Go Back  Offshoreonly.com > Technical > General Q & A
Cylinder Head info/Specs??? anyone? >

Cylinder Head info/Specs??? anyone?

Notices

Cylinder Head info/Specs??? anyone?

Thread Tools
 
Old 03-01-2019 | 01:39 PM
  #1  
Thread Starter
Registered
 
Joined: Mar 2019
Posts: 4
Likes: 0
Default 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
3rdcoastpowersports is offline  
Reply
Old 03-01-2019 | 04:26 PM
  #2  
Registered
 
Joined: Apr 2018
Posts: 134
Likes: 1
Default

Personally I would be looking at 290cc large oval head for your application. Not sure if your raw water cooled or closed loop.
Camalot is offline  
Reply
Old 03-01-2019 | 04:44 PM
  #3  
Thread Starter
Registered
 
Joined: Mar 2019
Posts: 4
Likes: 0
Default

Originally Posted by Camalot
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.
3rdcoastpowersports is offline  
Reply
Old 03-01-2019 | 05:11 PM
  #4  
Rookie's Avatar
Registered
20 Year Member
 
Joined: Jan 2003
Posts: 6,020
Likes: 1,522
From: Grand Rapids, MI
Default

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
Rookie is offline  
Reply
Old 03-01-2019 | 05:15 PM
  #5  
SB
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 14,105
Likes: 3,692
From: On A Dirt Floor
Default

Originally Posted by 3rdcoastpowersports
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.
SB is offline  
Reply
Old 03-01-2019 | 05:19 PM
  #6  
Rookie's Avatar
Registered
20 Year Member
 
Joined: Jan 2003
Posts: 6,020
Likes: 1,522
From: Grand Rapids, MI
Default

There's better heads out there...
P/N 19256827 2.06"/1.72" valves., 99cc
Rookie is offline  
Reply
Old 03-01-2019 | 05:30 PM
  #7  
SB
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 14,105
Likes: 3,692
From: On A Dirt Floor
Default

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 is offline  
Reply
Old 03-01-2019 | 05:31 PM
  #8  
SB
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 14,105
Likes: 3,692
From: On A Dirt Floor
Default

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

Originally Posted by Rookie
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 is offline  
Reply
Old 03-01-2019 | 05:45 PM
  #9  
Thread Starter
Registered
 
Joined: Mar 2019
Posts: 4
Likes: 0
Default

Originally Posted by Rookie
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.
3rdcoastpowersports is offline  
Reply
Old 03-02-2019 | 07:44 AM
  #10  
Registered
10 Year Member
 
Joined: Feb 2012
Posts: 4,031
Likes: 10
From: westville, NJ
Default

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.
dereknkathy is offline  
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.