Commprestion

[Pimpdady753]

ok im going to be putting a 393 in my fox body 1990 gt,

kB dished pistons
H-beam super racing rods
twisted edge heads at 58cc
http://www.coasthigh.com/Assemblies/Ford/ford_393w.htm block
not sure on the cam yet

i was woundering what compretion i should run or tell them i need, that would be great thanks.

[getstars5]

Originally Posted by Pimpdady753

ok im going to be putting a 393 in my fox body 1990 gt,

kB dished pistons
H-beam super racing rods
twisted edge heads at 58cc
http://www.coasthigh.com/Assemblies/Ford/ford_393w.htm block
not sure on the cam yet

i was woundering what compretion i should run or tell them i need, that would be great thanks.

first of all, if youve already decided on the pistons, rods, head volume, and block, youve already decided on the compression. the only other thing you can do at this point is to choose what kinda compressed thickness head gasket you want.

check out this site, you may find it intresting: http://www.angelfire.com/fl/procrastination/motor.html

[Pimpdady753]

well then what is going to be my comprestion, and is it a good one, lol

[getstars5]

what are you gonna do with the car? go to the store? drag? street race? oval? all of this makes a difference. but your compreSION is somewhere around 12-13:1. thats really high. are you gonna turn it into diesel?

[SkylineUSA]

Originally Posted by getstars5

compreSION is somewhere around 12-13:1. thats really high. are you gonna turn it into diesel?

LOL, funny

[Pimpdady753]

no its going to be a week end car\show car\streat race, not so much streat race tho.

[351wStang]

Shoot for about 11:1 if your going n/a. But you will need to know your compression in order to select a cam.

[Pimpdady753]

ic, when i get the block and the internals bild i will just need to tell them 11:1 compresion, witch cam should i get then with that compresion.

[351wStang]

call cammotion or comp. a cam company would be able to recomend a better cam for you than I could.

EDIT: I wouldnt go much over 11:1 compression. 10.5-11.2:1 with aluminum heads and a good tune is a great pump gas compression ratio.

[getstars5]

Originally Posted by Pimpdady753

ic, when i get the block and the internals bild i will just need to tell them 11:1 compresion, witch cam should i get then with that compresion.

compression is decided by the parts you use to build the engine. you may need to get a shorter rod to lower comp. or a head with more volume.

Comp cams always seems to be the fav cam. Lunnati cams if you got the money. when you call to select a cam, youll need to tell them hp goal, torque goals, usage, desired powerband, desired redline, sometimes even transmission ratio's. most people tend to cam the engine towards the end of a major build.

[SkylineUSA]

Time to learn

http://kb-silvolite.com/calc.php

[Pimpdady753]

should i get a diffent head then, one that is bigger.

[SkylineUSA]

What did you come up with?

[Pimpdady753]

i dont know were to find all the number at like
Gasket Thickness
Piston Head Volume
Deck Clearance (in.)
Note: Neg. nubmer above deck, Pos. number below deck
were do i find these numbers at.

and would i better to go with like afr heads.