I was thinking about saving for a few months and resleeving my b18c1 block. What size sleeves do you guys recommend. I have a gsr head right now with a 5 angle valve job, stock bore, and jun3s. I was thinking about opening the head up to 85mm and going with an 85mm bore with JE pistons. I've heard JE's give more clearance than other pistons. ANyone have any other suggestions? Should i keep the stock rod/stroke ratio? Maybe go with some longer rods and get the rod/stroke to like 1.6+ and lose some displacement?

thanks

sam

 

Sleeves come in one size. Its how far you bore it out that makes the difference.

You put too much stock in rod:stroke ratio. NA needs displacement.
If you are going to bore and then destroke, then dont bother wasting your
money in the first place.

 

well if you you have a stock GSR block than you already have almost a 1.6 rod ratio. and i disagree. rod ratios are very important and displacement is not the only thing NA engines need. its a choice. get the extra CCs or higher rev.
examples;
Lnatural 2.6 revs to 8800rpm
toda crx 1.8L b16a no vtec but spins to over 10,000
but yet Spoon and F1 over 12,000 mind blowing RPMs
look at all the NA drag cars and compare the CCs to the redline. thats the difference.
two things to keep in mind
1 adding displacement sacrifices reliablity and top end power in most cases.
2 RPM= Ruins Peoples Motors

 

adding displacement decreases reliability - why? I dont agree with that statement, its far too broad a statement and generally incorrect if built properly.

 

How do the spoon cars rev up the 12,000 rpm? I saw that in GT3 but didn't think it was real.

 

Rod ratio isnt as important as you want to make it seem.
Sure there are limits, Im not going to try to get a million miles out of a motor
with a 1.4 ratio, but 1.5 and above are fine.

Also, increasing displacement by increasing bore is fine, increasing by stroke has
its limits. Yes, the function of displacement dictates that the torque will be MORE
but will also peak earlier and drop off faster making the high rpm gain less but
the overall gain is more.

As far as your RPM comment, believe it if you want, but you will always come in
second with that mentality. My motors have no trouble with high rpm and longevity
and they have been going for quite some time now.

 

yeah what he said

 

I'm thinking about the same thing for my future project. I've heard 84.5mm bore a lot, but is that what's recommended most? Is there a more ideal bore? Is there a max? What's recommended? Thanks.

 

i guess im arguing the wrong piont. What im trying to say is becareful how you add displacement. Ive seen several B20s spin to 9000 daily. Look at what R&D has done. what they wont tell you is that the bore on the B series is close to 86mm. and look at how high they can spin. On the subject of rod ratios the Lnatural crx has a high 1.3. and again spins to 8800.
As for the spoon engines spinning to 12000. i dont see the point. look at the biggest baddest cams. most wont make power over 9000.
But keep in mind that these are not reliable engines. And if your going to open the bore remember with this comes added weight. which will slow the revs. and add stress to the engine. Like i said just be careful how you addd displacement. and yes John if you built it right it is very reliable.
As for the rod ratios. im not going to comment on that one again. The long rod Vs short rod has be argued to death.

BTW John i wish you best of luck and hope your almost finished. i look forward to hearing about you getting kicked off the strip for not having a cage. I love the coupe.

 

To tell the truth, I am a firm believe in displacement as well.

Reason I tried the 1.7 crank in my B20 was for three reasons...
1- I had the crank already. I got it dirt cheap.
2- I was willing to get the custom rods, and wait for them.
3- I've already done B18's and B20's before, and I was curious about this combo.

The torque IS more than your typical 1.8.. but then again, my displacement is 1847cc(50cc more than stock GSR/ITR). I rev this motor to 9100 on a daily basis, and the top end torque is unreal. It doesn't drop at high rpm like a motor w/ 89mm stroke does.

It's not for everyone.. but at least I can say I have tried it.

When this motor takes a sh*t, the 89mm crank is going back in and I'm shooting for 160+ torque.

 

well you are comparing drag engines to streetable engines. I think I've found it costs just the same no matter which way you do it.

I just got my head back from portflow, man is it pretty!

Pictures are here https://honda-tech.com/zerothread?id=135909

Now if only I had the time to finish it

 

hmm.. insightful responses. I was more interested in what bore you thought i should end up with than rod/stroke discussion, but interesting reading none the less. Does anyone have any bore suggestions? I think I will keep the stock rod/stroke ratio.

 

ttt

 

my suggestion would be 84/84.5mm. You can go up to 86mm when you sleeve, but I dont like leaving myself without any options should something happen and I have to overbore. I would also recommend a http://www.cometic.com headgasket, and having your combustion chambers reworked to accomodate the larger bore. I would absolutely balance the crank, and use upgraded rods. That should get ya rolling. BTW, B20's love fuel and cams, so think about that.

 

Im looking into fuel upgrades as I type. Thinking about a better fuel pump and injectors. Need about 2 or 3 months of good saving to go this next step. Has anyone actually dyoned before/after combustion chamber opening?

 

you likely won't need a pump, but a set of 310cc injectors minimum. You could also go Hondata, but I've seen it work nearly as well without. You probably won't see a before and after dyno, at least anytime soon, seems as though most people either do it, or don't do it, all together.