Manifold and riser on 454
- Thread starter Don Tyson
- Start date
- Mar 28, 2016
- 499
- Boat Info
- 1999 Sea Ray 290 Sundancer
2005 Sea Ray 320 Sundancer
2005 Sea Ray 340 Sundancer
- Engines
- Twins V-Drives
8.1 Mercruiser
Yea, Just make sure you drain them first from the bottom... And take off all the hose's before unbolting them... Because sometimes the drains are clogged... And Change everything and go with OEM Mercruiser,,,,, NEVER NEVER go aftermarket....
Saverio
Well-Known Member
- Aug 31, 2010
- 1,506
- Boat Info
- 1995 450 DA
- Engines
- Cat 3126 420hp
900 hours Westerbeek Generator
the only negative with mercruiser is the price lol
- Mar 28, 2016
- 499
- Boat Info
- 1999 Sea Ray 290 Sundancer
2005 Sea Ray 320 Sundancer
2005 Sea Ray 340 Sundancer
- Engines
- Twins V-Drives
8.1 Mercruiser
Aftermarket usually last half the time.. And sometimes leak... And if they do start leaking inside u prob won't know in-till u blow your engine... Its the Number 1 engine killer in boats.....
Rod Buster
Member
- May 8, 2018
- 66
- Boat Info
- 1985 Sea Ray Sundancer 340
- Engines
- Twin 454 Mercruiser 340MIE : BW/Velvet 72c v-drives
It is straightforward. In addition to the advice above (do not risk aftermarket), the nuts on the manifold can be difficult to reach and turn, so be prepared to have a lot of various length socket extensions and an articulating joint. I go through about 3-4 different configurations to get all the fasteners. Mine is harder because I have two engines and only about 2" to separate the two manifolds in the middle. Your access is probably better.
You need to pay close attention to torques. If your risers look like this,
the circled nut location cannot be properly torqued without an adapter like the one below. A crow's foot will not work because the access it too tight, and even a shallow socket does not fit. You can risk it with the loop end of a box wrench and get "hand tight," but this tool is magic for a few different bolts/nuts on the engine, so it's best just to get it and do it right. Make sure you do the torque conversion for your torque wrench (the lever arm of the adapter places more torque on the nut, so you have to reduce the torque accordingly) so you do not over-tighten.
https://www.engineersedge.com/manufacturing_spec/torque_wrench_1.htm
https://www.zoro.com/proto-torque-adapter-38-in-dr-2-1316-in-j5118/i/G4067077/
You need to pay close attention to torques. If your risers look like this,
the circled nut location cannot be properly torqued without an adapter like the one below. A crow's foot will not work because the access it too tight, and even a shallow socket does not fit. You can risk it with the loop end of a box wrench and get "hand tight," but this tool is magic for a few different bolts/nuts on the engine, so it's best just to get it and do it right. Make sure you do the torque conversion for your torque wrench (the lever arm of the adapter places more torque on the nut, so you have to reduce the torque accordingly) so you do not over-tighten.
https://www.engineersedge.com/manufacturing_spec/torque_wrench_1.htm
https://www.zoro.com/proto-torque-adapter-38-in-dr-2-1316-in-j5118/i/G4067077/
rcknecht
Well-Known Member
If you are in salt water, there you may have trouble getting the bolts out... You should spray a rust remover on the bolts before you try to get them out. Run a tap down the OEM manifolds, and a die on the studs before you screw in the studs into the manifold. I use Neversez on the bolts. I could not get a torque wrench on my manifold bolts, so I did by feel... Also change your spark plugs when you have the manifolds off
A cool tool. Gosh thanks
Rusted Nut
Member
If you can run the engine to get things hot. Heat is your friend in this one.