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 12-26-2001, 08:25 PM
dodgit's Avatar
dodgit dodgit is offline
Inactive User
 
Join Date: Sep 2000
Location: trenton,ontario, canada
Age: 64
Posts: 59
Question 318 beef up

Hey guys !! If I was going to beef up a 318(1972) with 1968 340 heads(202) valves and dual plane intake mounted with a Thermoquad (big one) off a 400, also running hooker headers with 2 1/4 exhaust. What would be the best Bump stick to use for streetability????????? It had be mentioned to me that I should use something out of 360 !!!

Any thoughts !!!!!! Oh Ya Happy Holidays
Reply With Quote
  #2  
Old 12-29-2001, 01:51 AM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Default

A bit vauge on the discription, but I'll take it from where it stands. Assuming it's a 360 T-Q intake, "Not" a performer, I would,

1. Mill the heads to get the allready dead compresion out of the basement to a 9.0-1 ratio.

2. Depending on rear end ratio, (Read, intended use) I would do the MoPar 260-268 duration cam for mild use around town with good mpg's. Ratio - up to 3.23's or,

The stock/updated version of the 4bbl cam used in HP 340's.
Ratio up to 3.73's Light port work in the head helpful. or,

The 280 duration cam with good head work to comploment the cam and a rear ratio of 4.10.
This cam would benifit from a better intake. RPM/Stealth.
Reply With Quote
  #3  
Old 12-29-2001, 08:54 AM
Jims451 Jims451 is offline
Inactive User
 
Join Date: Mar 2001
Location: Littleton, Colorado
Age: 59
Posts: 924
Default

You forgot the Three most important peices of information; The application, The RPM power range (tire size and gearing) and the engines compression ratio.

A stock 360 cam is very mild at 252/256 duration, 0.410"/0.412" lift.

For general performance the 340 cam is decent, but there are better cams avaliable that might match your application/engine configuration better.
Reply With Quote
  #4  
Old 12-29-2001, 02:50 PM
Ausydad's Avatar
Ausydad Ausydad is offline
Inactive User
 
Join Date: Jul 2001
Location: Ft. Wayne, In.
Age: 57
Posts: 1,024
Default

Just run with the .441 cam and go to 2 1/2" exhaust instead.Enjoy!
Happy Holidays and a Faster New Year!
Reply With Quote
  #5  
Old 12-31-2001, 01:05 PM
cuda66273's Avatar
cuda66273 cuda66273 is offline
Banned
 
Join Date: Dec 2001
Location: Beaverton Oregon
Age: 71
Posts: 3,685
Default

You better check your valve to cylinder wall clearance. The 2.02 valve in that cut head may want to tag the cylinder wall, a dye grinder will work to put a samll notch in the bore for clearance.

Here's couple of hot tips:
If your replacing the guides have the machine shop intall the smaller 11/32 Chebby style guides..think about it....smaller, less restriction, lighter easier to lift and less velocity on the seat.

Get in there with a dye grinder and get rid of that big valve boss in the runner.

Be sure and gasket match that intake.

Have the valve bowls bull hogged.

Check and double check the valve geometry.

After you run it for awhile pull the rocker arms and look at your valve tips, the wear line should be dead center on the stem and if you have a star pattern on the tip your floating the valves.

Mystery of valve float?
It occurs at too high of RPM or....maybe at about 3500-4500 rpm, this float is harmonics building up in the spring and vibrating through the valve train causing the valve to bouce, you won't hear it or notice it but eventually it'll cost you big bucks. That inner flat spring is a vibration dampner and when they get tired they allow the harmonics to build just like in a crank shaft.

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
beef'n up the chasis Lil J Performance Talk 3 09-18-2006 09:15 AM
Pacifica/Neon beef Dart Rumors and Gossip, etc... 14 08-03-2003 09:54 PM
Rear end questions: Where's the beef? HemiAdda2d Dakota Truck Forum 6 07-26-2001 05:20 PM
More Beef hemikota Dakota Truck Forum 1 03-24-2001 01:36 AM
Beef up your Security WEDGEMAN3 Dakota Truck Forum 11 12-04-2000 10:03 AM




All times are GMT -4. The time now is 04:58 PM.


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