Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 01-25-2001, 11:27 PM
gmblows's Avatar
gmblows gmblows is offline
Inactive User
 
Join Date: Dec 2000
Location: NJ
Posts: 56
Post

The Cordoba is burning oil at start up now and I'm thinking of replacing the heads. My concerns are finding good used heads that I can just bolt on for better flow, without loosing any compression. My understanding is that 360 heads have bigger combustion chambers? Does anyone know any specs on these stock heads; valve size, CC's? Is there any potential in the stock heads?
Current specs are; '79 318 stock bottom end and heads, Lean burn removed, MP electronic ignition, Performer intake, Carter 625 CFM, hyd. 218-228 @.050 .441"-.441" 114LSA, stock exh. manifolds into 2 1/4" duals. The car runs real good for a daily driver, don't think it will ever make it to a track though.
Reply With Quote
  #2  
Old 01-25-2001, 11:54 PM
goldduster goldduster is offline
Inactive User
 
Join Date: Dec 1999
Location: Corry, PA
Posts: 535
Post

360 Heads have 85cc Chambers, and 318 heads have 82.5cc chambers. If you want to keep 318 heads, get some #302 casting, as they are the best. All mopar small block heads are pretty close in potential, except the 302/308's and the Magnums. You can keep the oil from burning by replacing the valve seals. It should only notacibly burn oil when you first start it if its in the heads.

------------------
Goldduster
'70 Duster 318 2bbl
http://duster.svhost.com/duster70?REC=0
The Plymouth Duster Homepage
http://duster.excelland.com?REC=0
Reply With Quote
  #3  
Old 01-26-2001, 03:10 AM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Post

Those head cc's are incorrect. Thats to much. Besides, to be sure , you'll have to take them off and measure them yourself. Or have a shop do it.
360 chambers max at about 74cc's. They can be a lot smaller as well, @ about 65cc's.
The best thing to do is have them rebuilt. Install new vavles that are 1.88 (360's intake) and 1.60 exhaust (36o again) that are stainless steel. HEY! for a dollor or 2 more it can't hurt. It will help in breathing.
Reply With Quote
  #4  
Old 01-26-2001, 05:17 AM
speedfreak speedfreak is offline
Inactive User
 
Join Date: Nov 2000
Location: lehighton pa usa
Age: 55
Posts: 232
Post

if you bolt the 360 heads right on you will lose to much compression,the exsrta flow gain will not be enought to make a diffrance.thay should be milled,the specs on the milling i'm not shure,i think it's 50 thousand's on the compression side,and 12 thousand's on the intake side for every ten thats take off the compression side, so the intake match's up.i hope you can follow that,and get a second apinnion[if i spelled that wright]good luck.

Reply With Quote
  #5  
Old 01-26-2001, 05:48 AM
gmblows's Avatar
gmblows gmblows is offline
Inactive User
 
Join Date: Dec 2000
Location: NJ
Posts: 56
Post

Goldduster; What years would I find the 302 or 308 heads? Are those from the premag rollercam motors?
Rumblefish; Assuming the stock heads magnaflux OK, and not knowing what size valves are in there now, I figured they would need bigger seats installed for the bigger valves, is this true or can they cut the original seats? I like that idea but don't know if the ports would support them.
Speedfreak: Thats why I was looking for the specs on the heads that are on there now, so I could get another set ready to go with the right size combustion chambers. And on the milling procedure I found some info on that too.
Thanks
Reply With Quote
  #6  
Old 01-26-2001, 03:00 PM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Post

gmblows;

The valves in there now are (int.) 1.75 & (exh.)1.50 unless its a 4bbl. from the factory. If it is then they allready have the larger vavles. The stock 318 (small valve head) will take the larger 360 valve with a cut of the seat, no problem.
You can find the valves in a MoPar performance catolog. P4876397=1.88 int. & P5249187=exh. Or elsewhere like Jegs or Milodon, etc.
The ports will handle the flow fine. This is not a major flow increase. Just a little bit more to help out.
I'll ans. the other questions if they don't. ( don't wanna step on toes )

[This message has been edited by rumblefish360 (edited January 26, 2001).]
Reply With Quote
  #7  
Old 01-26-2001, 10:00 PM
goldduster goldduster is offline
Inactive User
 
Join Date: Dec 1999
Location: Corry, PA
Posts: 535
Post

oh S--T! that was supposed to be 62.5cc and 65cc. The 302 head is found on '85-'91 318's and has the stock 1.78 intake and 1.50 exaust valves. The "308" is an '88-'91 360 Head. it has factory 1.88 intake and 1.60 exaust valves. Find some "308"'s, or put the 360's valves in the "302" head. Oh yeah, you will have to block the air injection ports on the exaust side. A good place to look for "302" heads are '85-'89 Diplomats, and Gran Fury's.
Reply With Quote
  #8  
Old 01-27-2001, 03:41 AM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Post

OOOHHH Crap! As I sit here reading!, I can't believe I typed 1.75 for the intake valve. I even edited the damn thing too.
"I sit, corrected!" Goldduster is correct!
Reply With Quote
  #9  
Old 01-27-2001, 04:11 AM
gmblows's Avatar
gmblows gmblows is offline
Inactive User
 
Join Date: Dec 2000
Location: NJ
Posts: 56
Thumbs up


I will start looking locally for a set of "302" castings and if I find a good pair I'll probably put in new 1.88" 1.60" valves, bowl port, and gasket match.
At that time I'll cc the chambers to compare with the heads that come off.
Any tips on a good cranking pressure for 87 octane; min, max?
Thanks for your help
Reply With Quote
Reply

Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
lean burn no more tedbear Off-Topic Forum 4 10-29-2010 11:12 PM
Lean Burn 86FifthAve Performance Talk 15 06-17-2010 09:36 PM
Lean Burn Pimpin' Rumors and Gossip, etc... 2 06-26-2004 01:25 AM
Lean Burn, how can I get rid of it? Ted Bromback Vintage MOPAR chat 6 05-30-2003 10:04 AM
doing away with lean burn billh Performance Talk 4 04-28-2002 08:55 PM




All times are GMT -4. The time now is 03:06 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .