Trojan Boat Forum

I just ordered a new starboard manifold for my Trojan F-25
Mercruiser 228HP
I originally asked for OSC7235B, the part has been back-ordered almost a year now from the manufacturer, it seems that they are having a problem with the mold.
Marine Manifold out of B.C. suggested Sierra,SIERRA 18-1951-1 MANIFOLD STB LOG STYLE =which I went ahead and ordered.

Any remarks, opinions about Sierra over OSCO or vice versus?
I guess after 32 years old, some metal parts just rust out. Especially since they have raw water running through them constantly.

Hope I made the right decision, can't wait much longer, need to get it fixed, it is rusted on the bottom (small rust through)and pisses water into the bilge. No water in the engine or oil, engine purrs like a kitten.

Why not change over to a center riser type ? you should be doing both sides anyway .

prowlersfish wrote:Why not change over to a center riser type ? you should be doing both sides anyway .

Port side was done by seller last year when I bought the boat.
Didn't know I could go centre risers, just going along with what was originally there from Trojan.

sierra, use their stuff all the time, supplier for Merc. And he'd have to buy new risers and exhaust hoses if he went with center style, right ? But I'd change the other manifold if you have the $ for it...

On my S/B engine I have center rise manifolds, with rw cooling. The "center rise" manifolds dissapate the heat more than log or end style manifolds on rw cooled engines... as was explained to me by an engineer with Osco.
Here is the set up I use with Osco. I use the number 4 riser in diagram.

http://www.oscomotors.com/catalog/catalog39.asp

I am running Chryslers so can't comment on the Merc-specific details, but Sierra parts are generally good and MarineManifold.com is the Cdn version of the US outfit MarineParts.com, so as an organization should be reliable in knowing what they are doing. I have ordered a couple things from them in the past as well and had no issues.

Stripermann2 wrote:On my S/B engine I have center rise manifolds, with rw cooling. The "center rise" manifolds dissapate the heat more than log or end style manifolds on rw cooled engines... as was explained to me by an engineer with Osco.
Here is the set up I use with Osco. I use the number 4 riser in diagram.

http://www.oscomotors.com/catalog/catalog39.asp

I under stand they improve exhaust flow also . The do requirer some re-pluming . I would consider it a up grade , you will notice thats what the newer engines use . they can be used raw or fresh water on the manafolds just by a simple gaskit change .

Don't forget Bob sells all types of manafold and risers

I may be wrong but if memory serves me correctly, I touched base on this when you brought up (I think it was you) a manifold issue last year. I don't recall the year it was changed but the ealier manifolds had a different sized exhaust opening. These have no longer been available for some time. If this is the case with yours, your existing riser if used, and elbow will have a different foot pattern than that available on the market today. Did the PO change the elbow also when he replaced the other side?

prowlersfish wrote:
Don't forget Bob sells all types of manafold and risers

I realize that, but with the cross border duty, shipping and exchange rate, it usually comes out quite a bit more. I truly wish to support him, but it's all about the bottom line sometimes.

I have a decent starboard log manifold you can have for free, just pay the actual shipping cost. I have the end caps and some risers as well.
these parts came off of 1977 mercruiser 228's

I have tried to sell these parts on craigs list for a while with no luck, and I'm tired of looking at them on the side of the house.

Please note, they need to be cleaned and painted

THESE ARE FREE TO A FELLOW TROJANBOATS.NET FRIEND

2 throttle cable mounts for a 4 barrel quadrajet cabs
4- 3" risers
2- block off manifold end caps
2- 1" dia port end caps (freshwater cooling system)
2- transmission cooler mounting brackets
2- GM bell housing

California ZIP code 92131

that's so cool of you .....and remember ship FedEx....we'll throw it your way...

throwing packages is not just for fed x anymore , UPS and the post office have joined the action ,

prowlersfish wrote:Why not change over to a center riser type ? you should be doing both sides anyway .

+1. Much better way to go, and usually less expensive for the manifold as well compared to logs. Your investment in the upgrade would be well worth the extra money.