E36 S50/S52, single VANOS, and VANOS shims.

[kalimero56]

It's a weakness of any interference engine ... which is probably 100% of modern engines. You probably can't get valve pockets deep enough to eliminate the issue, but it can be reduced for sure. I overreved my build m54 to 12900 rpm. There was no valve contact, but the vanos sprockets broke apart. This was with massive piston pockets, supertech springs, and solid lifters (which help with the valve float a lot). So it CAN be helped, but I think I still got very lucky that it didn't grenade the engine.

I think you you should not worry about the $shift, and just build the engine in a proven way ... it can happen, but if you back-hand the 3->4 shift, it's pretty unlikely.

Quick question guys if anyone maybe knows, what are the biggest cams i can safely run on my m50b32 non vanos by that i mean max lift, duration etc without my double springs binding? Any ideas? Thanks in advance

[dallas02E39]

Great timing on this topic. Going to clay measure clearance on my S50, 12.5/1 CP Pistons, Supertech Springs, Epic Race Cams (.276/273) this weekend. Been running the car with a thick Cometic head gasket but now time to see how it works with a "normal" head gasket. Also on the springs topic, I had been using Supertech springs with Titanium retainers which ended up causing problems for me. Over time the retainers wore unevenly on the spring and caused guide and valve issues, it was hard to see when on the spring. I am now using the steel retainers.
My plan is to cover the piston top with clay then install the head with the gasket and bolt it down (running ARP studs so not an issue). Then install the came bearing retainers but only install the lifters for cylinder 1, on the intake cam. Keep the #1 piston to to center then gently rotate the cam thru a revolution. Take it apart and measure the thickness of the clay in the valve recesses. Question is, will this read accurately without oil pressure in the lifters? Is the
I have a Vanos eliminator kit but doesn't disabling Vanos also require a change in the ECU?

[NeilM]

In an ideal world the hydraulic lifter's internal check ball would retain internal pressure and this method would work. But in the real world we know that they wear and leak down, so I don't see how this could possibly be relied upon for such a critical measurement.

I'm guessing that for clearance measurement one might want to use a properly shimmed solid lifter, perhaps even a dummy lifter made or modified for the purpose.

[dallas02E39]

Thanks Neil, that was my concern. I have thought about taking a clay measure between TDC and the valves and then factor in the lift (276\.449) but I am not sure that is a true 1 to 1. I like the dummy rigid lifter idea...

[bluptgm3]

Thanks Neil, that was my concern. I have thought about taking a clay measure between TDC and the valves and then factor in the lift (276\.449) but I am not sure that is a true 1 to 1. I like the dummy rigid lifter idea...

There is a guy running M50 non-VaNos to 8k rpm. He has developed a solid lifter shim kit. Talk to him about getting 2 possibly 4 solid lifter setups.

I think “someguy2800” is who you are looking for.

[pshooter]

When checking valve to piston I use a "soft" spring. The ones I have kicking around are from old Mikuni M/C carbs. The hardware store is a good source.
I can use my finger to open the valve.
As you rotate the crank at any time you can push on the bucket to open the valve beyond cam lift, with an indicator you know how much room you have.
I also generally use small pieces of soft solder as it permanently deforms and is easily measured with a caliper. Usually .060" If it doesn't hit you are good to go.

Ti retainers are a maintenance item. Titanium doesn't like to rub or slide against other metals.

[aeronaut]

Great idea on the soft springs. If using solder, yea, best to use the lead solder, it's softer than the lead-free.
(My experience is from my 2-stroke engine days.)