Upgrade exhaust cam only? M52B28

[LemonHunter 583]

I'm not keen to pull the vanos side out, but as I have the exhaust cam out anyway to sort the lifters, would there be much point/gain getting the exhaust cam upgraded? 

Will eventually have forced induction if that makes any difference. 

[Mad_Max 233]

Surprised no one has chimed in yet....... my opinion? You won't notice much of a performance gain with an N/A engine by just changing the exhaust cam, but if you're planning on going FI in the future, it would make sense to upgrade the cams as well - both intake and exhaust - while you've got it out. Do some research into which cams and even if you need something reground to suit the FI.

I don't believe removing vanos and swapping the intake cam is all that much harder to do than the exhaust cam.

[dirtydoogle 383]

Any of the bmw OEM cam swaps are fairly mediocre and the biggest benefit would be more gas extraction lowering chamber temps and not increasing much hp. 

If you were keen a set of decent aftermarket cams will do wonders, but I personally wouldn't bother with the m50nv intake cam on the exhaust side, or the m54 cam swap, both are poorly specced cams and lend very little power gain 

[LemonHunter 583]

My concern of removing the intake side is cocking up the timing, I don't have the timing tool. 

[polley 916]

Timing tool not required. You just need a square. The single vanos setup is very easy to assemble and time.

[LemonHunter 583]

The good news is I found the stuck lifter on the exhaust side as anticipated. 

Am going to go ahead and leave the vanos alone. 

[dirtydoogle 383]

I have a tool in hastings I'm happy to lend out. They're very easy to make up and much handier than a square to use 

Glad you sorted it 

[Mad_Max 233]

9 hours ago, EurolessNoMore said:

My concern of removing the intake side is cocking up the timing, I don't have the timing tool. 

Couple of quick clamps from the Warehouse and a pair of vice grips, you'll get it within factory spec easily. Have always done Jap twin cam motors using only a couple of spanners and vice grips, it's not hard to get it within the spec using simple tools.

12 hours ago, dirtydoogle said:

Any of the bmw OEM cam swaps are fairly mediocre and the biggest benefit would be more gas extraction lowering chamber temps and not increasing much hp. 

If you were keen a set of decent aftermarket cams will do wonders, but I personally wouldn't bother with the m50nv intake cam on the exhaust side, or the m54 cam swap, both are poorly specced cams and lend very little power gain 

Agreed they are mediocre in terms of lift and duration, better/faster gas extraction is definitely a worthwhile exercise though while the cam is already out and everything is open, especially given he is wanting to go FI later down the track. I do agree aftermarket is the way to go though.

2 hours ago, polley said:

Timing tool not required. You just need a square. The single vanos setup is very easy to assemble and time.

Hopefully you're only talking about getting a factory cam within "factory spec"....... sorry not trying to be a smarta**e, I've heard of horror stories before where people do this sort of thing to aftermarket/ground cams and end up destroying motors because they get the wrong advice.

There are some small power gains to be had by advancing the intake cam and retarding the exhaust cam slightly from factory specs, all depends on how deep into the rabbit hole you wanna go and where you want to be making the power.

[LemonHunter 583]

Thanks @dirty doogleI'll keep that in mind. 

At this stage I'm probably going to leave the cam change alone, might ask Kelford what a regrind costs tomorrow, assuming these cams can be. 

[Mad_Max 233]

Speak to Kiel at Kelfords (if he's still there), I gave him all of Cat Cams and Schricks specs 4 years or so ago when I was looking at getting mine done so he knows what is around.

The problem is, the last I heard, is that no one is producing blanks for the M5X cams, there isn't a lot of material you can take off the BCD, and there is only so much you can do before the lobe becomes too large for the bearing ledge, as well as the lifter clearances becoming a problem. I'd have to look further into it but I do believe there is a VW? Audi? off the shelf solid lifter that drops straight in and reduces a lot of the problems with the lifters.

[dirtydoogle 383]

You won't be running in to a restriction as such with forced induction on the standard cams until the 600+hp mark anyway. There are definitely gains to be had with a better cam design but it all depends on what you're wanting as an end result 

 

A basic re-grind will only take off some of the base circle, leaving you with a longer duration but the same slow ramp speeds. It is possible to build the lobes up and grind them to a better spec but for that cost you could get an off the shelf unit

 

 

[polley 916]

20 hours ago, Mad_Max said:

 

Hopefully you're only talking about getting a factory cam within "factory spec"....... sorry not trying to be a smarta**e, I've heard of horror stories before where people do this sort of thing to aftermarket/ground cams and end up destroying motors because they get the wrong advice.

 

The factory tool he was after would produce the same result as using a square. If the aftermarket or ground cams are designed to be used at anything other than the factory setting you'd hope the manufacturer of the cams would make you aware of this and then you can get your degree wheel and dial gauge out and set them accordingly.