Have you even seen the model that were talking about? It's very good but some dimensions on the block and crank are incorrect which makes me suspicious.

This is not a complicated part to recreate CAD for by measuring an OE part. 3D printing is a good tool that can be used to validate everything as well.

Getting the correct finish and hardness on critical surfaces will be the more difficult task.

The model appears to be for the OE which is cast or forged not billet so the geometry is not made suitable for CNC billet. The catcams rockers are how you would do billet.

http://www.catcams.com/tabid/432/def...?tabfile_ID=61

compared to the attached

You need to get a new oe one and get it cmm if you are serious about billet CNC not use random cad files. 3d printing is not accurate enough to validate the radii and centrelines thereof for the foot etc in other words the cad file is pretty much useless

[discoelk]

I think we've covered (ad nauseum) that OEM parts should be measured.

Everyone is welcome to their own opinions about what measurement techniques should be used.

[1bluemcm]

Wanted to say thanks for the info thus far. What I overlooked inadvertently, this work happening on a Z4 M, is that without pulling the engine I think removing the rocker arm/follower shafts is damn near impossible with out pulling the entire front end of the car apart. Hell, I've heard and been told that the vanos unit can be pulled off with the engine in the car and not having to loosen motor mounts or anything else but I'll believe it when I see it, it's so close to the core support. So ultimately, probably passing on the cam idea until I have the engine our for some reason, or if I were to pick up a long block to fiddle with and build out for the fun of it.

[heinzboehmer]

Wanted to say thanks for the info thus far. What I overlooked inadvertently, this work happening on a Z4 M, is that without pulling the engine I think removing the rocker arm/follower shafts is damn near impossible with out pulling the entire front end of the car apart. Hell, I've heard and been told that the vanos unit can be pulled off with the engine in the car and not having to loosen motor mounts or anything else but I'll believe it when I see it, it's so close to the core support. So ultimately, probably passing on the cam idea until I have the engine our for some reason, or if I were to pick up a long block to fiddle with and build out for the fun of it.

Slideways and I pulled the VANOS unit out of a Z4M without removing pretty much anything the other day. It's tight, but definitely doable. The rocker shafts sound much harder to do.

Could just pull the head and refresh the head gasket at the same time. Not a ton more work to pull the head if you're doing cams.

[Slideways]

Wanted to say thanks for the info thus far. What I overlooked inadvertently, this work happening on a Z4 M, is that without pulling the engine I think removing the rocker arm/follower shafts is damn near impossible with out pulling the entire front end of the car apart. Hell, I've heard and been told that the vanos unit can be pulled off with the engine in the car and not having to loosen motor mounts or anything else but I'll believe it when I see it, it's so close to the core support. So ultimately, probably passing on the cam idea until I have the engine our for some reason, or if I were to pick up a long block to fiddle with and build out for the fun of it.

With such a low mileage engine, I wouldn't consider cams.

Have you driven a Z4M with a CSL style intake? You'll forget about the idea of cams real quick.

The VANOS can be removed with the engine in the Z4M engine bay. No need to touch motor mounts or anything else. The only difference is that the crank locking pin is shorter for the Z4M (to clear the crossmember) and the VANOS regulating valve that connects to the cylinder head has to be removed before pulling off the VANOS unit. Then when installing the VANOS unit, the regulating valve has to be install first into the cylinder head before mounting the VANOS unit. On the E46, the regulating valve is put on the VANOS unit because there is plenty of clearance.

[1bluemcm]

Slideways and I pulled the VANOS unit out of a Z4M without removing pretty much anything the other day. It's tight, but definitely doable. The rocker shafts sound much harder to do.

Could just pull the head and refresh the head gasket at the same time. Not a ton more work to pull the head if you're doing cams.

That is a good point about the head, hadn't considered that. That said, head gasket is probably solidly ok with my mileage too. But yeah, makes sense if one was to get into cams. Thanks for the input on the vanos too.

With such a low mileage engine, I wouldn't consider cams.

Have you driven a Z4M with a CSL style intake? You'll forget about the idea of cams real quick.

The VANOS can be removed with the engine in the Z4M engine bay. No need to touch motor mounts or anything else. The only difference is that the crank locking pin is shorter for the Z4M (to clear the crossmember) and the VANOS regulating valve that connects to the cylinder head has to be removed before pulling off the VANOS unit. Then when installing the VANOS unit, the regulating valve has to be install first into the cylinder head before mounting the VANOS unit. On the E46, the regulating valve is put on the VANOS unit because there is plenty of clearance.

Funny you mention that, about the intake. I was kind of coming to this realization in the last couple of days thinking this over. I could do intake work, maybe go forward with the euro headers I have and put a little time and effort into reworking the exhaust, and still do a tune and probably be heck a plenty happy with it. I might look into the Karbonius unit that is more OE styled and stick with standard ECU tune vs alpha-n etc, although I gather it had some issues. More to look into.

Thanks for the additional tips on the vanos. Feeling a lot more confident about it. With the crank locking pin, I haven't seen one specific to the Z4M, maybe I haven't looked hard enough. I suppose I could just cut down the E46 M3 pin to make it work, yes?

[Slideways]

That is a good point about the head, hadn't considered that. That said, head gasket is probably solidly ok with my mileage too. But yeah, makes sense if one was to get into cams. Thanks for the input on the vanos too.



Funny you mention that, about the intake. I was kind of coming to this realization in the last couple of days thinking this over. I could do intake work, maybe go forward with the euro headers I have and put a little time and effort into reworking the exhaust, and still do a tune and probably be heck a plenty happy with it. I might look into the Karbonius unit that is more OE styled to allow for continued use of the MAP sensor, although I gather it had some issues. More to look into.

Thanks for the additional tips on the vanos. Feeling a lot more confident about it. With the crank locking pin, I haven't seen one specific to the Z4M, maybe I haven't looked hard enough. I suppose I could just cut down the E46 M3 pin to make it work, yes?

Yes, you could as Heinz was nice enough to do, but the part number for the Z4M crank pin tool is 83300495528.

One other weird thing about the Z4M is setting timing. Unlike the E46, you cannot install the VANOS unit with the splined helical gears attached. In the Beisan instructions, this is important because they have you push both splined gears into the VANOS unit to fully bottom out and retard the VANOS intake and exhaust pistons. Instead, you have to put both intake and exhaust splined shafts into the cam hubs while they are loose, put the regulating valve into the cylinder head, then mount the VANOS unit with the long bolts, pull the splined shafts towards the VANOS unit, tighten the splined shafts to the pistons and finally lever the splined shafts out of the hubs and fully press them into the VANOS unit. Then you can continue with the normal timing procedure.

[1bluemcm]

Yes, you could as Heinz was nice enough to do, but the part number for the Z4M crank pin tool is 83300495528.

One other weird thing about the Z4M is setting timing. Unlike the E46, you cannot install the VANOS unit with the splined helical gears attached. In the Beisan instructions, this is important because they have you push both splined gears into the VANOS unit to fully bottom out and retard the VANOS intake and exhaust pistons. Instead, you have to put both intake and exhaust splined shafts into the cam hubs while they are loose, put the regulating valve into the cylinder head, then mount the VANOS unit with the long bolts, pull the splined shafts towards the VANOS unit, tighten the splined shafts to the pistons and finally lever the splined shafts out of the hubs and fully press them into the VANOS unit. Then you can continue with the normal timing procedure.

That makes complete sense with the limited space. Just not enough room for the splined helical gears to go in with the VANOS all at once. This helps a bunch. Is it difficult or harder to fully press the splined shafts into the VANOS and get the VANOS pistons fully retarded with it all in place and partially installed compared to being able to do it on the bench as with the M3?

[Slideways]

That makes complete sense with the limited space. Just not enough room for the splined helical gears to go in with the VANOS all at once. This helps a bunch. Is it difficult or harder to fully press the splined shafts into the VANOS and get the VANOS pistons fully retarded with it all in place and partially installed compared to being able to do it on the bench as with the M3?

Pulling the splined shafts out of the hubs to press them fully into the VANOS unit is a bit tricky since you have to position the intake and exhaust pistons far enough out to be able to access the hex portion of the pistons while having the splined shafts pushed into the hubs far enough to clear the VANOS unit. Once you thread the splined shafts into the pistons, it is hard to grab the splined gears with your fingers due to oil covering them and the force required to pull them out of the hubs (the pistons with new seals also add some friction, plus the pistons are compressing some air in the VANOS unit). Using the small wrench that was used to tighten splined shaft to the pistons, you can grab the flat portion of the splined shaft and lever the splined shafts out. Once they are far enough out, you can fully press them into the VANOS unit with your hands while it is hanging on by the long bolts and butted up against the core support. On the M3, this is all done on the bench along with mounting the regulating valve on the VANOS unit rather than the cylinder head.

If you had the VANOS air tool to move the pistons (which almost no one uses / everyone chooses the Beisan method to manually retard the pistons), then it would be easier to extract the pistons to tighten them to the splined shafts and bottom them out in the VANOS unit using compressed air rather than positioning everything and manipulating with tools and hands.