Engine/ Trans Combo?
Thank you for all the information. I am going to have to read it a couple of times because there is so much. I am trying to keep this project on a strict budget. I have both of these parts now. Is there a more reasonable/ streetable way to do this with this combination. I don’t want to sacrifice all but I am on a budget.
On a budget, with that od ratio package, in a streeter;
It's all about torque, and a wide powerband.
This takes careful forethought.
To make torque takes cubes or cylinder pressure;
and with 360LA iron open-chamber heads you are limited in what you can do compression/squish wise. Lemoore Ca is listed at ~230ft elevation ,so you got that going for you. With flat-top pistons like KB107s, and uncut parts, you are looking at a total chamber volume of ~86cc, and at 4.02 bore,a compression ratio of ~9.46.. On a strict budget that's about as good as it gets. And you get no squish with those heads.
That limits your cylinder pressure to about 155 on pumpgas, depending on the engine loading and your driving style, and where exactly in CA you are gonna be driving. That pressure dictates your Intake closing angle, and therefore limits your power production at higher rpms.
Plugging those numbers into the Wallace Calculator it spits out an Ica of 60*, for 157psi and a strong VP of 138.
So now you just go shopping for a cam that slams the door at 60*Ica, and let the horsepower be what it will be.
Ok, so remembering that you are on a strict budget, lets not spring for fancy valve gear, nor headers. And lets marry that engine to that od ratio package.
I come up with an HFT cam of about
262/270/114+5, o/lap of 38*, Compression of 120*,and extraction of 106*..
if you can find a fast-rate-of-lift, this could get you .050 numbers of up to 222/230, and your lift has to stay within the working limits of the heads. But more likely is that you end up with a half size smaller @.050 cam; say 218/228. And yes for a wee bit more extraction (fuel economy) and log manifolds you could go with a 112 LSA; something like this;
262/268/112+3. o/lap of 41*, compression of 120*, and extraction of 111* ; yeah that looks like a reasonable trade .
Ok so a 262cam is relatively small, peaking at ~5000rpm, meaning no where near 400hp. But put some decent springs on it and you can wind her out another 600 or more rpm. The thing is, at a predicted 157psi cylinder pressure and 138VP, and 112/114 LSA. this 360 is gonna make very significant torque, to drive that 1-2 gearchange; and that is gonna put you into second gear at an rpm where she can actually pull that 1.67 ratio, without tortoise-like acceleration.
Now you just have to put that gear where you want it speed-wise, to make her a fun car. Earlier I suggested a 2nd-gear road gear of about 6.9 and that still stands, and that leads to a rear gear of 4.10s. While that sounds steep, with the .73overdrive those 4.10s become 2.99 hiway gears. Thinking this over I suggest an upgear to 4.30s because this will put you engine at 5350@60 mph, about just right for low-ET to 60 with that long flat powerband; and on the hiway 65=2535rpm.Those 4.30s will put you at 30mph=2700 and now in the roadgear of 7.18, so again; depend on the torque to spin the tires to get you rocketing ahead. With a big-cam,low-pressure 360, 2700rpm would be a dog. And 4.10 will be a lil softer as well. So I would go 4.30s on this combo.
For a streeter; it's all about having the right torque at the right mph. I can't stress this enough.
IDK how much power the above engine might make, and honestly I wouldn't much care, cuz she's gonna spin almost any street tire you can fit into the factory car, to close to somewhere after 50 mph. If I had to guess, I don't think it would top 300hp . But consider this; your only significant costs are;the pistons,boring, camkit and gasketry... oh and the 4.10/4.30/ SureGrip. This pkg will work with 3.55s or better, but the closer to 4.10/4.30s you get, the more fun, and the quicker to 60mph it will be. Oh yeah; yur gonna need tires; big fat sticky tires,lol
IMO, this is about the cheapest and best way to get where you wanna go with those two major items.
Somebody said that van trans will not work. The reason is that the rear mount does not bolt into a car, any car,period. But changing that only takes the proper A/F body tail and mainshaft.
If you go to a GM wrecking yard, you can find a cast-iron longtail A833overdrive there. Stealing the tail and mainshaft from one of those, allows you to put the shifter back between the buckets, making for a comfortable driving experience because with 4.30s, you will be doing a lotta shifting.And that would require bucketseats. And you will look like Mr.Cool, not being hunched over the shifter anymore. And yes you can use an aluminum tail, if you can find one, but that might require a different rear bearing.no big deal.
I ran almost this exact combo for a couple of years, 223/230/110 cam with 4.30s ..allbeit with aluminum heads and a lot more pressure. I was very happy.(With aluminum heads and tight-Q some guys here are running up to 200psi cylinder pressure, still on pumpgas; I was only at 180ish)
That same engine went 12.9@106mph at 3650# and 720 ft elevation; but with 245/60-14s and 3.55s, but with a regular 2.66 low trans...... Mr Wallace says 335hp (367 cubes at 11/1 Scr)
