Cam holder bolt torque sequence? / When to install cam seals?

[Toddp]

hello everyone, I am in the process of replacing the LMA's in my nsx and have reached the point where I need to torque down the cam caps, I use the service manual on this site and the torque sequence is difficult to tell. From what Ive read you start in the middle and work your way out but I want to be sure given the amount of bolts that need to be torqued. I took a screen shot of the illustration, maybe someone has one which is more clear?

Also when it comes to cam seal replacement am I better off replacing the seals while the cams are outside of the car, or should I wait until the cams are in the car for some reason ( being more difficult with the amount of room I have to work in that area )

 

[MotorMouth93]

Here is an easier to read photo. The same pattern applies for both heads but the rear head doesn't have the 4 small bolts by the cam gears.

The procedure I use for installing cam seals (from the service manual) is to install the cams first, then the seals, then the cam caps.

Keep in mind though that the cam seals can end up a bit crooked, so after you place the caps on the head and before you torque them down it's good to use a big socket to gently make sure the cam seal is fully seated against the ridge behind it and straight.



Also, thread moved to DIY section.

 

[Toddp]

Hey MotorMouth thanks for that information, and moving the thread too. One more question when I go and torque down the cam gears would you advise the best way to do so is using the 5mm punches to hold the cams in place while I torque the gear to 51 ft-lbs?

 

[MotorMouth93]

Yes that is the correct method, I wish there was a better way but I haven't found it yet.

 

[goldNSX]

The are cam gear holder tools out there which reduce the stress on the cam bearings.

 

[Honcho]

Hey MotorMouth thanks for that information, and moving the thread too. One more question when I go and torque down the cam gears would you advise the best way to do so is using the 5mm punches to hold the cams in place while I torque the gear to 51 ft-lbs?

I use a spanner wrench to hold the cam gear itself while I torque.

 

[Toddp]

Going to add some information. Up to this point in my LMA replacement I had used 3/16 drill bits to hold the cams in their positions, they were not going to hold the cam while being torqued so I was not going to risk it with that. I did consider buying a special tool to hold the cam gears however did not get very far as each cam is different from one another, and some tools might run into a space issue with the rear bank being so close to the side of the engine bay. I did not have the right spanner wrench to fit the gear either. So at that point I considered buying the honda pins to hold the cams while being torqued to 51 lbfts as they should be much stronger. However I then went to the local parts store and found a "hardened steel chisel set" with a 3/16 chisel inside costing 11$ I bought it and cut the 3/16 one down to fit in the engine. It worked and held the cam in place well while I torqued the gear. Here is a picture of the set I bought if someone ever wants to go that route.

 

[Toddp]

Aside from that putting the timing belt on and insuring the marks line up after a few revolutions went smooth. I followed the manual's procedure down to loosening and torquing the tensioner on the blue mark. However after a few revolutions I noticed the timing belt is off center on the crank gear, it is hard to tell but I think it may be rubbing on the rear guide of the crank gear. I did take my white out pen and put some marks on the inside of the belt to see if it would rub off on the inner guide when they go through the gear and it did not so I am not totally worried about this. I am just wondering if it is common for the belt to sit that far back on the crank gear? It looks good on every other gear and the crank pulley is not torqued to spec but tightened down to see if it would push the gear back at all.

 

[Kaz-kzukNA1]

For your reference, the 5mm hole on the cam holder pipe/plate is not designed for holding the torque when tightening the camshaft pulley bolt.
I know many people done that way and while I don't know any damages can be done or not but not the official way in the engine assembly manual.

Next time, please get a suitable pulley wrench.

If working with the engine kept inside the bay, you need to find the tool that can fit at the rear exhaust cam pulley where it has very limited space.

Regarding the position of the TB, as long as you installed both guide plates in the correct orientation (looks like you've done it correctly), all four cam pulleys (check the dowel pin) plus the tensioner installed correctly and TB tensioned properly, you are fine.
If you look at the above photo, you'll notice that the inner guide plate can rotate over the time.
Just visually double check the installation from different angle.


Kaz

 

[Toddp]

Hey Kaz thanks for the information, this is my first time going this deep into my nsx's engine so I am just being cautious as I go. The photo you posted above looks similar to the position my timing belt is in which makes me believe this is normal. I do plan on going back into the engine 300-500 miles later just to double check my work though I am confident everything will check out. In regards to tightening the cam gear. Next time I may try and source a pulley wrench so I can tighten the gear to the cam outside of the car and drop in the cam / seal / gear as one unit into the engine to help make things eaiser with the rear bank.

 

[Ready2RetireAt21]

Here is an easier to read photo. The same pattern applies for both heads but the rear head doesn't have the 4 small bolts by the cam gears.

The procedure I use for installing cam seals (from the service manual) is to install the cams first, then the seals, then the cam caps.

Keep in mind though that the cam seals can end up a bit crooked, so after you place the caps on the head and before you torque them down it's good to use a big socket to gently make sure the cam seal is fully seated against the ridge behind it and straight.

View attachment 168431

Also, thread moved to DIY section.

Tnx for the photo. Waiting on my Helms manual and my digital PDF has illegible cam bolt numbers….life saver