When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I think you'll be fine. Those studs put an enormous amount of torque down on that head. Those bolts look brand new to what I've removed.
If I recall correctly, when doing the rotational torque sequence on mb head bolts, we were hitting around 80ftlbs.
That's funny, I was thinking as I was removing those bolts that they felt like they were only 80ish ft lbs. Which is a huge difference compared to the 110 ft lbs the ARP studs call for. So, I'm still crossing all my fingers and toes for the passenger side of the block. Something I'm curious about, since it sounds like you've done a few of these; my repair manual says that anytime the cam phasers are removed, they have to be recalibrated using the STAR diagnostic system. Did you have to do that? Or did everything work out as long as you used the phaser tool to get them located properly???
Just an FYI Justin, the updated bolt design, while they are a better design than the previous bolt design, they are still a torque to yeild bolt, which means they are designed to stretch. The ARP studs are very rigid and they can sustain a much greater torque than even those updated factory bolts. Even if you aren't running the blower, they can still stretch like the older, poorer design bolts and cause leaks.
Been thinking about the updated bolts vs ARP studs for the last couple of weeks. Just ordered the studs. Decided, do it once do it best. Labor price is the same either way since I ain't messing with these heads.
By the way, have you taken a look at your cams, buckets, cam phasers? I passed on an r63 I had closely inspected as the with the valve covers off 2 cams were clearly worn.
Been thinking about the updated bolts vs ARP studs for the last couple of weeks. Just ordered the studs. Decided, do it once do it best. Labor price is the same either way since I ain't messing with these heads.
By the way, have you taken a look at your cams, buckets, cam phasers? I passed on an r63 I had closely inspected as the with the valve covers off 2 cams were clearly worn.
Regards,
Justin Wade
2007 R63
I have, I'm replacing my old valve buckets with the SLS valve buckets, my cams look good and phasers are what they are, I hear they quit randomly and there's no warning and no real way to determine when they're going to quit. So, I'm putting the old ones back in for now, we'll see how that goes.
You don't need to recalibrate anything if you put it back together with the mb tools correctly and the tooth gears on the cam are secured and don't move.
You need the flat edge placed in the back of the cam, flush with the head surface. The cam holder over the top front and the phaser plate over the phaser. Loosen the big bolt in the phaser, get the cam setup where it should be in relation to the mb tools and set the phaser with the plate, then tighten that big bolt. All this MUST be done with the engine at 40degrees.
I have, I'm replacing my old valve buckets with the SLS valve buckets, my cams look good and phasers are what they are, I hear they quit randomly and there's no warning and no real way to determine when they're going to quit. So, I'm putting the old ones back in for now, we'll see how that goes.
Looks like all the cool kids are on the forum right now. My fingers are crossed that my cams look good.
I haven't figured out what the deal with the cam phasers is, but at $650 each I decided to do nothing with them preventatively.
But at least we can have faith my ARP head studs won't break And for the price I hope they give me hummers too.
Looks like all the cool kids are on the forum right now. My fingers are crossed that my cams look good.
I haven't figured out what the deal with the cam phasers is, but at $650 each I decided to do nothing with them preventatively.
But at least we can have faith my ARP head studs won't break And for the price I hope they give me hummers too.
Regards,
Justin
Ha! I concur! $1k was REALLY hard to gulp down for 20 bolts, but I justified it by telling myself that a used m156 on eBay was, at minimum, $10k if I blew mine up, and the cost was going to only balloon from there if I had to rebuild one I got used. So, with 25k miles on mine, I decided that a $2500 investment in some bolts, lifters and gaskets, etc, was well worth it. AND, as an added bonus, if I get real stupid one day and decide that I need to strap a $12k blower to the top of my m156, the foundation will already be laid. 😆
You don't need to recalibrate anything if you put it back together with the mb tools correctly and the tooth gears on the cam are secured and don't move.
You need the flat edge placed in the back of the cam, flush with the head surface. The cam holder over the top front and the phaser plate over the phaser. Loosen the big bolt in the phaser, get the cam setup where it should be in relation to the mb tools and set the phaser with the plate, then tighten that big bolt. All this MUST be done with the engine at 40degrees.
Well, I've got the tools and the manual, I only lack the experience at this point. I'm taking my time, working from the manual and trying to triple check my work so as not to miss anything or do any damage.
dang my thread is back from the dead and on fire. Just an update it's been about 10k since the repairs and everything is running flawlessly. Only other issues since then is killing tires and a power steering pump i don think they like seeing redline that often.
Ha! I concur! $1k was REALLY hard to gulp down for 20 bolts, but I justified it by telling myself that a used m156 on eBay was, at minimum, $10k if I blew mine up, and the cost was going to only balloon from there if I had to rebuild one I got used. So, with 25k miles on mine, I decided that a $2500 investment in some bolts, lifters and gaskets, etc, was well worth it. AND, as an added bonus, if I get real stupid one day and decide that I need to strap a $12k blower to the top of my m156, the foundation will already be laid. 😆
Anyone know the length and thread pitch of ARP studs?
Anyone know the length and thread pitch of ARP studs?
They're different threads at the bottom of the stud than at the top of the stud. I think the bottom threads are metric, and I believe the top threads are 1/2 - 20, but I'll verify that tonight and let everyone know. The only other thing I think that sets the ridiculously expensive Weistec studs apart from anything else on the market is they are stainless steel and are incredibly strong. Stainless because they go into the water jacket and are constantly submerged in coolant, which is why I believe the original bolts have a tendency to pop the heads off because a small amount of corrosion develops where the bolt head meets the shaft and weakens that fastener. At any rate, I'll take some pictures with measurements and thread pitches tonight when I get home.
They are ARP 625 studs which I believe are the strongest tensile strength studs ARP makes. ARP isnt going to sell you studs because you copied weistecs threads. You need all kinds of info, deck height etc etc before they will make you studs.
The MB bolts snap because of a faulty design with little material around the head from the female torx.
They are ARP 625 studs which I believe are the strongest tensile strength studs ARP makes. ARP isnt going to sell you studs because you copied weistecs threads. You need all kinds of info, deck height etc etc before they will make you studs.
The MB bolts snap because of a faulty design with little material around the head from the female torx.
Anyone know the length and thread pitch of ARP studs?
Here you have it; the overall length of the stud is just shy of 8 inches, the thread size and pitch on the bottom is M11 x 1.5 and the thread size and pitch on top is 7/16 x 20. While I'm guessing it's not necessary that the top thread be different than the bottom thread, I'm sure ARP used the more readily available to them, standard hardware. At any rate, I'm in no position to tell anyone what to do, so while I'm sure you could find a similar stud kit with the same 7/16 x 20 thread on top, I'm guessing the M11 x 1.5 is what makes this particular stud unique. But if you did, I believe what Merc63 said still holds true; ARP makes the strongest, most durable hardware known to man. That's why their hardware is in just about any racing engine, anywhere in the world. They're expensive, but they don't break. Period. Just my $.02.
Just order them from Weistec, look what these guys have done for this platform. If we don't support them, no more cool goodies for us is the way I see it.
Side note, you don't even need studs unless your going with a blower. The revised bolts are just fine for an NA engine and a hell of a lot cheaper.
Just order them from Weistec, look what these guys have done for this platform. If we don't support them, no more cool goodies for us is the way I see it.
Excellent point dude. Those guys engineer some of the best stuff for our vehicles and in addition to that, they have phenomenal customer service. They had accidentally sent me a second order of cam phaser bolts when I had actually ordered the cam cap bolts. I contacted Weistec on a Friday morning, they had the cap bolts in a box and next day aired them to me with Saturday delivery. I work for UPS and know exactly how expensive it it to next day air something, let alone including Saturday delivery. I told the customer service rep that I dealt with, Zack, that they'd earned a customer for life with that gesture. Buy from Weistec if you can afford it.
Just order them from Weistec, look what these guys have done for this platform. If we don't support them, no more cool goodies for us is the way I see it.
Side note, you don't even need studs unless your going with a blower. The revised bolts are just fine for an NA engine and a hell of a lot cheaper.
You could get away with the 425 for not much more than the TTY OEM revised though.
Ive got a set of new updated stock bolts laying around i'll let go for 120$ shipped in the u.s. They go for around 20$ a bolt and there's 20 of them, which is quite a discount if anyone is interested. just figured i'd throw that out there
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
And for the price I hope they give me hummers too.
and a power steering pump i don think they like seeing redline that often.
