Help

[mojo-jojo]

Posted this earlier in the 73-91 forum got a lot of views but no responses, maybe I'll do better here:

Just got a 454 out of an 82 c-30 crew cab. Had it running before we pulled it and it needs freshened up. I've been researching parts and different combos. This is the first BBC I've attempted to tear into. All my rebuild experience is with small blocks. I'm confused about cylinder heads, can some one please explain; open chamber, closed chamber, oval port, rectangular port and peanut port. It seems from what I've been reading for low end torque, the peanuts are the way to go. Thanks for any help

 

[pauly383]

Are you wanting to freshen it up , or make godly amounts of power up high where a truck can't really use it ?

I would just rebuild what you have , unless the heads are cracked , and then new heads

 

[mojo-jojo]

Don't want a race car. Just a strong low end motor. The engine has 104,000 on it so some parts are gonna need replaced. There were no raps or knocks so it's essentially rebuildable. I didn't have the time to run any diagnostics on it such as compression or leak down sounded like and ran like it had stretched timing chain and possibly jumped a tooth. If the heads aren't cracked I'll have those redone. But I am expecting the worst and don't really understand the options as stated above. This is going to be a low buck "rebuild" just want dependability. I will be using as much of the stock parts as possible with the exception of a mild RV grind cam.

 

[stano]

Let me try this

Square port has a intake runner ports look like this, retangular higher than wider, of about 325 CC's; bottom head has intake runner http://www.gmpartsdirect.com/performance_parts/store/dbimagecache/588.gif

Oval port has a intake runner port look like this , oval all most round (oval), and about 260 CC's; http://www.gmpartsdirect.com/performance_parts/store/dbimagecache/587.gif

Peanut port would be even smaller oval port on the intake runner of about 225 CC's.

Larger the runner the better the flow. Square ports for high RPM (6500 or higher) and Oval for lowwer Rpm (red line of 5500). But peanut port to me came on two barrel big blocks.

Cylinder Head Chamber has Closed, Modified, and Open. Closed was like a bath tub with straight sides on both sides and rounded on the ends and has a chamber size of about 97 to 98 CC's chamber. Modified has a chamber that is like the bath tub, but has one straight side and the other side (spark plug side) is rounded out to the edge of the piston wall, but has built up of cast around the spark plug hole making a smaller chamber than open chambers. kind of like this http://www.gmpartsdirect.com/performance_parts/store/dbimagecache/1025.gif (picture not really right only for explain) and has a chamber size of about 101 to 108. And open chamber has one side like a bath tub and the spark plug side is rounded out to the out side of the piston and has a chamber size of 113 to 118 CC's

This may help; http://www.nastyz28.com/bbcmenu.html and http://www.mortec.com/

Hope this helps
87 K5
thank you
stano

 

[stano]

There is a book for Big Block called;;

Chevrolet Big Block V-8 Interchange Manual
It has pictures which I like Pictures....

The ISBN # is 0-7603-0117-4

Check your local book store, if they don't have it they will get it in and not charge shipping (ussaully)

87 K5
thank you
stano

 

[mojo-jojo]

Thanks, that really helps alot. At least now I have an idea of what I'm looking at.

 

[diesel4me]

I have casting # books!

I have books with casting #s in them if you cant find them listed online,let me know if you want to de-code the heads or block numbers...I'd say you want the peanut port heads or oval ports for the street(probably the truck came with either of theese,unless someone swapped different heads on it)--the rectangular port heads are mainly race only,they kill low end torque and HP,and drivability...

 

[mojo-jojo]

Thank you, I haven't pulled anything apart yet so I don't have casting numbers at hand. I have been thinking just what you said oval or peanut, peanut seems to be relatively newer. This engine looks original except for a rebuilt Q-jet. I don't see any blue goo around any of the gasketed surfaces except for water pump. So best guess is stock 82 454 for c-30 crew. Thanks again.