Stupid revelation #74392743

[shiroitenshi]

Hmm. apart from the pistons.. I've recently found out that the conrod bearing width is VERY DIFFERENT from the R versions when trying to mate XXX conrod with the R crank... hahaha..

Might seem obvious to you guys using the R... well.. I learn something new everyday.

Damn.. no chance of having of having a crazy hybrid engine. (>.<)

 

[xxxx]

wat brand is ur XXX conrod?

if it's normal stock honda conrods, then it's different.

 

[shiroitenshi]

Eagle B20B rods.. try to mate with R crank only to find out it's too big.. oh well.. use the B20B crank then...

 

[hattech-v]

the conrod got number to match with the crank...
then fr there u will now which bearing to use.
but to match with eagle rods then use eagle crank laa... haha

 

[shiroitenshi]

not the bearing problem lah hattech.. the fact that the conrod bearing width is just too different.. anyway, that's how R cranks are lighter... they have have smaller radius for at the conrod connections than the non-R versions.

 

[hattech-v]

the smaller radius that u mean is crank or what?

 

[xxxx]

shiro,

r u sure it's lighter?

later i check 1st.

 

[hattech-v]

lighter in term of weight or rev?

 

[shiroitenshi]

Lighter in terms of weight... it's due to the size where the conrod is mated together with the crank is smaller, so less weight there.

 

[hattech-v]

i weight the crank edi. n the b18cr is about 16kg.
whats the weight for non r crank?

 

[shiroitenshi]

Dunno.. I don't have a scale over 10kg.. (>.<)

I'll try and get some weights, but not so soon.. these are busy times for me.

Anyway, you should be weighting the B18C non-vtec one for comparion.. that one a closer comparison, as it's stroke is the same, just the bearing journals(<-- finally remembered the term) for the conrod is like the rest of the of the non R B-series.

The B20B has near 2mm longer of material for the extra stroke.. of course it'll be heavier.

That one.. I don't have.

 

[hattech-v]

ok if i got chance will do it.. anyone volunteer to open up the block n pass me the crank? hehe

 

[shiroitenshi]

What's the price of a B18C non R now ah? just curious, because I'm told they're now in the region of 3K or so?

 

[chris2000]

Any B20B rods will not fit any B18C crank whether its GSR or Type R.

B18C GSR (Non Type R) conrod can fit B18C-R crank no problem. Conrod and main bearing also same between all B18C R or no R.

The main bearing of the B18C R or no R is smaller than B20B because Honda designed the B18C to rev safely 8000+rpm. With the smaller width, there is less frictional force exerted on the crank so less power loss and smoother and higher safe rev compared to B20B.

B18C-R crank 87.2mm is actually heavier than B18C GSR crank.

If want to use the B18C 87.2mm crank, you will have to use the B18C conrods. Trade in your Eagle B20B rods for Eagle B18C rods then use 85mm piston and you will end up about 1975cc if i not wrong. Will have higher revs and power peak latter but lower torque compared to the B20B or B18A/B 89mm crank.

I may be wrong, but this is what i found when i fiddling around my B18C.

 

[hattech-v]

b18A/B 89mm crank? or stroke u mean?

 

[shiroitenshi]

Hmm.. so the B18BC GSR crank has the same conrod bearing width as the R?

Interesting....

Never had the opportunity of exploring the B18C GSR...yet.

Anyway.. the original idea was B20 crank.. just 'gatal tangan' a bit.

Hattech.. the crank is the stroke..

A 89mm crank will give 89mm of stroke, and etc. etc.

 

[chris2000]

b18A/B 89mm crank? or stroke u mean?

I meant B18A/B or B20 crankshaft all share the similar 89mm stroke. :confused_smile:

 

[hattech-v]

btw, i wonder whats the exact stroke size for b20b? is it 89? if 89 then the cc is 1972cc. in that case, 2L registration will not give any problem. if its from 1595 -> 1972. coz still not exceed 25% increase of displacement.

 

[shiroitenshi]

yes.. it's not a full two litres.

even the CF4 pistons won't exceed 2 litres, last I calculated. (not sure though)

Only the 86mm gives near 2.1L...

forgot exact numbers sorry.. I did the calculation last at maybe 2-3 months ago.

 

[hattech-v]

86mm x 89mm = 2068cc
86mm x 90mm = 2091cc
84mm x 89mm = 1972cc
84mm x 90mm = 1995cc