Author Topic: Lightweight M52 hydraulic lifters (Read 30688 times)

Boyracer · « **on:** March 19, 2007, 03:00:43 AM »

Hi there!

There has been some talk about using 49 g hydraulic lifters from some VW models to lighten the valvetrain.

I happened to notice from internet ETK that BMW also uses 49 g lifters on M52 engines!

I did bit of calculations (found useful equation from a book I have) and valvetrain (lifter, spring, spring plate, valve, collet) would be about 10% lighter with 49 g lifter compared to standard 67 gr lifter. That means that everything else staying as it is, engine rev limiter could be safely raised from 6800 to 7200 rpm.

M52 engine does have other interesting parts too... Spring plate is 2 g lighter (8 vs 10) and spring itself is whopping 13 g lighter (38 vs 51).

If those parts would be used on M42, valvetrain mass would be 18,8% lighter which means safe rpm goes from 6800 to 7550. That is of course in case that lighter M52 spring has same spring rate as standard M42 spring. I somehow doubt this as I suspect that BMW just optimized valve train power loss by using softer springs (hence their lower weight) made possible by lower lifter and valve plate masses.

Anyone know actual spring rates of standard BMW springs? Or Dbilas or Shrick springs? Lighter M52 lifter and 20% stiffer springs would guarantee happy revving all the way up to 8000 rpm

Of course then you would have to worry about bottom end holding up :p

Boyracer · « **Reply #1 on:** March 19, 2007, 03:47:27 AM »

Good news everyone!

Did a bit more research... Most E36 M42's have lifters that have mass of 67 g which I used on my calculations. All E30 M42's have lifters that stop scale on whopping 78 g!

So if you swap E30 M42 lifter to M52 lifter you lose 15,5% of valvetrain mass and can safely rev to 7400 (provided that M42 in E30 has limiter in 6800 rpm).

romkasponka · « **Reply #2 on:** March 19, 2007, 04:39:23 AM »

Dont you think it's better to swap to solid lifters?

Boyracer · « **Reply #3 on:** March 19, 2007, 06:10:40 AM »

I think none of the solid lifters BMW used on S14/S50 will fit M42? And aftermarket performance parts are more expensive. New identical lightweight VW hydraulic lifters have been sold at 10$ / each.

I think someone in this board stated that Metric Mechanics are using OEM hydraulic lifters up to 8000 RPM which I think is at the upper limit what stock M42 bottom end can take. 8000 RPM is certainly enough for me

Also, lightweight hydraulic lifters are quite easy and maintenance free modification to valvetrain that does only require removal of camshafts.

asubimmer · « **Reply #4 on:** March 19, 2007, 07:29:58 AM »

I rev to 7200, stock at 240k miles...

Boyracer · « **Reply #5 on:** March 19, 2007, 07:42:59 AM »

And with lighter hydros you could rev up to 7800 since you know it will work ok in 7200 :p

Of course there is quite a bit of designed-in leeway on RPM before things start to break... Also manufacturer has to build in margin for spring getting softer with age of engine.

e9nine · « **Reply #6 on:** March 19, 2007, 08:14:11 AM »

..I like this thread :cool:

asubimmer · « **Reply #7 on:** March 19, 2007, 09:43:59 AM »

depending on how this thread goes I may add this to my to do list. Right now I have been working on something real nice for the s52 bore project and this may be the icing on the cake

romkasponka · « **Reply #8 on:** March 19, 2007, 10:20:54 AM »

Quote from: Boyracer;21628

I think none of the solid lifters BMW used on S14/S50 will fit M42? And aftermarket performance parts are more expensive. New identical lightweight VW hydraulic lifters have been sold at 10$ / each.

I think someone in this board stated that Metric Mechanics are using OEM hydraulic lifters up to 8000 RPM which I think is at the upper limit what stock M42 bottom end can take. 8000 RPM is certainly enough for me

Also, lightweight hydraulic lifters are quite easy and maintenance free modification to valvetrain that does only require removal of camshafts.

you can use them from ford, even not new. http://212.110.107.100/febi/webartikel4.api?p_proc=eigenschaft&p_session=440437&p_masternr=24&p_gui=0

Gunni · « **Reply #9 on:** March 19, 2007, 10:31:59 AM »

Is that a solid lifter conversion using ford parts?
the link says it�s mechanical

I like this thread as well

revs + boost = happy faces

Gunni · « **Reply #10 on:** March 20, 2007, 02:48:51 AM »

M42B18 E36 Info
eature
height or thickness    26 mm
inside diameter    33 mm
outside diameter    35 mm
operating mode    hydraulic

M52 info
Feature
height or thickness    24 mm
outside diameter    33 mm
operating mode    hydraulic

There is a 2mm diffrence in the diameter of them ?
How would they sit securly in the head?
Apart from beeing 2mm shorter as well

Gunni · « **Reply #11 on:** March 20, 2007, 03:46:30 AM »

I checked the febi website and found alot of hydraulic lifters that fit the specs.
So I sent Febi a question about the weights.
I�ll report when I get something back

kowalski · « **Reply #12 on:** March 20, 2007, 04:28:42 AM »

I'm very excited for this... especially with my valve tick it will definitely be something i'll be doing when i get home from the EU.

Gunni · « **Reply #13 on:** March 20, 2007, 06:30:10 AM »

Update #1.

E30 M42B18 Febi replacement cam follower weight : 70gr. (0.07kg) Not sure if the weight is exact.

E36 M42B18 Febi replacement cam follower weight : 60gr (0.06kg) again not sure if the weight is exact

I�m going to need to compile a list of followers that have the same outside diameter and heigh and get the guy at febi to mail me the weights back,

EDIT : I have now done that and send our friend Florian at Febi the item numbers for various VW, Volvo, Merc, Seat and so on hydraulic cam followers

kowalski · « **Reply #14 on:** March 20, 2007, 03:08:34 PM »

perfect i look forward to these results.