CA18DET Torque Plate

[float_6969]

Yay! It's finally done! It took me a while to find a local machine shop who would do it for a reasonable price. The bores are 85mm. In hindsight, maybe I should have gone bigger, but oh well. It will work for my motor, and most other CA's out there. I will probably rent it out once I'm done with it. I have $500 into this stupid thing though, so I will probably want $500 as a deposit, plus shipping and some money to cover my time, so there may not be any takers. Anyway, enough of my rambling, on to the pics!


And this is why you need 2 washers over the head stud over the water pump housing (the torque plate is the same thickness as the head)

[Izento]

Hmmm, I just looked at what a torque plate does. Interesting technology, but yeah, that s*** is a steep price, lol.

[float_6969]

Yea, but even at $500, it's $150 less than what BHJ wants for one. Plus I'll just be renting it, so you would get the $500 back.

[mdb4879]

When building mine I actually called up ARP about the head studs and explained to them about the head stud over the water jacket. The representative told me that stacking washers may be one of the reasons we get a leak there because the clamping load somehow differs from the rest because the relative length of the stud from the deck to the nut is longer. It may also be why they loosen up on us in the first few hours of run time. I asked about cutting off threads from the stud an he said it wouldn't hurt anything and was a better option than stacking washers. It made sense to me since the threads only go in so deep into the block, so why have threads on the stud sticking up from the deck? So here's what I came up with:











I haven't checked the torque on the head studs, but I have 10,000 trouble free miles on the motor. So I'm going to assume they're ok. I also asked if the ARP representative could cross reference an extra stud specifically for this application. He gave me this part number: ATP 4.650-1LB I can't remember if it was exactly what we needed, but it's 3/8" shorter than the rest of the studs. I do remember that if it wasn't the exact length we needed it was close enough to work.

[float_6969]

But ARP said it was OK to cut it? I had contemplated that, but a machine shop told me that it would weaken the stud and not to do that.

[mdb4879]

Yep, and it made sense to me. You aren't loosing any threads into the block because the uncut stud bottoms out. There's still the same amount of unthreaded length going out of the head. If you don't cut it then the stud is relatively longer than the rest because of the stack washers and part of the stud is threaded. Which I would assume is weaker anyways. Just if you cut it make sure not to get it hot so it doesn't change the strength of the material. I cut mine with a hacksaw then cleaned it up with a bench grinder and polishing stone with plenty of water.

[float_6969]

If ARP said it was OK, to cut it, then I'm DEFINITELY doing that instead of stacking washers!

[Izento]

Wait, so the ARP part for head studs is too long for the motor? So we have to either cut all of them or get that other part number ATP 4.650-1LB? Does this only concern using a torque plate?

[mdb4879]

No, the ARP head stud kit is proper (well, mostly). Our problem is that the stud/bolt hole above the water pump is more shallow than the rest, so that stud will bottom out. The stud sticks up too high because of this and the but will bottom out on the stud before it torques down the head. Usually people put two washers on that stud instead of one. I chose to cut off the proper length of threads from the bottom of the stud to remedy this. It should be about 3/8" taken from the bottom of the stud. Just be sure you don't get it overly hot or it will change the properties of the stud.