My head rebuild, valve springs, seals, cams

[TH3 Shifty]

So I thought I would share my head rebuild, seeing as I have not come across one that incorporated all of it.

So first off this isn't really a "how to" but there are a few things I can show to make things go a little easier.

Reason for rebuild:
I noticed oil consumption was going up, about a quart every 800 miles.

Symptoms: smoke on deceleration
This is a sign of bad valve seals. If I was on acceleration is usually rings. Compression check was 6% difference across the cylinders in the 190 range.

So since the head needs to come off to do these, the head gasket and everything will be done.

So first off, I started the tear down


486906

This is the valve cover removed

Then moved onto removing the cams, I used the tools from Baum Tools, 100$ on eBay to get the cam turning tool, tensioner pin, cam blocks, and flywheel lock pin.



486907

I also removed the intake manifold and other various parts

I got the head off, then realized my valve spring tools I used on my LS1 car would not work on this head. The BMW specific tool was over 300$, a generic C clamp tool was 100$, so I decided to make my own tool.

I started out with 1/8" steel flat bar. Drilled a hole and welded a nut onto it.

486908

Weld looks like crap because I had to flux core weld it. Then I made a bottom plate, with cuts made from my cut off wheel. I used the cam bearing ledge studs as the brace and the nuts to hold it down. Used a 14mm 6" long bolt to bolt throught the welded nut and put pressure on the plate, which pushes down the springs to unlock the valves


486909



486910



486911



486912



486913

As you can see, you can do 2 valves at once. Cost me $8 in materials and 1hr to make.

Removed all valves, sent the head to the machine shop for cleaning and deck surfaced, got the head back today


486914

I started the intake valve assembly already, I'll be posting pictures of how to assemble the valve seats, valves, seals, and springs tomorrow

[flyfishvt]

Nice tool. wish you had posted this a year ago. I was struggling with the valve keepers on a rebuild M50

[pbonsalb]

That looks like a good solution. Could someone without a welder just double nut on both sides of the lower plate?

I had thought about making a fitting for my drill press, so I could quickly lever down. I once used a little twisty tool that fit perfectly, but which was tiring to use 24 times.

[TH3 Shifty]

Well I'm not sure a double nut would work. But you could tap the hole instead. I didn't have a tap big enough and I knew it would take longer to do do that's why I welded it

[cward]

Very nice! I did this same job back about 10 years ago on my 95. I think the hardest part was removing the intake manifold.

[TH3 Shifty]

Ok so I completed the valve install, VAC springs and seals.

These are the valve Goetze seals, come in a 12 pack so you need 2 packs for a full head. Unlike GM cars, there is no difference in intake seals and exhaust seals.


487009

I first started off by wiping down the valve, then lubing the valve tip and stem with new 5-40w synthetic oil, this helps slip the valve into the guide.
Once the valves are in, you then place the steal valve seat on,


487010



487011

Then if noticed in the valve seal package, 4 little red things. These are valve stem condoms. You slip these over the tip if the valve stem. These help the seals not catch on the grove at the top.


487012

They slip pretty easily over the valves


487013



487014

Next come the valve seals


487015

You need to lube them before install, I used the same 5-40w oil, poured some in the cap and used a pick tool to help


487016

You don't need any special tools for installing these seals, the BMW book states to install using hand pressure to seat them. They simply slip over the condom, and I pressed them down to the base with my thumbs


487017



487018

To remove the condom, it's covered with oil, I used a pair of needle nose plyers. They slip off easily, don't grip them too tight as they are just plastic


487019

Next come the springs. Since I'm at 148k miles and thinking about cams, I decided to go to VACmotorsports and get their upgraded valve springs. These are meant for mild cams like schrick 256/264.
Shown below are the difference in height. New spring on the left, stock old spring on the right.


487020



487021

Place the springs over the valve stem and seat them in the spring seats.


487022

Then place the retainers on top of the springs


487023



487024

I then used my tool I made, to depress the springs down and insert the tedious part of installing the valve locks, there are 2 per each valve stem, it's handy to have a small weak magnet for install and well as a set of picks. My picks happen to be slightly magnetized already so that really helped out.

I didn't take picks of the locks install, but here are the valve locks


487025

The attach at the top of the stem, you then, slowly release pressure in the tool, the retainers sandwhich the locks into the retainers, done.

[najnad]

Subscribed, I am going to have to have my head gasket done soon, will want to get as much done as long as the head is off as possible.

Anyone recommend pre-emptive replacing the rings? Is there a normal wear cycle for those?

[TH3 Shifty]

If anyone is interested in a tool I made for the valve springs, PM me, I am going to make some

[david2991]

Hey I was about to post a question to the board... I am spending lots of time and money getting a 95 m3 up to spec and while my mechanic was doing the oil gasket he noticed the side of the head said 2.5. Can you tell me what is stamped on the side of your head on your motor says? I am very concerned I bought a 95 m3 with not an M motor... Thanks in advance.

[hide1]

http://i5.photobucket.com/albums/y160/AD_Happy/BMW%20Parts/vacSPRINGS.jpg


Cool info!

It would be good to know stock vs VAC: spring coil bind heights & seat pressures at peak cam lift. A good valvespring will not have overly excessive seat pressure and slightly oval coil to avoid binding and subsequent damage to cams/ head. You aren't running aftermarket cams but this would be good info to know for those who will.

[IR M5]

Man its looks like the PO neglected to change the oil on a regular basis, look at all that varnish!
How many miles are on this car?

[TH3 Shifty]

148k, I originally bought the car in 07 with 79k miles. Changed oil pretty regularly with 5-40 synthetic. Not sure what was used for the first 80k miles

Sold it at 106k miles, who the hell knows what he used. Bought it back at 136k miles

[uconnr]

Hey I was about to post a question to the board... I am spending lots of time and money getting a 95 m3 up to spec and while my mechanic was doing the oil gasket he noticed the side of the head said 2.5. Can you tell me what is stamped on the side of your head on your motor says? I am very concerned I bought a 95 m3 with not an M motor... Thanks in advance.

Head castings are essentially the same between M50/M52/S50/S52 motors so they all say 2.5 on them.

[TH3 Shifty]

Yep, mine says 2.5 on the side as well

[RobertFontaine]

Nice set of pictures... Will be going into my engine next fall with a little luck and posts like these help

[david2991]

Yep, mine says 2.5 on the side as well

Thank you!!

[TH3 Shifty]

In getting ready for new cams, I had to remove the vanos gear off the intake cam. It's on there pretty tight, I placed the front of the cam in a vice

And used an H10 Allen impact socket with a 2 ft breaker bar, and slid a 4ft jack handle over that to break it loose


489449



489450

I'm going with RiotRacing regrind S52 cams. For 18-20rwp for $450. Schrick claim 20-25 but cost $1100

Don't need to hear the debate of Schricks vs Riot vs Sunbelt vs whynotgoforcedinduction debate

[28Chillin]

Cool info!

It would be good to know stock vs VAC: spring coil bind heights & seat pressures at peak cam lift. A good valvespring will not have overly excessive seat pressure and slightly oval coil to avoid binding and subsequent damage to cams/ head. You aren't running aftermarket cams but this would be good info to know for those who will.

If these are the springs in question, VAC says they add about 10 lbs. seat pressure. (http://store.vacmotorsports.com/vac---high-pressure-oe-style-springs-for-m52--s52us-p2402.aspx) Also, Here's excellent data on the stock springs. (http://forums.bimmerforums.com/forum/showthread.php?1210231-Valve-spring-comparison-M50-vs-M52-vs-S52)

Thanks for the write-up, Shifty, good stuff. Can you post a picture of a combustion chamber?

[TH3 Shifty]

Yep those are the VAC springs I just put in.

I didn't take a picture of the chamber, the head is on now, and torqued down, sorry


My Riot racing cans shipped out today,

[TH3 Shifty]

Cams from Riot Racing came in today


490015

[ak5]

subd

[Da Infammus 1]

Another cammed, refreshed estoril sedan. Gotta love it. I did mine differently than yours but I think I went overkill lol. Nice job, keep it coming!

[TH3 Shifty]

490218

Cams are in, hopefully I did it right, I followed that Guide from you tube, looks like its right

[Economist]

This is great. Can't wait to hear what you think of the refreshed head and cams.

[TH3 Shifty]

Would have finished it tonight, had to work at 6, need to finish the valve cover, intake, fan, wires for the new VDO gauges, torque the Bimmerworld oil adapter, place pcv air tube, drain oil, fill oil, fill with coolant

That's the major stuff left, very nervous as this was my first time messing with BMW internals and the VANOS timing

[TH3 Shifty]

:UPDATE:

finished everything last monday. I've been driving it for a week. Start up was peferct. It searched for an idle for about 20 seconds then just hummed perfectly.

power: wow, these cams are fantastic. The pick up range is around 2k-6500.. much more power than before. This is like a whole new car.

current mods:

M50 Manifold
Bimmerworld M50 kit
Cold air intake (3" tube, foam filter located in lower bumper)
stock MAF
Bimmerworld 90* instake elbow
traction delete
Stock injectors
Stock Tune
Beisan system VANOS rebuild kit
Bimmerworld Fan Delete
VAC valve springs
Riot Racing Cams
stock headers
AA track pipe
Stromung exhaust

I do have access to 2 different Dyno's.. a DynaPack5000 and a DynoJet. In a few weeks, i'll head to both to get numbers, right now i only have 105miles on the rebuild, want to at least have 3-500 miles on it.

in the future im going to get EpicMotorsports cable and remote tuning, as i have heard nothing but good things from them.


Anyone intrested in doing the Riot Racing cams.. DO IT.. they are great.. I followed the DYI on you tube, and it was easy to follow and he covers everything.

[MarketMaster]

why must everyone continue to tempt me with these cams.

[TH3 Shifty]

Because we must, the bang for the buck is awesome

[aeronaut]

^ Damn it. If I do my vanos this winter, I just may go all in and do the RR cams on my 95.

[Da Infammus 1]

Because we must, the bang for the buck is awesome

If I didn't find a deal on VAC cams I'd have definitely done these instead. Although the bigger cam idle is pretty gnarly lol. Glad to hear the good results! I'd also say the dyno jet is going to give lower but more accurate results

[TH3 Shifty]

If I didn't find a deal on VAC cams I'd have definitely done these instead. Although the bigger cam idle is pretty gnarly lol. Glad to hear the good results! I'd also say the dyno jet is going to give lower but more accurate results

Actually that's a misconception, the DynaPack5000 AWD direct hub Dyno notoriously reads lower, with DynoJet having the highest readings.

My friend owns the Dyno, bought it direct from New Zealand where they are made, I used to work in his shop yrs ago, setting up cars on his system, people would always get upset at the numbers compared to what they pulled on a DynoJet. The DynaPack can/does simulate real world world scenarios. It's a tuning Dyno and not a numbers Dyno. Almost all F1 teams use it, and a large portion of GT teams use it.

You can't fake the or stack the numbers like you can on a roller Dyno. Such as tightening the straps, or slipping the clutch or dropping the clutch, inflating or deflating tire pressure. All those are variables on roller dyno's where as the DynaPack, is directly connected to the hub of the car, and used fluid inertia to push against.

Example: my bone stock 98 LS1 car, did 292rwhp on his DynaPack, same day, 2hr later did 319rwhp on a DynoJet, let tire pressure down to 24psi and pulled 325rwhp.

Not advocating one or another, not trying to start a pissing match, but I've had 7-8 yrs of experience in a Dyno shop working with both

[Da Infammus 1]

Well that's something I didn't know, thanks for the info! I always thought a dynojet read lower. My car read higher on a mustang dyno than it did on a local dyno jet, maybe that's where my misconception spawned from