How to replace the multi-air brick safely
Posted: Thu Jan 09, 2020 3:17 pm
This was originally posted in the Facebook group, but I forgot to put the credit here. I can't find the original post, but thank you whoever you are.
So like I promised I experimented with a MA brick install on an engine I have to attempt to replicate the "bent valve" issue a few people have had. My initial hunch was correct, it's an alignment issue when installing the brick due to the MA plungers extending when the brick is placed on the carrier assembly.
Attached are three photos.
In photograph one you will notice there are 3 lines.
*note, this brick is sitting in its alignment pins*
The two lines running parallel represent the pitch left or right in which the MA brick is sitting. My first hunch was that improper pitch could cause the valves to bend. this is not the case.
The second curved line to the left of image one represents roll. Roll forward or back towards the camera. This is the critical indication. If the brick is rolled too far backwards or too far forwards, you will have plunger to valve misalignment.
Due to the tip of the plunger and the tip of the valves smallness, this can happen quite easily. Picture 2 indicates that the MA brick is rolled too far to the rear (even though the brick is aligned on its dowel pins)
Now, a lot of positions will also occur in different variances depending on the current rotational stop state the cam is in. I played with this too. Aligning the rollers in different positions across all the valves and the results didn't change.
in picture two you will see two red circles. the bottom circle roughly indicates the plunger tip position and the top indicates valve tip. If I were to begin the tightening process without visually checking the plunger position, upon completely tightening the brick the plungers would put a lateral force on the valve, thus bending it.
In picture three you can see how I remedied this issue.
When installing the brick, insert 4 bolts into the corner positions and hand start until you have a few threads in.
at this point, visually check the positions of your MA plungers. use a bright flashlight as it is hard to see. for this instant i lifted the back of the ma brick to align the plungers as you can see in photo 3.
while holding the brick, tighten the front two bolts nearest the cam on each side evenly. I did 3 turns on one side and 3 turns on the other.
Now you can also watch the sides of the MA brick nearest the mating surface on the carrier to ensure the brick is seating perfectly level.
This is how valves are being bent.
I attempted this install 5 different times in as many janky ways as i could and i had the same result every time.
Cheers. Hope this helps anyone removing an MA brick.
*YOU MUST ENSURE THE MA BRICK SITS DOWN PERFECTLY EVEN* constantly do visual checks of your actual valve contact points and plungers as they will extend fully when the brick is placed in the carrier for tightening*
So like I promised I experimented with a MA brick install on an engine I have to attempt to replicate the "bent valve" issue a few people have had. My initial hunch was correct, it's an alignment issue when installing the brick due to the MA plungers extending when the brick is placed on the carrier assembly.
Attached are three photos.
In photograph one you will notice there are 3 lines.
*note, this brick is sitting in its alignment pins*
- multiair1.jpg (145.93 KiB) Viewed 15464 times
The second curved line to the left of image one represents roll. Roll forward or back towards the camera. This is the critical indication. If the brick is rolled too far backwards or too far forwards, you will have plunger to valve misalignment.
Due to the tip of the plunger and the tip of the valves smallness, this can happen quite easily. Picture 2 indicates that the MA brick is rolled too far to the rear (even though the brick is aligned on its dowel pins)
Now, a lot of positions will also occur in different variances depending on the current rotational stop state the cam is in. I played with this too. Aligning the rollers in different positions across all the valves and the results didn't change.
- multiair2.jpg (46.56 KiB) Viewed 15464 times
In picture three you can see how I remedied this issue.
When installing the brick, insert 4 bolts into the corner positions and hand start until you have a few threads in.
at this point, visually check the positions of your MA plungers. use a bright flashlight as it is hard to see. for this instant i lifted the back of the ma brick to align the plungers as you can see in photo 3.
- multiair3.jpg (41.18 KiB) Viewed 15464 times
Now you can also watch the sides of the MA brick nearest the mating surface on the carrier to ensure the brick is seating perfectly level.
This is how valves are being bent.
I attempted this install 5 different times in as many janky ways as i could and i had the same result every time.
Cheers. Hope this helps anyone removing an MA brick.
*YOU MUST ENSURE THE MA BRICK SITS DOWN PERFECTLY EVEN* constantly do visual checks of your actual valve contact points and plungers as they will extend fully when the brick is placed in the carrier for tightening*