ARP 425 ?'s
- Thread starter Jfurr
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rbmedic75
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I am currently debating the exact same thing man I mean we are only talking what 25,000KSI difference in clamping force. I can get a set of 425 for $375 but the best I could find a set of 625 was $975 :umno: but dont want ot end up wasting the cash on the 425 if they are not gonna hold my upcoming twins and 70 LBS of boost
TheBigNasty
Project bish
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Stock mls gasket or have you o-ringed? If its mls then go straight to 625's. If o-ringed with 12v gasket then you would be ok with 425's but I'd have the 625's just to sleep better.
Scooter's Roofing
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what kind of power are you looking to make?
TheBigNasty
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MLS and 625's have been proven to over 1000 hp
Scooter's Roofing
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if you're looking for 900 on fuel, I would just do the 425's
rbmedic75
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OK guys I dont want to steal the OP thread and I thank him for starting it, but I dont want to double post the same question in a new thread. My overall goal is 750ish Daily driver 6.7, fuel only will not see spray twin turbo at around 70ish lbs of boost, and about a 150-175 set of stix with the support needed.
we have mixed suggestions here which is normal. I dont mind spend the 950 if its really warranted and that much better but im not one to buy just because... I have done a lot of looking and reading and talking but still undecided
oh yeah and I can get a solid copper gasket with orings that dont require any machine work on the head or blocks so if I need to pull the head that is what will go back in
we have mixed suggestions here which is normal. I dont mind spend the 950 if its really warranted and that much better but im not one to buy just because... I have done a lot of looking and reading and talking but still undecided
oh yeah and I can get a solid copper gasket with orings that dont require any machine work on the head or blocks so if I need to pull the head that is what will go back in
rbmedic75
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One of the more usefull articles on studs I have came across
Don Trapp of A1 Technologies says his company starts out with the basic alloy 4340 or 8740 that is 190-ksi minimum. From that point it goes up to 280 ksi. “The 4340 or 8740 is already far above an OEM fastener in strength and quality. We use a lot of H11, which is a toolsteel for Top Fuel, Funny Car and some in Top Alcohol and Injected Nitro classes use it also. This is a 240 ksi minimum graded material.”
Trapp says almost every team in the top classes of drag racing uses this bolt material, because these cars are some of the most extreme applications. “As far as boost for superchargers and horsepower, to clamp a head and main studs down on a Top Fuel engine is a pretty extreme proposition. We also use this material quite a bit in Sport Compact classes because they use extreme boost levels in many cases. There are many teams running 60 lbs. of boost on top of high compression, so the cylinder pressures are what you would call extreme.”
The next step up from 4340 or 8740 steel is 1722 (AMS 6304). Manufacturer ARP calls it ARP 2000 and it’s all the same material, a 220 ksi material. The next step would be H11, which ARP calls L19. It too is the same material and also comes from Carpenter. Those are getting up to 240-250 ksi. You can go higher than that but it becomes brittle, according to Trapp.
The next step up include two materials: Custom Made 625 and Aerospace Material Specification (AMS) 5844. Trapp says A1 Technologies gets both materials from Carpenter as well. “The AMS 5844 has a trademark name MP35M, which means it’s multiphase,” says Trapp. MP35N is an age hardenable Nickel-Cobalt base alloy that has a unique combination of properties - ultra high strength, toughness, ductility and outstanding corrosion resistance. MP35N resists corrosion in hydrogen sulphide, salt water and other chloride solutions. ARP calls this material ARP 3.5.
Both of those materials are considered a super alloy and are a very high nickel base. The last two are stainless steels because there’s so much nickel in them. One is mostly nickel and the multiphase is Nickel-Cobalt. Right now the multiphase is about the strongest fastener material out there. But the material alone is $75 a pound before anyone begins making the fastener.
Preload
There is definitely a relationship between torque and preload, but there is some confusion as to the difference. With connecting rods it is not too difficult to use the stretch method and to measure the preload by measuring stretch. But in head bolts it is much more difficult to measure and you’re basically reliant on the torque wrench to stretch the bolt. A torque wrench needs to be recalibrated often and you need very clean threads that have been burnished in so there is very little friction. The preload is the force on the bolt that clamps the joint together. Torque, however, is just the mechanism used to get the desired preload.
Don Trapp of A1 Technologies says his company starts out with the basic alloy 4340 or 8740 that is 190-ksi minimum. From that point it goes up to 280 ksi. “The 4340 or 8740 is already far above an OEM fastener in strength and quality. We use a lot of H11, which is a toolsteel for Top Fuel, Funny Car and some in Top Alcohol and Injected Nitro classes use it also. This is a 240 ksi minimum graded material.”
Trapp says almost every team in the top classes of drag racing uses this bolt material, because these cars are some of the most extreme applications. “As far as boost for superchargers and horsepower, to clamp a head and main studs down on a Top Fuel engine is a pretty extreme proposition. We also use this material quite a bit in Sport Compact classes because they use extreme boost levels in many cases. There are many teams running 60 lbs. of boost on top of high compression, so the cylinder pressures are what you would call extreme.”
The next step up from 4340 or 8740 steel is 1722 (AMS 6304). Manufacturer ARP calls it ARP 2000 and it’s all the same material, a 220 ksi material. The next step would be H11, which ARP calls L19. It too is the same material and also comes from Carpenter. Those are getting up to 240-250 ksi. You can go higher than that but it becomes brittle, according to Trapp.
The next step up include two materials: Custom Made 625 and Aerospace Material Specification (AMS) 5844. Trapp says A1 Technologies gets both materials from Carpenter as well. “The AMS 5844 has a trademark name MP35M, which means it’s multiphase,” says Trapp. MP35N is an age hardenable Nickel-Cobalt base alloy that has a unique combination of properties - ultra high strength, toughness, ductility and outstanding corrosion resistance. MP35N resists corrosion in hydrogen sulphide, salt water and other chloride solutions. ARP calls this material ARP 3.5.
Both of those materials are considered a super alloy and are a very high nickel base. The last two are stainless steels because there’s so much nickel in them. One is mostly nickel and the multiphase is Nickel-Cobalt. Right now the multiphase is about the strongest fastener material out there. But the material alone is $75 a pound before anyone begins making the fastener.
Preload
There is definitely a relationship between torque and preload, but there is some confusion as to the difference. With connecting rods it is not too difficult to use the stretch method and to measure the preload by measuring stretch. But in head bolts it is much more difficult to measure and you’re basically reliant on the torque wrench to stretch the bolt. A torque wrench needs to be recalibrated often and you need very clean threads that have been burnished in so there is very little friction. The preload is the force on the bolt that clamps the joint together. Torque, however, is just the mechanism used to get the desired preload.