here is a thread on that point.

https://honda-tech.com/zerothread?id=285461

i did not re-size my rod ends...

t..

 

I don't see the point of revving a b20 to 8000, let alone 9000. That would just be utterly pointless since you're not going to be making any power. But I believe it's a little different for b20vtec. There is a power possibility at 8000rpm using vtec head and cams. Also about R/S ratio, it seems like b20vtec has the most potential as N/A monster even though the R/S ratio isn't perfect like GSRs or B16s. Yet owners of CRVtec take it up to those and higher rpms no problem. So I think this is a case where practice weighs more than theory.

Jay Kim

 

Thanks for the link..., some say you have to and others say you don't.

So I guess its better if you do.?

 

no!!! this is where the advantages of a larger bore come into play!!!!

ever heard of Bore/Stroke ratio?

look into it...

B20 guys will be pleasantly surprised

t..

 

BS ratio? jk

I've never heard anyone talking about significance of B/S ratio. Would you care to explain?

Jay Kim

 

http://www.bhrmotorsports.com/EngineRelated.htm

 

ok, this simple stuff.

the BS ratio determins revability too.

the higher BS is above 1, the better it will rev (in theory)...

eg F1 cars have massive bores and little strokes and are like 1.5 BS ratios and rev to 15'000rpm.

the B16A is 1.052 and is a great rever.

all ratios of over 1 are called "over square"

a ratio of 1 is called "square"

a ratio of under 1 is "under square" (duh!)

anyways,

here are the numbers:

B16A = 1.05
B20B = 0.94
B18C = 0.92
B18B = 0.91

dunno the B17 off top of head, but im sure it is just below 1.00

so there you have it.

take from it what you will. i am no expert, but B/S ratio can't BS...

i hope soemone else can expain BS ratios and the affect on power/torque in detail, cause i am just about to dissapear for the weekend...

t..

 

Gotta chime in... haven't been on the board in a LONG time.

B17A stroke = 81.4mm, bore = 81mm... so B17A B/S ratio = 0.995

My B20/VTEC is pretty much all OEM except for Eagle rods, Wiseco pistons, and ARP bolts/studs holding it all together. I've got 41k miles on it already after just a year, and everything's held up just fine revving to 8000, sometimes 8500 rpm. The engine sees 8000 pretty much every single day. My leakdown test still shows up good and the power output is the same as the day I first tuned it.

Good parts and good engine build is key.

 

i don't even thnk the sleeves would handle that

 

COOL!!! THIS MEANS I CAN REV TO 9.4K WHEN I GET EVERYTHING READY!!!


[Modified by 10K2HVN, 11:23 PM 11/22/2002]

 

I had a H23 VTEC Hybrid That revved to 8000k and I just snapped the forged crank!

R/S = 1.49
B/S = 0.92

I had a few things working against me haha. Now with F20B crank and rods I will have:

R/S = 1.65
B/S = 0.99

What do you think I can rev to? I have stage 3 cams...power will be made up there....

 

if thats what you interpret those numbers to mean, for sure, but there are so many other factors when determining revability.

like the materials used to make the reciprocating assembly, the harmonics of the assembly, the amount of load placed on it,

so yeah, if you used some super strong alloys, in a perfectly balanced assembly to move a 400kg cart, sure 10'000rpm for sure.

one factor alone will never give you a correct answer.

the Bore/Stroke ratio was mentioned just to show that you cannot DIRECTLY compare the Rod/Stroke ratio of engines with DIFFERENT bores.

sure compare teh R/S of the B16 to the B18C, that is fine.

but it's much harder to compare the R/S ratio of a B20 and a B18 and still be talking apples with apples...

t..

 

Dont argue this tinker, let them figure it out...you and I have.

 

whos argueing? and im not really gonna rev past 9.1 after i get everthing set anyways... im probably gonna lose power after 8...

 

well, yeah, thats right - it does come down to your camshaft design and timing doesnt it.

anyways, if you wanna rev high, maybe a B18C would have been a better choice of blocks?

i needed a nice smooth powerband from 2k upwards, not a peaky high revver...

t..

 

Ok, well if it helps matters, mine pulls all the way to 9600 with a 100 shot.

 

does anyone in here have direct experience with b20 vtec's or is all of this information coming from internet message forums.

i have not heard one person mention resleeving a b20 and i know of 5 in this area that have cracked cylinder walls between #2 and #3 pistons. its just a matter of time before this happens which means at any time your whole bottom end could be fucked.

a friend of mine has spent around 10k on his b20/vtec and according to several high profile engine builders in the miami area resleeving is the only way to go when making significant power for long periods of time...ie reliability.

so everyone building crvtec's can go the easy route and not resleeve your block, but its only a matter of time before something happens to the block, especially if you're revving over 8k on a consistent basis.

 

I'm only planning to rev up to 8k i.e. b16, b17 redline. AND I do plan to resleeve my block before getting serious with my mods, probably Golden Eagle.

So I'm gathering that it's safe to rev UP TO 8k. thanks guys. For such a extensive answer to my simple question. I love Honda-Tech....

Jay Kim

 

i reckon you are full of it chet boy!!!

if you knew ANYTHING about Honda, you would KNOW if you gonna resleeve a block, you would do a B18 block.

they are cheaper and can be sleeved EXACTLY the same as a B20 would be.

same stroke/crank etc!! ask your Miami builders about that?!?!

sit down and listen.

when you learn something...

then you may comment.

t..

PS i have a B20VTEC, Jeff does and a few of the posters in this thread do.

i hope we are helping Jay out here.

that is what Honda-tech is for.

PPS the sleeves on a B20 will crack under EXTREME pressure, eg 16 lbs boost, or under NOS detonation etc.

it is tuning man, not resleeving that is the only way to go when making significant power for long periods of time...ie reliability.

PPPS please dont swear on this board!

 

well good luck. i'd like to see how long your crv block lasts without being resleeved.

and this is what i've seen working with cory thompson, who put an all motor ls/vtec in the 11's and is building a crvtec that should have around 300whp. he knows what he's doing and to make real power over an extended period of time you need to resleeve the block.

as a matter of fact, we just put a crvtec in a 92 integra last night, unsleeved, with eagle rods and forged je pistons with 11.5:1 compression. this motor has 3200 miles on it so this one remains to be seen...but of the crvtec's that have come into his shop, they have all had cracked sleeves.

all i can say is i woulnd't rev it that high, and i wouldn't drive any long distances...

honda designed the crv block for 150hp with relatively low compression. once you start putting down 60-70more hp with increased compression you run into problems.

 

11.5 CR..?? Were those custom made?? Cause i want 11:1 but $700 is a lot of money for customs so i think ill go 10.5...
..or did you mean 12.5..? how much did he pay for them...?

 

neither cory or i built the motor. he's at the point where he won't build build a crvtec unless the block is sleeved. basically, several kids have come in with the same problem in the same part of the block...and it sucks when motors have to be pulled continously.

honestly, its hard to say how long this motor will last, i know the kid who built it and he hasn't put many together, nor did i see the parts he used so for all i know the compression could be 10:1. hopefully the car runs well...but again that remains to be seen.

as far as building a motor, go with a gsr block, much more reliable and designed by honda to withstand higher rpm's. unless you plan on spending a lot of money, then go with a crv bottom end.

 

Did you not read my sig?!?!?!?
Do you have any information/details on these setups?
LOL!!! Good one t..
I bought my JE's for $575 and they are made to order so for that price I could have gotten any c/r I wanted. Email Ben at and talk to him.
Me too.

 

i dont think you are able to make any valid points not already made chet boy,

so unless you have new info or some actual information (not hearsay) on these blocks with cracked sleeves,

please stop trolling.

t..

 

i don't know what else i have to tell you, from the b20 blocks that have come into my friends shop, they have all had cracked sleeves in the same general area. and i know of other people who have had similar problems.

are you in australia? i wonder what the import scene is like down there, and i'd like to compare the number of motors and swaps being done in this area vs where you're at.

since you seem to be an experience member on the board, email kenji and ask him what he thinks about unsleeved crv blocks. he is a local guy here and we have autox-d together.

and what kind of numbers are you putting down, and what kind of times are you running...