05-14-2012, 11:43 AM #1Member
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m54 e46 330ci installed valve height question and cams wanted!!!!!
I am in the process of installing 1mm larger Ferrea Intake valves and .5mm larger Ferrea Exhaust valves in a M54 330 head. I can't seem to find any data on the maximum and/or minimum installed valve height (which should be fairly critical for the hydraulic tappets) and the obvious valve spring seat pressure. They measured 1.441" on the intakes - when removed, and 1.445" on the exhausts.
Any help would be greatly appreciated!!!!
I am also looking for some new or used cams that are REASONABLY priced!!!!!!!!
Total upgrade includes ---bigger valves, chamber work, valve pocket modifications, port mods, exhaust guides, .040" head mill, time-serts on all head bolt locations, teflon vanos seal kit, new coils, ceramic coated headers, cats removed, electronic exhaust diverter (for the track), 02 simulator, under driven pulley, N20 (100 shot with separate dedicated fuel cell), cold air intake, my garage made (R&D machine shop) over sized electronic throttle body (that does not whistle or jerk like some over priced store bought brands), and then a custom tune.
05-14-2012, 12:15 PM #2
@PEI330Ci should answer thisSome people live long, meaningful lives.
Other people eat shit and die.
I'm not racist, I hate everybody equally; especially fat people.
05-15-2012, 03:58 AM #3
Moved to M54 as I think @PEI330Ci can help you with this.
05-16-2012, 04:55 PM #4
PEI330Ci is at a conference, and will answer you're question next week.Rep Points > Posts since 2010
05-16-2012, 07:09 PM #5
05-18-2012, 07:48 AM #6
Back in 2009 I was having problems with idle on a new engine build, and after doing a leak down test I found that the valves were leaking. With the engine still assembled, I had assumed that I had a lifter clearance issue, and that the valves were being held open.
Taking the head off the engine, I found that the company that did the valve work on the head did a very poor job. None of the valves were seating properly, some with a visible gap between the valve and the seat. We tried lapping the valves, but found that the seat was somehow machined at a slight angle creating too much of a gap to grind down with lapping paste. I sent the head off to my local machine shop, and the problem was fixed.
However, this whole process got me thinking....
I played a bit with the BMW hydraulic lifters; trying to pressurize them to see how much the central portion would move....and couldn't see anything by eye. I'm sure they work, but to my naked eye is very very little movement in the adjustment mechanism.
From a clearance perspective, I was specified 0.20mm/Intake and 0.25mm Exhaust for a solid lifter conversion I was doing on an M54. I don't think that would be too far off for hydraulic lifters.
The bottom line for me is not the seat height of the valve, because you may need to machine that beyond spec to get the correct angles, but the lifter clearance. I definitely would measure the position of the top of the valve before and after having the valve seat cut to see if it has moved. However, I am not an engine builder so I don't know if grinding the top of the valve to get the correct measurement is a good idea. It doesn't seem a bad idea, just not a proven idea to me. Grinding under the lifter bucket, or the top of the lifters I think is a bad idea.
That said, I didn't have any issues with valve seal on the head mentioned above after the 2nd valve seat job....so I guess there's some room to play. Also, the BMW technical manual referencing the angles for the valve seat to be cut makes no mention of the measurements discussed above.
I would run the larger 34mm intake valves, but I would not run oversized exhaust valves. (I've got flow bench data to prove it's not an advantage)
Valve seat pressure: I can't remember for sure, but I think the seat pressure was around 65lbs? I actually tested this a couple of years ago...but then I've run after-market springs on everything I touch so it really doesn't matter to me. I would not pre-load the OEM springs to increase seat pressure, as the valve motion (dynamic response) is still the same once the valve starts to move.
Never seen an O2 simulator work. Not saying it can't be done, just that people struggle.
I have spare M54B30 cams....but I buy them to take the VANOS spline bolts. You can't buy these bolts from BMW, and I like to have a couple of spare for cam swaps. I know is sounds strange, but I can "feel" them start to fatigue if you tighten them a couple of times. I should really find another source. LOL Oh....and if you buy a set of cams, make sure they come with the spline attached, and it has never been removed. They are aligned a certain way, and you need a special tool to put them back on if the bolt is loosened.
If you have any other questions, don't hesitate to ask here or PM me if it's private.Rep Points > Posts since 2010
05-18-2012, 12:18 PM #7
^ That's as detailed as you are going to get.
Thanks for the help.
05-21-2012, 11:34 AM #8Member
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Thank you for your response. From what I have read on this forum, you are the M54 guru!
Grinding the valve stem tip is common and not a problem (if needed). On many engines, you must grind the stems to remove wear patterns (usually seen on rocker arm engines).
I am going to take measurements from a low mileage m54 motor and go with those numbers (that will give me a range between the low mileage motor and this 140k motor). The hydraulic lifters have a range in which they will operate. If you go too large, the lifter will collapse and clack. If you go too tight, you burn the valves. This is the case that you describe from your first head builder. He sank the valves too deep into the valve seats. That caused the valve stem tips to sit too high (and would have caused the valve spring seat pressure to drop substantially unless they added shims to restore the installed valve spring height).
As for the exhaust valve size, I reviewed your flow data. It is very helpful and saved me hours of time doing the same thing. My only question has to do with the chambers when you went with the big valves on the exhaust. The chamber design actually shrouds almost 1/2 of the opening area of the valve. Obviously, placing a larger exhaust valve in the hole will make the shrouding (choking) effect even greater. I went ahead and de-shrouded the valves although I am only going with .3mm over sized exhaust valves (based on your research and my desire to get the valve head to sit further out of the seat area to improve flow at low valve lifts). Did you engine porter do any chamber work for the over sized exhaust valve flow data you posted?
I also pressed reducers into the intake port holes for the crank case vent system. Those holes were too large and had an impact on the flow. I am also adding a catch can and using a vac-u-pan system to vent the crank case. The vac-u-pan system is old school but it really works. You simply take an exhaust one way check valve from a 70's or 80's era American car (used as part of the air injection system on the exhaust manifolds), take a 3" piece of 1/2" pipe, cut the pipe on a 45 degree angle to create a venturi effect, weld the pipe into one exhaust pipe below the car, attach the check valve on the pipe and connect a hose from the catch can to the valve. When the engine is running, the exhaust velocity will create a large vacuum and pull the engine blow by out the exhaust. If there is any exhaust back pressure (blocked exhaust, backfire, etc.), or low exhaust speed at idle, the check valve instantly seals and prevents exhaust from pressurizing the engine. This will keep the intake system spotless, virtually eliminate any possible oil leaks, help keep the oil cleaner and make more power! (At least it did back in the day.)
Concerning O2 Simulators --- What do you suggest?????? I am running the upstream 02 Sensors but the cats are being given a rest.
05-21-2012, 08:24 PM #9
One trick we used to test valve's sealing was to put alcohol into a port and see if it would stay. This is obviously with the head installed on the engine block with the cams installed.
Regarding the port work: Erland Cox is the guy you want to talk to. He's made some great posts in the advanced tech section on the speedtalk forum.
I'm familiar with your choice of evac system....I see it a lot at the drag strip. With a cat converter in my exhaust though, I'm a little reluctant to use it.Rep Points > Posts since 2010