i searched but couldnt find the exact info i was lookin for...

i know a few of you have b20V with GSR crank and rods...how much will this lower my compression if i have 11.5 pistons for a b20 with a b18c head. I wouldnt mind lowering my rod/stroke ratio, thats why i ask.... Should i even bother or just run b20 crank and rod? thanks for the info or links ....

 

im also looking into doing this and at first i also thought the compression would drop but the b20 and all b18c blocks have the same deck height (or so ive heard) so you could drop in a gsr crank and as long as you used the gsr con rods in theory the compression ratio should not drop

but if you throw in a b16 crank and rods the compression would drop due to rod lenght (problem solved by getting custom lenght rods)

 

why whould you want to destroke a long stroke motor?
build a b20 if you want lots of low end grunt, build a gsr if you want revs.

 

the b20 is cheap and has the advantages of a 84mm bore
but its r/s ratio is not comsidered great for road racing ie. to much lateral stress on the bottom end.

also the b20 stock sleeves and handle mild na builds ie. 11.5:1 comp.~ with revs of around 9000k
the stock rods also when given some rod bolts.

my 12.5:1 motor had stock sleeves but i kept the revs to around 7000k
(if you go higher then 12:1 you should sleeve the block and get aftermarket con rods, in my opinion better safe then sorry)

 

i have a set of crower rods for a gsr so i wanted to use them in my b20. I also wanted to rev higher (only up to 9000), but not sure about the r/s ratio of the b20. Im building a b20 for the 84mm bore, like eg_type_r93 said

 

so does anyone know for sure, how the compr. will be with the GSR crank and rods? or if it is possible to put the GSR Crower rods on the b20 crank?

 

compreeion will be lower by .2
so if its 11.5 with the 89mm crank
and if you use a gsr/itr crank cr will be 11.3
but why would you do this
just run the 89mm crank you will be much better off
you will also drop the displacement from 1.97 to 1.93
the 89mm crank will make more hp and torque through out the whole power band

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by riceball777 &raquo;</TD></TR><TR><TD CLASS="quote">compreeion will be lower by .2
so if its 11.5 with the 89mm crank
and if you use a gsr/itr crank cr will be 11.3
but why would you do this
just run the 89mm crank you will be much better off
you will also drop the displacement from 1.97 to 1.93
the 89mm crank will make more hp and torque through out the whole power band </TD></TR></TABLE>

thx for the info, the reason i ask is because i have aftermarket rods and i want to put them in use BUT the main reason is that i have 11.3-12.0 wiseco pistons. Im using a GSR head and with the piston and flat valves, resurface head (min amount) i dont want my comp. to be too high. it might be at 12.0:1 or higher. oh is there any way to put the gsr rods on b20 crank? possible, stupid idea, etc? Im in cali too and i dont know how safe it is with 91 oct. for a daily driver...work school etc...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Supah_Eg6 &raquo;</TD></TR><TR><TD CLASS="quote">

thx for the info, the reason i ask is because i have aftermarket rods and i want to put them in use BUT the main reason is that i have 11.3-12.0 wiseco pistons. Im using a GSR head and with the piston and flat valves, resurface head (min amount) i dont want my comp. to be too high. it might be at 12.0:1 or higher. oh is there any way to put the gsr rods on b20 crank? possible, stupid idea, etc? Im in cali too and i dont know how safe it is with 91 oct. for a daily driver...work school etc...</TD></TR></TABLE>
like i said a gsr crank will only lower cr by .2
and yes its a stupid idea to put gsr rods with a 89mm crank unless you want you pistons to hit the head of course.
to use gsr rods with a ls/b10 crank you need a raised deak or deak plate or raised wrist pins. which is too much work.
just use gsr rods for a gsr crank and ls rods for a ls crank

 

the reason to go destroker is so you have a safe r/s ratio, the ability to rev like crazy, and a flat powerband. i wish i had a copy of my old dyno sheet. i built a destroker in late 2001 when i lived in florida. basically it was a b17a crank, b20z block, 85.0mm wiseco pistons, and custom length eagle rods. gsr head, skunk manifold, jun2 cams and a sms header. when all was said and done it was like the same size as an LS motor, or a hair bigger.
212hp and 143tq at the wheels. there's probably an archived thread about it, but i dont feel likesearching.
btw.. it made peak power @ 8800-9000. it looked like a b16a dyno sheet.