jhholloway

Alright, I have quick question that team integra and ht failed to agree on when I seared them. I am building a basic all motor dohc vtec, to get me by while a get ready to boost. (So I am not buying any parts that will be all motor only except pistons.)

basic set up:
81.5mm GSR block 87.2 stroke
stock b16 42.7cc combustion chamber (but with head port and polished valve job....)
JE piston 7.4cc dome 12:1CR

So here is the question, will it be worth the 37cc to increase the stroke from 87.2 to 89 with an LS crank and rods? this will make my motor 1857 not 1797 making it about 3.3% larger and bumps .22 to 12.09:1 from 11.87:1.

Just to get an idea- let's say the motor made 200hp.(but it won't I know not with out some good cams and IM) There would be a gain of some where around 6 to 7 hp and 4-5 tq if it maintained a 3.3% gain across the curve.

Please feel free let me know if my logic is wrong or anything and if you think that it's worth swapping out cranks and WHY you feel that way

Big Boosta

With out getting into it. Yes, the torque gains are worth it for how easily its done. Your basicly running an LS vtec, just because the block isnt an LS block doesnt mean thats its not an ls vtec. Your just making use of the built in oil passages. Im more of a low comp - turbo kind of person so i would check the valve clearense on the pistons.

Edit** Get the golden eagle oil squiter plugs. You will be fine if your running forged internals.

b18b

Also remember since we are on the topic of displacement. Swaping cranks is not the only way to increase displacement. Increasing the cylinder bore size to 82-86+mm while still maintaining a stock 87.2mm stroke will net you the same displacement you choose. In your case yes swaping the crank is the cost effective solution to increase displacement on a budget. IMO, torque is worth more than hp.

Big Boosta

I wouldnt start thinning your sleeves if your planning on going boost on a stock sleeve car. If your looking to make over 400 run after market iron sleeves.

Fabrik8

Odd, because one is mathematically derived from the other. You can't increase torque without increasing HP.

jaqattack02

Would you be doing anything to the crank and rods to strengthen and balance them? As I understand it, one of the bigger differences between the bottom end of the B18C and the LS is that the C has the bottom end built to hold up to the stresses of all the high rpm revving required for regular VTEC use, and the LS is not. The LS rods aren't as strong, and the crank isn't as well balanced. Someone correct me if I'm wrong, but unless you're going to be strengthening the rods and balancing the crank, there's a good chance something in the bottom end could break.

NasTHatch

if you put the LS crank in the GSR you need to either A. get oil squirter block offs from golden eagle OR get the crank knife edged to allow them to fit because you WILL have clearance issues.

PM me for any questions, i have built 3 set ups the way you are trying now.

jhholloway

Yes, I am getting the crank balanced. I am getting Manley h beams too. I have already taken that into consideration

NasT, thanks for the info about the oil squirters. forgot about those.

Big Boosta

Did you NOT read my above post? I said something about the oil squirters way before he even read this thread. Smh...

NasTHatch

i didn't see your post if i did i would not have posted the info