Manifolds and risers

[nickmo]

Hi all,
I'm replacing dry joint manifolds and risers on a 2008 5.0 TKS and have a couple of questions.
1. Do you use any gasket sealer on the manifold or riser gaskets if so what product?
2. Do the threads on the brass fittings that were removed from the old parts have to be sealed before installing on the new parts if so what product?
3. Any other tricks or secrets you're willing to share?
Thank you.

 

[DeepBlue2010]

No tricks or secrets at all. It is pretty straightforward job. The you buy will determine the need for a sealer. If you received this cheap paper gray color gasket with you risers, trash them and go get a set of good quality composite gaskets from a good marine store (they are green or blue color). Most of these goes dry and sealant actually damage them but ask the sales person for the factory recommendation on the specific gaskets you buy.

All brass fittings needs to be sealed with liquid Teflon. Sold in the same marine store you will buy your gaskets from. Teflon tape will also work, I just prefer the liquid one.

Torque the bolts to the recommended torque sitting but MAKE SURE to check the torque again after the engine heats up to normal operating temperature.

 

[Bondo]

Ayuh,..... 1) I use the Mercruiser grey carbon metallic gaskets,... Dry,.....

2) For thread sealant, Perfect Seal, Perma-gasket #3,....

3) If ya got the space, which most boats don't,...
Get some inch longer manifold bolts, cut the heads off, 'n use 'em as guides to hold the gasket, 'n weight of the manifold as ya screw in the right bolts,....

 

[mr300z87]

I just did a dry joint conversion and followed the Merc Manual that calls for dry on the exhaust section and Perfect Seal on the round orange water gaskets to prevent corrosion . Use the Merc gaskets with fixed orange o-ring attached in the proper configuration, although they are bit pricey. I use Bondo's advice and put perfect seal on all threads.