pump gas compression question
#1
Registered Member
Thread Starter
Join Date: Jun 2007
Location: Norfolk,VA
Posts: 3,168
Likes: 0
Received 0 Likes
on
0 Posts
pump gas compression question
I am planning on building this gsr i got and i want to do an all motor setup. I don't care about putting down astronomical numbers i just want it to be a quick daily driver. i was thinking about about doing like 11:1 or something like that but i am curious on what is a safe compression ratio on 93 octane for a daily with some kick to it. i would also like to see what machine/race shop in the 757 does the best work at a fair price. i heard abacus did good work but i have never had a motor built so i would just like some info from those of you who have
#2
Registered Member
Thread Starter
Join Date: Jun 2007
Location: Norfolk,VA
Posts: 3,168
Likes: 0
Received 0 Likes
on
0 Posts
Re: pump gas compression question
19 views and nobody can at least point in the right direction or let me know who is the man to talk to about this
#3
Re: pump gas compression question
I was trying to figure out the same thing a while ago, i read somewhere that 12:1 was the line for pump gas or race gas. Dont hold me to it but it was in a write up on building frankenstein b series motors
#4
Registered Member
Thread Starter
Join Date: Jun 2007
Location: Norfolk,VA
Posts: 3,168
Likes: 0
Received 0 Likes
on
0 Posts
Re: pump gas compression question
well i wasn't looking for 12:1 cuz i kinda would like my motor to last a little while but i was debating on 9:1, 10:1, or 11.5:1 and the way its looking its gunna be 10:1 but seeing as i have never fully built a motor i would like some input on what all i should do to help with horsepower and longevity of my motor.... i was thinking JE 10:1 pistons, crower rods, ACL race bearings and thrust washers but i'm still not sure of my top end... would aftermarket springs, retainers, etc.. (skunk2) or type r internals be better and its either gunna be crower cams or skunk2 cams i'm not set on anything right now but if somebody could tell me what would work and wouldn't be a good idea... or if anybody on here works at a machine shop and builds motors could point be in the right direction because i am planning on building this within the next month or so
#5
Racetracks
Join Date: Nov 2002
Location: How long is a piece of string?
Posts: 15,668
Likes: 0
Received 0 Likes
on
0 Posts
Re: pump gas compression question
Your stock GSR engine should be 10:1 already. You can go 11:1 or high 10.x:1 without any problems using a fairly conservative tune. You could go all the way to 11'5:1 if you really wanted, but you're really walking the fence for tuning safety, gas quality, and ambient air temp. There are too many variables for a daily driver to make me feel safe about that in all seasons and all conditions. People do compression ratios like that all the time on the street, but I think the safety margin is just too small on pump gas.
#6
BAMBOOZELED!!!
Join Date: Oct 2007
Location: virginia
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Re: pump gas compression question
I had a gsr motor with a block guard running 11.5:1 cr on 93 octane tuned on s100 with no problem. It was daily driven to and from work and trips to syracuse every 5 months. i would say with a block guard and the right blue print and cam grind you might be able to push 11.7 or 11.8 on 93 octane.
#7
Registered Member
Thread Starter
Join Date: Jun 2007
Location: Norfolk,VA
Posts: 3,168
Likes: 0
Received 0 Likes
on
0 Posts
Re: pump gas compression question
i thought a gsr was 9:1... and i really don't wanna go to high because i am not trying to have to keep rebuilding this motor...
Thread
Thread Starter
Forum
Replies
Last Post