Hey smart engine guys... can you help me?

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jimharvard

jimharvard

JimHarvard
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I am getting very close to tracking down a beloved fastback formula s to buy. But I am facing the big block vers small block issue. So here's the question:
1. do any of you know the weight of the old stock 340's ... 67-69?
2. do any of you know the weight of the old stock 383's and 440's?
3. does anyone make an aluminum big block close to the weight of a 340?

now on an entirely different point....

my wonderful high school 340 formula s was a 4 speed and the plymouth mechanic who ordered it got it with the "optional" 4 speed cam. Do any of you know the specs (lift, duration, exhaust..etc) of the "optional" cam that could be ordered in 1968 for the 4 speed formula s?????

I appreciate any help you guys can offer ... this a body site is the best i've found on the internet..

jim coster, pittsburgh... (soon to be "fishing" again)
 
Approxiamate weights were 340-520#, 383-620# and 440-670# but that changes significantly with aluminum manifolds and headers. I've never heard of a 440 aluminum block, there was the Donovan Hemi (I think is was a 417) and of course the Keith Black Hemi's. Mopars also trying to sell an Aluminum Hemi but it's a little pricey.

Terry
 
hey thanks terry for the information...

while my first choice for my formula s was the small block 340... i do have a chance to get a 383 formula at a good price... so my thinking was that i could put the big block on a diet with aluminum heads, manifold, rockers, valve covers, light starter .. and anything else that could be ripped off or changed so the car might handle more like the small block fish and not feel so nose heavy...

i found mopar.com which appears to be chrysler's mopar performance web site and they have all kind of stuff available ... especially engine stuff...

do you have a tech book that lists the optional cam that i mentioned that was available on the 68 340 motor??? my car had that cam and it had a great louping sound and was good for 6k rpm with no problem.. if you know where i might find that information.. let me know...

thanks for your input..

jim c... steel town...
 
Couldn't tell you the specs on that cam but in 1968 ALL 340 4speed cars got it. Automatic cars got the regular 340 cam, as well as all 340's from then on. Seem to remember that it was around 8 degrees bigger that the regular 340 cam. As far as engine weight, if you want that big block, use a 383-400 block and stroke it. to get the seight down, use an alloy waterpump and housing, master cylinder, mini starter, aluminum heads and intake, etc. and the front end of that Cuda will weigh less than the original 340.
 
Keith Black made or makes the 383 or 440 blocks in Aluminum. Very pricey. It's a thing you have to want.
 
if i remember correctly it was 284*/292* duration with a .445/.455 lift where the regular was 268*/274* duration. the shipping weight for V8 cars was 2950lbs. i would add about 150 lbs for a 383/440.
 
Stroke out an inexpesive 360 and go from there. Much cheaper than a big block and has the small block weight and big block torque. Yes as stated above..ALL 340 4 speed's in '68 had that cam. '69 and on later, ALL 340's had same cam ('68 auto cam). Terry.
 
WOW!! ... you guys are just too cool.... i never knew that my 68 formula s 4 speed cam was stock from the factory... and to think.. for the last 35 years i've been telling stories about how "trick" the plymouth mr. good wrench was for "ordering" that special cam in the car when he bought it.. . that's just too funny... but to his credit.. he did bolt on an edelbroc aluminum high rise, 750 dbl pump holley,hooker fender well headers and a 3.91 rear. he ran a 12.29 1/4 with the car with open headers with a set of slicks at the old pittsburgh international dragway. then i got the car and did wacky things to it like tightening up the torsion bars and jumping coke bottles with the left front wheel at the local Big Boy parking lot.
Thanks for the engine information ... you guys are the best..
 
The old myth of the big block feeling nose heavy was due more to the tires and shocks of the day. My son's 440/4sp Dart convertible (factory big block torsion bars and sway bar) actually feels firmer and more stable on the road than my 68 340 GTS convertible (not much done to improve it). We've autocrossed my other son's 67 383 Barracuda. Also a 340 car with air, power steering, and power brakes is about as heavy (maybe heavier) in the nose as a big block car with manual everything.
 
jimharvard said:
I am getting very close to tracking down a beloved fastback formula s to buy. But I am facing the big block vers small block issue. So here's the question:
1. do any of you know the weight of the old stock 340's ... 67-69?
2. do any of you know the weight of the old stock 383's and 440's?
3. does anyone make an aluminum big block close to the weight of a 340?

now on an entirely different point....

my wonderful high school 340 formula s was a 4 speed and the plymouth mechanic who ordered it got it with the "optional" 4 speed cam. Do any of you know the specs (lift, duration, exhaust..etc) of the "optional" cam that could be ordered in 1968 for the 4 speed formula s?????

I appreciate any help you guys can offer ... this a body site is the best i've found on the internet..

jim coster, pittsburgh... (soon to be "fishing" again)
Click to expand...


Slant 6 -------------------------------------------- 525
273-340 ------------------------------------------- 525
360------------------------------------------------- 550
361-400 ------------------------------------------- 620
413-440 ------------------------------------------- 670
426 Street Hemi ----------------------------------- 765

If you take a 383 at 620 lbs, -10 lbs Alum water pump, -50 lbs alumnum heads, -15lbs aluminum intake. You now have a 545 lb big block. Make it a stroker and you have a 550 lb 500ci monster, with a mild cam, you will be running 11's.
 
headsbikesmopars said:
Stroke out an inexpesive 360 and go from there. Much cheaper than a big block and has the small block weight and big block torque. Yes as stated above..ALL 340 4 speed's in '68 had that cam. '69 and on later, ALL 340's had same cam ('68 auto cam). Terry.
Click to expand...

Not true. A balanced stroker kit for a 400ci BB which will give you 500ci is $1600 balanced w/bearings, rods, pistons, rings.

The same kit with all the same will cost $2150 for the 360. A set of Aluminum Edelbrock heads cost $1350 for each motor, same on the carbs, intakes, headers, Trans, etc. This the whole reason I gave up my plans for a 408 stroker was when I priced both out, I was surprised to find out 500ci was $800 cheaper than a 408.
 
flyboy01, how did you come up with those numbers? ive been wondering the numbers myself and couldnt find them anywhere..

Does the year of the block make a difference in weight?

Good Post.
 
Cerwin, block weights would fluctuate year to year, depending on the cast. The earlier 71-74 blocks would weigh more, due to the fact they have a thicker cylinder wall. Later blocks would be lighter, but also couldnt be overbored as much, the magnum block is the lightest as of now, I believe is it 155 pounds? The weight difference would be barely noticeable Im certain.
 
A smart engine guy, I am not , but I can read the manual. Here`s some cam spec`s from the 68 Chrysler service manual for your 340.

Intake Exhaust Lift
276* 284* 453" at 0 lash manual

268* 276* 444" at 0 lash auto

The manual transmission does have a little "more" cam.
 
As I said before... this is the best mopar site on the internet and you guys are great...

thanks again for the information ... now i can start thinking about an engine budget..

jim coster
 
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