NPI & PI cam specs

96blak54 · Jan 5, 2018

Been mapping these cams. Ive noticed some flaws in my previous mapping and the data was incorrect. Although not to far off, im stickler about making it right. After mapping 3cams i realized a flaw in my process. Had to go back, remap those cams.....geez. oh well...all in fun!

I issue the data here soon and correct the data earlier in this post.

Here is the odd with my findings!

The 96-98 npi cam is the most performance cam made we with almost 40Â° of overlap and desired valve events. Looking at the differences along with a pi cam just doesnt make sense. The mustang pi cam is really half of what the npi is. So, it got me thinking.

The pi head has heavy valves and almost 40lb LESS seat pressure springs, which in turns suggest valve float. The pi cam has .050" more lift on the exhaust over the npi, again offering a floating valve at higher rpm.

If valve float does occur with pi heads, then the pi cam makes sense. At higher rpm where the valve springs cant keep up with pulling them heavy valves back and there is also the lasher continuously pumping, maintaining follower to cam to valve pressure.....i can see why the pi cam is good.

The pi cam has .040" more intake lift and favors in the npi head.

So thinking that Ford designed a controlled valve float(ive always thought this along with variable lasher lashing rate) then i believe a low pound spring in the npi head would be more beneficial that swapping out to pi cams.

OLD H2S · Jan 6, 2018

I'm beginning to think some of this is to lower the harmonics going to the crappy oil pump gears so Ford doesn't have blown engines to deal with. Cheap springs cost less than good gears.

96blak54 · Jan 6, 2018

Yea, not to mention a plathora of springs are made and only one gear is needed. I can see what your saying. Alot of times the 4 chain tentioners in a 4v get slapped around with 2step limiters or rev limiting. Since these tentioners have no orfice, extreme back pressures happen when getting slapped, spiking the oil system.

OLD H2S · Jan 6, 2018

Ford has gone through a lot of trouble to keep all Mod motors low RPM until lately even the Terminators were set with the Eaton 112 to weez above 4600 and slow down the rate of rise to higher RPMs. I think the 3v heads might have the best high end with the least effort, a little porting and some cams...
I got a set of 2005 3v stock cams here too.

96blak54 · Jan 6, 2018

Hmm....think they'd work...lol. Be interesting to map

Silver95bird · Jan 6, 2018

OLD H2S said:
I'm beginning to think some of this is to lower the harmonics going to the crappy oil pump gears so Ford doesn't have blown engines to deal with. Cheap springs cost less than good gears.

Add to this the balancers were revised several times, each to a larger, heavier damper.

As to your second post, I've thought the most power made cheaply would be a 3v, with cam phaser lockouts and aftermarket cams. More power than a stock n/a 4v, but for the 4v to match it they'd have to spend a ton more to get there.

96blak54 · Jan 6, 2018

You boys think about it....2 intake valves, one exhaust. Blow down is a better match unlike 4v where literally no blow down cause of 2exhaust valves. How the exhaust blows down / de-pressurizing the cylinder while the piston moves towards the bottom has ALOT to do with hp. Having 2intake valves and one exhaust valve really makes alot of sense!

07GtS197 · Jan 6, 2018

Hey blak I have unknown spec comp cams for a 3v I bought used. If youre up for a challange you can map them. Id like to know the specs myself.

96blak54 · Jan 6, 2018

I can do it! Honestly, i would love to! Only spec i can not harvest is the installed center line of course that one is up to the user. Send them on over with paid return.

OLD H2S · Jan 7, 2018

The 3v gets rid of a lot of parts, weight, massive size in a small engine bay ,shady expensive used parts...not much new out there, no virgin cars left. I got a whole 3v compleat motor for cheap just to get a good unmolested aluminum block.

07GtS197 · Jan 15, 2018

Ill look into shipping here soon. Im guessing its not going to be cheap lol.

Eddie Dover · Nov 18, 2019

Know this is old thread but following to keep up with specs om building a budget beater have 3 different sets of cams available will have them by end of week

96blak54 · Nov 19, 2019

The thread is on going as i aquire more cams with different part numbers to map out. Its cool that you show intrest!

This latest round will be a 2v cam set from a 2009 5.4l. Most likely from a service F250 or E250 considering all civilian modulars came 3v or 4v.

Glancing over the part # on these cams reveal a repeat middle #. The 1st set of the number must be date and model type while the middle set is cam type. The last few digits could be revision.

Once upon a time Ford production # was easy to decode but sometime after 2000 it changed up and didnt follow the same pattern.

Eddie Dover · Nov 19, 2019

96blak54 said:
The thread is on going as i aquire more cams with different part numbers to map out. Its cool that you show intrest!

This latest round will be a 2v cam set from a 2009 5.4l. Most likely from a service F250 or E250 considering all civilian modulars came 3v or 4v.

Glancing over the part # on these cams reveal a repeat middle #. The 1st set of the number must be date and model type while the middle set is cam type. The last few digits could be revision.

Once upon a time Ford production # was easy to decode but sometime after 2000 it changed up and didnt follow the same pattern.

ive got 2 sets ordered from different sources 1 windsor with press on gears and 1 romeo will post part numbers when i get them in hand see what you think im building a stock engine from left over pieces i have to save a 96 vert from crusher . im now out of work on disability so keeping costs as minimal as possible

Eddie Dover · Nov 20, 2019

Here are part numbers i received today one i see you have mapped as 5.4 2v is the other number just for other side and the same? xl3e6251a8c xl3e6255b8b