I would like to know if I should dump my turbo on it or leave it n/a.
I am using six different engines in one:
93 del sol head
92 gs-r exhaust cam
97 gs-r intake cam
98 itr crank
? jdm itr pistons and rods
94 ls block
Head is milled 4 thousandths
Block is decked 3 thousandths
I have some equations but none of them include using a different block from block internals. How do I equate this?
Any ideas?
http://www.zealautowerks.com/ all you had to do was type “compression calculator” in google to find this
Outcome…
Sorry, CTR pistons and rods, and oem head gasket.
Static Comp Ratio
39.02: 1
Effective Comp Ratio
39.02: 1
Does this mean, I should divide this by 4? 9.755:1?
I change the connecting rod and the numbers are normal.
B18a/b 12.47
B16A 9.23
B17A 7.92
B18C 13.99
B16B 39.02
WTF?
[QUOTE=mellowgorilla;1876923]Sorry, CTR pistons and rods, and oem head gasket.
Static Comp Ratio
39.02: 1
Effective Comp Ratio
39.02: 1
Does this mean, I should divide this by 4? 9.755:1?
I change the connecting rod and the numbers are normal.
B18a/b 12.47
B16A 9.23
B17A 7.92
B18C 13.99
B16B 39.02
WTF?[/QUOTE]
with pct’s ur above 13.0/1, and with a miled head and deck, ur in trouble man. to make it worse ur using stock cams which won’t bleed of a dust particle worth of compression. good luck, don’t drive it untuned without race fuel and get a pair of cams with big primaries. lastly, ctr rods will only work if u use a ctr crank. itr crank= itr rods, ls crank= ls rods, b16b crank= b16b rods…get it?
wik.com compression ratio waste of time
((PI/4)BoreSquaredStroke+Compression Chamber Volume)/Compression Chamber Volume
((PI/4)8181*87.20)+42.70)/42.7
(449113.57+42.70)/42.7
449156.27/42.7
10,518.882
Whatever that means
I have done a compression test of cylinders
the highest was 240psi and the lowest was 220psi
from http://www.geocities.com/dsmgrrrl/FAQs/compression.htm says:
Compression ratio 9.8:1
Standard compression 220 psi
Service limit 159 psi
From http://www.locashracing.com/instructions/Locash%20Racing%20Tuning%20Checklist.doc says:
8:1~8.5:1 compression: 150-170 psi per cylinder
8.5:1~9.5:1 compression: 170-210 psi per cylinder
9.5:1~11:1 compression: 210-275 psi per cylinder
is it far to say that for every 10 psi of your compression would give you .3 on your compression ratio?
9.8:1 = 220 PSI
10.4:1 = 240 PSI
so I have somewhere between 9.8 and 10.4:1?
If it means anything, I need 93 octane or it will ping…
CTR pistons in an LS block, doesn’t leave much room for error in tuning with FI. Even with 8 psi, you’d better be careful. If you were planning on putting a turbo on it, it sounds like you didn’t plan it too well. Building a turbo engine, and high compression engine take very different routes. My previous DSM 4G63T turbo engine had 7.8:1 CR with 12 lbs. of boost. The later LSvtec engine I had was 11.5:1 CR with 275 psi compression test values. Two very different engines. IMO, figure out what you want the engine to do, and plan accordingly.
I wasn’t sure what I had, just trying to get a close figure on it to see which way I should go… Probably better off staying NA
honestly, even with pct’s in a non f.i. state , its very difficult to tune or get any real use out of the motor. at such a high level of c.r., the motor will wear fast. besides the fact that a bad tank of gas will blow it apart. high comp is good in an all out, full race situation, where race fuels are used and longevity is not a concern. but, too much is a hinderance. alot of power is extracted thru the timing maps when tuning. people sitting at over above the 13.0/1 area can barley run any timing in the maps to avoid detonation. point being, too high c.r. eventually turns into more of a detrement than anything
oops
Yeah, I don’t know how long this engine will last, I have only used the block setup with an LS head for 2 years for 20k miles and 1 year for 12k on the block with the B16 head.
I do agree, I need some cams, but didn’t want to bend valves and haven’t thought too much about fuel management.
how can I measure?
Is there a way that I can measure the total distance between my valves and pistons without dropping the valve keeper or taking off the head?
Where can I locate piston rod descriptions? I have a b18c5 crank and my rods are attached. So, do I have b18c… rods?
Clay your motor to find the distance.