AJ's Opinion; Just for you 318 streeters
However, AJ is now going to whine about the gear choice and how bad it sucks for a verity of reasons that may or may not apply. OD transmissions solve that issue.
I think we've lost sight of; how I opened this thread.
I am not a 318 hater.
I'm gonna tell you how it is, and you decide for yourselves.
On the street,
hi-rpm power means almost nothing because on the way to 60/65 mph,you only pass thru the power-peak once.
But, the vast majority of the time, a streeter is between idle and less than 4000rpm, and usually at Part Throttle.
I could not care less about dragracing.
I could not care less about third gear.
Since I live in a world where the speed limit is, for the most part 100kph/62mph, I am talking about a streeter. And, since I live an average of 20 miles from anywhere, my definition of streeter includes touring.
Now as to overdrive, few people can afford an overdrive, for one thing. And the only reason to have one is why? Hyup, cuz the cruise rpm is so high. And why is that? cuz to get low rpm performance with your big cam small engine, you had to gear it up. And this cost you IDK say $4000 at least. So waitaminute; why wouldn't you just start with a bigger engine that already comes with a boatload of lo-rpm power? to keep the street gears, and spend that $4000 on something that makes a lot more sense?
So check this out;
Say you have a lo-C 318 with a modest cam, say a 262/270/110, The pressure at 8/1 is predicted to be 126psi at 800ft, and the VP comes to 99. I mean this is what guys are building.
So now, to get your 3600 pound car moving, briskly, even 3.23s won't cut it. So in goes a 3000 stall and away you go. But hang on, that 262 cam might power-peak around 4800, and with an auto, you will shift it at ~5500. Which is ~48 mph in first gear with 3.23s........ and so, on the 1-2 shift, the rpm plummets to 3245. Now, the 126psi cylinder pressure comes into play. My lawnmower makes more than that.To get to 65mph@4200 is a 955 rpm climb with the engine in the doggy-zone.
So out come the 3.23s, which cruised at 65= 2750, and in go the 3.91s; now cruising at 3320, yeah IDK..... ok so now, the engine hits 5500 at 40 mph, and on the shift the rpm plummets back to 3245, and 65 will be 5100 in Second about perfect, but the engine still got stuck in the doggy-zone beginning at 3245 for a fair ways.
With the TorqueFlite automatic, this is a fact of life, on the 1-2 shift..
The cure for this is more cylinder pressure or a very much higher than 3000 stall, Ima thinking a 3800.
Ok but wait the whole reason for the dogginess is the small cylinder volume when the intake closes, combined with the very low Effective Dcr.
I mean at 8/1Scr, the Effective swept volume is just 535cc and the Effective Dcr is just 6.58/1
To give you an idea of what 535cc is, this is 32.65 cubes, times 8= 261 cubes of engine size.. that is where you are getting your performance from. And compressing it to just 6.58, instead of perhaps 8.0/8.2, well that is the death knell for low-rpm power right there.
You decide.
