I’ve been looking around and it seems that there is little information on the subject, so I am wondering if anyone on here is running a ls or b20 with a b16/b17 crank?
Destroking the Ls/B20 defeats the whole purpose of the long stroke which creates more torque. Just balance the whole rotating assembly (Ls/B20 crank,rods and pistons. Then use arp rod and main bolts. A Gsr girdle is always a plus.
the only sensible destroke kit for a b20, would be a 87.2mm crank and rods
I am looking at it in terms of rod stroke, With a b17 crank mated to b18 rods you could have a rod stroke of 1.68.
well going from 89mm to 87.2mm will slightly raise ur rs ratio. with the 17 crank, ur looking custom rod (18a/b might fit) and wrist pin location for ur pistons. in the end, its a waste of time and monney. if ur searching for a superior rs ratio (only God knows why) just sleeve a 17 block and there u go, 1.68 rs with slightly more than 1800cc’s at 84mm
Don’t worry about it, you don’t seem to realize why I would start with a taller deck to improve rod stroke. I may or may not try it, depends on what parts I can find.
I’ve looked very deeply into doing the same thing your talking about darin d. Your going to be looking at getting custom pistons with a different compression height. Eagle makes a B16 stroker rod that you may want to look in to for putting into an ls block. I’ve actually got a B16 crank i’d sell if your serious about this. I was thinking of doing this around a year ago and just didn’t have the time. If your looking at doing this so you can get more rpm out of the motor it really isn’t worth it and thats another reason why I didn’t do it. What are your plans with the motor and what all did you have in mind? Here to help ya if ya need it man.
trust me, i know what ur trying to achieve, but at what cost? a big displacement, good r/s motor that makes power to 10k will cost u $1k per rpm. is it really worth it??? no. at that point, might as well build a K or just go f.i. if ur trying to be different, i admire that. its nice to not follow the common trend. but, what ur looking into is very, very expensive. don’t listen to the bullshit that people try to feed u. the im to extract max power and top end breathing capabiliteis will cost u not a penny less than $1200, because it will be a custom unit. not to mention the extensive head and near perfect combination of parts necessary to extract serious power, sustain extended periods of high rpm. did it also mention that u will need to run a super light/super strong rod to withstand big rpm? its monster paper man
The motor would be fi to begin with, and headwork isn’t going to be such a big deal then. As far as the bottom end, rods and pistons are still cheaper then getting a block resleeved, and even at higher rpms the stress on the rods is decreased by the changes in rod/stroke and reduction of piston velocity. With a b16 crank and ls rods the r/s is 1.79, and with the right sized turbo and valvetrain I’m sure that motor could put down respectable numbers.
Dude, with a B16 crank and using the stock length rods the pistons are going to be almost a quarter of an inch from the top of the deck. That isn’t going to work.
The rods I was referring to are the eagle 5.531(140.48mm) rods which are for a B20 or LS with a deck plate. Look into getting these with a dished piston for your turbo setup with the B16 crank. With this setup the piston to deck height is still going to be a little more then normal. Piston velocity is going to be a big problem at higher engine speed, even though your changing the r/s ratio. Your going to have to rev the motor higher to achieve the same power. Side loading on the cylinder walls will be decreased with the better r/s ratio but the rods and pistons will be under extreme stress at those speeds and it will be mutiplied since your putting boost on top of that.
Thanks for the input, I think I am going to play around with the idea some more, but it seems that with 8-10lbs of boost in the mid-upper powerband would make a fun daily setup while still achieving decent mileage off boost.
Your only shooting for 8-10 lbs.? I figured you were going for more. Not to talk you out of this but you might as well just stick with a standard LS stroke and rod length. The sleeves will be fine if the motor is tuned properly and it will make plenty of power within the stock RPM range with the turbo. Just curious as to how high you were actually wanting to spin this motor out to?
Well its not that I am looking to make a lot of power. I like the idea of boost peaking around 8k and running the motor to 9. I would like to run 9-10:1 compression, and have toyed with the idea of using a b16a2 head.
just boost ur motor now at 30 psi!! im right behind ya!!! :rockon:
nar93da: I noticed you said those rods were for a b20/ls, Would I be better with b16a crank or a b16a2 crank. I have a block torn down now that I might send out to be sleeved.
All B16 cranks are going to be the same. They all had the same journal size and stroke. Those rods I mentioned would be good for an LS/B20 with a B16A crank. I would get custom pistons with a little more compression height if you were going NA but your going FI.
B17 crank with “stroker” eagle rods in a sleeved and overbored B18a block.
1.73 r/s
Yes, a B17 crank would be a perfect combo. On the downside though, those cranks are very hard to come-by and if you find one with good journals and someone willing to sell it, your gonna have to give up a nut!