Technical Lots of contradicting N54 Head Stud Info online…..who’s got the facts?

rev210

Corporal
Feb 24, 2019
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335i - 08 Coupe .
Apparently there are some other OEM manufacturers bolts that can potentially act as an effective and low cost upgrade. Zero to 60 channel on YouTube had a go with some larger Hyundai diesel ones from memory (with clamping torque increases noted)
 

Jern54

Sergeant
Oct 18, 2019
289
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E91 N54 335i
Agree about the pump fuel for sure. You can push stock gear further if you regap the rings (open them up), this is a general rule for power vs gap . That's where most of the issue is for the ringlands on stockers but, if the pistons are comming out for that it begs the question.
Correct, but I haven't seen anyone so far who has done this.
It would be very interesting how far you can go with this set up on twins and ST.
 

IQraceworks

Corporal
Jul 7, 2020
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07' BMW 335i
Agree about the pump fuel for sure. You can push stock gear further if you regap the rings (open them up), this is a general rule for power vs gap . That's where most of the issue is for the ringlands on stockers but, if the pistons are comming out for that it begs the question.

Yep.....I agree. Tight ringlands in these motors is what causes most of the broken ringland issues.....even on lower poweered motors. That's what it makes my wonder if I should just pit a stock cast piston back in my motor, install all new rings on all the other pistons, run larger ring gaps...and run it. I can think of all kinds of other cool things I can do with $2K besides dump in into forged pistons and rods.
 

shushikiary

Sergeant
Jun 4, 2018
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335xi
After having measured enough sets of pistons, I would not trust it when they say their forged set are made small enough for a simple re-hone.

I'd order the pistons and rods, do your full balance work up to get it well balanced, re-balance the crank, then measure all the piston skirts properly with a micrometer and then hone each cylinder to match the piston you picked for it with a proper torque plate to the proper clearance for each piston. Then once your hone is proper you can actually set proper ring gap for you power level. A proper material piston, top ring, and second ring with a napier will really help make sure you don't have issues (keeps oil from lowering your effective octane).

If you don't do that and one of your pistons is off, you're asking for piston slap when cold on those forged pistons.

You might get away with a larger ring gap on cast pistons and a ball hone if you're confident in your detonation control.

If I was you, the question I'd be asking my self is, what is my risk tolerance? How much wallet pain am I willing to have to make sure I don't have to do all the labor I just did over again? Only you can answer that question for your self.

I know my self well enough to know I'd rather pay 3-4k dollars for pistons, rods, bearings, a proper hone, a closed deck insert and ARP 11mm proper length studs to make as sure as I can that I don't have to do all that work over again any time soon. That answer may not be the same for you, which is perfectly fine, just make sure you consciously made that choice going forward.
 
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IQraceworks

Corporal
Jul 7, 2020
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07' BMW 335i
@shushikiary

Thanks for all the great info! Yes, lots of things things to consider at this point. This is just a "play" car for me. It might get driven to work a couple of time a week in the summer, and towed down to the track every now and then. Everything you said makes sense.......at this point I think I have two options. Either just throw another stock piston in the motor, put it all back together with new rings and rod bearings, and stock head bolts.....this would be the cheapest option, and for my power levels (sub 600)....probably just fine.

OR....go full in with forged pistons and rods, strip the block down to have it honed with a torque plate, do full 11mm head studs, get the rotating assembly balanced, etc, etc....probably an extra $4K over the "cheap" option mentioned above.

In the end, I just need to figure out what that extra $4K is going to get me. Can the turbos still fail on me? Yep. Can the transmission still take a dump? Yep. Can the diff still fail? Yep. Can any number of other things still fail? Yep. Does that $4K mean that I'm never going to have a motor related issue? Nope. Do I want to put $4K more into this car at this point? Not really sure.

At this point....I think you have convinced me to take the cheap route. Maybe.....:grinning:
 
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driver01

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Nov 25, 2022
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A bunch of that is true, some of it is false.

I agree I would not go all 11mm without a closed deck. By the time you need 11mm studs you're pushing enough power to want a closed deck anyways, so I wouldn't do one without the other. Personally I'd say 600-650 whp and you're ok being not closed deck and stock head bolts but your ring lands are on a ticking clock, under 600 whp and you'll be fine with stock everything for a good while. Personally I would not go above 600 whp without doing forged pistons, and if I'm going to go to the work to go to forged pistons then I'm going to put a closed deck in, which means doing 11mm proper length studs and then you're good for 800 whp. Yes there is indeed a GM kit with the studs too short and if you use that kit you will likely strip the block when you try to tighten to ARP's suggested torque (Make sure you use their suggested lube and put it on the threads the nut goes on and under the nuts washer surface!).

Billiam can get the correct stud kits and its where I know most people source them from, they are indeed longer than the GM kit and give you enough thread engagement so that you don't strip the block threads. (When Ghassan did my first motor build they used the GM studs and didn't tighten them properly, then when the second shop tried to tighten them (octane enterprises) they stripped as stated, from there we found out Ghassan had used the wrong head stud kit (shorter one) and had to order the proper one, which resulted in having to replace the block as there was not enough space for a time sert where it stripped... so with new block and new proper length studs from ARP it is now working properly).
hey, i also do 9 to 11mm as head is lifted (thread in block probably damaged). do you think it will not be possible to tap 11mm there? you had same problem ?
 

driver01

Lurker
Nov 25, 2022
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My input based on my experience so far:

On my build engine I went initially with stock head bolts.
At around 750whp the head lifted at cyl 6 next to the M9 head bolt.

Decided to order the Full M11 ARP studs from Billiam which are exactly the same from VAC and are advertised for way too much money(700 euro).
Installed the studs together with NS300L inserts from Huhn Solutions.
Since then all is fine as I made 927HP at the crank.
Coolant pressure is stable as well all the time.

FWIW I have multiple full M11 studs available.
These are the same as the ones advertised from HCR.
All studs are heat treated as well.
Thread on the block side is 55mm instead of 35mm (only) from the ARP ones.

Let me know if anyone would be interested.
Price for them is: 499 euro
did you do timeserts with 11mm? on 4 studs or all ? is there enough room for that? I have same problem, lifted head with 9mm standard studs, now dillemas which way to go
 

Jern54

Sergeant
Oct 18, 2019
289
1
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Netherlands
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E91 N54 335i
did you do timeserts with 11mm? on 4 studs or all ? is there enough room for that? I have same problem, lifted head with 9mm standard studs, now dillemas which way to go
I placed timeserts on the 4 outer corners only. The rest is not necessary. PB in case you need studs, I have plenty of them in stock with washers and nuts.
 

IQraceworks

Corporal
Jul 7, 2020
209
121
0
Missouri
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07' BMW 335i
After having measured enough sets of pistons, I would not trust it when they say their forged set are made small enough for a simple re-hone.

I'd order the pistons and rods, do your full balance work up to get it well balanced, re-balance the crank, then measure all the piston skirts properly with a micrometer and then hone each cylinder to match the piston you picked for it with a proper torque plate to the proper clearance for each piston. Then once your hone is proper you can actually set proper ring gap for you power level. A proper material piston, top ring, and second ring with a napier will really help make sure you don't have issues (keeps oil from lowering your effective octane).

If you don't do that and one of your pistons is off, you're asking for piston slap when cold on those forged pistons.

You might get away with a larger ring gap on cast pistons and a ball hone if you're confident in your detonation control.

If I was you, the question I'd be asking my self is, what is my risk tolerance? How much wallet pain am I willing to have to make sure I don't have to do all the labor I just did over again? Only you can answer that question for your self.

I know my self well enough to know I'd rather pay 3-4k dollars for pistons, rods, bearings, a proper hone, a closed deck insert and ARP 11mm proper length studs to make as sure as I can that I don't have to do all that work over again any time soon. That answer may not be the same for you, which is perfectly fine, just make sure you consciously made that choice going forward.
FYI.....the new Mahle pistons all measured out perfect. After a light hone to break the glaze on the cylinders, I'm getting .0030" piston to wall clearance on each cylinder, which is right in the middle Mahles suggested range (.0025-.0033"). So far I'm really happy with the Mahle pistons, and Manley rods. I went ahead and set the ring gap to .022" on the top ring, .023" on the second ring. Rod bearing clearances are all between .0025"-.0027". So far, everything is spot on as far as clearances go. I couldn't be happier with how the building is "measuring up". Ha!
 

driver01

Lurker
Nov 25, 2022
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I placed timeserts on the 4 outer corners only. The rest is not necessary. PB in case you need studs, I have plenty of them in stock with washers and nuts.
good. its 11mm studs ,with timeserts? which timeserts did you get? i am lost with numbers..is that m10x1.5 ?

you sent empty block to shop or done it by yourself?
 

driver01

Lurker
Nov 25, 2022
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I think it was a lot more. I remember torquing all the head bolts equally to 95ftlbs
ok. did you do it yourself or sent block to shop? maybe it will be good to buy those hcr diy kit for that , or shops dont need it?

also which studs you use?

thanks
 

SLOWESTN54

Captain
Feb 9, 2021
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2007 E92 335i
ok. did you do it yourself or sent block to shop? maybe it will be good to buy those hcr diy kit for that , or shops dont need it?

also which studs you use?

thanks
did it myself, just bought the correct bottoming tap and sent it. I used the vac 11mm studs.
 

IQraceworks

Corporal
Jul 7, 2020
209
121
0
Missouri
Ride
07' BMW 335i
So just run the correct sized drill down the 9mm corner holes for an 11mm tap. Tap the hole for the new 11mm stud. Run the stud in there, and run it? No need for the steel inserts everyone is talking about? What about the stud kits that use the oem 9mm sized studs on the corners? I'm still going back and forth between using new oem head bolts, or studs. So much contradicting info out there. Remember...the motor should be making 575-ish hp at 25psi with twins on E40. Nothing crazy.

The rest of the build it coming along great. Just got my pistons (Mahle) and rods (Manley) assembled last night. Went with a .022" ring gap on the top ring, an .023" gap on the second ring.

zra5Iwi.jpg
 

IQraceworks

Corporal
Jul 7, 2020
209
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Missouri
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07' BMW 335i
ok. where did you get tap and other things for that job? did you used some leveling thing, for drill?

There are companies that sell kits that come with the drill, tap, and drill jig. Search online...I don't remember the names of the companies right off hand.
 

driver01

Lurker
Nov 25, 2022
16
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There are companies that sell kits that come with the drill, tap, and drill jig. Search online...I don't remember the names of the companies right off hand.
ok. is possible to mess angle with that kits? or those align plates are workong fine?