imported_2join performance

Ok, so lately i have been researching the lsvtec engine, and i have probably read every article i can find.

From what I understand the lsvtec has a bad r/s ratio, and in order to stabilize the engine at higher rpm's, it is recommended to use arp bolts and some sort of girdle. Hope i have this right.

However i was also doing some research on how to improve the r/s ratio and i was playing around with some numbers. I found that if one were to use the golden eagle .137" oversized rods, you would recieve a r/s ratio of about 1.58. It's still not good, but better then before and really close to the itr and gsr r/s ratio.

Now here is my main question, if i were to use these oversized rods, what effect does this have on everything else besides r/s ratio. I am having a hard time seeing how all these things are related. So for example would my compression be affected? Would torque be affected? Or maybe it would defeat the purpose of using the ls engine in the first place?

Thanks for any help, I am a little confused right now so i need all the clarification i can get.

zeeman

iTrader: (1)

the r/s ratio of a LS is what gives it the torque desired with a lsvtec, also gives it its slightly larger displacement over the itr/gsr.
I think your compression would get jacked (maybe even too high) with a larger rod b/c it would be moving the piston up the cylinder further (possibly causing contact of the piston to the valves) unless you use a custom piston with a higher wrist pin placement.
.....waiting for steve leitner to chime in.....

LEITNER

ok... the eagle rod that is longer for the LS is designed for larry at endyn, he has the pistons that have the pin moved up the same amount so everything jives. you cant just use those rods in your engine because the piston will stick out of the block over .100", you need those matching pistons. stroke is where the torque comes from, a higher r/s lets the engine spin free'er because you have reduced the severity of the rod angle in the bore, a bigger bore also aids in r/s ratio (bigger as in 3-4mm not .5mm)

zeeman

iTrader: (1)

....thanks steve....
So yeah, in order to obtain a better r/s ratio just get a b16.
if its a high revvin LS that you are after just get some ARP rod bolts, i don't think for how much effort/money it takes to use a main girdle its really worth it. Besides its not likely you will be using a cam that makes power much past 8-8500rpms.

imported_2join performance

Well, if i do go the lsvtec route it really isnt a problem because i do a ****load of street driving where i rarely rev above 4k. So its 7k rev limit isnt bad for me, and i need its low end torque.

However, i was just thinking if there was anything i could do to improve the r/s ratio while i was building it. But i guess if i were to add arp bolts and and a girdle (although zeeman says i dont need one) Could i expect to safely rev to 8k?

Also, if i were to bore it, lets say to 83mm. I believe stock is 81mm. What does that mean? I know i get more displacement, and i guess i also get a better r/s ratio, but would other things be affacted? Once again, things like compression, block strength, torque, the power band (would i push the peak power up or down) etc.?

Sorry for all the questions, but i just wanted to get it all out of my head :P Thanks.

zeeman

iTrader: (1)

all you need to run an lsvtec to 8K is arp rod bolts.
You cannot bore a b-series more than .5mm over. Because of its open deck design the cylinder walls are thin and over boring would make them way too thin. But during a rebuild its good practise to bore it .25mm over.

imported_2join performance

So let me see if i have this right. In order to build a fairly sturdy lsvtec this is what i need:
-B18 block
-B16 head
-Golden Eagle lsvtec conversion kit
-ARP Rod bolts (or do these come in the GE kit?)
-Vtec pump
-vtec timing belt
-gsr or b16 tranny
-ecu (which one?)
-b16 pistons
Is that it?
And one other thing. With the pr3 pistons i would get a compression ratio of 11.2:1 if i remember correctly. Would i be able to use regular pump gas for that c/r?
Thanks.

zeeman

iTrader: (1)

your ok on pump gas up until about 12-12.5:1
a vtec oil pump would also be a good idea. Which ecu you use depends on which car this is going into....i'd say a p28 w/uberdata would be your best bet.
I don't think that ARP rod bolts come in the GE conversion kit, but you can get them online for like $35 US, i would also get some ARP head studs for GSR/ITR. Also make sure to get a 94-01 GSR timing belt the b16 one is too short.
And if its in the budget maybe some itr/ctr cams and adjustable cam gears....with this you'd have a pretty sturdy, peppy lsvtec that could take 8.5K all day, especially if you used the itr valvetrain, and make power that high if using the itr cams.
But you sound like you are on the right track.
If you are going to be using pr3 pistons and new rings you should get new rod and main bearings and have yourself a fresh lsvtec.
Good luck with the build.

imported_2join performance

Thanks a lot mang. I think that just about answers every question I'll just let all this info soak in, and then ill go figure out the cost of all this.
Thanks again.