OMC exhaust manifolds and risers, 302, 5.0 1989

[Capt. Zack]

I am rebuilding the 302 motor that was in the boat due to a hydro-lock. It is a OMC 1989 302 motor. I am not sure if the manifolds and risers are any good and think I will replace. What is the best to use now on my motor. Any input would be appreciated.

Thanks
Jack

 

[alldodge]

Howdy, the exhaust are all after market, There isn't much which is better then the others. Many recommend Barr, but the issue is check for flatness on gasket surfaces before installation. Just do a search on the net and they will come up

http://www.ebay.com/bhp/ford-marine-exhaust-manifold

 

[Lou C]

You can get Barr from Partman (Lighthouse Marine) on Long Island. I just installed a set and found the machining excellent (checked with a straight edge and feeler gauge after cleaning off the paint).

You should be trying to figure out what caused the hydrolock because there can be other causes (ie rotted out intake manifold or cyl head) although these might have been obvious when you took the engine apart. If it was all from the exhaust, then be careful when installing the riser gaskets, use sealer and proper torque specs.

Normally you check exhaust manifolds for water leaks by propping them up level and filling them with acetone which has less surface tension than water. Look at the 4 ports that line up with the cyl head exhaust ports to see if you see wetness after it sits a while. If so they are junk. Be careful if you use acetone because it is highly flammable.

 

[Capt. Zack]

I appreciate the replys. I was very lucky in that a friend had a ford 302 out of an F150 sitting in his garage and he gave it to me. It was a good running motor when stored. It seems that Barr is the most mentioned risers and manifolds.

Thanks
Jack

 

[alldodge]

Sounds good, don't use any of the ancillary items from the truck motor. The water pump can look the same but a marine water pump is brass inside, the truck motor is not

 

[Capt. Zack]

Intake manifold off a Ford F150, 2 barrel will work on omc Cobra 1989

I am installing all marine gaskets, brass freeze plugs, Carb, Starter, altinator, Exhaust manifolds and risers on a ford f150 motor to install in my boat. Has good compression. Am I missing anything?

Thanks
Jack

 

[GA_Boater]

Moved your thread about using the intake manifold, mainly because the thread didn't ID what motor and this one does.

Another reason is to avoid the forking threads, where questions are asked in multiple threads about the same issues and you brought up the truck motor in post #4.

So all for clarity and good answers from the members.

 

[alldodge]

I am installing all marine gaskets, brass freeze plugs, Carb, Starter, altinator, Exhaust manifolds and risers on a ford f150 motor to install in my boat. Has good compression. Am I missing anything?

Thanks
Jack

If your also using the marine distributor and intake you should be good

 

[Scott Danforth]

I am installing all marine gaskets, brass freeze plugs, Carb, Starter, altinator, Exhaust manifolds and risers on a ford f150 motor to install in my boat. Has good compression. Am I missing anything?

Thanks
Jack

Check the firing order. The marine 302s normally use the 351 cams which swap 2 cylinders compared to the auto 302. The marine motors usually use the GT40 heads too

AllDodge covered the marine water pump

 

[Capt. Zack]

I want to add that I am using the marine cam out of the bad motor along with the marine distributor.

 

[Redrig]

. The marine motors usually use the GT40 heads too

are you sure about that ? I thought those heads are in Cobras , later explorers , kinda higher end deal. That would be awesome if they were stock in boats , cuz I am looking at eventually swapping in some GT40s into my boat , some say you can get like 30-40 extra HP and more efficient .

and I hear the gt40P heads work too

to the OP , I went through the ford manifold saga a while back and made a thread about my conversion , it may have some good info that you will need.

https://forums.iboats.com/forum/engi...onversion-ford