Hey guys I wanted to know what is the overall bolt length for the long head bolts on a Toyota Van 4y. I want to get ARP bolts for mine and I need the overall length and the length without washer from underneath the bolt head to the end of threads. I will post part numbers from ARP when I figure it out.
Not familiar with "ARP" bolts? Are they something special?
When I need something like that, I just go to the dealer and pay the toll, it hurts but I find solace in knowing that whats in there is the correct spec, I don't have to worry about QC or fitment and if it does fail, I have a local bricks and mortar store to take my complaints too.
ARP is a performance bolt manufacturer that makes bolts and studs for performance cars. The reason I want to go that route is for more clamp up and less stretch and so the bolts are reusable. I know Toyota bolts are good but this is another level and Toyota bolts are tty which means one use. To do this since my engine is still in the van I need specs such as bolt length to figure out which model of bolt works.
Last edited by amcdave; 02-23-2018 at 02:49 PM.
"The reason I want to go that route is for more clamp up and less stretch and so the bolts are reusable."
What benefit do you hope to achieve from more "clamping force"?
Unless you plan on pulling the head on a regular basis, I can't see why reusable bolts would be an advantage.
If repairs are done properly, it really should be a once in a lifetime event.
Toyota has used both styles of head bolts, so I would have to assume there's a reason the engineers chose TTY for the 4Y.
Here are rough lengths of the 4y head bolt. (sorry, I'm a woodworker, not a machinist)
Stud length: 4 5/8"
Head with no washer: 9/16"
Overall: 5 3/16"
I would be interested in the ARP bolt. Every time I think I won't need to revisit a project area, I'm wrong. I practically don't use glue anymore in my carpentry.
I assume you already have the diameters, notice the area where the diameter increases.
I am interested. Please let me know if you do get the correct numbers from ARP. I would like the added assurance while running a turbo.Originally Posted by amcdave
Last edited by VanCo; 02-25-2018 at 08:22 PM.
Thanks for the dimensions i am very grateful. I want to go ARP because I hove noticed when servicing valve stem seals on two of my vans that the bolts seem to be loose as you go further back on the engine where it gets hotter. 4y engines seem to have a descent amount of leaking head gaskets and blown ones. Some of this is because of overheating but alot is from the head expanding when you run it as it warms and cools and that is what seems to finish the gasket off. Good clamp up would prevent as much motion making the gasket last longer. Car manufacturers use TTY bolts because there is no re-torque necessary so they don't have to take the car back in and re-torque head after you buy. I don't car to re-torque if it makes the gasket last longer. I also know the clamp load can be higher so that motion should go away. I don't know if the tty bolts stretch as much as the head gasket gets thinner because of the relative motion of head and block. The hot temp of the engine because of the cover does not help either with the motion.
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