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 06-25-2001, 12:07 AM
sundrop_440 sundrop_440 is offline
Inactive User
 
Join Date: Apr 2001
Location: St. Croix Falls/ Wisconsin
Age: 66
Posts: 119
Question r raise my compression "help" ' help

the car,a 68 charger.The motor 74 440.I built the engine about 2years ago.I installed a summit engine kit in it had trw pistons at about 9:1 comp. If anyone knows the exact advertised comp. that would help. I think it's 9.23:1 but I'm not sure. I ordered 10:1 but they sent me the 9:1 I wanted to get the motor together so in they went,now I wished I'd waited.I want to raise the comp. as much as I can without pulling pistons.What changes can I make,and about what can I expect from each change. I have 906 heads and I don't think they have been shaved. How reliable are those .020 head gaskets? Brian addressed this a while ago but I can't find it,I know you guys can help thanks.
Reply With Quote
  #2  
Old 06-25-2001, 12:19 AM
Lee Pritchard's Avatar
Lee Pritchard Lee Pritchard is offline
Inactive User
 
Join Date: Apr 2001
Location: st petersburg fl
Age: 67
Posts: 369
Default

whats the part number on them trws??? if there 2266 you have more like 8.1 if their 2355s you would have close to 9.8.. if their 2266 mill the heads 60 and use the steel M/P head gaskets, they work just fine... but dont spay them with n2o... you need felpro 1009s for that........
Reply With Quote
  #3  
Old 06-25-2001, 12:31 AM
sundrop_440 sundrop_440 is offline
Inactive User
 
Join Date: Apr 2001
Location: St. Croix Falls/ Wisconsin
Age: 66
Posts: 119
Default

Lee do you know what kind of gains I'd get?I don't have the numbers on the pistons but I'm going to look.
Reply With Quote
  #4  
Old 06-25-2001, 09:25 AM
kamstra kamstra is offline
Inactive User
 
Join Date: Jun 2000
Location: ON, Canada
Posts: 293
Default

1967 915 Heads will raise the compression as they are a closed chamber head.
Reply With Quote
  #5  
Old 06-25-2001, 12:04 PM
Jims451 Jims451 is offline
Inactive User
 
Join Date: Mar 2001
Location: Littleton, Colorado
Age: 59
Posts: 924
Default

If you can measure the distance the piston sits below the block deck at TDC, then we cam probbly estimate compression ratio a bit easier. Knowing the head volume we could probbly tell you fairly accuratly the compression ratio when using different gaskets or milling the heads.
Other options are milling the block, or offset grinding (stroking) the crank will also increase compression.
Reply With Quote
  #6  
Old 06-25-2001, 02:04 PM
Lee Pritchard's Avatar
Lee Pritchard Lee Pritchard is offline
Inactive User
 
Join Date: Apr 2001
Location: st petersburg fl
Age: 67
Posts: 369
Default

sundrop ... 60 off the heads with 19 thou steel head gasket will get you close to one full point of compression.... about the same as adding 67 close chamber heads.....Lee....
Reply With Quote
  #7  
Old 06-25-2001, 10:35 PM
HOLESHOT HOLESHOT is offline
Inactive User
 
Join Date: Nov 2000
Location: canada
Posts: 331
Wink

Im going through the same issue,my 440 checks to have 145 PSI cranking which works out to 8.75-8.9.This was with the.040 head gaskets.We calculate that the .020 gaskets will go approx.to 9.15-9.24 or 160-165 cranking psi.We at this time will wait to see what our deck is and possibly cut the heads as well since we want more cr with our 292/509 cam change.
Reply With Quote
  #8  
Old 06-25-2001, 11:02 PM
sundrop_440 sundrop_440 is offline
Inactive User
 
Join Date: Apr 2001
Location: St. Croix Falls/ Wisconsin
Age: 66
Posts: 119
Default

Lee, this may sound stupid, but when you say 1 full point do you mean 8:1 to 9:1? Or 8.2 to 8.3????
Reply With Quote
  #9  
Old 06-25-2001, 11:05 PM
Lee Pritchard's Avatar
Lee Pritchard Lee Pritchard is offline
Inactive User
 
Join Date: Apr 2001
Location: st petersburg fl
Age: 67
Posts: 369
Default

Quote:
Originally posted by sundrop_440
Lee, this may sound stupid, but when you say 1 full point do you mean 8:1 to 9:1? Or 8.2 to 8.3????
one full point like 8.1 to 9.1
Reply With Quote
  #10  
Old 06-25-2001, 11:15 PM
sundrop_440 sundrop_440 is offline
Inactive User
 
Join Date: Apr 2001
Location: St. Croix Falls/ Wisconsin
Age: 66
Posts: 119
Cool

Thanx alot guys, if I can get one full point, thats enough for now!!! (awhile anyway) I can put my money elswhere for performance rather than pistons.
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
Will "LA" valve covers bolt onto later "Magnum" heads? 340_GTS Performance Talk 7 06-14-2011 07:52 PM
1972 "340" DUSTER-"H" Car--MATCHING NUMBERS--A Real ONE binky4 Rear Wheel Drive - Vehicles For Sale 0 01-05-2008 03:22 PM
any problems with "Hedman" parts ? - "X" pipe question RAM MAN Performance Talk 39 02-06-2007 01:01 AM
i want to "lower" compression moopa Performance Talk 5 11-05-2002 01:17 PM
"1971" Duster 340 true compression ratio? Duster_340 Performance Talk 9 09-14-2002 10:18 AM




All times are GMT -4. The time now is 04:03 AM.


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