Triple Square Clearance Issues on 6 Speed

[Benjamin]

OK, then going by this diagram, if the right lower cam (since this drawing is from the flywheel side) is locked, I can see how that bank's intake cam is also held in place, but if you remove all three tensioners, what keeps bank 1-3 from moving?

[DennisAN]

That diagram has always confused me too. (Edit - delete text)

From the LN instructions.

6. Use appropriate long cam lock tool for 3-chain or short cam lock tool for 5-chain engine to lock cams prior to removing chain tensioners. Lock camshaft in head with tensioner accessed from underside of the engine, closest to flywheel.

7. Remove the IMS to crankshaft chain tensioner as well as well the chain tensioner on the cylinder head for which you have locked the cam. If tensioners are worn or were noisy at startup, replace. NOTE: If the flange does not come off easily, the bearing is not centered, or you cannot reinstall the flange, then loosen and/or remove the third chain tensioner and verify or correct camshaft timing.

[Benjamin]

After doing some more reading, you are correct about the bank numbers. Cylinder 1 is behind the passenger seat (left hand drive) and cylinder 4 is behind the drivers seat. I think you might be right about the chain locations as well.

Attempting to interpret the LN instructions: It kind of sounds like you can lock down either side, bank 1 locks in the front and bank 2 locks on the flywheel side. Whichever bank you choose, remove the IMS to cam tensioner for that bank and the crank to IMS tensioner. Then optionally loosen or remove the other bank's tensioner.

I'm still not clear what keeps the non locked bank's cams from moving when that tensioner is (optionally) loosened or removed.

[Benjamin]

After doing some more reading, a lot of thinking, and a bit of sketching, I think I have it ironed out. It makes sense to lock down the bank 1 exhaust cam and remove the bank 1 IMS to cam tensioner, as well as the crank to IMS tensioner. I see little to no value in removing the bank 2 tensioner because of it's location and potential skewing effect on the IMS bearing end of the IMS. The reason to remove the tensioners is so that the end of the IMS will not be pulled askew when the bearing is removed. With the IMS bearing removed, the flywheel end of the shaft will have quite a bit of potential for movement (hence the need to remove or greatly loosen the two tensioners mentioned above). The bank 2 chain is on the pulley end and is subject to almost no movement at all and any tension put on the IMS shaft would result in comparatively little movement on the IMS bearing end. Here is a sketch I threw together as to how I understand the internal components to be laid out. (Obviously things aren't to scale and it's lacking quite a bit of detail with the cams, etc, but you get the idea)


The intake cams were left off for clarity and due to laziness.

[DennisAN]

(Edit - delete text) But we need someone more expert than I to critique your sketch.

[Benjamin]

I think everything is correct except that the IMS to crank tensioner is on the wrong side. What do you think is wrong?

[DennisAN]

Edit

Delete

[Benjamin]

No, the bank 1 tensioner (passenger side bank) is on the right side at the flywheel end. Bank 2 tensioner is behind the drivers seat.

[Benjamin]

I had to go climb around on the garage floor to take these pictures:





The drawing in Post 21 is from the pulley side.

[DennisAN]

OK I think I got turned around under the car.

From Wayne Dempsey's book/website.

Project 16 photo #16



This shows bank 1 (cylinders 1,2,3,) and the cast mark showing "which kind" of tensioner goes in there (purple arrow).

Project 16 photo #23



This shows bank 1 (cylinders 1,2,3), note cast boss for engine serial number The tensioner comes in the bottom adjacent to the chain driving sprocket. The lock on the exhaust cam (5 chain design) needs to be at the far end of the cam opposite the chain driving sprocket, so for this bank it's at the front of the engine behind the (US) passenger seat.

I believe the drawing you posted above in post #21 is from the front of the engine (with serpentine belt pulleys).

[Trey T]

What are you working on? ...you mind taking more photos (detail if possible) to share?

[Benjamin]

Originally Posted by Trey T

What are you working on? ...you mind taking more photos (detail if possible) to share?

(Assuming you're asking me) I am changing the IMS bearing and installing the Direct Oil Feed system by TuneRSMotorsports. I plan on taking pictures and making a new post because, while this isn't breaking any new ground, I did have to comb several sources to get everything figured out. If I can help the next person get it done, I'll be happy.

[Trey T]

Are you chaning out the bearing or keeping the existing one?

[Benjamin]

Changing. The change may surprise a few people, but I will explain it in depth when I put the post together.