|
#1
|
|||
|
|||
I have currently have a 340 which has a mild cam (don't know the specs),
probably 8.5 or 9.0:1 comp ratio, 815 heads that have 1.88 in 1.60 out, stock 360 exhaust manifolds, edlebrock 600 CFM carb on top of a edelbrock performer intake. All of this is in an A-body with 3.55 gears and a 4-spd with manual disc brakes. It runs great, but I would like to have more power in the 4500-6000 RPM range. Now it really dies after about 5000 RPM, which seems like an embarrassment to the heritage of the 340, and not as much fun as it could be. I would eventually like to upgrade all components, hotter cam, better heads, headers, different manifold and carb (?). I would really like everyone's advice on what I should be heading towards as a complete package, but also how to do this in a step by step way- due to time and current available funds, starting with the lower cost - easiest first. This is a car that is a daily driver for about 3-4 months every summer, but if I get sick of driving it after 4 months due to a lumpy cam etc, that would be about perfect. Should I really know the exact mechanical compression ratio before I start making plans? Is the easiest way to calculate this by pulling the heads, rotating the engine, and doing the math? For particular components what do you think of (and please comment on cost if possible) : Edelbrock heads Vs mopar performance ported assembly Vs valve job and port on existing heads? Mopar purple cam 474 vs 484 lift? Single plane vs double plane manifold? M1 or Edelbrock or other? Best brand of headers? Ceramic coatings for street cars? Any comments on any part of this message would be greatly appreciated. Keith |
#2
|
|||
|
|||
Keith:
Since this is a street driven car, I think to get the best bang for your buck would be to drop the heads. If you have access to a Dremel or you can use grinding stones with a drill. Being very careful, smooth the bowls under each valve out to as close to the valve seat as possible being careful no to nick the seats. You need a better intake manifold such as an aluminum dual plane. Do not use a single plane for your application. This would be overkill. Then I would go with a mild cam which I would get a recommendation for a reputable cam grinder. Ultradyne or Hughes are two good ones. If funds allow, you need to upgrade your ignition system. If electronic, control box update, distributor spring kit, and constant output voltage regulator. Rearend gear is good. Good luck Wedgehead |
#3
|
|||
|
|||
Don't forget to up-grade the fuel system! That 5/16" fuel line & stock mechanical pump are probably the reason you can't turn the engine as fast as you should/could. Got a 68 Cuda here with a stock 340 that will turn 6K+ RPM's no problem with cast iron exhaust, because it has an "over-kill" recirc fuel system with all ½" lines. I'm willing to bet your fuel system is your biggest restriction right now. An up-grade to a complete 3/8" fuel system will probably end up costing about $300 with a good electric pump. I like the Mallory pumps, quiet & strong. The object is to get sufficient fuel VOLUME, pressure will only get you in trouble.
My 2¢ worth! <font color = 990033>DB</font> ------------------ Experience is something you don't get until just after you need i |
#4
|
||||
|
||||
I would suggest a 484 mopar cam, a performer RPM dual plane intake (single plane is for high rpm), a edelbrock 750, 1 5/8" headers, with 2 1/2" exaust, put 340x heads or just have your heads cut to 2.02 and gasket match the heads and intake. you can shave the heads to raise the compression, maybe .20 - .50 defenitly run the mopar performance electronic ignition and hell just for the fun of it throw in a serpantine belt system with alluminum pulleys (looks cool, and helps a little) lol. put a 3:55 - 3:90 gear in it for some fun in town or a 3:23 or so for both fun in town and still driveable on the highway.
If you do some good porting on the heads you can run a bigger cam and it will help even more, but if you put in a 508 or something now, it wouldnt get enough air, luckily you have a 4 speed so you dont need to get a stall converter etc... like some of us unlucky people. good luck. ------------------ Laine Lmopar69@hotmail.com |
#5
|
|||
|
|||
Just wanted to remind you not to try cutting your heads .20-.50 but I think Imopar69 meant .020-.050". Good luck!!!!! Wedgehead
|
#6
|
|||
|
|||
The setup described by Lmopar69 is basically what I had in mind. But a few questions:
Since I really can't afford to do everything at once, is there some part that I shouldn't do first, ie will putting in a 484 with no other mods make it run like crap? Would I have raise compression to run the 484, or is that a seperate performance gain? What are people's opinons of different brands of headers? MP sells headers. Would they be easier to install? Are they really made by someone else (JC whitney ?) What do you think of a MP viscous fan package? Is it worth it? And also, I probably have the facilities to install a set of headers, if there was no major tricks, and I didn't have to pull the ingine, but I wouldn't have what is nessesary to match of the exhaust to them. What do you do then? |
#7
|
|||
|
|||
Keith,
I had a great running 68 340 w/4spd 323's in my 72 demon.It had a little more compression than yours 10.5 but the combination of parts worked great.It had a mild cam under .500 lift, X-heads ,tm5 intake (similar to 340 torker),electronic igniton,1 5/8 headers and a 700 holley dubble pumper.The intake and carb played a huge part in the performance in the motor.The car really cam to life when i installed a set of 4.30 gears.The car really pulled hard. |
#8
|
||||
|
||||
I run the following; all parts seem to work well together. 1975 Duster w/ '69 340. "X" heads MP284 .484 cam 9.5:1 compression. Weiand 8007 dual plane high rise intake (love it) 850 TQuad. 4 speed 8 3/4 w/ 3.91 gears. Hooker comp headers w/ dual exaust and xover pipe. 14" wheels and 255 tires out back. Does low 14's in the quarter. The Weiand intakes seem to be overlooked on this NG. I have put two on separate Dusters and loved the performace that each gave.
|
#9
|
||||
|
||||
oops, yeah, thanks guy. .20-.50 would be just a little too much! .020-.050 IS what I was trying to say. As far as the intakes go, Ive always used edelbrock just cause I could get them cheap (used). Im sure just about any dual plane intake would be good. Maybe an LD340. Wish I had one. But when you are on a buget like mine (none) you do what you can.
The headers you can probably get on the car with minimal difficulty, depending on the brand, but they would connect to the rest of the system in a different place than your manifolds do, so you cant really just bolt them on and go, unless you live on one end of a drag strip and work on the other! Putting in the cam now and doing other mods as you go will work, but I dont think you will see a HUGE improvement until you get the heads you need on it (its gotta breath). I would pick up a old set of 360 heads and have them done up with the 2.02s and some porting etc... that way when they are ready you can just swap them. You can usually get some for $75 - $100. I would also try to pick up a used intake and have it media blasted for $30 (it will look new again). But the carb, I would buy a new one (but thats me). Your lucky though, I am in Germany right now and the only mopar I have here is a 92 Spirit ES. I miss my V-8s! good luck ------------------ Laine Lmopar69@hotmail.com |
#10
|
|||
|
|||
What's a fair price for a shop to take an old pair of 360 heads and add 2.02 intake with some porting?
|
#11
|
|||
|
|||
Thanks,
I will definately check out the fuel lines. I'm sure that it is still stock. I'm looking forward to pulling it out of winter storage. You guys in the south really are lucky. Keith |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
360 builders for sale (2) | Dart | Rear Wheel Drive - Parts for Sale | 0 | 01-06-2006 12:04 PM |
For all of you engine builders... | Fury361 | Performance Talk | 6 | 04-03-2004 04:03 AM |
engine builders? | NavyNorm | Drag Racing Forum | 40 | 06-24-2003 09:29 PM |
Help from the 273 builders guys | 6 packin | Performance Talk | 2 | 07-29-2002 04:39 PM |
engine builders can you take a look at this? | keng | Performance Talk | 4 | 07-27-2002 12:03 PM |