Manifolds and Risers

[CC Rider]

I looked at the price of Volvo manifolds and risers for the 7.4l and was amazed at the cost. Has anyone replaced theirs with Osco, Sierra, Barr or some other brand? If you used Volvo parts, have you found a source where they are reasonably priced?

[Bullish]

I don't have any info. on those parts but regarding the least expensive cost for Volvo parts, I go to www.marinepartsexpress.com

I haven't found a cheaper dealer but would like to know if someone else has.

[billh1963]

I replaced my manifolds and risers in March. I have a raw water cooled 7.4L carb'ed engine. The risers were two years old but the manifolds were original (1997) with 630 hours on the engine and I changed them out in the interest of safety.

Anyway, I shopped everywhere and could not find any aftermarket manifolds. You can find aftermarket risers but not manifolds. I bought my stuff from www.basicpower.com (based out of Harker's Island, NC). The total for new Volvo manifolds, OSCO risers, new 4" exhaust hoses and clamps, new gaskets, etc. was right at $1,000. That included NC sales tax and may have included some other odds & ends...I can't remember at the moment.

I have bought stuff from marineexpress.com as well but Basic Power had the parts in stock and a little better pricing.

Anyway, with the help of a mechanic friend we changed everything out in about 3 hours total. My original stuff looked great so I am keeping them and will be sending them out for cleaning/painting.

Yes, the parts are expensive but I feel better knowing they are new and I shouldn't need to do anything for several more years.

[CC Rider]

That's a cost effective solution. I've been studying my set-up since my first posting and have taken a closer look at what I have (my first year with this boat).

Mine is FWC, so I can't seem to find any direct replacements for the volvo parts, which are costly. But what I've noticed is the manifold (presumably original) isn't corroded at all so I don't think I need to replace. The two piece risers though are corroded and should get me through this year but I should replace next year. But the volvo two piece riser kit is also expensive. So, what I need to figure out is can I use the osco 1 piece riser that you used to replace my expensive 2 piece volvo riser.

Where do you send your manifold to be cleaned? How do they clean it?

[billh1963]

External corrosion is NOT indicative of internal corrosion.

My engine is as clean as any 2 to 3 year old engine around; however, with the manifolds I felt it was too risky to take a chance.

Here is a picture of the engine (BEFORE I changed the manifolds and risers):



Although externally everything looked great the chance of failure was still very high because of the age of the manifolds.

The folks as Basic Power are very knowledgeable and can answer your questions. There are aftermarket risers in place of the Volvo riser.

I haven't sent the parts out. I'll do that over the summer. However, any automotive shop that machines engine blocks/heads should be able to acid dip and paint the parts.

[usrower]

volvo parts

I've purchased all my volvo and westerbeke parts from Engines Inc. located in Atlantic City, NJ. (609) 344-0083 These guys are knowledgable and the prices are the best I have found.

[CC Rider]

I agree that external corrosion isn't very helpful on riser and manifold condition. I pulled one of my manifolds last weekend and there doesn’t seem to be a bit of rust in the water jacket. I'm guessing this is a result of the non-corrosive coolant that's been pumping through them. On the other hand the riser and exhaust outlet (2 piece riser set-up) have a fair amount of corrosion in the water jacket so I should address this soon.

Thanks for the suggestions on vendors I will give them a call.

If anyone else has any insight with aftermarket risers to replace the two piece set-up on the 7.4l let me know.