Head/cam questions

[Guffinator]

Some of you are aware of the difficulties I'm having with my car. My car weighs 3000lbs with me in it. I have a 306 with the following mods: AFR 165's, Ported Cobra intake, Lunati 51012 cam, Mac shorties, Edelbrock 65mm TB, C&L 70 mm MAF.

My car should be running somewhere in the 12's...bottom 12's I would think weighing in at 3000 lbs. But it doesn't. It just doesn't seem to make the power.

My cam specs can be found HERE (http://www.holley.com/HiOctn/ProdLine/Products/IEC/IECC/Ford3.html) (51012)

Fred seems to think that I have too much cam. Any thoughts. I have an E cam available to me. While this might not be the best cam choice I'm thinking about trying it to see what difference it makes.

[Guffinator]

Wow...you want my social security # too? LOL

It's a standard T5 with 3.73's in the back. Yes I have done a compression check and all cylinders held the same (180 if I remember correctly).

At the dyno day it pulled a meak 250hp. The car was blowing alot of blue smoke which I later realized was coming from a bad intake gasket. Since then I switched from the Holley SystemaxII intake to the Cobra and installed Fel Pro 1250 intake gaskets...so the dyno was obviously a waiste of time.

My last trip to HRP just a couple of weeks ago (BEFORE the manifold swap/repair) it ran 13.6 @ 102 (if I remember correctly). Since the swap the car runs fine (no bucking or chugging...and no more smoke) and it does seem to be a bit stronger....maybe just a tad. But it's still no where near a low 12 second car at this point.

Right now I'm shifting it at about 5800 but I can run it up to 6k. Right now my timing is about 14 and I've dabbled with it a bit.

I have no idea about the o2's or the cylinder balance test (wtf is that??? lol).

The car seems to be pretty stout out of the hole actually (baffled I know!) but it seems to flatten out in the mid range and upper end. I beleive the balancer is fine (Fluidamper)

[Shaggy]

I have to agree with fred you have a cam that should breath a 306 well past the 6250 you are limited to but you have the small afr heads and a "street" intake..My old 84 had a cam fairly close to what you have now and I was shifting at 7 and running 10.30's (10.28 best) now I did have more head, intake and less weight than you.

Now my few question,
Which pistons did you go with on the 306?
ARe you willing to invest the money to properly eliminate the 6250 rev limiter?

cam wise with your set up I would recomend(this is an erson shelf grind) http://www.mrgasket.com/pdf/Ford.pdf 2nd cam on page 11 3rd cam would work well to but a little less driveabilty but more power.

[Saleen91]

I've been drinking since 4pm so I haven't read everything in your post but I do have to say... DAMN THAT'S A BIG CAM!

I'm running a 51014. Look up the specs on that. You've seen where that's put me, but then again I have a totally different power adder than you.

Now where's my beer? I make a post and loose a full beer in the process. Ugh.

[Guffinator]

Originally posted by Saleen91
DAMN THAT'S A BIG CAM!



I bet you say that to all the fellas :D

[Guffinator]

As for the pistons. They are TRW 10:1's. As for eliminating the rev limiter I guess it would depend on what it would take.

[HoustonLX]

Get an MSD 6AL Chris. You can control your rev limiter through that. Also, its much safer cause the MSD 6AL cuts spark when you DO hit the rev limiter where the factory limiter cuts fuel which is VERY bad cause it could make the car go lean when it needs the fuel most.

[Blue91]

The 6AL will not get rid of his factory limiter though Shane. If he has an 6AL, the only way he'll hit the MSD limiter instead of the stock eec limiter is by having the MSD limiter at a LOWER RPM than the stock 6250.

To raise the limiter, he'd need to get a FMS extender, a tweecer/eec tuner, speedbrain, pms, etc, or a chip.

[HoustonLX]

Well DAMN!! LOL

[Shaggy]

Originally posted by Guffinator
As for the pistons. They are TRW 10:1's. As for eliminating the rev limiter I guess it would depend on what it would take.

If tou are at 10:1 with the combustions chamber in the afr scratch the couple of choices I suggested i would highly reccomend a custom grind or look for a shelf grind ground on 112 centers high lift short duration for your current combo or you yank the heads off bring them to me (we work out the labor maybe help me get my garage clean) get an extender or (tweecer for the price they seem to be the best bet my favourite is the PMS price not withstanding though).

[TxBandit]

We had a similar problem a while back Chris. We messed with the motor and the tune for about a month and could never figure it out. Finally we decided to yank the front cover off and make sure the cam was installed correctly. Come to find out we missed it by three teeth. It's kind of a PIA but worth looking into.

Troy

[Guffinator]

At this point I'm planning on a cam swap anyway...so I'll definitley take a look at that before the timing chain comes off.

[red95gts]

What's the fuel system consist of? What pressure are you running?

That cam is definitely huge, but I would think it would pull better than 102 mph... The Cobra intake probably isn't too bad of a match for the 165s, although something along the lines of a track heat would make better power with that large of a camshaft.

Good Luck

[Guffinator]

The fuel system is stock except for a 190 pump and 24 lbs. injectors. I just installed a Kirban fpr and haven't installed a fuel pressure guage yet so I'm kind of lost on how much pressure it's running currently. I know this could be a large source of the issue...but I checked the plugs and they didn't look too bad in either direction...so I don't think this is what's killing my hp.

Just to add...at this point I've almost definitley made up my mind to put an S Trim blower on it. Any suggestions on a cam choice that would work well with this setup? I would like to stay emissions legal.

[red95gts]

Well..definitely figure out where your fuel pressure is. Judging by the parts combo, I'd wager you'll end up in the mid 40s (vac off) on fuel pressure.

How did you check the plugs? Unless you killed the car RIGHT after a WOT run, they can be pretty misleading. At idle and part-throttle, the computer uses the O2s as a "check and balances" against the MAF. If things are a little lean (i.e. not enough fuel pressure), it "sees" that via the O2s and it adds some fuel (increasing inj pulse width/duty cycle). However, at WOT, the O2s are ignored. Basically meaning that your fuel delivery is based upon rpm and fuel pressure. If you are lean at WOT, the computer will never know it.

Chances are your problems are a combo of the cam and some other factor. Even with the cam being too big, you should have laid down more than 250 at the wheels (although with the intake leaking, it's hard to say how accurate that is)

Good Luck