F20a block + F22B head = 9.9:1 CR
Would this be safe for an 8psi boosted daily driver?
Would this be safe for an 8psi boosted daily driver?
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considering s2k's boost the stock blocks and have 11:1 compression no its not too high but you'll need some decent tuning to make it last. You won't even be close to exceeding the 93 octane's potentialKnowledge is power...in EVERY sense of the word
FSAE (F Series Accord Enthusiasts) ..."A dying breed thats taking it to the next level" #12 -
The CB7 and the S2000 share the same block?
How about boostsed ITR? They also have a high compression motor.
Why must these questions be ask about can my motor hand xx psi and how much power can I make running xx pis without listing any parts? I just don't get it. Its like bench racing, who knows what the results would be.Comment
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Im taking it its the sohc block. what is the stock compression on it and whats the head cc?
i know the dohc is 9.5:1. it has 85x88. i doubt it will be anything higher than 9.5 with stock pistons.
until we know those numbers, we cant tell you the the exact compression.
either way, its only high if you dont know what you're doing and dont know how to tune.
I plan to go somewhere between 10-10.5:1 when i go turbo.
CrzyTuning now offering port servicesComment
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Its an F20a4 (85x88) sohc engine with a stock compression ratio of 9:1, the head (F22B) has a 47.2cc volume.Originally posted by d112crzy
I thought it would give me a 9.9:1 CR but please prove me wrong
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no it doesnt. the f22b head is 50.5. the bump in compression from the f22b dohc comes from the pistons.
I need to know the stock head's cc so i can figure out the piston cc(f20a).
CrzyTuning now offering port servicesComment
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lol thats what I though also and was wondering why the S2000 motor came into being compared. Even if it is a high compression motor the architech of the motor is different.Originally posted by Accord R33Comment
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the higher comp the less boost u will need to make power and the less comp the more boost u will need to make power its all up to u but i will always sayOriginally posted by s0hc
its all in the tune !
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Ah, well I got the f22b head volume from the FAQ on here:..http://www.cb7tuner.com/vbb/showthread.php?t=41915Originally posted by d112crzy
It may or may not give you the correct info on the pistons?Comment
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the "architect" of almost every motor is different in one subtle way or another. GSR's have over 10:1 compression along with b16's, so do the h22's. I could have picked any one of those motors and used them as comparison but i went with one of the highest stock compression motors. Its all in the tuning when said and done.Originally posted by HondaB18Knowledge is power...in EVERY sense of the word
FSAE (F Series Accord Enthusiasts) ..."A dying breed thats taking it to the next level" #12Comment
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yea, if some mod could please edit that page. change the F22b DOHC specs to the head cc being 50.5
Cylinder Heads
HEAD VOLUME
H22A = 53.8cc
H22A1 = 53.8cc
H22A4 = 53.8cc
H23A = 53.8cc
H23A1 = 50.0cc
F20A = 50cc
F20B = ???
F22A = 50.5cc
F22B = 47.2cc<<<50.5cc is correct.
F22B1 = 50.6cc
F22B2 = 50.6cc
F23A = ???
CrzyTuning now offering port servicesComment
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going by the FAQ my stock f20a4 sohc head has a volume of 50cc..
When I calculated the compression ratio as 9.9:1 I gave a compression height of 31mm as theres no answer to the F20A comp height on the FAQ list.
If I were to use a compression height of 30.5mm it would give a compression ratio of 9.54:1
pls can someone advise on the compression height of the F20a and / or the compression ratio of the F20A sohc block and the JDM DOHC F22B head.Comment
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there are other factors with compression too...the difference in 9.5:1 and 10:1 aren't worth mentioning in this case to be honest......
but NO, it's not too high, although i personally think 9-9.5:1 is perfect when doing a real, I-4 turbo motor buildup......
that comment about compression being a substitute for boost is fucking stupid too, by the way......think of it this way
if you want impressive power from your torqueless inline 4, then boost is a great thing.....if the compression is too low, then your boost will feel like it's coming on late......if it's too high, those pistons shooting through the hood are unnerving
it all comes down to tuning though.....if you could safely run 15:1 compression with 30psi, then that would be better than 9:1 and 10psi......
put it like this.....if you could climb down a ladder from 10,000ft in the air, would it be as fast as just jumping off? hell no, but without a parachute, it's gonna be a rough ending
your tuning is your parachute....if it's perfect, then yay.......if it's too rich and conservative, then you may simply float on the chute all the way down and not really do much better than the goob on the ladder......open it too late and it's really worth nothing......
your setup will be fine and should run well with that CR.....with 10psi or 30psi.....the higher the boost, the less room for error in tuning....at 10psi, you may hear detonation and it not do much but let you know something needs adjusting.....at 30psi, it means your engine is milleseconds from being fucked
in my merkur, they really come with a CR that is too low at 8:1.......feels sluggish with a larger turbo like a t4.......some simply increased the stall on the torque converter to compensate but that ruined transmissions.....i upped mine to 9:1 and lowered my boost to around 20psi, and boom, ran MUCH better off the line and improved power all around......maybe near redline i made less power, but the engine wasn't as stressed and it ran faster in the 1/4....and on the 7th day, deevergote rested and called his mom.Comment
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