Cam Plan

new 4/09/03, updated 4/14/03, 4/18/03

I have been thinking, always dangerous. Six months ago a V8 SHO cam cost $1180.00, last week Don purchased a new one for $115.00. That opens a few doors. The 4.6L DOHC mustang motor has been out long enough to give cam grinders some experience.

So here is the plan. Get 4 new SHO cams, (cost $460). Send them to Crane Cams have them reground with a new base circle. Now computer based engines are cam fussy, you can only get about 10 degrees more duration or the computer thinks your all hosed up and goes in to limp home mode. Or get more cam and run a chip.

Our cams have 215 degrees duration. Crane has DOHC cam patterns for the 4.6L in 211, 217, or 220 degree with all the lift we can use. How much lift can we use? I don’t know. Cost for a regrind with a “button” to adjust for the new base circle is $512.

Then you need to weld the sprocket on the new cams and maybe the lobes, because how much can you cut a lobe on a composite cam? I don’t know?

Then you need to install the 4 new cams. That is 20 hours labor. 

So you have $972 bucks plus 20 hour labor invested and I don’t know if it will make more HP or not. Still less than the cost of one cam this time last year. I promised Crane cams this would be for “off road use only” – cross my living bra and hope to die. 

It took 4 years since I thought that one up for the first 3.99 final drive V8 SHO to happen. One might have 260 HP V8 or nothing at great expense and trouble. I don’t know. I think Crane know knows more about 4V DOHC Ford engines than they did in 1998 when I last called them.

4/12/03

Vadim always warned us you can't make HP everywhere. If you want more peak you will lose some off the bottom end and verse visa. Somehow one always loses more than you gain going either way. Remember HP & TQ here is measured at the flywheel not at the wheel.

Stock cam 215 degrees duration
Hot cam 225 degrees duration
Mild cam 205 degrees duration

I imported the dyno charts into Desktop Drag and changed the tire size back to 25.7" tall. (which is why the numbers are different than what I sent the list. On a graph all the runs are on top of one another, the graph can not be read. Hence the table below.

Now the 200 HP, 200 Ft-Lb SLO with 3.99 gears was never a slouch. This is a clue why. I don't know I would trust a V8 SHO cam reground with a reduced base circle. It would be expensive and as Don noted a blower may be a wiser investment. 

As Kirk noted, was the shims wear and duration and lift decrease your car may not be much slower.

I don't know that the "best cam" is one that gives the lowest ET in a quarter mile. Comments or remarks? Send them and I'll post them here.

Buford

4/11/03

A few years ago I built up a drag motor for my 1962 Nostalgia drag Pontiac Catalina.

When getting ready to do the cam I went to three different well-known Pontiac engine builders and asked for advice on the cam and how to set it up.

I got three TOTALLY different answers. One took the middle road and one on each end of advance or retard the cam.

I took the advance route and went for a bit more high end HP since the motor was a low rpm monster anyway. The trade off was good, but the experience was wild with the builders.

From what Tim has reported, we seem to have a near perfect cam grind right now. When a FWD car can't put the power down from the start anyway under most situations, I don't really need a lot more Low rpm power, especially with an automatic that won't downshift when I want it to.

Blower seems the better way to spend a few grand and get GRAND results. I don't care to spend $2000 or more for a trade-off.

Don Mallinson

In fairness to Don his letter above was in answer to an earlier version of "Cam Plan" which showed different results. His conclusion however is valid. A blower is a better use of funds.- Buford

4/14/03

All these theories sound nice but regrinding the cams to get more duration will only move the power band higher, and along with some more lift you might get 15 to 20 more hp at the flywheel, and its gonna cost big bucks. As I understand, a stock SHO puts out in the 190 hp range at the front tires. I have talked to one of the guys at SHO Fast and according to them one of their supercharged SHOs put out 318 at the front wheels. Now I'm no mathematician, but $900 in parts (cams and perf regrind) along with 20 hrs labor at say $50 an hour to R&R the cams and your spending $1900. For even a 25hp gain, that's still $95 per 1hp. -OR- $4500 for a supercharger kit (which in my opinion most mechanically inclined SHO owners could install themselves) that would yield say at least 310 hp at the FRONT TIRES. That's $37.50 per 1hp. Sounds like a better deal to me! 

Jason 
97 SF

4/18/03

In defense of the SHO motor using a blower, mine failed not do to a material breakdown directly caused by the SC but rather a fuel component failure/plugging that resulted in a lean out condition in just one cylinder. The fuel problem was something that I should have resolved before it caused the issue. The other important thing to note is I did boost the pressure about a month earlier from 6 psi to 10 psi, which was at the limit of the stock injectors delivery capability. Had I utilized a more prudent foot or replaced the injectors to match the increased blower pressure I may still have burned the piston if the injector had plugged during a redline run into the triple digits. Don't know, that is why my car is the Beta test. By the way, other then that one piston and the cylinder all else inside the motor looked brand new, even with 26,000 supercharged miles. It does make me giddy though when it launches and matches the speed of the unsuspecting Vette's up to 100.

Carter Fuji
Just another former customer that cost Ford millions of dollars
'97 ES Whoosh
Greenwood, AR.