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Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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Do I have to follow these on my 96 stock MAF
Not as long as you get it tuned for the new cam. The MAF OBDII computer will handle a more aggressive cam than the speed density.
 

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Re: How to pick a CAMSHAFT

The very first line I typed was:


I never said anything about mud drags. Anyone running fuel injection on a mud drag vehicle is too stupid to worry about picking the correct cam.

If anyone buys a higher performance cam than the above limits for a stock truck computer, they will ruin the dependability of the truck. Fuel ratios will be way off, and idle will be so bad the owner will sell the truck.
Agree with you ? percent I have seen this before and it was a badass truck and it would have been a monster with a 4 barrel Holley but it was the stock CPU and idled like it had the wires crossed and was rich as hell wish I could have bought it but didn't ever see it again.
 

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I got a new 351 block for my '94 with the
COMP Cams Xtreme Energy Camshafts 35-512-8
installed in it.
That was with me staying Speed Density.
But I'm having second thoughts about maybe converting to MAF now?
And if I do convert to MAF, should I consider a more aggressive cam instead of my 35-512-8?

Have high flow heads that are really only good up to ~5500 RPM.
Edelbrock upper/lower, which is also really only good up to ~5500 RPM.
33" tires on 16's with suspension leveling.

Future plans are 4" lift.
4:10 gears
Sticking with E40D.
Maybe a hydro-boost brake conversion (so no worries about vacuum).
Will be my daily driver, used primary as a grocery-getter with some mild offroading once in a while.

I do like to drive a little spirited when the mood hits.

I shouldn't/can't really afford it, but I'm entertaining the idea for the moment.
 

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I put a HO roller cam in mine.
The 88" block is roller ready.
Paired with gt40 iron heads and explorer intake. Shorty headers and dual exhaust. Also a mustang GT ecu rounds it out.
You can feel the difference.
 

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Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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17,659 Posts
Rocker Arms

This post was in response to rocker arm ratio and design on another forum. I have withheld the author for privacy sake. -BB94

Quote::
Happy New Year.

I was the dynamometer performance development engineer on the Fox bodied 5.0 GT V8 program from its inception in the late 70s through the late 80s, when I moved on to the new Modular V8 program. [My,my, how time flies...lots of good and humorous memories]

I did the rocker arm study in the early '80s, during the roller cam development period which was slated for the '85 GT, the last of the Holley carbed engines. We were looking to reduce friction in many ways to improve engine efficiency. These ways included low friction valve trains, low friction ring packs, lighter weight lubes, and other similar stuff. Ford historically rated their rocker arm ratios based on the instantaneous rocker arm ratio at the midpoint of the valve lift of the cam that was in use at the time the rocker arm was designed. This makes sense since at the midpoint of the lift the rocker lever arm will be at right angles to the valve stem, where the multiplication would be the greatest. Just because the instantaneous ratio at the mid-point is 1.5:1 does not mean the maximum lift at the valve will be 1.5 times the lobe lift. (Try that experiment on your next cam install with the stamped rocker arm. I guarantee the valve lift will be less than advertised and clearance-to-coil-bind will be greater.)
The rocker arm was not redesigned for the 5.0 GT - it was carry over. The ratio was based off the early, standard issue milder cam. So lets say the earlier standard V8 cam had a lift of .400" and the hipo GT cam had a lift of .500" (I've forgotten the real specs, it was likely less, but for the sake of discussion and keeping the math simple call it .4 vs .5.) That would mean the rocker arm had a ratio of 1.5:1 at .200" valve lift. Clearly that is not the midpoint of the GT cam but the budget did not call for a new rocker arm to match the GT lift profile.
When I looked at rollerizing the rocker I bought several brands to try on the dyno. That was a lot quicker and cheaper than designing our own. To our surprise the performance gains were more than could be explained just by the reduction in motoring friction, which was measured. At first I thought the stamped rocker arm may be distorting and flexing with a more aggressive and higher lift GT cam. But then I plotted valve lift vs lobe lift for all the brands. All the aftermarket brands raised the valve higher. So either the aftermarket rates its ratios in a different way, or more likely looked at the Ford stamping and decided to go more aggressively on the ratio. Of course we did design our own roller CAM to meet the performance criteria we wanted using the stamped rocker arm.
As a side note I have a reverse engineered flat tappet hydraulic cam in one of my hot rods that closely matches the roller cam lift profile. Nice!
Ever since then I've tried to use aftermarket roller rockers whenever the budget will allow. I even put together a 300 recently with roller rockers using the original pressed in studs and Crane cam, yet to be installed, break-in tested only.

So it wasn't any emissions conspiracy. It was a "follow the money" thing. New rocker arms for every cam profile Ford used over the years were never in the budget.

End Quote
 

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Would then the whole package (cam, intake, exhaust) make you fail CA emission testing? Are you able to make both intake and exhaust mods and still pass smog from an emissions standpoint??

And then as far as a viz inspection I think I could get away with headers and they probably wouldn't notice anything else.... Or would they.... Maybe I don't have a proper visual on what these mods would look like under the hood.... But say nothing on the outside is changed; All I ever remember "them" looking for is pipes, O2 sensor cat, muffler etc.... And there's no reason you can't put all that on and maintain performance and flow right???

And to finish the questions.... It seem like doing one mod is a slippery slope. Can't do cam with out intake, can't do intake without exhaust etc.... so is it better to do all or nothing? Or can there be a middle ground where one can build a good-solid- long running motor making the improvements Ford couldn't back when my truck was originally put together.....
 
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