'86 535i M30B34: Camshaft Conundrum

[code]

I'm doing some maintenance on my bone-stock '86 535i and am at a crossroads with regard to the head. Just a touch over 164k miles, 2nd owner, not abused. I'm doing the headgasket and related items, and took the head down to my local machine shop to have the valve seals replaced, the valves cleaned and lapped, the head cleaned and pressure-tested, and decked (with the top timing cover, too). The head is in perfect shape, but a few of the camshaft lobes are worn out of spec, and a few of the rockers show wear as well. Camshaft and rockers (and associated hardware) will need to be replaced.

Here's where I'm stuck. The stock camshaft is NLA, and finding a good B35 camshaft hasn't been fruitful as of yet. Also, I've read that putting a 284 cam into a stock head might not yield the best results.

Option 1: Find a B35 camshaft (or a Bimmerheads 284 regrind), with HD Rockers, rocker arm locks, rocker arm shafts, springs, etc. Cost should be around $700. Results could be mixed ... some say there will be a lumpy idle, some say it works fine with Motronic 1.0 and a stock head.

Option 2: Get the complete performance head assembled from Bimmerheads, totaling about $1650 if I turn in my head as a core, with all of the above (plus a few extras), including extensive porting and polishing. From what I've read, the work done to the head should make the 284 cam more streetable.

Curious if anyone has personal experience with the Bimmerheads performance head, how it idles, low end torque, power band, etc., and if it's worth the extra outlay vs. being patient and finding a B35 cam and using my stock head. Thanks in advance!

[SlickDizzy]

Don't overthink the head work too much unless you plan to add a lot of compression in the future, the US low compression B34 can't take advantage of much more than a mild cam upgrade. I wouldn't put a heavily worked head on a stock 8:1 bottom end, the low compression combined with the extensive porting will cause a big drop in charge velocity and the thing will drive like a dog at low RPM.

Bimmerheads charges a lot of money to do heads with grinding stones and not a Serdi-type cutter (which is recommended for the M30), and they claim that their regrinds don't require oversized eccentrics, which is...not typical. There was also a guy on here who got his head back with a ding in it that wasn't there when he sent it out. Others have had good experiences though so

If you can't find a B35 cam I'd probably buy a new billet cam before buying a regrind: https://www.iemotorsport.com/product/ie ... ate-style/

[JohnH]

I think its worth pointing that a "bone-stock" 535i uses an M30B34 not a B35. Have you changed the engine?

[kojo96]

Look here, Andy is a good guy and very reliable. Also, and since you're doing all that work, I'd look into new valve train parts, rocker arms, possibly rocker shafts/bushings depending on their condition, the rear "duck gasket!!", banjo bolts & crush washers, and your eccentrics if they look bad. Rocker arms I'd do for sure with a new cam, the other parts are a while you're at it kinda thing but I'd give it some thought.
Look up modifying the oil spray bar at the #1 cam lobes, a slight pinch helps oiling at the #1 cam lobes.

viewtopic.php?f=4&t=154405

[code]

Thanks everyone for your time and input. I’m planning to keep the car OEM+, I should have mentioned that in the opening post.

John, you’re correct, it’s an M30B34 with the 3.2/3.5 intake manifold.

SlickDizzy, thanks for that info. That was my main concern; losing performance after putting in a performance head.

Kojo, thanks for the info about the spray bar above the #1 lobe, I hadn’t heard that before. #1 is one of the lobes that’s worn. I was also using 20w-50 dino oil, but only put roughly 2000 miles on the car since I’ve owned it. After this I’ll be using an oil with ZDDP. Also planning to do the rest of the items you mentioned, I’m a firm believer in doing things right the first time.

[Mike W.]

It's always the first cam lobe that wears first. I take a different tack, I ream out the hole in the oiler bar for #1 with a 1/16 drill bit to get more oil there. Just the #1. I've also seen the oiler bar put in backwards which guaranties oil starvation up front.

As to wear with the OP only putting a couple of thou on the car, unless you have a perfect record of it's history, no telling what happened before, banjo bolt loose or MIA, 5-30 oil from a quickie oil change place, 15K oil changes and so on.

[code]

It's always the first cam lobe that wears first. I take a different tack, I ream out the hole in the oiler bar for #1 with a 1/16 drill bit to get more oil there. Just the #1. I've also seen the oiler bar put in backwards which guaranties oil starvation up front.

As to wear with the OP only putting a couple of thou on the car, unless you have a perfect record of it's history, no telling what happened before, banjo bolt loose or MIA, 5-30 oil from a quickie oil change place, 15K oil changes and so on.

Thanks Mike for that tip on the #1 oiler. And agreed, although I’ve maintained it properly over the last two years and have a binder of records from the PO, there’s something that caused this lobe wear.

[adam_poll]

I just went through something similar when I replaced the headgasket on my M30B34 a few weeks ago (I had external oil and possibly coolant leaks from the gasket after 400,000 km). I was lucky enough to have a spare B35 head that I pulled from the junkyard that had been gone through soon before the car sadly ended up there so it had a brand new set of Febi rockers along with a cam that showed no wear. I ended up moving the rocker shafts (mostly because these ones had the hex plugs in the end rather than the flat plugs so they were easier to install/remove), the new rocker arms and the B35 cam to my B34 head, the springs and clips are all original and seem like a fine solution to me in a pretty stock motor to keep the rockers located.

All this to say, I'm happy with the B35 cam, it made a noticeable difference over the last 500 -750 rpm where the stock cam falls off as you pull to redline. Maybe there is a slight penalty down low below 3500 rpm but it is really hard to say, this is all just butt dyno. My car is mainly used on the track and at autocrosses so 3500 - redline is where this engine spends its time. Down the road I'd like to do a high compression build with an aggressive cam in that B35 head but for now this will do (I also didn't dig into the head right now as deeply as you because of this).

[code]

After seeing what’s available and wanting to do what’s best for the car and my budget, I’m looking at the following from ireland Engineering:

12 Heavy Duty Rocker Arms
1 IE New Billet Performance Camshaft - M30 Late, 270 Grind
12 Rocker Arm Eccentrics
12 Rocker Arm Hardware
12 Rocker Locks
1 Rocker Shaft Hardware Kit
1 Rocker Shaft Set

I’ve read polarizing info about the IE camshafts, but I don’t want the lopey idle that a 284 cam would do to a stock M30B34. It will be new billet and not a regrind — has anyone had a negative experience with their new billet camshafts?

[Tiit]

Sub’d

[code]

Ordered the parts from IE. When they get here, I'll post photos before assembly

[code]

The IE parts have arrived, but there are some quality issues. I'm in contact with customer service to get a few of the rockers and the camshaft returned and replaced with satisfactory examples.

[LeiseyJr]

After seeing what’s available and wanting to do what’s best for the car and my budget, I’m looking at the following from ireland Engineering:

12 Heavy Duty Rocker Arms
1 IE New Billet Performance Camshaft - M30 Late, 270 Grind
12 Rocker Arm Eccentrics
12 Rocker Arm Hardware
12 Rocker Locks
1 Rocker Shaft Hardware Kit
1 Rocker Shaft Set



I’ve read polarizing info about the IE camshafts, but I don’t want the lopey idle that a 284 cam would do to a stock M30B34. It will be new billet and not a regrind — has anyone had a negative experience with their new billet camshafts?

A 284 cam does not give a lumpy idle.

[code]

A 284 cam does not give a lumpy idle.

That's news to me! Everything I've read said a 284 would be aggressive and lopey in a stock head with m30b34 N/A compression. I couldn't find any video of a stock car with a 284 cam.

[code]

The replacement new billet 270 degree camshaft from IE arrived today. The first camshaft they sent looked like a regrind and had small raised bumps across the lobes, but to their credit they sent this replacement right away. This new billet cam has grooves across all of the lobes, deep enough that they catch your nail. Is this normal for a new cam, or should the lobes be polished smooth like the cam journals?

[SlickDizzy]

I haven’t bought a ton of cams, but when I have they’ve always been polished or at least smooth on the contact surfaces.

That kind of roughness seems like it could wipe out a set of cast aluminum lifters in a hurry. If you can catch a nail, that can’t be right. The cam bearing surface doesn’t look perfectly round either, but maybe that’s just the lighting.

For a quick expert opinion you might want to post this on a more active message board like the Grassroots Motorsports forum or similar.

[code]

Thanks, I’ll wait to hear what Ireland says first. I checked the lobes again, just to be thorough, and you can really feel the ridges just with your fingers. I think you’re right in that this would destroy those brand new rockers.

[Mike W.]

I haven’t bought a ton of cams, but when I have they’ve always been polished or at least smooth on the contact surfaces.

That kind of roughness seems like it could wipe out a set of cast aluminum lifters in a hurry. If you can catch a nail, that can’t be right. The cam bearing surface doesn’t look perfectly round either, but maybe that’s just the lighting.

For a quick expert opinion you might want to post this on a more active message board like the Grassroots Motorsports forum or similar.

The rockers are aluminum, but have a hardened wear pad, steel/cast iron I suspect, but much harder than Al. Still, I think you're right, looks like a file that would wipe them out.

[RobertRO]

dbilas Dynamic in Germany has an interesting offer of new BMW M30 camshafts. You may want to check them up:
https://dbilas-shop.com/en/engine-valve ... -camshaft/

Back in 2015 I purchased a dbilas M30 camshaft p/n 04.042.008. The quality of the product was excellent.

[code]

IE got back to me this morning via email, after seeing the photo of the lobes they feel that I received a raw camshaft. Waiting to hear if they have a finished 270 new billet cam available.

[Tiit]

I was almost ready to order a cam from IE, but I'm not so sure about it anymore. Quality control seems extremely sloppy and they should get it right at least the second time.
Why did you remove the first set of pictures? Truth should be out there.

[code]

I was almost ready to order a cam from IE, but I'm not so sure about it anymore. Quality control seems extremely sloppy and they should get it right at least the second time.
Why did you remove the first set of pictures? Truth should be out there.

I agree that QC is sloppy, but the customer service has been nothing short of great. They sent out 12 new rockers (which were perfect) and said keep the others that were good as spares. The quality of the second cam was good, it just wasn't finished. Not making excuses, though, I agree the replacement should have been checked before being sent.

I am sending the two camshafts back, but can take pictures for posterity. I wouldn't hesitate to order from them ... hopefully I'll have the finished 270 cam here by the weekend and can post photos of that. Now, if the third cam is not up to par ...

[code]

The third camshaft arrived this morning. Feels like I'm taking a step backwards here. While it doesn't have the raised bumps on the lobes that the first camshaft had, the lobes on this camshaft are the same (not polished). Attaching photos of the first cam, and a side-by-side with #2 and #3. Is the third cam (on the right in the side-by-side) what I should expect to receive for a new billet? Notice the slot in the cam journal is shorter, also (if that is of any significance).

Camshaft #1


Camshaft #2 (on left) and Camshaft #3 (on right)

[code]

I reached out to IE this morning, and Jeff Ireland provided some insight. He said, "We buy the unfinished cams so we can do various different grinds locally. Our cam grinder gives the cams a coating to aid break in and prevent rust." Makes sense, if these are coated the way they are that they wouldn't have a high polish. There HAS to be more members out there who have purchased IE camshafts. Right now, I'm leaning towards running it since the lobes are indeed smooth.

[SlickDizzy]

There HAS to be more members out there who have purchased IE camshafts.

They have a pretty mixed reputation on this board, the M30 cams have been discussed a fair bit but as far as I know you're the first to buy one and post about it.

They sell a LOT of M10 cams to 2002 guys, it's what they built their business on, you may have better luck getting a point of reference from an 02 board or asking on a board with lots of general engine building knowledge like GRM.