Opinions - B18CR Bottom End with Alaniz head

[fatboyz39]

Mostly, yes. Unless you are chasing a smooth idle or building stationary type engines (gensets etc) But you can't race a genset!!!!


You are correct, a high rod stroke ratio does offset some of the problems with flame propogation through the chamber. To be specific. It allows the use of less timing and a later spark initiation because the piston dwells at TDC longer but accellerates away faster.

Thats a little to technical for this site dude All I meant by the B18B comment was CTR pistons with a reshaped combustion chamber it will be interesting to see what this engine does whn its running.

[82911]

All I meant by the B18B comment was CTR pistons with a reshaped combustion chamber it will be interesting to see what this engine does whn its running.

OK, I understand..

But as for being too technical.....
I believe that having good SOLID acurate tech is the only way to refute the internet myths that abound regarding the Honda engines and what does, and does not work.
I appologise if any of it makes your head hurt!!
But ask yourself this.......Don't you want to understand "why it is so" rather than just believe the crap that some other internet "wannabe engine builder" has reguritated from some US based site??? If we challenge the "myths" with solid proven theory then we will find the truth.... That is the advantage that engine builders use over those who run what everone else says works...

does having larger diameter pistons also help flame propagation? or does the long stroke hinder this?

meaning they rely on displacement?

All other things being equal, the larger bore diameter will always make more power.

[ewendc2r]

Thats a little to technical for this site dude All I meant by the B18B comment was CTR pistons with a reshaped combustion chamber it will be interesting to see what this engine does whn its running.

The only way I can see this site ever getting technical is with more posts like this. This is the all motor forum anyhow -- The Tech information is what I love about Honda-tech..

TB -- Even with the clutch on the AC I am assuming there will still be parasitic losses driving the belt etc, maybe I am overestimating them...

........................ Pure curiosity. I've seen stroker 2L kits (bigger stroke) & 2L Bore kits (retainign stock 1.8 stroke). Both achieve same capacity through different ratios, I am assuming that because the bored version squares up the R/S ratio that it is a better option? With the 2L stroke kit, I guess that are then boring and sleeving to get 2.2L ?? (only benefit?)

[tinkerbell]

The only way I can see this site ever getting technical is with more posts like this. This is the all motor forum anyhow -- The Tech information is what I love about Honda-tech..

TB -- Even with the clutch on the AC I am assuming there will still be parasitic losses driving the belt etc, maybe I am overestimating them...

the belt free spins when A/C is off, Honda already got that covered mate!

........................ Pure curiosity. I've seen stroker 2L kits (bigger stroke) & 2L Bore kits (retainign stock 1.8 stroke). Both achieve same capacity through different ratios, I am assuming that because the bored version squares up the R/S ratio that it is a better option? With the 2L stroke kit, I guess that are then boring and sleeving to get 2.2L ?? (only benefit?)

pardon?

[ewendc2r]

Sorry -- I've seen a stroker kit retaining the stock b18 bore. I've also seen 2L retainig stock stroke b18 (approx) but with bore work.

I understand now that the main reason is to create a 2.2L engine race application. Was just thinking how much torque that 2L stroker would deliver (as opposed to stock stroke and over-bore). Apparently it massively increases ring wear due to increased stroke & limits RPM (thus why the CRVTEC combination is favoured, even over the 2.2L, even in some race applications including drag).

I've got the flow chart for the head, I'll upload it tonight. Quoted from Joe Alaniz:

In our dyno testing our Competition Head performed better through the entire RPM range as compared to the Street Master. The Competition Head work has a good "clean up" on the intake side for good port velocity while the exhaust has plenty of work so flow dosnt choke up.

The one thing that did make a big diffrence and a good RPM curve was camshaft selection with good Vtec point.

All B18C N/A road race engines I have built make aobut 217-220HP @8200 rpm's dynojet model 248.

I'm really struggling now which way to go.. The head is great value and hate to see it go to waste however as pointed out I'm just not ready for it (well, considering the gain I'd see in any case). If I don't get this, is anyone else interested in a serious head? Esp. you guys with the B20's already?

Geez --- this whole process is pretty stressful! lol decisions decisions.

[Benson]

Why would you make a 2.0l out of the 1.8l block? Why not just start with a b20 from a CRV. Too many myths with weak sleeves with the CRV blocks, and we have proven the strength with the stock sleeves. It just a shame all these guys who crack there sleeves have BAD TUNERS.

[Chr1s]

To be honest,

You're wasting your time making a B18C a 2.0L. Just use the CRV bottom end.

[tinkerbell]

guys chasing big power from B's are using 92mm and 95mm cranks... with 85+ bores...

but with "tall deck blocks" and long rod combos... so mitigating (somewhat) the extra stress of big stroke cranks...

a 85 x 89 block is pretty good compromise, particulary considering the 'high-revving' B18C7 has a stroke that is only 1.8mm shorter...

i note the B20B has a better "piston to bore" ratio than the B18C engine... whislt the B18C has a marginally better rod/stroke ratio of 1.58 vs 1.54...

the "worst" thing about a B20B is the cylinder insert being one-piece, compared to multi-piece...

IMO - this is not a problem at all, provided you are clever and dont try to detonate the engien by bad tuning...

see here for info about the unique B20B sleeves:

http://dwolsten.tripod.com/articles/jan96a.html

(i use this article to explain to people who ask: "why didnt Honda just make a 84mm bore B-series in the first palce? that would have kicked ass?")

[Chr1s]

I would rather 200cc than a very slight lower R/S.

To me, R/S is a big conception from the V8 stroker days that has carried through to the sport compact era.

[ewendc2r]

Thanks TB -- I'll read into that.

Oh and Chr1s that was just out of curiosity. I think we've covered the fact that I was thinking crazy like haha.

NOW!

ITB's. Now in any other circumstance I wouldn't buy OBX full-stop, too many horror stories about cams breaking, LSD's with play in them etc.. I understand the OBX ITB's to be a basic replica of the Toda / Hayward units albeit rougher casting etc. What are your thoughts? With a bit of TLC (disassemble, loctite, reassemble, sand / polish etc) could these really be OK? I can't find any realworld tests lol, although comments have been made as to the 'copy' nature of design (which is a good thing, because Toda / Hayward work well).

Further -- I wonder if because the design is simlar to the Toda if you could fit the Toda SIK Plenum?

[fatboyz39]

Stick to a single manifold.

[ewendc2r]

Stick to a single manifold.

ROFL -- I can't win. Figured this way I could pick up some more mid-range without cracking the block. Given stock cams run out of puff at about 8200-8400rpm I also thought that the normal restriction from ITB's at top end would be a non-issue?

Well -- At least there is another thread that may help someone else in the future lol.

Appreciate all your inputs --- Very much apprecaited.