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1990 Pantera 1988 GM 305 sterndrive

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Pantera1990

New member
Hi boat lovers
I have purchased a 1990 Pantera with a Merc GM 5.0l cid V8 and would like suggestions
I had steam coming out of the rocker cover hoses into the carb flame restrictor
I noticed water in the oil, after looking under the filler caps, greyish color and thought the worst so I started with
the intake manifold removed it and the gasket seal looked fine, took off the port riser and all looked good, bit
blackish maybe rich but looked ok, then took off the stb riser and it was full of water, thought this was strange as it
was not the same as the port one, then removed the exhaust manifolds again seal and housings looked ok
so I then removed the starboard head, again the seal looked fine, but now had water in the cylinders soaked it up
and hit them with WD40 seemed like it came from the riser which was full of water as mentioned earlier
any ideas why the stb riser was full of water and not the port one.
I suspected a cracked something but every thing looked very good for an engine of this age
I am wondering why the port riser had no water in it but the stb one did?
Any suggestions would be appreciated before going to expense of replacing anything
Before noticing any problems
the boat had been sitting for nine months got it going on the muffs and took it for a water test but could not get it to
rev over 2200rpm or so adjusted the timing and got some improvement to 3200rpm temperature climbed from 170
to 200, so backed off and it came back down to 170, it sits at 150 or so when at 1000rpm so I wasn't to concerned
 
Thanks for your imput guys
Now that the elbows and risers are off I can stick my hand down the exhaust and feel the flappers they are intact and flap freely I was wondering should they be closed with a bit of resistance or are they freely moving.
Any ideas why steam would be coming out of the rocker hoses and into the flame arrestor showing like there would be a bad gasket somewhere
 
Pantera1990 said:
Thanks for your imput guys
Now that the elbows and risers are off I can stick my hand down the exhaust and feel the flappers they are intact and flap freely I was wondering should they be closed with a bit of resistance or are they freely moving.
Any ideas why steam would be coming out of the rocker hoses and into the flame arrestor showing like there would be a bad gasket somewhere
Click to expand...

Ayuh,.... It's steamin' off water in the oil, either from condensation, or a cracked block,....

Have ya put in a new Impeller,..??
 
Thanks bondo
the impeller was pumping well
But I have found a bad head having i hole through into the chamber not good
Can you tell me what engines I can put in front of an Alpha one drive
Looks like I'm up for a new one
Is a Reman TBI a marine engine or just for vehicles
Any info would be helpful
Cheers
 
Pantera1990 said:
Thanks bondo
the impeller was pumping well
But I have found a bad head having i hole through into the chamber not good
Can you tell me what engines I can put in front of an Alpha one drive
Looks like I'm up for a new one
Is a Reman TBI a marine engine or just for vehicles
Any info would be helpful
Cheers
Click to expand...

Ayuh,.... 'bout Any SBC,.... 305, 350 are the easiest 2,....
 
kghost
Done that but finding it hard to get one to match the intake manifold which has a centre port for what I believe is for TBI Rochester 4 bbl
 
Pantera1990 said:
kghost
Done that but finding it hard to get one to match the intake manifold which has a centre port for what I believe is for TBI Rochester 4 bbl
Click to expand...

Ayuh,.... It's one or the other, not Both,...

Are you gonna reuse the dressin's off the 305 ya got,..??
Boltin' 'em to a rebuilt Long Block motor,..??

Or are ya lookin' for a Full Dressed Bobtail motor,....
 
Thanks for all the imput,
I would like to use the existing motor, have the block checked and reconditioned if needed, and fit it back together but I'm having
trouble finding heads to match the intake manifold i.e the heads have a centre port that matches up to the
manifold, there is a stainless steel insert that fits into the gasket with a 3/8" +- hole in it for both heads,
not knowing enough about this TBI I'm assuming that this is the difference...I am frustrated and want to get the thing back on the water
So if I have to buy a Long Block it need
 
So if I have to buy a Long Block it needs to match the manifold ( with 4 barrell Rochester carb) otherwise I need a base engine..... getting expensive
Sorry for any questions about where to get things from but I'm lost for what to do
 
If you are going to recondition the current motor, who ever you use as a machine shop will get what you need or tell you what to get and maybe where to get it.

If you need heads ANY replacement head matching the intake will be ok to use. BUT if they are used they should be reconditioned also!!

There is no mystery to Small block chevy parts...........there are millions of 'em.

Most head have the center port, the stainless steel block off comes in the gasket kit.....

Purchasing one or two heads having them reconditioned and having the 305 reconditioned will cost you the better part of $1200 to $1500 anyway if not more. WHy not purchase a complete 350 long block and simply bolt on all the perifial stuf, Alt, manifolds , engine water pump etc etc.

A remanufactred 350 will cost ~ $2000.

This will give you 50 + hp power more and significantly more tourque!

Just my opinion..........
 
Yes,

therer is no difference in the physical block. The difference is the pistons and bore.
I am not 100% sure about the head cumbustion chambers if the 305 and 350 heads are the same. They may be slightly different.

But considering you need a new head (s)...............

All the add ons such as exhaust manifolds, intake, brackets, water pump, motor mounts etc etc will bolt right up...........
 
Thanks kghost
I feel much better now knowing what you have suggested
Can't thank you guys enough
Will be getting a new 350 long block soon and be out and enjoying myself
Cheers to all
 
Pantera1990 said:
So kghost
Are you suggesting that all the 305 stuff will fit to a 350 long block including the intake manifold?
Click to expand...

Ayuh,.... All of the external dimensions, includin' where All the bolt holes are, are Exactly the same,...

Of course, the 305, 'n 350 need to be of the same Vintage,...

The changes that occurred with the SBC happened to all the motors, at the same time,...

Yer motor has the basic changes from 1986,...
It's a 1 piece rear main seal,...
It has the cast bosses for a roller cam,...
The 4 center intake manifold bolts go straight down, 90° to the carb flange, insteada 90° to the head flange,...

So, to bolt on yer 305 accessories, ya need a 350 from '86, to '95,...

Buy a new intake manifold, 'n electric fuel pump, then you can go to the Vortec, from '96 to present,...

You keep sayin' rochester Carb, than ya say TBI,....

Which is it,..?? It Can't be both,...
 
Hi bondo
Sorry the boat has TBI "get in sit down shut up and hang on" on the back or it but I didn't understand the TBI bit
Anyways, I have rocker covers with 4 hold down bolts and a small bar to spread the tension
I have sorted a 350 hp chev marine engine to match the manifold which has 12 bolts 90 degrees to the head
Apparently as kghost has said all will fit the 350 but I need to check the flywheel stud pattern, I made need to source another flywheel if it doesn't match
As I said thanks guys for all your imput it is greatly appreciated
Cheers
 
Pantera1990 said:
Hi bondo
Sorry the boat has TBI "get in sit down shut up and hang on" on the back or it but I didn't understand the TBI bit
Anyways, I have rocker covers with 4 hold down bolts and a small bar to spread the tension
I have sorted a 350 hp chev marine engine to match the manifold which has 12 bolts 90 degrees to the head
Apparently as kghost has said all will fit the 350 but I need to check the flywheel stud pattern, I made need to source another flywheel if it doesn't match
As I said thanks guys for all your imput it is greatly appreciated
Cheers
Click to expand...

Ayuh,.... Then it's Not a 1988 motor,.... or those are Pre-'86 Heads,...

The 4 center intake bolts should be a different angle, than to outer 8 bolts,...
 
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