Author Topic: 340 rebuild  (Read 6320 times)

Offline Mpdlawdog

  • Full Member
  • ***
  • Posts: 657
340 rebuild
« on: October 11, 2013 - 04:23:27 PM »
Ive been looking for this in the threads but couldnt come up with anything....Im rebuilding my 73 block 340 with 360 heads (it came that way to me).....Im replacing the cam....what are the specs on a 340 6 pack cam or any ideas what would be a good choice...
its a 4 speed car with 355 gears...fun street car is the goal....thanks




Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340 rebuild
« Reply #1 on: October 11, 2013 - 09:49:38 PM »
Cam design has come a long way , I assume you are replacing the springs ? lunati has new Voodoo designs using more lift & less duration , using a milder cam will increase the dynamic compression which is critical with the lower compression 73 340 engines like this http://www.jegs.com/i/Lunati/638/10200701LK/10002/-1

Challenger - You`ll wish You Hadn`t

Offline Mpdlawdog

  • Full Member
  • ***
  • Posts: 657
Re: 340 rebuild
« Reply #2 on: October 14, 2013 - 10:57:05 AM »
Great.....just what I was looking for....how does that compare to the purple cam?  They heads were already redone...someone redid the engine a while ago but didnt run it...since like the early 80's so Im going through it again...the cam was not new and looked like they redid the heads..pistons...and so on but reused the cam for some reason :dunno:...thanks for the input!!



Cam design has come a long way , I assume you are replacing the springs ? lunati has new Voodoo designs using more lift & less duration , using a milder cam will increase the dynamic compression which is critical with the lower compression 73 340 engines like this http://www.jegs.com/i/Lunati/638/10200701LK/10002/-1

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340 rebuild
« Reply #3 on: October 14, 2013 - 05:10:10 PM »
DO you know what pistons were used in the build ? The 340 High comp piston sits above the deck & has 4 valve reliefs in the top . if you have that piston I would recommend a different camshaft , if the piston is below deck & is lower compression I would go with the cam I initially recommended .
 Most of the Lunati Voodoo cams offer smoother idle , wider powerband just overall better drivability & performance from the 40 year old Purple Shaft cam designs

Challenger - You`ll wish You Hadn`t

Offline Mpdlawdog

  • Full Member
  • ***
  • Posts: 657
Re: 340 rebuild
« Reply #4 on: November 07, 2013 - 01:37:17 PM »
OK the engine guy said get this cam....LUNATI 318-340-360 CHRYSLER MOPAR 268/276 VOODOO HYD CAM & LIFTERS CAMSHAFT KIT......I hope hes right....now for the carb...my buddy suggested the 750 demon but I think it might be too much....Holley 700 is what I am thinking...Ideas?  thanks
ohh and yes the pistons sit above the deck


DO you know what pistons were used in the build ? The 340 High comp piston sits above the deck & has 4 valve reliefs in the top . if you have that piston I would recommend a different camshaft , if the piston is below deck & is lower compression I would go with the cam I initially recommended .
 Most of the Lunati Voodoo cams offer smoother idle , wider powerband just overall better drivability & performance from the 40 year old Purple Shaft cam designs
« Last Edit: November 07, 2013 - 01:39:30 PM by Mpdlawdog »

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340 rebuild
« Reply #5 on: November 07, 2013 - 02:02:43 PM »
I would not use a Demon on a lawnmower , 700 is about right , look at Proform instead

Challenger - You`ll wish You Hadn`t

Offline Mpdlawdog

  • Full Member
  • ***
  • Posts: 657
Re: 340 rebuild
« Reply #6 on: November 07, 2013 - 02:16:16 PM »
ok  :roflsmiley:...well proform doesnt make a 700 that I can see...is the 750 too much...and is Holley 700 an option
http://www.ebay.com/itm/Holley-Model-4150-Carburetor-4-Bbl-700-CFM-Mechanical-Secondaries-0-4778C-/190952445768
I would not use a Demon on a lawnmower , 700 is about right , look at Proform instead
« Last Edit: November 07, 2013 - 02:18:59 PM by Mpdlawdog »

Offline blown motor

  • Resident
  • *****
  • Posts: 3013
Re: 340 rebuild
« Reply #7 on: November 07, 2013 - 04:10:41 PM »
I have a 650 Edelbrock in mine and really like it. I believe it's the 1806 Thunder Series but would have to check to be absolutely certain.
In search of the eternal buzz!

Offline 7212Mopar

  • Full Member
  • ***
  • Posts: 595
Re: 340 rebuild
« Reply #8 on: November 07, 2013 - 06:07:13 PM »
I have a 650 Edelbrock in mine and really like it. I believe it's the 1806 Thunder Series but would have to check to be absolutely certain.

I got the same for my 340 too. Easy to setup and tune. Secondary opens up nice. No blog off the line.
1973 Challenger Rallye, AT with 1971 340
2012 Challenger SRT8 392 YJ,  6 spd

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340 rebuild
« Reply #9 on: November 07, 2013 - 11:02:10 PM »
I bet a 650 Profrom would perform extremely well , I will not use Eddy carbs no tunability

Challenger - You`ll wish You Hadn`t

Offline bandt

  • Jr. Member
  • **
  • Posts: 434
Re: 340 rebuild
« Reply #10 on: January 31, 2014 - 12:36:35 PM »
7212Mopar,

Any update? How did things work out for you? Any numbers, or opinions on your set up?


Brian

Offline Cuda54

  • Jr. Member
  • **
  • Posts: 237
Re: 340 rebuild
« Reply #11 on: February 02, 2014 - 08:31:08 PM »
Did you ever check into the roller cams roller lifters and roller rockers? Made a big difference in my 440 6 pack.

Offline Mpdlawdog

  • Full Member
  • ***
  • Posts: 657
Re: 340 rebuild
« Reply #12 on: February 03, 2014 - 09:31:51 AM »
hey guys...honestly I have not had time to put it back together....its sitting in my barn...with all my other parts waiting to go on.....I just love Ohio...the car is under a car port...so I dont have a place to work on it right now....

I am still looking for a carb...was thinking about a six pack set up but money will probably be too tight with all the car needs....I was thinking about a 700 holley double pumper with mech secondaries....

I am so ready to get this car on the road....

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: 340 rebuild
« Reply #13 on: February 03, 2014 - 11:17:57 AM »
Proform would be my choice over the Holley , The Holley HP series is good too

Challenger - You`ll wish You Hadn`t

Offline erat340

  • Jr. Member
  • **
  • Posts: 322
Re: 340 rebuild
« Reply #14 on: February 03, 2014 - 12:33:22 PM »
Had conversations with Neil awhile back with cam choice, he knows what hes talkin about. Had a hotter lunati, ran terrible in lower rpms only. Now using the same cam he recommends (with Eddy heads) and a Holley Street HP. Couldnt be happier. Course, in Ohio, you"ll want to have a choke.