Do I really need arp bolts?

[rvca3112]

I'm in the process of doing a engine build. Nothing too crazy. 98 aeb motor... Knife edged crank, 144x20 scat rods, 82 mm pistons, 034 fuel pump, 660 cc injectors, Gt3071r eliminator turbo, j fonz tune. Do I really need arp head bolts and main bolts? I'm not making THAT much power (I don't think). I'm not trying to cut corners since the motor is already apart and I'd prefer better parts, especially if they will be more reliable. Just wondering if I really need them.

[pac1085]

You definitely don't need the head bolts. If for whatever reason you DO lift the head (you wont...) you can just swap to studs without much work.

But I would do the main STUDS - they are cheap and it's good insurance. Plus if you decided to add them later its a ton of work.

[rvca3112]

Thank you PAC, but what exactly is head lift?

[M-Hood]

Thank you PAC, but what exactly is head lift?

When the head lifts up off the deck when the bolts stretch and then the gasket blows. But even at nearly 500whp I had no issues with stock head bolts.

[Seerlah]

I am using stock hardware in my short block, minus ARP rod bolts. Was not pushing that much power, so can't really say anything about stout at higher power. There was a conversation in the B6 section a little while ago and people had different views, especially since one chimmed in with a higher HP application (350+whp) and said he never had an issue. But another who is a mechanic said he worked on a vehicle that had a main bolt head break off just from dd on a stock block. If I had to do it all over again I would add ARP studs. Just for more security.

[zandrew]

I called ARP to get specs on the mains and they are the same size as the head studs (M11). I would be hard pressed to believe they would give you any issue as well. If you ever plan on turning it up its nice to have those in so your not tearing shit down a second time.

[AudiA4_20T]

ARP stuff is NOT needed for a 1.8T. I ran daily 35psi with stock head bolts and mains, 0 issues. It's all about following proper torque specs. These are great motors

[pac1085]

Main studs are only like 100 bucks. Worth the peace of mind in my opinion. especially since they would be a pain in the ass to change later on.

[redline380]

i agree that arp stuff is not needed for anything short of a full on track only motor.

[M-Hood]

i agree that arp stuff is not needed for anything short of a full on track only motor.

Well a good reason for using aftermarket non stretch bolts/studs is for the fact that they can be reused over and over instead of having to buy new ones every single time. For most street daily driven car owners they don't plan on taking the head off again, but if building the car to make some good power you never know when that part might need to be pulled.

[nynoah]

Well look at it this way, do you plan on taking the engine apart again in the future? If so... buy ARP. They can be reused.

[Seerlah]

ARP stuff is NOT needed for a 1.8T. I ran daily 35psi with stock head bolts and mains, 0 issues. It's all about following proper torque specs. These are great motors

Good to know. Now I know I can chase 400whp with my current block

[rvca3112]

Thanks everyone for the input. I think I'm going to just get the main bolts and skip out on the head bolts. Prior to the rebuild, my car put down 322 horse. Now with my rods and fuel pump I'm going to have jfonz tune it further. I should post some pictures of this stuff soon.

[zandrew]

Well a good reason for using aftermarket non stretch bolts/studs is for the fact that they can be reused over and over instead of having to buy new ones every single time. For most street daily driven car owners they don't plan on taking the head off again, but if building the car to make some good power you never know when that part might need to be pulled.

What makes you think they are non stretch? You can reuse them but they still stretch. I had 4AGE head studs and I was concerned they could not be reused and actually documented the entire build down to the installation length of the main bolts, head studs, and rod bolts (all ARP) and the head studs strecthed considerably. All were within .004"-.007" but one rogue stud stretched to .010". I called ARP and they said they were reusable.

I plan on reusing my main bolts since I could not source stock ones.

[M-Hood]

What makes you think they are non stretch? You can reuse them but they still stretch. I had 4AGE head studs and I was concerned they could not be reused and actually documented the entire build down to the installation length of the main bolts, head studs, and rod bolts (all ARP) and the head studs strecthed considerably. All were within .004"-.007" but one rogue stud stretched to .010". I called ARP and they said they were reusable.

I plan on reusing my main bolts since I could not source stock ones.

First off "non stretch" is a term that it is used when talking about a bolt that doesn't have to be Stretched by going an extra deg turn after it is already tightened down. It isn't like we have to word it out for everyone here every time something is post because most of the people here already knows what it means seeing that this is in fact a car forum. I am 45 years old I know what a bolt does, stop being so anal about every single detail.


Yes it is really hard to source stock OEM main bolts.

058 OEM Main bolts
06A OEM Main bolts

[Info@EuroCode]

In a addition to the OEM head bolts, the washers should be replaced too.

[redline380]

yeah, main bolts, rod bolts, head bolts, flywheel bolts, axle bolts, anything that needs to be critically torqued, ect are all "stretch bolts" which are desgined to stretch. they are not reusable after they are removed because they are meant to only be stretched once to give a more consisent torque. arp stuff isnt a stretch design, but of course they techincal do stretch a little, but not enough to compromise the integrity of the bolt. they are not a bolt designed to stretch only once, thus are reusable.

as mike pointed out which i forgot to, arp stuff would make sense if you plan on stripping down the motor a couple times a year to inspect. i'm guessing you wont be doing this, so there is no need. with that said, i could see how head studs would come in handy. odds are that most of use modified guys will be removing are heads sooner or later for various reasons, so the fact arp is reusable would come in handy. also, it makes aligning the head gasket much much easier. are these two reasons enough to warrant spending $150 on a few studs and nuts? thats your call. as for finding the bolts, its called your local dealer. remember, vw dealers have the same parts