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-   -   Cylinder Head info/Specs??? anyone? (https://www.offshoreonly.com/forums/general-q/359334-cylinder-head-info-specs-anyone.html)

3rdcoastpowersports 03-01-2019 01:39 PM

Cylinder Head info/Specs??? anyone?
 
GM Marine Big Block Cylinder Head P/N 19256827

Looking for Intake runner CC size, Combustion chamber size and Max lift cam lift the springs will support...

I just got off the phone with GM directly and they had no other information available other than what I could readily find online.

Planning on putting these on a pair of brand new 489CI Gen 6 Big blocks that are going in the bilge of my 36' cabin cruiser so im looking for a set of head that produce alot of TORQUE at low rpms

Camalot 03-01-2019 04:26 PM

Personally I would be looking at 290cc large oval head for your application. Not sure if your raw water cooled or closed loop.

3rdcoastpowersports 03-01-2019 04:44 PM


Originally Posted by Camalot (Post 4675086)
Personally I would be looking at 290cc large oval head for your application. Not sure if your raw water cooled or closed loop.

Close Cooled. I thought the 19256827 was a large oval head, for some reason I was thinking it was a 269 or a 290cc intake runner and a 118cc chamber but I cant seem to find where I found that before.

Rookie 03-01-2019 05:11 PM

Those heads are to the tall deck GM 488 multi-fuel generator engine. Vortec heads, small chambers, higher compression and oval port that comes on this engine.
https://www.jegs.com/i/Chevrolet-Per...28586/10002/-1

SB 03-01-2019 05:15 PM


Originally Posted by 3rdcoastpowersports (Post 4675052)
GM Marine Big Block Cylinder Head P/N 19256827

Looking for Intake runner CC size, Combustion chamber size and Max lift cam lift the springs will support...

I just got off the phone with GM directly and they had no other information available other than what I could readily find online.

Planning on putting these on a pair of brand new 489CI Gen 6 Big blocks that are going in the bilge of my 36' cabin cruiser so im looking for a set of head that produce alot of TORQUE at low rpms

Those are the heads used on the 488cid Tall Deck GM motor right ? Appears so after quick diffing around.

If so , see here:
https://sdparts.com/i-24080510-gm-en...et-engine.html

And speaking of which, I would not be afraid to call them(Scoggin-Dickey) about more info on those as they are not ust a GMPP parts place. They buildmotors and other thing too. :) They have been around seemingly forever.

Rookie 03-01-2019 05:19 PM

There's better heads out there...
P/N 19256827 2.06"/1.72" valves., 99cc

SB 03-01-2019 05:30 PM

Yup, they definitely know this motor and cyl heads - which appear to be the L29 Vortec's.

They built a motor around this 488 long block.

See here:
https://sdparts.com/n-9418-sdpcs-198...ct-update.html

SB 03-01-2019 05:31 PM

Sorry, I missed this. Would have saved me a lit of time see this post. LOL.


Originally Posted by Rookie (Post 4675097)
Those heads are to the tall deck GM 488 multi-fuel generator engine. Vortec heads, small chambers, higher compression and oval port that comes on this engine.
https://www.jegs.com/i/Chevrolet-Per...28586/10002/-1


3rdcoastpowersports 03-01-2019 05:45 PM


Originally Posted by Rookie (Post 4675101)
There's better heads out there...
P/N 19256827 2.06"/1.72" valves., 99cc

Thank you
So they are tall deck heads and I have a std deck engine with pistons designed for 8.5 w/118 chambers.

So........
What heads do I buy for my boat (36' chris craft commander... think RV on the water) to put atop my two new Gen 6 489ci Big blocks.... I just want as much torque as possible. I do not ever plan to rev past 3800rpms.

Any and all advise is appreciated as im new to the big block platform.

dereknkathy 03-02-2019 07:44 AM

It doesn't matter tall deck or standard deck. They interchange. And does not look like a vortec combustion chamber. those are same chambers from 781 and 088 and virtually all open chambered heads. so it looks like these are updated 049-781 heads. which would actually be optimal for your build.


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