318 Port match heads to Performer RPM Intake

C2ndLTpigeon said
Well I don't think there is any going back with parts that have been assembled. Looks like I will have to make what I have work.
Gears will be a 8 1/4 with 3.55 gears.

Here's what Hughes has to say;
Whiplash Flat tappet hydraulic small block "LA" camshaft.
Hughes "real" Chrysler cam

WARNING: Our Whiplash cam is designed for basically stock, low compression engines. This cam will run on pump gas in a 318 with 8.6:1 or less compression and iron heads. If your compression is higher than this you may need to use a higher octane race fuel. Your vacuum should be in the 9"-11" range using this cam.
(Figures calculated using stock stroke & compression at 750' altitude.)

Basic guidelines (These are not absolutes, just guidelines to help you get close on a cam choice)
Use: Street and some strip
Idle: Like it wants to bite your head off! Very aggressive
Vacuum: Low
Converter: Stock or a mild stall
Rear gear: Stock or up to 3.55
Benefits: Tons of low end torque and a super aggressive idle that scares Mustangs, Camaros and rice burners from even thinking about messing with you.

The OEM Distributors have terrible advance curves. Many go as far as 50+° advance which will cause major damage and have very poor acceleration. When you order a Whiplash cam ask for the special whiplash advance curve specs or we can supply you with a new Pertronix distributor (P/N PRT 7141700) and we will custom curve it for no extra charge.

Lets talk about this;
First;(Figures calculated using stock stroke & compression at 750' altitude.).
You are not at 750 ft, but Wiki says; in places below sealevel! That's 5psi right there.
Second; " Like it wants to bite your head off!
"Come on!, it has just 48* of overlap, just 4* more than a 340. Nobody ever said that about a 340. If you want "bite your head off, you'll need a 484cam or more, and 11/1 compression. So this is strike one against the advertising hype.
Third;
"Many go as far as 50+° advance which will cause major damage and have very poor acceleration". I have never seen even ONE ,50* PLUS in centrifugal timing, never ever. Yur lucky to get 30* plus 5 idle =35*. So where is the "many"
So strike two
Fourth;
Vacuum: Low/ Your vacuum should be in the 9"-11" range using this cam. This is true, and is partly why you need a looser than stock, TC. Yet they say; "Converter: Stock or a mild stall. Strike three.
Fifth/Sixth
pump gas in a 318 with 8.6:1 or less compression and iron heads. If your compression is higher than this you may need to use a higher octane race fuel
Here they are protecting their butts. There never was an 8.6Scr 318 from the factory, so this is like saying ice-is cold. Empty words and useless information. to get to 8.6, you will have to get your total chamber volume down to ~86cc. With pistons down at .057, that's 11.2cc; add 8.6 for the gasket,add 1cc for the crevice volume, and you are up to 20.8; leaving 65.2 for the heads. So your factory open chambers heads are what? about 72cc and that makes your total chamber volume ~92.8 and the Scr comes to 8.0 on a good day, cuz in some in 318s the pistons are down even further than .057.
Bottom line is the only way to get to 8.6 is spend the money to get there. To their credit, they do say 8.6 or less.
But as I have previously shown; with an estimated Ica of 54*, even at 8.6Scr,your pressure will still be in the basement;
Static compression ratio of 8.6:1.
Ica of 54*, sealevel
Effective stroke is 2.78 inches.
Your dynamic compression ratio is 7.37:1 .
Your dynamic cranking pressure is 146.84 PSI.
V/P (Volume to Pressure Index) is 118
So; two strikes on this point.
Seventh;
Converter: Stock or a mild stall
Rear gear: Stock or up to 3.55
You gotta take these two together.
Lets say the factory stall is 1700 and
the factory gears were 2.76s , and
say the factory teener makes 190 ftlbs at 1700.
So to the road with 27" tires this comes to;
190 x 1.8 in the TC, x2.45Trans x2.76 rear =2310 ftlbs at zero mph. A couple to a few carlengths out, the TC ratio has fallen to say 1.4, and the Rs have climbed to 2000, so the crank ftlbs might be 195; so the to the road ftlbs is looking like 195 x1.4x2.45x2.76=1856..
So what we have here is a few feet of rubber and not enough power to sustain the tirespin. This is exactly how the smoggerteen performs. Am I wrong?

Now, lets install that Whiplash and see what happens.
Right away we see a reduction in VP from 115 to 104 IIRC, lemmee go check; Hyup. that is down to 90.4% so lets say your torque is now 172ftlbs, so 172x1.4x2.45x2.76= 1610 to the road...... compared to 1856 with the stocker. You see what happened here? The bottom end took a dump, this new combo cannot even chirp the tires never mind spin them.
Ok so lets install your 3.55s. Now you numbers are;
172x1.8x2.45x3.55=2900 at zero mph, diminishing to say 2100 a couple to a few car lengths out. Again, no sustain. Oh wait, lets see if the 4bbl can help. Nope looks like not enough rpm is generated to make a difference. How about the headers? Nope, not enough rpm.
So what are you gonna do?
Hey I know, lets install a 2800TC.
So, say at 2800 your torque has climbed to 210 and lets add 20 more for the secondaries and headers which just came on line; so call it 230crank ftlbs. Your new numbers are
230 x1.8x2.45x3.55=3600 plenty of to-the-road torque,to smoke the tires and diminishing to say 2800 a couple to a few lengths out, that is plenty to sustain the spin. So now you can work the throttle, to spin about all the way thru first gear,at least.
And that is why you need a TC even with the 3.55s.
But Hughes says "stock to mild TC".
Yeah right..................
With 3.55s and 27" tires 65=2870rpm@zero-slip, so get you a 2800TC minimum.
With your predicted cylinder pressure, yur gonna need it.

Just trying to help.
Many of us at some point in our lives have slipped a 340 cam into a 318LA. This worked not too bad in the early 318s that had an advertised Scr of 9.0 or more.
But when I slid it into a smoggerteen, a '73, it was a total disaster. And 3.55s did nothing for it off the line. It took the 2800 to wake it up. And performance didn't start until the Rs were well past 3500. In the end it took 3.91s to wake it up for me.
This Whiplash is like a 340 cam, but traps a wee bit more pressure.
Happy HotRodding