good compression ratio??
11-05-2003, 12:34 PM
#1
Banned
Thread Starter
Join Date: Sep 2003
Posts: 342
Likes: 0
Received 0 Likes
on
0 Posts
good compression ratio??
whats a good compression ratio that the stock bottom end of a 305 will hold? 10:1? i know that isnt the stock ratio, im waiting to shave my heads a lil and was wondering what gains id see, how much compression should i run...what gains would i see out of what compression ratio....i know its hard to tell....so lets guesstimate ... i have 416 castings ported and polished....
11-05-2003, 12:43 PM
#2
Supreme Member
Re: good compression ratio??
Originally posted by SeanTimothy
whats a good compression ratio that the stock bottom end of a 305 will hold? 10:1? i know that isnt the stock ratio, im waiting to shave my heads a lil and was wondering what gains id see, how much compression should i run...what gains would i see out of what compression ratio....i know its hard to tell....so lets guesstimate ... i have 416 castings ported and polished....
whats a good compression ratio that the stock bottom end of a 305 will hold? 10:1? i know that isnt the stock ratio, im waiting to shave my heads a lil and was wondering what gains id see, how much compression should i run...what gains would i see out of what compression ratio....i know its hard to tell....so lets guesstimate ... i have 416 castings ported and polished....
The compression limit will depend on the octane of the fuel you are using.
10:1 is about the practical limit for street gas. (92-94 octane)
What fuel are you going to use?
11-05-2003, 01:31 PM
#4
Member
Join Date: Aug 2002
Location: Canada
Posts: 223
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Firebird
Engine: 350, 416's, 230/230 cam, torkerII, q-jet
Transmission: T5
Did you use a sheet of 1/2" plywoood for a head gasket?
That would be around 4-5:1 compession ratio?
93 octance since i bought the car....my compression now just plat out sucks because my head gaskets are .450 heh
11-05-2003, 02:40 PM
#5
Supreme Member
iTrader: (35)
Join Date: Feb 2003
Location: Albuquerque, NM
Posts: 1,229
Likes: 0
Received 3 Likes
on
2 Posts
Car: 1966 El Camino Custom
Engine: 350
Transmission: 200R4
Axle/Gears: 3:73 12 bolt with Brute Strength
Re: good compression ratio??
Originally posted by SeanTimothy
whats a good compression ratio that the stock bottom end of a 305 will hold? 10:1? i know that isnt the stock ratio, im waiting to shave my heads a lil and was wondering what gains id see, how much compression should i run...what gains would i see out of what compression ratio....i know its hard to tell....so lets guesstimate ... i have 416 castings ported and polished....
whats a good compression ratio that the stock bottom end of a 305 will hold? 10:1? i know that isnt the stock ratio, im waiting to shave my heads a lil and was wondering what gains id see, how much compression should i run...what gains would i see out of what compression ratio....i know its hard to tell....so lets guesstimate ... i have 416 castings ported and polished....
11-05-2003, 05:07 PM
#6
Banned
Thread Starter
Join Date: Sep 2003
Posts: 342
Likes: 0
Received 0 Likes
on
0 Posts
haha i ment .045 but yeah i have idle to 1500 rpm issues meaning i have like no power til i get up to 1500 then it throws you into the back of the seat....that prolly due to the porting and polishing i did...that and the 2500 stall...and its carbed.....and the 2.73s......
11-05-2003, 09:58 PM
#7
Senior Member
Join Date: Oct 2002
Location: Ohio
Posts: 603
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1985 Iroc-z
Engine: 355 sbc
Transmission: 700r4
sounds like you got too big of a cam in it.. smaller cam the lesser the rpm range is for making power, but you max out quicker.. people with big cams can have such when they have a tranny built or a nice manual to keep the rpm high and make that cam come to life, for us poor poppers who can't afford a 3.73 posi rear, 700r4 rebuild with a stall, we must make power the only way we can when it comes to the cam.
2500 stall, that rear end with a auto tranny, your best bet for performance would be to get a cam closer to stock specs (if u have one already?)..
2500 stall, that rear end with a auto tranny, your best bet for performance would be to get a cam closer to stock specs (if u have one already?)..
Trending Topics
Thread
Thread Starter
Forum
Replies
Last Post
