to much?
#1
to much?
i just bought a 1997 vortec supercharged mustang gt .they have comp 270 cams in with pi heads that were cut to make 11:1 compression.oh and it has a pms anderson system.some one told me the valves might tap at high rpm.so if so is it possible to degree the cams back one degree to keep this from happing? i forgot its also meth injection.should i just pull the heads and drop the original back on? or can this be tuned to work.
#4
if the pistons are aftermarket they are probably notched for clearance. I'd take the valve covers off and throw a ptv checker spring on one of the cylinders and check how much clearance you have tho just so you know.
#5
yes i do mean milled,but its a stock block.as far as i know.not to sure what to do with this thing.5.0's i know like the back of my hand but all this other stuff is new to me.thank you school boy,that at least points me in the right direction.
#6
new big problem
hi let me give you the run down,i have a 97 4.6 mustang gt.it has pi heads that have been milled down to make 11:1 compression.and put in 270 comp cams in.cams are degreed so they wont tap pistons.then we have a vortec supercharger with six pounds of boost along with meth injection.and a on board pms anderson system.heres my problem the pms doenst really do anything ,it really doesnt change anything,in third gear up around 5500 it predetonates really bad.screams like a monster till then.tried alotta things like took out timing and fuel and added it and nothing seems to change.
#9
That's a lotta compression for f/i. If a good tuner can't get it figured out, you may need to find a set of unmilled heads (or dished pistons, or both - depending on what you'd ultimately like to do with the car) to get compression back down around 9-ish.
Either that, or ditch the blower and spray it instead. N2O loves high compression.
Either that, or ditch the blower and spray it instead. N2O loves high compression.
#10
Agreed with all the above. That's a lot of compression if you plan on running pump gas and or any kind of boost. I'm running around 10.5:1 and that's pushing it. I get away with it because I'm running the trickflow heads but the regular PI heads don't do as well because of the chamber design.