B18 Connecting Rod Question CROWER & EAGLE

[adams86lxi]

Ok well im doin alot of research for me and basically for all of us of what might work for piston/rod combo's in are cars. I got enough friends with enough spare parts from different engines to compare alot of them too. Well so i remember seeing somewhere on here that b18a1 rods fit perfect? Is this true? Im not worried about the wrist pins slots being to big or small for are pistons im just talking about they fit on the crank perfect right? What bearings would i use the a20 bearings on the b18 rods or the b18 rod bearings?? Umm if this true about these rods then i think ive made a nice little discovery but i dont wanna say it until im sure this would work lol....

[Legend_master]

Ok well im doin alot of research for me and basically for all of us of what might work for piston/rod combo's in are cars. I got enough friends with enough spare parts from different engines to compare alot of them too. Well so i remember seeing somewhere on here that b18a1 rods fit perfect? Is this true? Im not worried about the wrist pins slots being to big or small for are pistons im just talking about they fit on the crank perfect right? What bearings would i use the a20 bearings on the b18 rods or the b18 rod bearings?? Umm if this true about these rods then i think ive made a nice little discovery but i dont wanna say it until im sure this would work lol....

I don't know anything from experience on this one, but I would assume you use the b18 rod bearing. I also think the b18 rod is longer then the a20 rod, but don't quote me on that one. If this was true I wonder how much and if this could be used to make higher compression or some form of a stroker kit. I also looked into other motors with 3 valves per cylinder so we could use the pistons to lower or raise the compression, had no luck on that one.

[bobafett]

LS rods will work PERFECTLY, but you need to be using a 21mm wrist pin, as opposed to 19mm or 20mm, or whatever the stock A20 uses. there 'may' be a way to modify the stock pistons to use 21mm pins, but honestly if ur bothering to get rods, ur probably also bothering to get pistons, and anyone who builds pistons for u can set you up with 21mm wrist pins and then your all set.

this works with stock a20 bearings AFAIK.

i have been using Eagle H-Beam LS rods in my motor with no problems at all.

[Legend_master]

LS rods will work PERFECTLY, but you need to be using a 21mm wrist pin, as opposed to 19mm or 20mm, or whatever the stock A20 uses. there 'may' be a way to modify the stock pistons to use 21mm pins, but honestly if ur bothering to get rods, ur probably also bothering to get pistons, and anyone who builds pistons for u can set you up with 21mm wrist pins and then your all set.

this works with stock a20 bearings AFAIK.

i have been using Eagle H-Beam LS rods in my motor with no problems at all.

Guess I was wrong on all my points. So has anybody compared the b18 crank to the a20 crank. I wonder if they are similar

[bobafett]

different strokes, but i am not sure about diameters.

we have 91mm stroke vs their 87mm stroke i believe.

[bobafett]

http://www.horsepowerfreaks.com/pric...Chromoly_Steel
we want the non-vtec rods. thats exactly what i am useing. i know they work just fine

[Legend_master]

http://www.horsepowerfreaks.com/pric...Chromoly_Steel
we want the non-vtec rods. thats exactly what i am useing. i know they work just fine

just to let you know the only difference between the vtec and non vtec is the area where the wrist pins go.

[bobafett]

cool. i didn't know that.

do you know specifically what the differences are?

[adams86lxi]

LS rods will work PERFECTLY, but you need to be using a 21mm wrist pin, as opposed to 19mm or 20mm, or whatever the stock A20 uses. there 'may' be a way to modify the stock pistons to use 21mm pins, but honestly if ur bothering to get rods, ur probably also bothering to get pistons, and anyone who builds pistons for u can set you up with 21mm wrist pins and then your all set.

this works with stock a20 bearings AFAIK.

i have been using Eagle H-Beam LS rods in my motor with no problems at all.

thanks for your help guys!!! This is awesome news!! Sooo has anyone ever tried to use the b18 pistons with the b18 rods?

[bobafett]

they are way too small if i recall.

http://www.superhonda.com/forum/arch.../t-125367.html

but according to that page, b20 pistons are 84mm, which is .050 overbore, which is what I am running. not know why the pistons wouldnt work if we are using the b series rod too. something to think about i suppose!

[adams86lxi]

they sell b18c1 pistons in a 83mm?? Will those work with b18a rods?? My current pistons are 83mm so this would be awesome..


http://cgi.ebay.com/ebaymotors/CP-Pi...spagenameZWD1V

[bobafett]

dunno what the compression would look like on a20, or if the pin location on those pistons is in a compatible location (ie would pistons go too far up, not far enough?)

[Legend_master]

you can get b18 pistons in any bore you want Check here, but I don't think think the 4 valve per cylinder designed piston will work with a 3 valve head unless you go low compression. As for the 18a/b and b18c rod difference all I can tell you is that you have to have the rod shaved out to put a vtec piston on a non vtec rod (I am only speaking of LS integra rods and GSR pistons).


P.S. the LS rods are a little longer then the gsr rods

[AccordEpicenter]

the pin height is much different or so im told, im gonna borrow an ls piston/rod combo and see how it sits

[adams86lxi]

alright well the reason i brought this whole thing up is i had a set of my friends old b18 rods and pistons sitting around and decided to see how they sit in are blocks and they look like they would fit PERFECTLY!!! And im serious... b18a/b pistons and rods seem to be the perfect height with are block/crank....

on the left is the b18 piston/rod and on the right is the stock a20 piston/rod. The engine is at tdc...

Remember these pistons are way too small for my bore so dont mind the big gap between the cyl walls and pistons but other then that they seem to be the perfect height!!

Check it out!!!

[gfrg88]

THANK YOU ADAM!!!!!! ive been trying to see why that wouldnt work!!!! i always wanted to try that out but i didnt have any b18 parts to work with, but you just found out some great things for us!!!!!! looks like its time for me to start building an engine

[adams86lxi]

THANK YOU ADAM!!!!!! ive been trying to see why that wouldnt work!!!! i always wanted to try that out but i didnt have any b18 parts to work with, but you just found out some great things for us!!!!!! looks like its time for me to start building an engine

lol no problem man!!! I couldnt belive it once i saw that they were perfect fit for us!! I dont understand how no one hadn't relized this before lol....

[rjudgey]

The only problem i can see is that the inlet valve relief pockets aren't quite in the right place, and also there is a deeper dish to the B18 piston so CR ratio will be lower especailly as the vlave relief pockets are really big too. I would order up a set without the valve relief pockets in just plain flat top and have just a 3 valve relief pockets machined into the right place to suit our heads, and obviously a 82.7 or 83mm size piston to fit our blocks and that would be perfect best CR for NA guys or if you are running turbo then have a Deep dish machined into the top to drop the CR ratio and have the valve relief pockets machined so they fit with the valves although with Turbo guy's running less duration and lift shouldn't be too much of a problem with vlaves hitting pistons anyway.

[bobafett]

the stock pistons have 4 valve reliefs, not sure if they are in the exact same spot as the b-series pistons or not, but it would be easy enough to check visually.

since you can order b-series pistons in particular sizes, like 83mm, this does open up a lot of options, but we have to keep in mind we don't know what the real CR would be. maybe a quick call to diamond would help figure this out. if they ended up making us custom 'b-series' pistons it would probably be cheaper anyway.

this is cool news though.

[adams86lxi]

yea im pretty sure the valve reliefs wont be too much of a problem though, in my case atleast... I would be using mostlikely low compression dished ones so there will be even more room for the valves... But im pretty sure even with comparing the 2 pistons the way they are in the block the valves wouldnt hit... I have put pistons in my old b20 where the valve reliefs were WAY different and it didnt give me a problem at all! I cant be positive though but i dont see it affecting us unless we get high compression ones where it has a domed shaped to it.

[AccordEpicenter]

id bust out a micrometer and see how much the difference really is in the pin height from the top face of the piston, it looks slightly different to me but maybe its just the pic/angle or the fact that its not the right bore lol. Can you measure them and post a pic side by side comparing the pin heights in the pistons adam? And yea, to make this even semi viable somebody needs to sit down and play doh the piston and see where the valves are gonna end up and if they are gonna hit, since the reliefs are much different.

[Legend_master]

Alright we can use this compression calculator, but we have to fill in all the Info manually. I know the bore and stroke, but I am not sure abour the Combustion Chamber Volume or the Piston-to-Deck Height.

[carotman]

Nice stuff!!

[adams86lxi]

alright guys im still having trouble finding b18a/b pistons in 83mm... anyone want to point me the right way?? I can find them for the b18c but not for the a/b!!

[gfrg88]

alright guys im still having trouble finding b18a/b pistons in 83mm... anyone want to point me the right way?? I can find them for the b18c but not for the a/b!!

guess youre going to have to get some new pistons and rods then, that just means more boost for you