5.7l 2bbl marine vs truck

[sillydilly]

Hello I will be replacing my marine intake (2bbl carb) as I suspect it is in poor condition due to improper winterization. I installed a truck 350 but user the marine intake and I'm finding a small amount of water in the oil

- is there any different between the marine 2bbl and truck 2bbl?

- if I find a 4bbl with a carb for the right price can I buy that and bolt it right on or will I have issues


thanks in advance for any help! and special thanks to everyone who's already helped me in my dozens of other threads asking for help

 

[Scott Danforth]

tell us exactly what you replaced and what you tried to reuse

your intake could have been cracked as well. your exhaust manifolds would have definately cracked, so dont use the old exhaust manifolds - get new.

as far as the short block goes, same heads, same pistons, same block, same crank.

the differences are a marine motor uses stainless (marine) head gaskets and brass core plugs along with a marine circulation pump. from there the marine accessories and electrics get bolted on along with the marine exhaust.

you did change the head gaskets and core plugs on your truck motor along with the circulation pump, didnt you ?

as for the 4barrel intake, if you are running in salt water or brackish, get a cast iron intake or a marine dual alloy intake

 

[sillydilly]

No Title

I reused the intake and exhaust manifolds


exhaust manifolds passed a submerged pressure check at 20 PSI

I suspect the intake so I'm replacing it for the price it costs

 

[achris]

... if I find a 4bbl with a carb for the right price can I buy that and bolt it right on or will I have issues...

Gotta be a marine carb. Automotive/truck will NOT be suitable.

Chris.........

 

[sillydilly]

achris I will use my marine 2bbl thanks !!

 

[Bondo]

Hello I will be replacing my marine intake (2bbl carb) as I suspect it is in poor condition due to improper winterization. I installed a truck 350 but user the marine intake and I'm finding a small amount of water in the oil

- is there any different between the marine 2bbl and truck 2bbl?

- if I find a 4bbl with a carb for the right price can I buy that and bolt it right on or will I have issues

Ayuh,.... Trucks ain't used carbs since the early '80s, or late '70s,.....
Findin' a 2bbl. truck manifold would be tough, 'n probably won't fit the heads of a later model heads/ motor,....

A cast iron intake, or aluminum, if in freshwater, 4bbl. conversion is a viable option,....

 

[hemi rt]

Also the cam in the marine engine is different than the truck engine, the power band will be totally different and the performance of the boat will suffer.

 

[Scott Danforth]

Also the cam in the marine engine is different than the truck engine, the power band will be totally different and the performance of the boat will suffer.

truck cam is close enough to a marine cam that you wont know the difference. in fact, most RV/Tow cams are marine cams.

 

[Bondo]

truck cam is close enough to a marine cam that you wont know the difference. in fact, most RV/Tow cams are marine cams.

Ayuh,..... Even an Oem car cam is just Fine,.....

The fallacy of the marine cam discussions amongest Boaters, relates to aftermarket Hot Rod car cams,.....

Though I completely agree, what's known as a RV cam is in fact the same grind as a Marine cam,.....
Same requirements, horsepower from idle to 5 grand,....
All the torque yer displacement can muster as low in rpms as possible,....

 

[Rick Stephens]

My understanding was the 'Mercruiser' cam was a direct 'off the GM assembly line' pickup cam for that year motor. Crank, pistons, cam, lifters, heads, the long block with the exception of head gasket and core plugs is OEM GM. I never worked for GM or Merc, so I could be mistaken.

 

[achris]

My understanding was the 'Mercruiser' cam was a direct 'off the GM assembly line' pickup cam for that year motor. Crank, pistons, cam, lifters, heads, the long block with the exception of head gasket and core plugs is OEM GM. I never worked for GM or Merc, so I could be mistaken.

Quite correct.

 

[sillydilly]

Ayuh,.... Trucks ain't used carbs since the early '80s, or late '70s,.....
Findin' a 2bbl. truck manifold would be tough, 'n probably won't fit the heads of a later model heads/ motor,....

A cast iron intake, or aluminum, if in freshwater, 4bbl. conversion is a viable option,....

are you referring to a 4bbl intake with the adapter to allow a 2bbl?

 

[Bondo]

are you referring to a 4bbl intake with the adapter to allow a 2bbl?

Nope,... I'm sayin' goin' to an Edlebrock 1409 on a manifold is a viable option,....

'bout 20 hp or so,....

 

[achris]

Nope,... I'm sayin' goin' to an Edlebrock 1409 on a manifold is a viable option,....

'bout 20 hp or so,....

:thumb: