ramz28

Whats the stock compression ratio of a 85 302? is it 9.5 or 9. and whats the cc of the head?
im looking to do a rebuild with the intent of supercharging. im looking at stock rebuild kits that are forged. about 600 bucks. The supercharger is a roots style about 5lbs. not looking fora amazing HP gains or 1/4 times as i wont be racing a lot. its more for a the classic look and sound of a supercharger. just looken to compare some specs of heads. thanks also if im running low boost is there any reason to go forged since the supercharger says its meant for stock applications? is hyperutectic good enuf or cast?

mjr46

I believe the carbed models were at or under 9.0

ramz28

nice! im lookin at stock rebuild kits and it says with a 58cc head itll be 10:1 and 1 says itll be 9:1 so im just trying to c what cc head i have. Thanks

projectresto83

85 had 8.4:1 CR with forged pistons and a 67.5 to 70.5 cc head. You will be fine boosting the stock block. How many miles do you have on it?

mjr46

I assume you are using a weind 174 or the old B&M 144 for an sbf

ramz28

@ project lol too many miles to boost. i got a 170k motor runs fine but i think boosting on that motor im asken for way too much blowby or possible blown rings. then id have to do the rebuild anyway. so imma rebuild with stock specs and just add a blower.
@mj yea the weiand 174

ramz28

any chance you guys would kno the specs on a 86 5.0 efi? I kno its a 9.2:1 but wha about head cc? i have that as a spare motor that i would do the rebuild on and just swap.

projectresto83

Pistons- Flat top (no valve reliefs at all so what out on aftermarket cams) 9.2:1 CR, forged, ring thickness and ring tension reduced; 30% on upper comp. ring & 35% on oil control ring

Cam-
I.O./I.C./Lift-17°/69°/0.278
E.O./E.C./Lift-67°/19°/0.278
Duration - Int/Exh 266°/266°
Lift 0.444"/0.444"


Heads have 62.9-65.9CC combustion chamber

ramz28

where do u get this info from?i mean damn!!!! ive been googlen shyt for days and i cant get #s like that. previous motor u had? thanks!!

projectresto83

Its just information that I have collected over the years.
The site is currently under construction but
http://www.jason.fletcher.net/
or google Fletch's 5.0 Carbureted Mustangs
His website is where I got the specs for the 85 and 86 motor but it helps to save little things like that on the computer when you come across them.