86 GT Cam Mod

[RichV]

I will be purchasing a 86 GT in the next week or so. I will be doing some mods right off the bat. Purchased is 100% stock, auto, no AC, 3.27 rear.

Mods I plan:
4.10 gear (no discussion please :lol: )
Comp Cam 268H (close to e303)
Am. Thunder cat back
B&M shiftkit

I am concerned with the cam since the heads/pistons are some special 86 only setup. I have heard some issues of piston/valve clearances. Has anyone cammed a stock 86 5.0? I do not want to go through the e7/new pistons just yet. If I can't cam it, I will choose another mod.

Thanks, Rich.

[twister]

your Comp Cam will confuse your Speed Density computer, use this cam instead http://www.stangcountry.com/forums/showthread.php?s=283e78b026ebbfe9b28bbf65f999b9cb&threadid=70 , it is an Isky 371-252/257

[RichV]

I'll look it up. The Iskys tend to be a bit more $$ than others. I really want to keep it around $100.

Just out of curiosity, what makes the cam confuse the SD system?

I will more than likely upgrade to MAF down the road so I would rather confuse for now and upgrade earlier than have to swap cams twice.

Any thoughts?

Rich.

[madmike8]

mainly vacuum is the main issue with Speed Density... The system uses the MAP sensor to determine load... So.. without reprograming the computer... It doesn't know how to deal with the lower vacuum of a performance cam...

[Eric86GT]

Speed Density setups only know what speed the motor is running and how much fuel it should be injecting based on the engine speed and the throttle position (and a few other things).

In general the more radical a cam gets, it is able to flow lots more air in at higher rpms than low. The SD system is used to the way the stock cam operates, which is more of a even ratio between rpms and flow.

An MAF system knows how much air is flowing into the motor, and adjusts to give a good mixture, not rich or lean, depending on the amount of air entering the motor, not just how fast it's turning.

I've had second thoughts on posting this, because the more I think, the more I wonder if I understand correctly. So if I'm full of BS, I'm sure I'll be corrected. :lol:

[Eric86GT]

It doesn't know how to deal with the lower vacuum of a performance cam...

That was where my above post was (should have been) going.

[RichV]

eric,

are you runing a cam in your 86

i kind of understand the speed density method, i will read up on it

any of the fms 303 series cams work, maybe just a mild cam

sorry for weird typing and no exclamation points, my keyboard just took a drink of coke

rich.

[PNY XPRS]

For drivability sake, a cam should be one of the last mods you should do to a SD car.

There are lots of other mods you can do too to prepare for MAF and a cam. Intake, Heads, Headers... My suggestion,

use that $100 towards a new torque converter. That will offer a much greater seat of the pants feel than a cam. :)

One other reason to hold off on a cam... The stock E6 heads and intake will be a big limiting factor on how much air the cam can pump through the engine. Even a mild cam will run out of breath way too early with the stock heads and intake.

just my opinions... you mileage may vary with driving style ;)

[twister]

eric,

are you runing a cam in your 86

i kind of understand the speed density method, i will read up on it

any of the fms 303 series cams work, maybe just a mild cam

sorry for weird typing and no exclamation points, my keyboard just took a drink of coke

rich.DO NOT USE A FORD RACING CAM WITH SPEED DENSITY!!! Lobe centers are the main maker of vacuum, and the alphabet cams do not make anywhere near enough vacuum for SD

[Eric86GT]

[quote]DO NOT USE A FORD RACING CAM WITH SPEED DENSITY!!! Lobe centers are the main maker of vacuum, and the alphabet cams do not make anywhere near enough vacuum for SD

agreed there. I've done some research on other sites and found a limited (about 4) different cams that seem to work well with SD. PNY XPRS is right that the cam should be about the last mod you would want to do with SD, and once you get to the point where a cam change would make a difference, you would be better off going MAF and getting a cam that would make much more of a difference.

[RichV]

I am pickin her up next week!!! :lol:

Anyway, I went through some 89 vintage mags. In a MM&FF they did a bolt-on section to a 87 stock 5.0. Just what I was looking for. They did some basic stuff, MAF conversion was high dollar at that time. Anyway they did the intake and exhaust, pulleys, cam (a Kaufmann "stage 3", claimed to work great with the computer), heads, and some other minor stuff. Got to a claimed 300 hp.

I know the 87 5.0 has the E7 heads but 300 is not too shabby with basic bolt-ons. I have an e-mail in with Kaufmann Performance on the cam specs. They specialize in engine swap kits now.

I am aiming to do the exhaust, maybe a Explorer intake and big T/B, and shiftkit. The cam may wait for a bit.

Well see, it all may change in a week. :D

Rich.

[Full Tang]

A comp cams XE264HR (part number 35-349-8 ) would work well on a stock SD car. 114* lsa to keep SD happy, and durations right around the stock cam's. It has more aggressive ramps though, and more lift.

I wouldn't worry too much about clearance. The valves in the E6 are about .200" deeper in the chamber than on E7s, so anyone who has put E7s on their 86 has taken away at least that much clearance at all lifts. You'd be hard pressed to find ANY cam that would be a fifth of an inch closer to hitting a piston than stock at any lift point.

[twister]

I am pickin her up next week!!! :lol:

Anyway, I went through some 89 vintage mags. In a MM&FF they did a bolt-on section to a 87 stock 5.0. Just what I was looking for. They did some basic stuff, MAF conversion was high dollar at that time. Anyway they did the intake and exhaust, pulleys, cam (a Kaufmann "stage 3", claimed to work great with the computer), heads, and some other minor stuff. Got to a claimed 300 hp.

I know the 87 5.0 has the E7 heads but 300 is not too shabby with basic bolt-ons. I have an e-mail in with Kaufmann Performance on the cam specs. They specialize in engine swap kits now.

I am aiming to do the exhaust, maybe a Explorer intake and big T/B, and shiftkit. The cam may wait for a bit.

Well see, it all may change in a week. :D

Rich.I strongly suggest not getting anything from Kaufmann...he has a bad rep and I know some people that he has ripped off

[RichV]

I strongly suggest not getting anything from Kaufmann...he has a bad rep and I know some people that he has ripped off

Thanks!! :!:

[gtluke]

i highly suggest leaving in the stock cam and bolting on a set of e7 heads instead. you can't do both but you'll gain the most from the better heads.
you really arn't going to gain much from a bigger cam, especially since its an auto and you can't rev it as hard off the line.
good move on the 4.10's

[Matt K]

Spend the money on the mass air conversion rather than a cam swap...more room to grow!