Need some help with bbc options manifolds/headers?
 

I'am in the process of buying a 88 baja force 220 or 235 (still not sure yet). Either way I'm getting it in the reassembly part of the build. The tank (cleaned and lined) and fuel system have been updated. The heads, intake and carb are off the 454 and have been rebuilt and ready for reassembly. While I have it apart I'm wondering if theres anything I should or could do to motor while its apart. I'm having my machine shop check out the bottom end before I put it back togethor. From the research I've done its a 330hp motor that came in 80's bbc. I am putting new pushrods and lifters in it while its apart and using a marine gasket setup when building the motor. Its also got a new water pump. This is my first speed boat and first inboard out board setup. It has a bravo 1 setup and was told its in good shape.

What I'm most confused about is the manifold and riser setup. The boat is not coming with any so I need to buy them. I see some guys running headers and some running manifolds. I see that water is running through the exhaust....I assume for cooling? What should I get? Are the headers lined for water to run through them or they standard style headers? I build custom drag bikes for a living which includes complete chassis, exhaust, turbo, nitrous and supercharger setups. If its a stardard header thats something I do on a daily basis so is it just that easy? I'm not trying to get out of buying manifolds. I'm just trying to understand manifolds and headers for boat applications.

My business is building high end drag bikes so I'm sure that will carry over to this boat so if there is anything you guys think I can do while its apart that will help with performance I'm interested in hearing them.


Sorry this is so long and I really appreciate any help you guys can give me.

Where is the stuff that was on there before ? If you can still talk to the previous owner, ask him what setup was on it, and try to go with that. This way the holes in the transom will line up, and everything will go alot smoother sir. :drink:

By the way...headers are for Higher hp setups. You dont need those yet. Just concentrate on getting it running the easiest way you can, so you and the family can enjoy it. Keep an eye on the "swap shop" section for parts, and dont be afraid to ask anything. The guys on here have wicked knowledge. :D

I haven't picked the boat up yet. I go next week to get it. He has the original manifolds and risers, but he said they are rusted out and he had planned on putting new ones on.

I'll keep watching the swap shop for some parts.

Thanks

Manifolds
 

Marine exhaust is water cooled. So regular headers will not work. For that application you just need some Mercury Exhaust Manifold Knock offs.. Like these. http://www.offshoreonly.com/classifi...o38207-en.html

Then the Correct size risers. Same place probably has them for 100.00 or so. Just get the old part and compare size to the ones listed on the website from the link above. If you have through hull exhaust then you are home free. Just need black exhaust hosing to go from riser to through hull exhaust. If it is through prop then you might need a couple elbows. This should work fine for that setup. I would not recommend those manifolds for a $15000 motor but for a stockish 454 they are fine. On a different subject YOU MUST REPLACE OIL COOLER AND LINES. Not clean but REPLACE. Otherwise you can either send me the money you spent on the rebuild or just flush it down the drain. Replacing is best bet but sending me the money is also good...lol...

Chris

You can soak the old manifolds and muratic acid which will remove the rust. Then pressure test them. If all is good run them until you get a feel for what you want to do next. If it has alpha drive you won't want to get too crazy with hp anyway.

It had a bravo 1 outdrive. I gather it's better the the alpha 1??

Just get some 496 HO manifolds. They are better and lighter than the old style.

Yes much better at handling hp. Bravos are good to about 500hp depending on the weight of the boat. Alphas were stretched beyond practicality with the 330hp bbc. Merc only did the bbc with alpha a couple years.

Where is a good place to look for used manifolds such as the HO 496 units? Ebay doesn't seem to have much and I'm watching the swap shop here like a hawk! LOL

Call Teague Custom Marine or Raylar. They have might have some take offs.