Whats the latest verdict on these? Are they worth using on a boosted sling? I did some searching and a lot of earlier posts said they were recommended, then as time went on some people said none of the failures would have been prevented with them so not necessary. Just seeing what the 2018 verdict was from the more experienced players in here?
ARP Head Studs
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At boost levels below 9-10 psi which most of us are probably running, I think the ARP head studs are for those who want a little insurance, but I don't think they're really needed at the boost levels the various kits offer as a matter of routine. Of course, if you start trying for boost over those levels, you need more than just the ARP head bolts and really need a purpose-built motor designed for high boost levels.
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I agree 100% with @BKL. (I didn't require the ARP's, but felt they were good insurance for the price)
One thing I highly recommend though, if you do not install the ARP's: Check the stock head bolts to confirm they are all torqued properly!!!!
Before Henry installed his alpha turbo & the ARP's on my Sling they said they had found some slings with at least one head bolt not torqued to spec.
Lo and behold, while as I was standing there watching them start removing the stock head bolts on my Sling.....two head bolts were only snug!!! So if nothing else, at least check your stock bolts for proper torque!! -
Unless I am wrong, it's not easy to check the torque of the oe head bolts. They are torqued in place to "X" torque, then tightened another "X" number of degrees. Plus they are a torque to yield bolt (if I remember correctly) meaning that they are a one time use bolt. And yes, the ARP studs are great to make sure the head doesn't walk on you, but really not needed at the low boost pressures. But if you want piece of mind that the head bolts were done correctly, just buy a set of these studs and install them correctly and you'll have one less thing to worry about
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Unless I am wrong, it's not easy to check the torque of the oe head bolts. They are torqued in place to "X" torque, then tightened another "X" number of degrees. Plus they are a torque to yield bolt (if I remember correctly) meaning that they are a one time use bolt. And yes, the ARP studs are great to make sure the head doesn't walk on you, but really not needed at the low boost pressures. But if you want piece of mind that the head bolts were done correctly, just buy a set of these studs and install them correctly and you'll have one less thing to worry about
I would agree with you with one exception. If you check the torque on a factory bolt and it moves before the recommended torque value is reached then that bolt should be replaced. jes my .o2
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Very true
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I stand behind them as cheap insurance for boosted slings. Got a set off eBay for $125 and installed less than an hour. Just piece of mind for a cheap price.
Sent from my SAMSUNG-SM-T537A using Polaris Slingshot Forum mobile app
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They did nothing for me in saving 2 motors and from all of the blown motors I have seen, I haven't seen a head lift.
Go ahead and do them if it makes you fell better, but I highly doubt they will help on a non-built motor. -
They did nothing for me in saving 2 motors and from all of the blown motors I have seen, I haven't seen a head lift.
Go ahead and do them if it makes you fell better, but I highly doubt they will help on a non-built motor.
They did nothing for me in saving 2 motors and from all of the blown motors I have seen, I haven't seen a head lift.
Go ahead and do them if it makes you fell better, but I highly doubt they will help on a non-built motor.At least you'll have them for your "built" motor when the time comes!
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Agreed. You need them anyways when you go to build a good motor.
Like @funinthesun said, the stock head bolts are torque to yield like several of the bolts in this motor. So once they come out, you need to switch to a re-usable ARP bolt.
These ARP head bolts are a great product, I am just not convinced they help you on a motor that isn't built... -
I have been running 10.5 inches of boost at 330 HP for close to 20,000 miles on an unforged motor. I have ARP headstuds, a coolant reroute kit, and an oil cooler system. They all might not be needed, but then again I bounce the rev limiter all the time and the motor is still intact.
As I have said before, it works for me and the insurance cost a lot less than rebuilding the engine which I have yet to do.
Now I said that, I am screwed. -
I have been running 10.5 inches of boost at 330 HP for close to 20,000 miles on an unforged motor. I have ARP headstuds, a coolant reroute kit, and an oil cooler system. They all might not be needed, but then again I bounce the rev limiter all the time and the motor is still intact.
As I have said before, it works for me and the insurance cost a lot less than rebuilding the engine which I have yet to do.
Now I said that, I am screwed.Start knocking on wood, you just completely jinxed yourself.
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We get a lot of calls about the ARP headstuds here when people call about the supercharger kit and about using them on a turbo kit. To date, we have never seen a stock engine with head bolts that seemed loose. We have also never seen any engines that failed with a turbo kit (around about 40 engines now) that would have been saved if the owner had installed ARP head studs. None of the engine failures where from a cylinder head lifting off of the block. The ARP headstuds are a nice way to make sure everything is tightened down on the cylinder head, but so far we have not seen any definite need to have them.
There are also a couple counter arguments to installing them, first they can be installed incorrectly. We have had a couple customers call us with cracked blocks internally immediately after installing the ARP headstuds. The engine blocks on the LE9/LE5 are a lost foam casting and we have seen about a dozen of them cracking internally over the years. When they crack, it typically allows coolant to get into the oil. This usually occurs in an area that is not able to be reached and means that the block is not able to be used any longer and an engine swap is needed. When installing the ARP head studs it is very important to make sure the bores that the ARP headstuds go into do not have any fluid in them and to also make sure that the new studs are only put in hand tight. If there is fluid in the hole and/or if they are over tightened, it can and has cracked blocks. I am not saying this is super common, but something that does need to be considered when installing the new ARP head studs. For customers like @Slingrazor who are very proficient at work on the engine, it is a easy install, but if you are not super comfortable working on the engine, I would definitely recommend having someone professional install them.
The other consideration to make is that the stock LNF engine, which is the 2.0L turbo from GM, uses the same head bolts as the LE9/LE5. Those engines come with around 215-220hp at the wheels, with a simple tune get up to around 300hp @25psi at the wheels and we do not even recommend building the engine until 400hp at the wheels. Even at 400HP at the wheels, we are not building those engines because of a need for better headstuds, but instead because of a stronger rod and piston combination.
For a relatively low price, the ARP head studs can give a lot of people a warm feeling when boosting, but if you do go that route, make sure that they are installed correctly. If you decide not to do the ARP headstuds, do not feel that they are the weak point in the engine either. Our Slingshot still has a junkyard engine with over 100K miles in it with stock head bolts that we have beat very hard on the track, street and dyno without any problems.
Hope that helps,
Dave
