GT40P-E303-1993 FACTORY STOCK 5.0
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Maryland Stang
Active Member
Compression should be somewhere around 10:1 I believe. The PV clearence would need to be checked since things were changed or are unknown like the degreeing of the cam.
I WILL INSTALL CAM "STRAIGHT UP"- DONT OWN DEGREE WHEEL-WILL HAVE UNTOUCHED HEADS CUT .030-BLOCK & PISTONS UNTOUCHED
THANK YOU FOR REPLY
90topdown
Member
PTV clearance should always be checked.
Even with the same combination of parts, every motor is different. Better to be safe than rebuilding.
I would reccomend either borrowing or picking up a used degree wheel. They are not that hard to use and it makes a difference !!
Even with the same combination of parts, every motor is different. Better to be safe than rebuilding.
I would reccomend either borrowing or picking up a used degree wheel. They are not that hard to use and it makes a difference !!
Maryland Stang
Active Member
Straight up really means nothing since it can vary from cam to cam. We're not dealing with the Space Shuttle here and variances occur in cams, blocks, cranks, pistons, connecting rods, pushrods and timing chains sets. I have 2 sets of Ford factory pushrods and between all 32 pushrods there is almost a .008 difference. That may not sound like much but it can be the difference between having the proper clearence and destroying 16 valves and 8 pistons.
If you're willing to guess at whether the cam is installed properly or not then you should be willing to guess at the valve clearence.
Maryland Stang
Active Member
Not to take this off topic, but I thought GT40P heads weren't allowed in FS? IIRC, only the standard GT40's were allowed.
SIR= I ONLY STATED FACTORY STOCK,BECAUSE THAT IS WHAT THE MOTOR IS= THAT WOULD
INFORM TECH. ASSISTERS OF WHAT I AM DEALING WITH=ON TOPIC= WHAT KNOWLEDGE
WILL YOU SHARE??
I STREET RACE 1/4 MILE FOR $$$$
ONLY GO TO STRIP TO SANDBAG
93 LX
Founding Member
Stop Street racing it kills people. You want to race for cash then keep it on the track. Just my 2 cents.
Lost a friend who was killed by a street racer.
AINT NO DUMB QUESTIONS=DUNNO NEVER DONE IT=THIS IS WHY I AM ASKING FOR GUIDENCE
FROM EXP. BUILDERS
THANK YOU SIR
A lot of cams are ground with advance or retard...i think you're safe going straight up unless you're trying to squeeze as much as you can out of your combo and you know what you're doing...if so then degree it. I went straight up with my X303 and it's fine. If i were a gambling man i'd say your PTV clearance will be ok, but CHECK IT. How dumb would you feel if you didn't check it and bent all your valves up the first time you started it up? Also, please turn off the caps lock 
I agree with maryland stang your compression would be around 10:1. As far as checking ptv clearance theres a couple ways. I think most people use modeling clay. Lay a strip or two across the piston where the valves would make contact, the strip should be about 1/4 in. thick, you can lightly cover the top of the piston and valves with oil so the clay wont stick to the valves and pistons. Make sure you put the cam in your gonna be running and also whatever else your swapping out if any. Your suppose to use a used head gasket when checking ptv clearance, but I imagine if you don't have one theres not much you can do about it. Put the head on your going to be using, put some bolts in the head, I think you only need to tighten them like 30lbs, then put your pushrods and rockers on the piston your testing, also your supposed to use solid lifters when checking ptv clearance. Once you have everything on the piston your testing turn the motor over a couple rotaions, if at somepoint it gets hard to turn over stop so you don't mess up the valves, once you have it turned over thru the compression and exhaust stroke pull the head, carefully remove the clay and check the thinnest area of the clay with a dial caliper intake should be .080" and exhaust .100". If something don't make sense go to FORDMUSCLE webmagazine: Fundamentals - Checking Piston to Valve Clearance
hope this helps. Also if you can find out what cc your heads are after you milled them, this site will help for the comp. ratio. Stock the GT40 heads are 60cc I believe.FORDMUSCLE.com webmagazine - Compression Calculator
hope this helps. Also if you can find out what cc your heads are after you milled them, this site will help for the comp. ratio. Stock the GT40 heads are 60cc I believe.FORDMUSCLE.com webmagazine - Compression Calculator
Thank you sir-my exp. is that most cams are 2 degree built in advance to compensate forA lot of cams are ground with advance or retard...i think you're safe going straight up unless you're trying to squeeze as much as you can out of your combo and you know what you're doing...if so then degree it. I went straight up with my X303 and it's fine. If i were a gambling man i'd say your PTV clearance will be ok, but CHECK IT. How dumb would you feel if you didn't check it and bent all your valves up the first time you started it up? Also, please turn off the caps lock
timing chain stretch,which usually occurs within 2 hard passes-straight up is cool with me
car gets street driven 400 miles a year-I use other cars to find that extra .1sec. / 2m.p.h. etc.
giddy-up! premium info again= many thanks for sharing links=will use method you described
thank you
One method i heard that kinda made me laugh was to use Tootsie Rolls...This was on Power Block i believe. They said take 2 Tootsie Rolls and leave them in the wrappers, but roll them in your hands to warm them up, then put them in the valve reliefs and do your check as per the usual routine, and then take the rolls out and freeze them. This way you can then unwrap them (the wrapper is left on to prevent them from sticking) and measure them while they're hard to get an accurate reading. When i did me i used pink playdough...i've always been told specifically to use PINK playdough...no idea why, maybe there's something particular about the texture or thickness of that color.
I thought about using playdough, but then I read not to use it cause it can throw off the reading because it starts to regain it's shape after being squished down. Just thought I'd throw that out there, see if anyone else has heard anything on it.
Mr. Rustypwnz
Advanced Member
so you race on the street for big $? So what do you run like go carts or something?
thats not gonna be the fastest thing around...
GOT 9 CARS DUDE/ ANOTHER 15 AT FRIENDS SHOP/THIS IS A MUSTANG II THAT DAD BOUGHT NEW AND JUST BOLTIN' ON A FEW THINGS/ AT 2900= NUMEROUS GEAR= TRANSMISSIONS=SLICKS=INTAKES= CARBS =NOS KITS=ETC.
WHEN I LOSE I JUST GRAB ANOTHER CAR
ITS ALL FUN WIN OR LOSE
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