Faber

Just wondering how hard it will be to swap out my cams. I am not replacing the stock springs or retainer, just the cams.

Anyone out there that has experience want to share any valuable lessons learned?

Glenn

bump

KenB

Have you ever done any of this type work before? One missed link and it can all be over very quickly. I get probably 5-10 calls a month on screwed up cam installs. Just a warning.

Faber

I understand the risk involved Ken. I am actually just looking for some advice on the install, pitfalls, and helpful tips.

I got an idea! how bout PM'ing me with a great package deal?! I tried to get some pricing from your shop four days ago but it was close to the end of the day and apperently the technical folks had gone home for the day. still waiting for a return call.

I am looking at the BBR Stage 1 which makes its power in the duration and does not require a spring and retainer change. The only thing that bothers me is the fact that they are reground cams, and require a shim.

If anyone has advice on this that would help me in my purchasing or install I would appreciate it greatly!!

boduke0220

i would like to about cams also because i cant decide if i should go F/I or N/A lol.

good luck man!

Faber

Thanks man.

I am only looking for about 450 rwhp with this car. I will be installing a supercharger later on, but want to get some cams in there for a little extra power, and a good lumpy idle. If the bbr cams will give me a lumpy idle and at least 15-20 more hp and torque I will be happy. I will lean on the blower to make the big power.

anthony05gt

Blower cams with a blower. I miss the lopey idle from the old days with my old sixtys cars, but they will just cause a huge hole in your pocket and a loss of bottom end power. Not worth it IMO. If I were to do cams I'd go all out and bump the compression with a nice rotating assy, install stage 3 or 4 cams with springs and do some porting on the heads. You might actually hit 400rwhp if done right, but it's expensive on a mod motor.

uberPony

BBR regrounds getting 15-20 hp?
Just regrinding to make a lopey idle wont get you anything for power gains.
Cams are a waste of money on these cars. The stock cams and VVT work fine up to 800 HP.

Faber

Sure the stock cams work fine up to 800 hp with a blower. I want a little lope in my idle. If i can get these cams for $565.00 and the idle is wicked sounding, plus they buy me a bit more power, and compliment a blower where am i going wrong?

bob

Whats the most prevalent issue? If I had to guess it would be the timing chains and/or followers?

bob

Gotta be careful here, a wicked idle is more the result of increasing overlap and the craptacular things that go along with it. FI engines can be particularly sensetive to this as well as fuel injected engines is general.

Faber

Expound upon the craptacular aspects please. The cams I ordered are more duration and a bit more lift than stock.

Five Oh Brian

More overlap allows for more compression ratio, so if you're putting in different pistons you can take advantage of that without running race gas. More overlap means the intake and exhaust valves are open simultaneously for a bit longer - can only guess that makes the engine more wasteful (additional unspent fuel mixture getting lost and worsening emissions that may upset the cats).

If you're keeping the factory compression ratio and cats (not an off-road pipe), then to make more power with an aftermarket cam properly, I believe you need more lift, not duration, and is likely why the major cam grinders out there go the lift route instead of just duration. Basically, get more mixture into the cylinder without allowing it to escape by keeping all valves open simultaneously.

Sure, you need new springs & retainers if you bump lift enough, but the extra money spent will be peace-of-mind that all the labor charges aren't for naught. A cam swap is very labor-intensive in our engines, so do it right the first time and don't cheapen out on the parts end of the deal.

Don't get me wrong, I love the sound of a big duration cam in a big-block musclecar V8, but the gains are minimal in a modern V8 with VVT like our 4.6L 3V's and the gains are mostly top-end rpm's.

281GT

Five Oh Brian makes some very good points. Using more duration than neccesary, thus holding the valves open longer effectively reduces the compression. Unless you increase the compression ratio to compensate you'll end up with a trade off where any increased power gained from longer duration will be offset by lost compression.
You would be better off increasing lift to get a power increase.
In regards to a lumpy idle. Keep in mind that with carburated vehicles a long duration cam wasn't the sole contributor to a lopey idle. Carburator idle curcuits do not work well under low vacum conditions. Modern fuel injection systems are not subject to this problem, thus you'd need a longer duration cam in a modern engine to get the same lopey idle. You can still do it on a modern engine but by the time you get a cam that has the idle you're looking for you will have gone beyond the point where the stock springs will work.
In summary, you can keep the stock springs and do a mild cam upgrade for some power gains in these engines but to get the idle you are looking for it's going to be an expensive job as you're going to need the whole package with springs and retainers.
Then say good bye to ANY power under 4000 rpm.

Faber

Stage I BBR cam
SOHC Great Street / Strip Performance cam with Noticable Idle. Recomend lower gears, Computer Programming Required, and 2300+ stall for automatics. RPM Range 1500-6000. 227/233 .050" duration, .480/.480 lift, 114 LSA. Recommend Replacing Valve Spring.
Gross Lift Intake- .480, Exhaust- .480
Advertised Duration Intake- 270°, Exhaust- 276°

4.6L/5.4L SOHC MODULAR (3 Valve)
Part No.: Stock
Description: FACTORY OEM SPECS
Adv Duration: 233 Lobe 242 / 242 Valve 254
Duration @.050: 186 Lobe 191 / 202 Valve 207
Gross Lift w/1.8: .461 / .466
Kit#: Stock

what do you guys make of these numbers?

Five Oh Brian

I see that Ford is very conservative on the duration (likely to minimize emissions and use more compression), and using decent lift (not to far off the aftermarket grinds) to fill the cylinder.

BBR's cams look better suited to a manual trans (or an automatic that's set up for high rpm's) as the lobe seperation is bigger than an automatic would typically need to build early cylinder pressure.

BBR's duration numbers aren't really that big, so I just can't imagine a 270° adv duration making much, if any, kind of the lumpity lump idle you're seeking. Somthing over 290° or 300° and you've got a heck of killer sounding idle, but not 270°. That's more of a low to mid range grind.

Also, BBR is recommending new springs. Don't take that recommendation lightly. Again, swapping cams is 2/3 labor expense, 1/3 parts expense. Do it right the first time, or you're going spend way more money in labor in the long run when you do it over.

Faber

I appreciate the insight and depth of your response! I talked to the guys at BBR and asked about the need for new springs. He said springs are really not needed on the stage 1 cams as the lift is conservative and well within the factory springs specs. But I will definately take your advice. He said the cams are making more power and torque throughout the rpm range, and that he had customers that have swapped their comp stage 4's for the BBR stage 1's and seen better performance.

Not knowing nearly as much as you about cams I took these claims with a grain of salt.

He said the idle sounded pretty aggressive, and he would provide a sound clip. I have not yet received that clip. I figure if it sounds a bit meaner, compliments the blower and I can reuse my springs then cool. If I have to replace the springs that is another $300 and about 8 more hours of install so I might just scrap the idea alltogether...

Five Oh Brian

I won't pretend to be a cam expert, and I have never swapped cams on any of the 4.6L V8's I've owned (2V, 4V, and now the 3V), but I've done a fair number of cam swaps on older OHV style engines. I've made mistakes in choosing the right cam for the intended use of the engine and desired rev range a couple times, so I thoroughly appreciate your diligence in asking lots of questions.

On a side note, I watched the movie "Christine" last night (own it on DVD and my teenage kids had never seen it). You know, the Stephen King story about a 1958 Plymouth that is alive. Couldn't help but notice that in the scenes when the car is all smashed up and smoking that the cam profile sounds so bad and bottled up. When the car is pristine and zooming around killing people it has a fairly wicked lope to it and great exhaust. Definitely two very different engines and cam timing! I mentioned that and my wife just gave me the deer in the headlights look and said "just watch the movie."

Faber

You are more of a cam expert than me! lol

I have been watching these forums and studying other peoples performance gains when making decisions about bolt ons that I am not sure about. The cams are by far my weakest subject.

I just want the car to sound mean at idle and low rpm, as well as perform a little better. when the blower goes on I think the stage 1 cams will shine a little more.

would it be fair to say that since the lift is within the factory valve springs spec that it would be a safe bet that the factory springs will do just fine?

Five Oh Brian

Looks like the factory lift and BBR cam lift are, indeed, very close, so it would be easy to assume that you could reuse the factory springs.

However, here's a thought. With the new cam profile, you will likely see a slight shift upward in the rev range for peak power. Ford sets the redline at 6,000 rpm's for a factory GT, but there is still power up to about 6,500 rpm's with the stock cams. The BBR cams will likely move the usuable powerband up. It's anyone's guess to where without seeing a dynograph, but it's likely safe to assume around 7,000 rpm's??? The tune in my 07 GT is set with 7,000 rpm's as the redline, but I shift at 6,500 rpm's at the track as I have factory cams. Do you suppose that with your new-found power and high rev characteristics that the factory springs may run out of capability the closer you get to 7,000 rpm's? You certainly don't want valve float, and an aftermarket spring with higher rates would alleviate that concern.

If you don't think you'll turn the motor faster than 6,500 rpm's, then the factory springs might be just fine in your application.

Ultimately, go with the advice BBR gives you. They spec'd the cams and they should understand the implications of how those spec's affect related valvetrain components, so they should be your guide in deciding what parts you need to use with their cams.