10mm ARP head studs in Australia headstuds

TME_Steve

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NSW
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Steve
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2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
I'm thinking we are still pushing more torque. I was at 550nm atw ish, that's a lot. Or they're not realising why they keep running low on water.... And are their 300kw a bit smaller than our 300 like the US hp seem to be?

After my car stretched bolts, i started stopping torque at 450nm atw referenced to engine speed but there are others that ran more than that without problem. Seems to be hit and miss, hence why i say they're on the limit stock rather than you need to go easy more. Trotty had two loose studs (some people said there was always a screw loose :D ) so his was different to the rest but i know of at least one other that pushes a tiny bit.
 

jungle

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Simon
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1 PFL & 1 FL Legnum
I'm thinking we are still pushing more torque. I was at 550nm atw ish, that's a lot. Or they're not realising why they keep running low on water.... And are their 300kw a bit smaller than our 300 like the US hp seem to be?

After my car stretched bolts, i started stopping torque at 450nm atw referenced to engine speed but there are others that ran more than that without problem. Seems to be hit and miss, hence why i say they're on the limit stock rather than you need to go easy more. Trotty had two loose studs (some people said there was always a screw loose :D ) so his was different to the rest but i know of at least one other that pushes a tiny bit.
hmm, i'm starting to feel a little scared for my engine...
 

trotty

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nsw
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Daniel Trotman
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2000 vr4 Legnum 5 sp man
2006 Suzuki Swift Sport 5 sp man
Definately a screw loose, oh we talking bout the car?

As we discussed my motor may have had a hard life or even overheated causing the weakness in the bolt.

In my case, I ran around for quite a few weeks with the odd blast that pushed water out before I fitted the arp studs. It managed to slow the leak 90-95%. I'm putting this down to a damaged head gasket. But still it made 193kw on 98oct and running rich from removed intake mods. If I don't thrash it I don't use any water at all. I did a drag night and pushed no water. Steve puts it down to the boost we can generate and cylinder pressure duration at low rpm.
Up higher the pressure may be higher with tdo4's but there for a shorter period of time, not lifting the heads.
 

6A13TT TYPE S

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Adam
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1999 Legnum VR4 Type S
You are on the money there Trotty. Ethanol burns slower so you get more cylinder pressure for more of the time. Unless you start revving it to like 10krpm where pistons start outrunning the flame front from slow burning fuels like ethanol :p
 

slickd1

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NSW
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Matthew Dundon
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1998 EC5W Manual Legnum.
You are on the money there Trotty. Ethanol burns slower so you get more cylinder pressure for more of the time. Unless you start revving it to like 10krpm where pistons start outrunning the flame front from slow burning fuels like ethanol :p
ohhh really! thats cool!

So ethanol is only good within a certain rev range because the expansion/flame front cant keep up with it when it revs too fast, love learning new stuff.

Is this just a limitation of the whole fuel/compression/knock/power system? Trade off with a bigger cylinder, lower revs for the same power, then the flame front does not have to travel as fast to keep up? But, bigger displacement engine then I suppose, which we cannot change easily, so only way to increase power is to add boost/advance timing and strengthen systems to suit.

You're making me think about engines a bit more scientifically. lots of tradeoffs aren't there. I suppose that's why they all operate within roughly the same rev range and displacement across all common automotive motors.
 

trotty

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nsw
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Daniel Trotman
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2000 vr4 Legnum 5 sp man
2006 Suzuki Swift Sport 5 sp man
More so found a good bore and stroke ratio for torque/hp vs economy/reliability, motors naturally give certain characteristics based around those and compression.
 

LDundon

Violent Violet
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Lindsay
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Pearl White 1998 PFL Legnum
This is a great read! I'm considering slowing down on my build a bit if 11mm is recommended and taking my car off the road and getting my little racecar roadworthy and driving it while the Legnum is out of action for studs and possibly other upgrades... Hmmm
Other option is the spare motor that's sitting there could be stripped and built. @slickd1 what do you think?
 

slickd1

Wizard
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NSW
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Matthew Dundon
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1998 EC5W Manual Legnum.
This is a great read! I'm considering slowing down on my build a bit if 11mm is recommended and taking my car off the road and getting my little racecar roadworthy and driving it while the Legnum is out of action for studs and possibly other upgrades... Hmmm
Other option is the spare motor that's sitting there could be stripped and built. @slickd1 what do you think?
Definitely rebuild spare motor broseph. Just do the lot, follow trotty and Adam, then when something horrendous happens to one of ours we'll finish and drop that motor in
 

jungle

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QLD
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Simon
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1 PFL & 1 FL Legnum
I'm thinking we are still pushing more torque. I was at 550nm atw ish, that's a lot. Or they're not realising why they keep running low on water.... And are their 300kw a bit smaller than our 300 like the US hp seem to be?

.
I'm not sure I agree that our TD03 can flow enough to out torque a TD04.
 

trotty

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nsw
First Name
Daniel Trotman
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2000 vr4 Legnum 5 sp man
2006 Suzuki Swift Sport 5 sp man
It's how low in the rpm the tdo3 can make the boost. Tdo4's may have more torque up higher so pressure duration is still shorter and is able to handle it better.
 

6A13TT TYPE S

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Adam
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1999 Legnum VR4 Type S
Bang on again. We just need to go all f1 style on it with 20krpm where they even start to outrun detonation. Piston acceleration of 10,000G which puts almost 6 metric ton of load on the crank journal!
 

TME_Steve

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NSW
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Steve
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2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
I'm not sure I agree that our TD03 can flow enough to out torque a TD04.
It's not flow it's low flow high pressure, we're talking under 4000rpm here. I've seen over 30psi of boost on the road in second great with a td03. So quick spool time and all and they still pushed crazy pressure meaning crazy torque given temps weren't ridiculously high. Then boost cut at 230% load over for over a second stopped the curve climbing. I think it was around the 260 or 280% load mark by then. Anyways. Fear not, they can generate torque
 

TME_Steve

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NSW
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Steve
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2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
ohhh really! thats cool!

So ethanol is only good within a certain rev range because the expansion/flame front cant keep up with it when it revs too fast, love learning new stuff.

Is this just a limitation of the whole fuel/compression/knock/power system? Trade off with a bigger cylinder, lower revs for the same power, then the flame front does not have to travel as fast to keep up? But, bigger displacement engine then I suppose, which we cannot change easily, so only way to increase power is to add boost/advance timing and strengthen systems to suit.

You're making me think about engines a bit more scientifically. lots of tradeoffs aren't there. I suppose that's why they all operate within roughly the same rev range and displacement across all common automotive motors.

Roughly yeah. A lot of it is piston speed and material limits. Like most things you'll find there is a sweet spot evermore of all the compromises. Where you are in the envelope is dictated by what you want to trade off. Eg torque vs power or cost etc.
 

ersanalamin

Leaving Skid Marks
Location
Indonesia
First Name
Ersan Al Amin
Drive
Year 2000 EA5A => FL EC5A
I am keen to buy 3SGTE 8740 ARP bolt, Just curious, how much power or turbo boost can the 8740 ARP handle before the cylinder head lift off? any experience guys? I am going to rebuild forging the engine and high flowing TD03 or fitting TF035HM 12T high flowing with TD04-15T compressor wheel, I dont know what the power range will gain, but 450-500 WHP is the target. Do you think ARP 8740 will okay with such power? 11mm ARP like adam told is the option but If ARP 8740 is strong enough i will be just buy ARP 8740 instead. thanks for any suggestion
 

pretzil

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Location
Qld
First Name
Rick
Drive
Legnum VR4
So I have bought a set of 8740 10mm studs from Performance Wholesale Australia.
I want to get them in before the next tune so I am just going to leave the head on and swap them out for the original bolts.
I have pushed coolant on extended hard running before, but none that I've noticed during over a year of normal driving.
(If it doesn't do the job then I will get the heads done and do it properly)

I am going to borrow a good torque wrench from a mate.
Can someone please tell me the best way to do it? torquing pattern, torque steps etc to use?
@trotty @TME_Steve etc.

If this is already on the forum somewhere I apologize, but I couldn't find it. Thanks.
 

naughtika

OzVR4 Stalker
Location
Brisbane, QLD
First Name
Christian
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'96 Galant VR4, '17 MB A180, '25 Macan GTS
thought I read somewhere that is thould be 60lb/f!?

someone correct me please
 

slickd1

Wizard
Lifetime Member
Location
NSW
First Name
Matthew Dundon
Drive
1998 EC5W Manual Legnum.
So I have bought a set of 8740 10mm studs from Performance Wholesale Australia.
I want to get them in before the next tune so I am just going to leave the head on and swap them out for the original bolts.
I have pushed coolant on extended hard running before, but none that I've noticed during over a year of normal driving.
(If it doesn't do the job then I will get the heads done and do it properly)

I am going to borrow a good torque wrench from a mate.
Can someone please tell me the best way to do it? torquing pattern, torque steps etc to use?
@trotty @TME_Steve etc.

If this is already on the forum somewhere I apologize, but I couldn't find it. Thanks.

See my original post guys, fastening torque is mentioned in there. I'll add the tirque sequence bow, but its as youd expect, alternating diagonally from the centre out.

Toyota guys fasten to 65ftlb arp reccommends somewhere between. If your already pushing water then maybe 65 would be a good idea.

Fastening sequence I believe is:
7 1 3 5
6 4 2 8
 

pretzil

2 AYC Bars
Location
Qld
First Name
Rick
Drive
Legnum VR4
60 ft/lb.
The above torque sequence is fine
Or alternativly
8 4 1 5
7 3 2 6

Thanks.
If doing a direct swap over like @trotty did, should I remove them all, then replace them all, or do them one at a time?
I assume I should use progressively higher torque and repeat the pattern? Or do I just go straight to 60ftlb?
 
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