It is for good reason that virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition powerplants. Simply stated, there’s not a better stud setup on the market today.
For openers, ARP uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Each stud is placed vertically in special racks and precisely heat-treated to 200, 000 psi. This procedure ensures complete heat penetration and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.
Following heat-treat, each stud is centerless ground to make it as close to perfectly concentric as possible. This procedure involves about ten very slight cuts and results in an exceptionally straight part. It’s important to note that lesser quality studs are not even centerless ground – the material is thread rolled in bar stock form (mostly before heat-treat, when the material is easier to machine). Because ARP studs are manufactured to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly aligned – something that won’t happen with inferior quality head studs.
ARP studs are thread rolled after heat-treat, which gives them about 1000% (that’s ten times) better fatigue strength than those studs that are threaded prior to heat-treat (a very common industry practice). It costs a lot more to do it this way, because it’s tough on tooling, but the results are well worth the extra effort.
You will also note that ARP offers specially undercut studs for several engines. This procedure (done only to the shorter studs) more equalizes the “stretch” of both studs, which makes for a more consistent clamping force – and one that compensates for head gasket compression when the cylinder heads are installed. This helps prevent blown head gaskets, and assures optimum engine sealing!
Premium quality heat-treated 8740 chrome moly steel head stud kits are available for most every domestic and import applications.
You won’t find a better quality stud on the market from any other source. Look for ARP stamped on each stud as your assurance of quality.
Clearly, ARP Head Stud/Bolt Kits are the best on the market today, and the favorite of leading professional engine builders in all forms of racing.
HIGH PERFORMANCE SERIES: High Performance head bolts are available with a reduced wrenching hex or 12-point and wide area flanged head that eliminates the need for valve train removal to facilitate cylinder head retorquing. All High Performance Series bolts are 180, 000 psi (which is 15% stronger than Grade 8) and kits come complete with hardened parallel-ground washers.
PRO SERIES: All Pro Series bolts are cold-forged to ensure molecular integrity, heat-treated prior to thread rolling and machining, and are rated nominally at 200, 000 psi. ARP Pro Series head bolt kits are application specific – designed for use with typically competition only components. These fasteners deliver superior strength and meet the ARP “ZERO defect – ZERO failure” quality standard. Hardened and parallel-ground washers are included with each kit to ensure even load distribution and accurate torque readings. All Pro Series head bolts have a reduced wrenching hex or 12-point head and wide area flange to eliminate the need for valve train removal for cylinder head retorquing and permits the use of larger diameter valve springs. Most applications have undercut short bolts that can help eliminate head gasket failures through providing more “stretch” to compensate for the additional compression of gaskets.
Head Studs vs Bolts: On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, it’s probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car.
For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing powerplant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment.
Studs also provide more accurate and consistent torque loading. Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode – never crank it in tightly using a jammed nut.
If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run.
When you are shopping for fasteners for your prized vehicle you want to find the product that will not only serve their purpose and keep things in place but also will be long lasting and fail safe and for this reason you need to buy a fastener from a company you can trust. You might ask yourself what attributes that company should have and we at LMPERFORMANCE feel you would be justified in doing just that and in fact would be negligent if you do not do that. And so if you are in the market for fasteners then we invite you to peruse the information we have garnered about Automotive Racing Products.
For those of you who are racing aficionados we know that you will recognize the ARP brand since they were the very first company designing and engineering fasteners specifically for you and as a result have delivered a multiplicity of patented processes for the manufacturing of high strength fasteners. Not being a company to rest on their laurels ARP continually improves their processes and their quality control can be compared to the best with operations that are ISO 9001 and AS9100 registered and you can’t get better than that. The company’s focus is on a superior product that is second to none and their goal is to satisfy a need with the best possible product so that you, their customers, will be consummately satisfied.
IMAGES: Images may be a representation and may not reflect the actual product.
California Residents: Prop 65 WARNING: This product MAY contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling. For more information, visit www.P65Warnings.ca.gov
California Residents: TIRE WARNING: LMPerformance will not ship Tires to California.
Legal: Some or all of these parts may not comply with Federal, State, Province, and/or Local laws, ordinances, and regulations. Buyer takes all responsibility to ensure that any modifications or upgrades that have done conform to all applicable laws and regulations for road use, especially pertaining to safety and emissions. LMPerformance is not responsible for buyer not complying with Federal, State, Province, and/or Local laws, ordinances, and regulations. This policy shall be in force for all past, current, and future purchases from LMPerformance, Inc. LMPerformance will not ship ANY non-CARB compliant products to California where California requires products to be CARB certified such as Catalytic Converters and Induction Kits.
FREE SHIPPING: Please note FREE Shipping refers to shipping within the contiguous continental US only. All other locations extra. Some items that require Truck Freight Delivery will require a Truck Freight surcharge. This surcharge is still a discounted shipping amount that is lower then the actual truck freight shipping charge that is charged to LMP. LMP will try to still give the lowest price possible for truck freight items.
IMAGES: Images may be a representation and may not reflect the actual product. Examples would be SPEC stage 3 clutch kits which all use the same photo.
TYPOS: LMPerformance tries to present the best most accurate information on our website. Sometimes we get mistakes in product information sent from vendors such as typos. We can not be responsible for these typos, if you see something that does not look right please let us know before ordering so we can double check for you first. LMPerformance will not pay for typos in any way, monetarily or otherwise.
SPECIAL ORDER ITEMS: Some items are special ordered and may not be returnable, or even cancellable as they are going into production specifically because you ordered them. Special ordered items can have a 5-35% cancelation fee.
Cancellations: Instock orders cannot be canceled due to our automated ordering & fast shipping system. To keep our prices low, all cancelations are subject to a 5% cancelation fee to cover transaction processing fees. We reserve the right to charge up to a 10% cancellation fee for cancelled orders due to merchant fees, special order fees and the cost of processing and shipping orders.When you request a cancellation of an order or a part, please note that it may take time for a manufacturer to cancel an order if the order is drop-shipped. We also have to confirm that the product has not shipped. If the product has shipped then this must be processed as a return.Also note that sometimes products ship more quickly than expected, so we recommend that you do not purchase alternative products until receiving final confirmation of the cancellation.
Returns:We cannot accept returns on parts that have been used or installed. No returns will be accepted after 30 days. All Returns must be in original packaging. Prior authorization must be given before any return can be made. Up to a 25% Restocking Fee may apply. Special orders may be subject to Additional Manufacturer Restock Fees as well. Shipping cost will not be refunded.Hoods as well as PCM Programmers may not be returned unless defective and only for replacement. ALL returns must be first filed using our online form found here: https://www.lmperformance.com/returns.
Lost Order ClaimsAll lost order/package claims must be made within 5 days of the shipping date or tracking information delivery date. All claimes made after this date will not be accepted due to Shipping companies policies of filing loss claims.
Damaged Items or Incorrect Items: Please contact us right away if your item has been damaged in shipping or are incorrect. Please note that we will ship replacement items the same method of shipping the order was originally placed for. LMPerformance can not ship packages overnight at our cost if the original shipping was not also overnight. Claims must be filed in order for replacement parts to be shipped.
Warranties:Any warranty claims must be placed with the manufacturer. All of the products sold by LMPerformance, regardless of the manufacturer, are designed for Racing and Performance applications. Many of our manufacturers offer NO WARRANTY on their products, either stated or implied, due to the unusual stresses placed on the parts and because we have no control over how they are installed and used. Many of these products are designed for off-road use only and are not legal for use on public highways. If you have a question about the warranty on a specific product, please e-mail or call us. Buyer assumes all risk and liability associated with these products.
Installation:We are not responsible for or any costs associated with the installation or the improper installation of any products. Purchaser assumes the risk associated with the installation of products. We, along with the manufacturer of each product are not responsible for any direct or indirect damage to the vehicle, personal, or costs incurred from the use of products.
Starting at 0% Order Now, Pay Later Learn More.
