I prefer the look of ARP black bolts, but do they stay nice and black over time? If not, does anyone have problems with the stainless hardware interacting because of the dissimilar metal properties?
Probably mostly depends on your climate and what weather and storage environments.. but I can tell you with little doubt that the black coated stuff lasts nowhere as long as the stainless hardware will. It WILL eventually corrode. Whenever I want black hardware on my stuff to hold back on the bling or go for that stealth look.. i just hand sand, acid etch, or preferably sand blast to prep for paint. More work and pricier but best of both worlds.
Looking at this chart I found a couple months ago, https://www.fastenal.com/content/feds/pdf/Torque of Stainless Steel, Non ferrous Torque.pdf The torque values of stainless appears to be somewhat lower than ferrous steel for head bolt sized fasteners
FYI, ARP stainless "300" are not your average stainless steel, they are stronger than grade 8. regarding their 8740 Chrome Moly head bolts, I have used them on my engines for over 25 years, I am in the Pacific Northwest where the climate is damp and right by salt water, over time they will develop a small amount of rust, mostly if the coating is scratched, but that was on my daily driver, if you only drive during sunny days, I would say black coating will last decades.......also, depends on how many times you are removing the bolts. The more often you are removing them, the more chance the coating can be scratched which will then corrode (rust). I have their stainless steel 12 point heads on pretty well everything else, nice and polished and never have to worry about rusting in my lifetime, stronger than grade 8. Never had any issues with them interacting with aluminum water pump or cast iron engine parts or body panels. Check out their website www.arp-bolts.com David you can also request for their free catalog, view their video's etc........
arp doesnt do stainless head bolts last time i checked. im sure the above chart is exactly why. all the bolts for engine covers and manifold dont get torqued to their max clamping force and are fine to be stainless steel. i like using the the stainless steel ones just because of the look of them. my only concern is them going into aluminum. i have never had them size or gall on any of my motors but i did have one customers lt1 camaro have a header bolt gall and break off in the head. i have also seen the black bolts get some rust color to them after a while. usually on the contact edges from the tools that tightened them and compromised the coating.
ARP does manufacture Stainless Steel Head Bolts for our 289/302/351 engines. Again, ARP stainless "300" is not your regular everyday stainless, check out their site and find out for yourself...... 454-3601 stainless steel hex head for 289-302 w/factory heads or Edelbrock 60259/379 454-3701 stainless steel 12 point heads I've used their stainless steel header bolts on my AR-1 aluminum heads along with ultra torque fastener lube and never had any issues.
Great responses, guys! Thanks for the feedback. Good point with the climate. 30 miles to my west is the brackish Chesapeake Bay. 60 miles to my east is the Atlantic ocean. Great info! Good to hear the stainless steel hardware plays nice with the aluminum parts. Good info, Bryant. Thanks! So, because I do not want any black bolts eventually rusting, and because I live near the ocean, I'm thinking of going with ARP stainless. Sounds like as long as I use the recommended installation lubricate, the SS hardware will work just fine. Guess I gotta shell out the extra dough for the SS stuff, lol!
Hi Rusty: I think you would be quite happy with ARP's SS bolts! Go to their site and request a free catalog or you can download a copy, lots of great info, charts etc... I used their 554-9501 SS 12 point head engine dress up kit, 9601 if you want hex head, also have for 351W too. Can find kits online for around $200, got mine for around $150, had spare set until recently sold......probably a little pricey for average person, but consider these are probably the best Automotive Fasteners that you can buy, well worth it in my opinion. Made in USA. Cheers, David thanks again for those MOOG upper ball joints!
Stainless into aluminum ? Always use antiseize on the threads (and shanks) . Matter of fact, always use it regardless of the bolt material into aluminum.
Yeah, that was my main concern with the SS hardware. ARP's installation lube seems to mitigate the dissimilar metal interactions.
