|
#1
|
|||
|
|||
I have a 72 Satellite 318 auto
8 1/4 rear with 2.71 gears Basically stock except chrysler performance ignition with orange ECU and dual exhaust. It is a daily driver. 75% of my driving is city with the occasional highway 80 mph blast Next month I am putting on a cast 70 340 intake with a rebuilt holley 600. I am also planning to go to an 8 3/4 with 3.23 gears. With resurfaced drums and new shoes and seals it will set me back $ 250.00. Is there a better way to spend $ 250.00 or stick ith the rear end. Thnaks in advance Fred.. |
#2
|
|||
|
|||
Fred, save yourself some grief and DON'T put a stock 1970 340 intake on your 318. The ports are way bigger than the 318 cylinder head ports which causes horrible fuel flow into the heads. The 600 carb is a good idea, but get a decent aluninum intake to go with it. Dual plane Edelbock or Weiand would be 2 good choices, and there are others. djs
|
#3
|
|||
|
|||
Unless you plan on exceeding 350hp, you can keep the 8 1/4. Spend the $250 on a set of headers and an Edelbrock performer 318-360 intake. also spend $6.50 and recurve your distributor using MP's spring kit
------------------ Goldduster '70 Duster 318 2bbl http://duster.svhost.com/duster70 The Plymouth Duster Homepage http://duster.excelland.com The Unoffical A-body Homepage http://abodies.cjb.net |
#4
|
|||
|
|||
Quote:
I was told that the manifolds like Edelbrock performer 318/360 are ported for the 360 which have bigger ports than the 318. And this does NOT have an effect on daily driving performance or milage . Is this True ?? |
#5
|
||||
|
||||
I'm under the impresion that the Edel. Performer has ports sized to the 318. Call Edel. on it.
Also, the bigger ports won't kill your combo. It won't kill your gas mpg's ethier. I have done this before. It is not a big deal to have mismatched ports. If you were racing, that would be different. In a daily driver, it's no big deal. The best thing to do with the 340 intake and 318 heads is to make sure the roof and the wall where the windows on the head meet are matched to each other. Take your time to jet it right for best results. the 8 1/4 rear is fine for general performance. |
#6
|
|||
|
|||
I friend who is going to help me with the swap has a 318\360 performer on his 318. He told me the ports do not match. He called Edelbrock to verify it. He also said his 318 runs much better with his performer and 600 holley that the stock 318 2 bbl setup. Fred.. |
#7
|
||||
|
||||
It very well should run better. Not to mention more power. Your set up will do well.
|
#8
|
|||
|
|||
Back to the 8 /3 with 3.23
The main idea is for my 0 to 60 mph. The 8 1/4 has a 2.71 rear vs the 8 3/4 has 3.23 , thats 20 % improvement for $ 250.00 Fred.. |
#9
|
|||
|
|||
All you need to do is run the .509 cam. This can be had for under 250.00. it will solve all your problems.
|
#10
|
|||
|
|||
with a .509 cam, the 318 would be extra lumpy...it would also kill your bottom end that you need using street gears. I wouldn't go any bigger that .450 lift. The factory 340 cam is as big as i'd go.
|
#11
|
|||
|
|||
just my 2cents,if you run the 8.25 with 2.71's and your making any real hp it will break,1st 8.25's wear the spider gears out at around 100K,add some hp and the tall gears and it will kaboom,Ive done it with a mild 318,you can build it to last but youll spend a minor fortune,I would run the 8.75 with 3.23s or 3.55s if you can,this leaves all the room in the world for future hop ups,the 3.23s will drop your 0-60mph times .5,or so,for the 318 add a 360 cam(.429/.444)and a 340 intake with 600 vac sec along with your duals and elect ign and youll be impressed with the perf and mpg....PRO...
|
#12
|
|||
|
|||
For a daily driven car, 75%city and 25% interstate, a really good combination would be the Edlebrock 1406 electric choke with a 273 high performance intake comp cams 252-268 xtreme energy and just plain old dual exhaust. This would be a real good dependable setup, it will give good gas milage, alot of power, will match the 4400 rpm governer and the transmission. The carb is about $250, the intake at the salvage yard would be about $25, the cam kit about $400. Please use the K kit. as the 72 year model valve springs have got to be weak by now. This is an inexpensive setup that will give very little trouble. The 273 high performance intake will flow as well as will be needed. All ports match perfect.
|
#13
|
|||
|
|||
the ports on an edelbrock performer 318-360 are 1"X2" I have one that isn't on an engine at the time being.
|
#14
|
|||
|
|||
Thanks for all the help
I just spent $ 4000.00 restoring my 72 Sebring. This leaves my Bank of MOPAR very very empty. Pictures at http://www.cadvision.com/schachtm/72satellite.html This year I can only go as far as the manifold carb and 8 3/4. I paid less than $ 100.00 on ther 340 cast manifold and the rebiuilt holley 600 I like PRO's the .5 sec possible increase in the 0 to 60 with the 3:23 . By the way I just measured the ports on the manifold, 1" X 2 " Next year cam and headers ?? Fred.. |
#15
|
|||
|
|||
Why?
Why Holley? I think they suck!
|
#16
|
|||
|
|||
About a year ago I did a VERY low buck build up on my 318 . I ported the stock 318 heads but retained the stock valves. The performer has smaller port openings than the 360 heads, but mine was used and opened to 360 size. So I opened the 318 heads ports to that size too. I also milled the heck out of the heads, over .080" to get the CR up to a whopping 8.66:1 with a Fel Pro gasket! The 318's do not have compression at all stock. The bottom end was completely stock, except MP 268/272 cam and a dual roller timing chain. The LA engines are hard on timing chains, so always use a dual roller when possible. The carb was a new Carter 625 electric choke and 1 5/8"headers with 2 1/4" duals with turbo mufflers leading to a single 3" pipe with still one muffler took care of the exhaust.
A couple of things I would have done differently; the cam was too big for stock gear ratios and converter. I think the car would have been quicker with one or two steps smaller cam and would have had better mileage too. The 318 seems to be really sensitive to the cam size compared to a 360. The other thing is that I should have chosen a 1850 Holley instead of the Carter. I couldn't make that thing work properly; a Holley with an electric choke would have worked better for me. I went to the track once with this car and it run 9.71/77 (~15sec in 1/4) mph in the 1/8 with 2.95 geared single legger 7 1/4" and a 904 with stock converter and the carb bogging. The carb seemed to open the secondaries too soon and there is no sensible way to fix that in a Carter/Edelbrock AFB style carb that I know of. Average mileage was 12.5 mpg, mpostly city driving, and the car was a '80 Aspen which is propably about the same weight as a '72 Sebring? |
#17
|
||||
|
||||
The Performer manifold has 360 size ports that are necked down rather abruptly to the 318 size. Edelbrock says that it wont hurt performance on a 360 because the mismatch is in the middle of the runner. If it bothers you, you can port match them for to gain a few cfm at high rpms. I was told not to put a 360 manifold on a 318 though....
|
Thread Tools | |
Display Modes | |
|
|