1987 Mercruiser 5.7 dry joint conversion

Hello, My name is Rob and i have a 1987 I.M.P. 24' cuddy that I'm re-powering. My question is can i convert from wet joint manifold and riser to the newer dry joint? Its a 260 mercruiser (5.7)Any help or part# would be greatly appreciated.

Re: 1987 Mercruiser 5.7 dry joint conversion

No one knows

Re: 1987 Mercruiser 5.7 dry joint conversion

FYI - This isn't a live chat room, it's a bulletin board style forum. It's great when answers appear within hours, but it often takes longer than that. For example, I just read these posts at lunch each day.

I would also be interested if there is a cookbook solution for this. As near as I can tell though, the risers have to change and the thermostat housing has to change. Most likely there are other parts that will change such as the boots and ells between the risers and the Y pipe. Don't know for sure though. Did you do a search on the forum? Seems to me someone was discussing problems with their dry joint system and there may have been information in that thread you could use.

John

Re: 1987 Mercruiser 5.7 dry joint conversion

thanks. Yeah ive been searching the INTERNET for days I cant find anything that says yes. So i'm going to do it anyways I'll post back what i had to do to make it work. Shouldn't be to hard.




Rob

Re: 1987 Mercruiser 5.7 dry joint conversion

The problem is this. The manifolds and elbows will fit your engine. After that, it's a different story. Are the heights and angles of the outlets the same, will the secondary elbows from the old drive fit the new Manifolds and elbows. Will they adapt to a pre-dry joint Y pipe? In particular your year and model.
Then you have to look at plumbing for cooling.
How about cost? These are a lot more expensive than your old system. A single gasket between the elbow and the manifold is around 40 bucks.
Is the rest of an 87 boat worth the conversion? Is it used in salt water or fresh water. How long do you plan on keeping this boat?

Very few people have made this conversion, they are usually looking for the cheapest aftermarket parts, not a top of the line upgrade.

Re: 1987 Mercruiser 5.7 dry joint conversion

Ok i finished the conversion everything was basically plug n play runs great. Just make sure the two restricted ports on the gasket are forward (raw water cooled).I used the lower ports on riser for the hoses coming from the t stat housing. fwiw it looks like you could use the dry joint riser and gaskets on the wet joint manifold (pull factory plugs on the outside of main exhaust/water port) but i cant confirm this.