89 Rinker Restore: Seeking suggestions for new SBC350

[Bshoot]

My first boat rebuild... this all started w a “hole patch”.... which I’m sure some of you might be able to relate. After realizing the floor needed to all be completely redone, I found JB weld all over the block & manifold.. so new engine it was, bought a SBC 350... also painted it, anxious to hear it in the boat now.. ANYWAYS, part of the reason for this post is I ran across some parts for sale & would love to find some help in regards to what route to go with things... because I am getting ready to purchase what parts I need & I would also LOVE to have a little extra performance and rumble to be honest.. I just may be able to get a decent deal w these parts, which then I could spend that difference and then sole hopefully on doing everything I can semi cost-effectively while I am in there now.. I am basically trying to get as much prepped & ready as possible.. I did add SOME photos for what has been done currently and also will add photos of the parts for sale ad, am supposed to reach out to him here this afternoon/tomorrow afternoon. I will also add below:
•The list of what I have wrote down currently of what I was told that I will be needing.
•Also, a handwritten note on questions of what parts might help me..? Which are basically all guesses for the most part...
I do not have a ton of experience of physically working on engines until now.. I do part-way understand how most things work.. I have already bought the exhaust manifolds & thinking I may need new risers as well(on for sale ad, why I am part-way interested). I will attach pictures of my old risers as well so that my help can have an idea on where I am at..

(PARTS LIST): I currently have down that I will need:
•I did buy some exhaust
•Already bought a pair of exhaust manifolds(factory basically, but would have considered better ones if I would have known prior the difference better ones would have possibly made).
•I am interested in some new risers because mine are a little rough(pic attached) and also i have heard a lot on how much the risers can help with performance..? I can see that on the pricing as well... lol but risers are on the parts for sale list, along w many others: which is where a lot of my handwritten questions marks came from.. I will also attach my Engine Specs as well.

•The parts for sale list also has a a single holler double pump 750 CF carb better than my original carb(pictured in attachments) if I rebuilt it?

•oil sending unit(SBC350)
•oil filter
•fuel pump
•fuel filter

_________
•Distributor: Part number
Marine HEI
look at ours & exhaust guys distributor to see if we need new.
90747A27(thomas)
*Whole assembly
—————
•Water Pump: unsure of part to get
Orig # is 82443
Micky listed a water pump impeller repair url.

—————-
•Marine Starter
————-
•Marine Alternator(Micky):
single-wire for the best

Water pump kit

Set of senders

Gimbal bearing kit

Gaskets(did not list all)

Exhaust Shutters

 

[achris]

Sure, in a car more power is great, you have a gearbox to help you stay in the power band. Not so in a boat.. When you increase top end power you sacrifice low end. It's just a fact of, engines. In a boat MOST of the time you are going to be in the mid range, not the top end. Increasing the top end will necessitate an increase in prop pitch to keep the max revs in check. With the reduced low end and the higher pitch, that boat/engine will be an absolute dog out of the hole. Marine engine engineers spend years getting to the right power such that the prop, engine torque curve and drive ratio balance such that the engine give good power AND is 'drivable'... Mess with that at your own peril.

 

[Bshoot]

Sure, in a car more power is great, you have a gearbox to help you stay in the power band. Not so in a boat.. When you increase top end power you sacrifice low end. It's just a fact of, engines. In a boat MOST of the time you are going to be in the mid range, not the top end. Increasing the top end will necessitate an increase in prop pitch to keep the max revs in check. With the reduced low end and the higher pitch, that boat/engine will be an absolute dog out of the hole. Marine engine engineers spend years getting to the right power such that the prop, engine torque curve and drive ratio balance such that the engine give good power AND is 'drivable'... Mess with that at your own peril.

So then it isn’t going to make any difference in some of these parts really then I assume? Unless I go with headers and all of that, correct? This engine that I bought is a car engine, but the motor company I bought it from(an old school motor builder: professional) and he said that it would be fine. So then to be clear, if I was to get headers and all that jazz, it would be horrible with getting out of the hole and all of that? I thought the top-end was for getting out of the hole?

 

[alldodge]

Don't need a 750 CFM carb for a SBC, its more carb then the motor can use. Only need 600 CFM like a Edelbrock 1409

Don't need a cooling crossover pipe, just a circulation pump

The distributor listed is for a TB 4 or 5, don't need a ECM need a TB module, or change to Delco EST

If your old exhaust is fresh water, more then likely their fine. Headers will do you no good because you do not have enough power to make them a benifit. Now if you went to aluminum manifolds and stainless risers, then there is a weight reduction which would help

I don't like one wire ALT's but they do work

 

[achris]

... I thought the top-end was for getting out of the hole?

Top end is for speed. For getting out of the hole you need low end, as your revs are right down when you're pulling from zero. In a car you select the lowest gear and slip the clutch to get the engine up into the high revs for a take off. In a boat you don't have different gear ratios to select, or a clutch to slip, you need to be making power right from low revs... Build an engine that makes solid power from 1500, and is done by 5000 and you'll have a very nice rig.

BTW, a car engine cam isn't right for a boat, get that cam out and put a truck cam in.. and change the head gaskets to non-steel, and the core plugs to brass.

Chris...

 

[Bshoot]

Top end is for speed. For getting out of the hole you need low end, as your revs are right down when you're pulling from zero. In a car you select the lowest gear and slip the clutch to get the engine up into the high revs for a take off. In a boat you don't have different gear ratios to select, or a clutch to slip, you need to be making power right from low revs... Build an engine that makes solid power from 1500, and is done by 5000 and you'll have a very nice rig.

BTW, a car engine cam isn't right for a boat, get that cam out and put a truck cam in.. and change the head gaskets to non-steel, and the core plugs to brass.

Chris...

 

[Bshoot]

Damn... we asked the guy if this cam would be fine.. he said yes

 

[alldodge]

I'm unable to say, but asked guys who should know on OSO

https://www.offshoreonly.com/forums/do-yourself-boating-budget/370776-350-sbc-cam.html

 

[Bshoot]

I'm unable to say, but asked guys who should know on OSO

https://www.offshoreonly.com/forums/do-yourself-boating-budget/370776-350-sbc-cam.html

Oh wow thanks man.. I appreciate you. I know a great guy that told me to get on here.. this is basically my first post & hard searching anywhere for true knowledge & experience. Thanks again

 

[alldodge]

Go to the thread I posted at OSO and see what the guy is saying

 

[Bshoot]

Having issues with my login, had to contact the administrator. Will reply ASAP on there. Thanks man!

 

[Bshoot]

Started with a “floor patch”.. then found a jb welded block.. pulled engine and bought a new one. Engine builder I got it from said the cam would be fine for a boat

 

[Bshoot]

Here are the new engine specs that came with the new engine

 

[Bshoot]

It will not let me post pics on that other OSO post bud.... I’ve tried over 20 times, extremely frustrated

 

[alldodge]

You need to post 10 times to post pics.
Your at post 4 now.
write post 5 and submit

write post 6 and submit

Continue until you have a post count of 10.
Once at 10, you can upload pics

 

[Bshoot]

You need to post 10 times to post pics.
Your at post 4 now.
write post 5 and submit

write post 6 and submit

Continue until you have a post count of 10.
Once at 10, you can upload pics

Thanks man

 

[tpenfield]

Cam duration and lobe separation are important for a marine engine, because of the 'wet' exhaust. Less 'duration' and more 'separation' are good things for a marine engine.

Google 'exhaust reversion' for more details. Essentially, at the top of the exhaust stroke, both exhaust and intake valves are open with high-performance cams (even many automotive cams). The exhaust is under pressure and the intake is under vacuum. So . . . . a slight reversal of flow happens, particularly at idle speeds.

In a car - this reversal is no problem. In a boat engine - water mixes with the exhaust at the end of the riser/elbow for cooling. A reversal of flow may/will cause the water to be pulled into the exhaust manifold (where it should not be). At that point water can be pulled into the combustion chambers and cause a hydro-lock.

 

[alldodge]

Posting for pics

No, no
You have to post on OSO site not here

 

[mickyryan]

Found ya !!

 

[Bshoot]

Found ya !!

#9 has the url that all dodge made and tagged me into OSO