choosing the right 350 chevy setup

[Scott Danforth]

Re: choosing the right 350 chevy setup

So he posibly could bolt the orig flywheel and housing from the boat motor to new vortec motor providing the starter teeth are a match?

not a chance in he# that a flywheel from a pre 86 (2-piece rear seal) will bolt to an 86 and newer (1-piece rear seal)

 

[Scott Danforth]

Re: choosing the right 350 chevy setup

So how much more power do you guys think the vortec will produce compared to the other engine, seeing as how it will still be carbureted. Also, would the vortec be more fuel efficient than the older engine?

the vortec heads alone add the approx 20hp due to the more efficient combustion chamber and ports. however since your in the engine, you have the ability to adjust the cam profile to match your boat vs the stock "one size fits none" 260hp approach.

if your running stock manifolds on a larger cruiser, I would run a 256 duration cam vs the stock 212 degrees. if you have a smaller boat, you can run 262-264 degrees of duration. add thru-hull exhaust and you can go a bit more.

what are your hp goals? stock 260hp? 300hp?

your boat is an 82 searay, however you never stated which model.

 

[capitan828]

Re: choosing the right 350 chevy setup

the vortec heads alone add the approx 20hp due to the more efficient combustion chamber and ports. however since your in the engine, you have the ability to adjust the cam profile to match your boat vs the stock "one size fits none" 260hp approach.

if your running stock manifolds on a larger cruiser, I would run a 256 duration cam vs the stock 212 degrees. if you have a smaller boat, you can run 262-264 degrees of duration. add thru-hull exhaust and you can go a bit more.

what are your hp goals? stock 260hp? 300hp?

your boat is an 82 searay, however you never stated which model.

My boat is an 82 sea ray 21' cuddy cabin. I'm don't really care much for horsepower, 260 is fine with me. I mainly got the boat for fishing fun. Economy and reliability is my main goal, but if I could toss a few extra ponies in there for free by going with the vortec then why not.

 

[RogersJetboat454]

Re: choosing the right 350 chevy setup

My boat is an 82 sea ray 21' cuddy cabin. I'm don't really care much for horsepower, 260 is fine with me. I mainly got the boat for fishing fun. Economy and reliability is my main goal, but if I could toss a few extra ponies in there for free by going with the vortec then why not.

You will definitely get more for your fuel dollar running the vortec heads. As far as cam's are concerned, I would stay on the mild side of things since you are not trying to build a high horse power engine. If you stick with a mild marine cam, you should be able to run the vortecs with out having to have them modified for a high lift cam. As I said before, you will need to get a hold of the vortec specific intake, and will need the self aligning rockers. One more consideration would be your piston and head gasket choice. Vortec heads have combustion chambers that are 10-12 CC's less then what should be present on the old school 260 horse engines. If you simply bolt them on with out consideration for your piston profile, you may be pushing a fairly high compression ratio (especially with flat top pistons) that wouldn't be friendly for running pump gas in a boat. D dish pistons seem to work the best with vortecs, and you should be ultimately speaking with a good machinist who can determine what head gasket thickness is required, especially if he has to plane the heads and deck the block. You want to keep your compression ratio roughly around 9:1, and could probably push it to as much as 9.5:1.

 

[capitan828]

Re: choosing the right 350 chevy setup

Question, will I be able to use the same older style distributor on the vortec engine? It would I need a different more expensive one? I was reading something about these vortecs turning in the opposite direction or something

 

[RogersJetboat454]

Re: choosing the right 350 chevy setup

Question, will I be able to use the same older style distributor on the vortec engine? It would I need a different more expensive one? I was reading something about these vortecs turning in the opposite direction or something

Any MARINE SBC distributor will work fine with your vortec.
Not sure where you read about a opposite rotation vortec (perhaps you were reading about reverse rotation water pumps?), but a standard vortec engine still runs in the same direction that Ed Cole approved of back in '55...

 

[buzzm19]

Re: choosing the right 350 chevy setup

Hi guys, I am changing over an older pre-87 motor for more power. If you check the head numbers gm 14011083 and 14096217. I am using the second number, these heads have the newer design head flow with 1.94 Intake 1.50 ex and they have the pre 87 bolt pattern so that you can use the older style intake manifolds and has center bolt heads (no valve cover leaks) I found a set on ebay for $103.00. If you want to rebuild your old motor I have experenced that a .030 over bore on a small block really wakes them up and you can get older pistons cheap today, flat top pistons will give you about 9.7 comp and the heads are 64cc. hope this helps on a good cheap budget build. Buz 81 nova 11 26' twin 260's

 

[Scott Danforth]

Re: choosing the right 350 chevy setup

Question, will I be able to use the same older style distributor on the vortec engine? It would I need a different more expensive one? I was reading something about these vortecs turning in the opposite direction or something

your distributor will be fine.

since your running a closed cooling system, an Edlebrock vortec intake will be perfect, and inexpensive.

have you determined which block your planning on using?

 

[Maddoxsdaddy]

Re: choosing the right 350 chevy setup

Hey Scott, I don't mean to Hi-jack you but i'm building a 350 Vortec and have a few questions about the cam if you have time to read my thread.... Titled building a 350 vortec.

Thanks, and no more hi jacking.

 

[capitan828]

Re: choosing the right 350 chevy setup

your distributor will be fine.

since your running a closed cooling system, an Edlebrock vortec intake will be perfect, and inexpensive.

have you determined which block your planning on using?

I'm gonna go with the 96 vortec

 

[FreeBeeTony]

Re: choosing the right 350 chevy setup

I'm gonna go with the 96 vortec

Good choice.

 

[Scott Danforth]

Re: choosing the right 350 chevy setup

I'm gonna go with the 96 vortec

Great choice. I am almost kicking myself for not finding a roller block, however that will be my next build in a year or so (most likely stroked).

 

[Black as]

Re: choosing the right 350 chevy setup

Question, will I be able to use the same older style distributor on the vortec engine? It would I need a different more expensive one? I was reading something about these vortecs turning in the opposite direction or something

Get your self one of these distributors, 5.7L (350 ci) Delco Voyager EST Marine Electronic Distributor Kit, I just installed one in my 5.7 litre vortec engine and it runs great

http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-
119.html

 

[capitan828]

Re: choosing the right 350 chevy setup

Get your self one of these distributors, 5.7L (350 ci) Delco Voyager EST Marine Electronic Distributor Kit, I just installed one in my 5.7 litre vortec engine and it runs great

http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-
119.html

That looks like a good deal. I might just get one.

Are all 350 vortecs four bolt mains? I'm taking mines apart for rebuild and the 3 center main bearing caps are 4 bolt units. Is this a 4 bolt main or do the 2 outer caps also have to be 4 bolt units?

 

[joewithaboat]

Re: choosing the right 350 chevy setup

That looks like a good deal. I might just get one.

Are all 350 vortecs four bolt mains? I'm taking mines apart for rebuild and the 3 center main bearing caps are 4 bolt units. Is this a 4 bolt main or do the 2 outer caps also have to be 4 bolt units?

On GM 4 bolt blocks only the 3 center are 4 bolt, not the front and rear. So You have a 4 bolt block. Not sure about the "all vortec" part of your question

 

[capitan828]

Re: choosing the right 350 chevy setup

What do you guys recommend I do with the heads? My original plan was to go with bronze valve guides and stainless steel valves. I was gonna hand lap them in my self because I know the machine shop will charge an arm and a leg. I want to keep the cost to a minimum. Any advise is greatly appreciated.

 

[joewithaboat]

Re: choosing the right 350 chevy setup

What do you guys recommend I do with the heads? My original plan was to go with bronze valve guides and stainless steel valves. I was gonna hand lap them in my self because I know the machine shop will charge an arm and a leg. I want to keep the cost to a minimum. Any advise is greatly appreciated.

Heads are a tough call... depends completely upon current condition of the heads and the machine shop you are using. Sometimes you can just disassemble, clean, mag (crack check), do a valve job, shim springs, replace seals, surface (or not) and bolt them back on.

On the other hand if the guides are badly worn, you need new springs, a few valves, maybe a seat or two... labor can add up quick. Sometimes its cheaper to buy new heads. Best to get referrals for a shop and have them checked out. Make sure you get a firm price before turning them loose on rebuilding them.

To fully rehab a set of cast iron heads...
clean, crack check, stainless valves, new springs, keepers, retainers, guides, seals, screw in studs, valve job, surface, etc. You will likely have $800.00 plus in them

Good luck!

 

[Scott Danforth]

Re: choosing the right 350 chevy setup

new heads are about $400 each fully assembled and ready to install

 

[joewithaboat]

Re: choosing the right 350 chevy setup

Jegs or Summit usually have good pricing for actual gm heads not copy castings... currently $320.00 each, tough to beat at that price.

http://www.jegs.com/i/GM+Performance/809/12558060/10002/-1

 

[capitan828]

Re: choosing the right 350 chevy setup

I took one of the heads apart and I noticed the intake valves having a little more play than the exhaust valves when wiggled from side to side. Is that normal, does anyone have any specs for these? Are the valve guides removable On the heads? It doesn't look like they are.