Lift is the same, duration of a 340 cam is 268* / 276*
Good price. That looks like the post 68 340 manual trans cam. That one was a different spec. That lift looks like the 68 auto trans lift spec than that .429/444 became the standard 340 cam. The SUM K 6901 is supposedly a good close 340 grind.
That's advertised duration. I don't think that there's
That's the advertised duration. Best to my knowledge, mopars formula for getting duration at 0.050" is multiple the advertised duration by .777 for stock cams and .850 for their purple shaft cams. Not saying that they aren't available, but I've never seen a actual repo grind of the 340 cam. I was told by a cam rep years ago that they can't grind a true 340 grind because Chrysler owns the rights to all of their engines.
I've seen a few good running sbm's that had a fairly stock 318, but the owner dialed in the suspension first. All the power in the world is useless if you can't put it to the ground. One that I remember fairly well was a duster, the guy who had it installed a adjustable pinion snubber, spring clamps. I think that he had traction bars. He ran 6 cylinder torsion bars. He also ran 340 cam,carb and intake manifold, headers. Gears, I don't remember what ratio he had. He was respected down on hall street in st.louis, that was the place to run back in the day.
KB 167's are a popular option. Near 0 deck height. They are around 10:1 with a .039 gasket.
Good to know. I do have an early 70s 318 like to the one UTG donated to Vizard. I wouldn't mind throwing some J heads on it and upping the compression see what it does.One day when I m retired and have all the time in the world to play around...
When I've looked into pistons for a 318 they was never a year specific mentioned as they all are the same, I know that there are different compression height's but all direct replacement pistons that I've found are still down the bore except for the kb's which have a 1.800" compression height. Am I looking in the wrong place for pistons? If I could get a decent compression ratio by using a replacement piston and still be close to a zero deck height that would be better. I'd like to get away from the pistons being so far down the bore
Nope! HP 273's were domed with 2 valve releif's.Yes, when following what I call the 340 recipe ( which IMO can be applied to the 318 if the parts are available) you have the 340 360 heads with the open chambers meaning you would use the piston to bump up compression with either zero or positive deck height.
The other way is what I call the 273 recipe which is zero deck height pistons and closed chamber heads, I am not 100 sure the 273 is zero deck height but in pictures it appears so and the 273 HiPo has 4 valve releifs like the low comp 340 of late 71-73, but that Hipo version had closed chamber heads.. I prefer the big port large valve 340/360 heads, but this is just to get into 5500-6000 rpm range. I have personally put a 600 Holley and a cam into an otherwise stock 318 added headers and it was fun but it wasn't a power maker at 5500 RPPM and I suspect it was the stock LA heads and valve float etc. Just my $.02
)Why rebuild a 273
96 to 99 mph trap speeds are mid 13s to highs 13s thats what they trapped stock
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I would if I had one, the Hi Po version they were good runners and where it all started with LA engine performance. I guess for me its nostalgia but I am a resto guy not a racer. A Hipo 273 for me in a 65-66 barracuda or Dart seems like a fun car.
They fly. A 273 will scream up to 6,500 rpm with a streetable cam and good mpg cruising. Factory mechanical cam and valve train, forged cranks, bushed rods, and floating pistons, heads flow very well at low lift, available 10.5 pistons, and the rest of the good stuff 340's inherited. Why build a 318 or 360?
Think of a Hipo 273 as the 340s older brother....for me its the internals that these Mopar Performance engines came with, good stuff. Yeah you can build any engine any way you want but at the initial investment why not start with "the good stuff"...
I am somewhat upset that someone somewhere might junk a 273 because the don't really know what it is, especially a Commando version I thought I saw a regular version on here going for cheap in the classifieds not too long ago. The seller wasn't getting any hits on it at all. I do seem to recall it had the black valve covers with the aluminum panel though.I passed on a car because it had a 273.Think of a Hipo 273 as the 340s older brother....for me its the internals that these Mopar Performance engines came with, good stuff. Yeah you can build any engine any way you want but at the initial investment why not start with "the good stuff"...
