LsVTeCTuRBo17

What do you guys think is better as far as turboing your motor goes?


[Modified by LsVTeCTuRBo17, 3:24 PM 12/30/2002]

b18tdelsol

do a search homes..

abraunb16

Depends on budget. I fully built an LS turbo, 7-8 lbs 263 whp and 200 ft lbs. This was partially tuned with AEM. Since I'm not a whiz at tuning it still had somemore left. Unfortunately a timing belt failure cost me the valves so I'm working on a new build now. The head, motor and all other parts are fine, just oversized valves decided they wanted to kiss each other and slightly bent the edge, thus not being able to seal anymore. Oh, well best of luck!

20lb.teg

be the kool one like me, the rebel, go LS and get your race on!!! Rally it's up to you, so good luck.

Later,

Sean C.

wanabecivicex

if you look at all the fast turbo cars out there, they havent pieced together the motor, its all the same, either a b18b, or a b18c, no switching of the heads. i have heard that its a lot more stable to keep the motor as one piece, especially when you are looking at alot more hp than 200

pissedoffsol

heard from who? your uncles cousin's sister in law's wife?

ANYTHING is only as reliable as it is/was built and tuned.
there is NO just statement in saying that an ls/vtec is not a good motor.

anyway,
my vote- LS/t

vtec + boost = overrated IMO

turbopanda

B20/VTEC turbo is better

wanabecivicex

I saw this at another forum and wanted to post it

"Tatsuro Ichisima (The guy that owns Spoon Sports) says, "I don't understand why people want to so this. (B20 block to VTEC head) There is a small cult following in Japan on the same swap, but are basically spending alot of money and going home crying. The B20 crank in a B18 (or B16) would have problems because the engines sleeve already has a vibration problem at the sleeves with the original crank. The B20 crank causes even more vibration. If the engine were onle revved up to 5000 rpm, it would be fine, but when you get up to 8000 to 9000 rpm, warping will start to occur. Again, this is a problem that occurs even with the original crank."

The origins of this quote i belive is from an old scc or superstreet

Here is some other info that i have seen on the web and some that i have seen my self

I have seen two dyno plots of crvtec setups both had higher compression pistons (11:1 jes) itr cams, cam gears, i.h.e. and v-afcs. They were on a dyno jet and both were tuned to 13.3:1 a/f ratio and were running on bp 102 octane race gas. Both were tuned with intake advanced 1 degree and exhaust retarded 2 degrees. Also both were running 2 degrees advancement from the stock static timing. Both were in 5th gen civic hatches i do not know what wheels they were running but both were testing on 15in wheels they said. The first crvtec laid down a best run of 182hp and 147lb-ft. The second crvtec laid a best down of 175hp and 138lb-ft. Both had nearly all usable torque from 2000rpm to 7000rpm. Both had redlines of 8600 which was allowed by retuned ecus that had base timing and fuel maps that allowed this higher redline although further tuning was done with there vafcs. The power began to fall fairly steeply at 8200rpm. Which has been experienced by many running on factory cams. Some have been able to cure this problem with toda cams but they have not found a really good solution. For reference i have seen two jackson racing supercharged gsrs with 9 pound pulleys, i.h.e. and v-afcs dyno significantly higher. The first dynoed on 92 pump gas and a 12:1 a/f ratio ran a best pull of 221hp and 173lb-ft, this run was on 17 inch wheels. The second gsr dynoed a little higher at 229hp and 180lb-ft, with a clutchmasters flywheel and an msd-6btm. It also was on 92 octane and ran a/f ratio of 12:1. It also was on 17 inch wheels. With the additional 40 wheel hp and 30lb-ft these gsrs have on the crvtecs, they would pull away on the top end, even though they are heavier than the hathches they would have higher trap speeds in the quarter. It is for these reasons that more crvtecs are done in hatches than in the honda coupes. The crvtec has yet to gain the same popularity amongst the honda coupes as they have the hatchbacks. Also the vortech gsr dynoed 240whp on an 8 pound pulley but i do not know the other specs of the car at the dyno run. My point here is that the crvtec even built midly does not make the same kind of power the b series vtecs make with f.i., which is proven by the dyno runs. A common misconception amongst some in the hybrid community is that only f.i. can outperform there hybrids. This is not true, the reason for this is that the setups that are beating them just happen to be f.i. setups. This is because the cost of a bolt on f.i. kit is much less than a fully built na vtec motor is. It has been proven though at the track a fully built na vtec has been able to perfrom the same and if not better than the fully built na hybrid. The fastest drag hondas out there are not hybrids they are normal vtec motors. This is not to say though that there are not fast hybrids out there cause there are many they just have not reached the same level yet. Here are some technical reasons why the crvtec is an unstable motor.

Here are the main reasons why the crvtec has had problems with reliability and making the same level of na power as the regular vtec motors do. Keep in mind since these crvtecs are na they need to make more power by more rpm. The first problem that has come with going past 8000rpm is that the valves start to float which compounds the valve relief problem further. But it seems to me that people havent yet put in upgraded springs and retainers which would help but definitely not bring an end to this problem. They just seem to have the attitude, its going to blow up but we dont care, which is seen on many sites and forums. To complement the high rpm the motor is spinning at it is important to help the motor breath. Some have tried toda or skunk cams (more power is made though with the todas it appears) to help the motor breath better since many have had problems with motors dying out at 8000 rpm. A lot of these people said that with the high lift, long duration and high overlap design of these cams the valve clearance problem was only amplified and that they put itr or ctr cams in it and that has seemed to be the safety limit although as you would imagine total power is decreased. The second reason for poor reliability are the stock rod bolts. They tend to be very weak and are prone to failure resulting in spun bearings. The second reason are the very weak sleeves. These sleeves are very prone to cracking and warping due to the high heat that is generated from the high rpm and detonation that is created by the very high redline even if the motor is used in conjunction with a retuned ecu that has basic timing and fuel maps and fine tuning with a vafc. Compounding the sleeve problem is that at high rpm the crvtec with its numerically lower rod ratio length and the angle the rod therefore sits in the block greatly increases the friction and sideloading that is forced upon these very weak sleeves by the pistons. A reason for this is that the b20 sleeves are essentially a bored out sleeve out of a b18b. So therefore the sleeve is thinner not being able to take as much abuse. Some have gone as far to say as that the iron that is used in the b20 sleeve is different and not as good as the iron that is used in the b18b sleeves. Others have said that the sleeve problem lies in the design more than anything else since the sleeve design is different with the b20 blocks than the other b series blocks. Also compounding this problem is the lack of piston oil squirters on the b20 block that are found in the b series vtec blocks. This results in increased temperature and can also increase the chance of cracking or warping the factory sleeves. Also the b20 crank is not fully counterweighted from the factoy like the b series vtec motors are. For the few that have been able to keep the crvtec together they have said that they have had to have the cranks knifed and fully balanced even in use at only 8000rpm. Vtec cranks are balanced from the factory with counterweights and are drilled for further weight balance. Another problem with the crank is the lack of a girdle which also hurts high rpm reliabilty. Also the stock rods tend to be quite weak since they are not forged of the same high chromium content carbon steel that is used in the b18c and b16b motors. Also the rod end cap is not very stong some have said. It does not look like a solid flat square design that is seen in the vtec motors. Also like i have mentioned the very shallow intake valve reliefs in the piston make it difficult to clear the high lift cam lobe of a vtec cam. This results with the pistons whacking the valves. It has been documentated that at a high enough rpm some have taken there crvtecs to 10000rpm they have had pistons totally shatter that valves or send the the valves through the head. One tuner said that they missed a shift and the motor hit 12 grand and expereinced this. This is no different than having a timing belt break on your honda sending this piston upwards while the valves are open. The difference though is one happens because of failure the other happens becasue of physics. A solution that has been proposed but has not been tested yet is to use a shorter rod and use a piston with a longer stroke. Good in theory but people have found many reasons why it doesnt work. First by increasing the stroke and using a shorter rod you are only compounding the rod ratio length problem. Secondly the height at which the piston is at at tdc does not change it stays the same so the overall cc volume is the same, in other words the pison does not sit lower in the block it stays the same. Some thought that this would not be the case. Also the stock pistons have had many problems at high rpm speeds of the ring lands failing due to the high friciton and sideload that is put on the piston. It has been proven to that the stock rings are very weak as well. People that have run stock pistons and rings with 8000 rpm redlines and up with alot of advanced static timing have had there rings fail on them. Some of these problems though can be fixed with a built motor some though cant be fixed cause you cannot bend the laws of physics. It is possible though to make this setup pretty reliable though but many have said the cost is higher than f.i. vtec and the same as built na vtec and both setups make more power than the crvtec. It depends really what kind of motor you like. The hyrbid has a beautiful torque curve and many have said in hatches they are road course monsters saying that they can out run built na vtecs. On the track though due to the lack of ultimate top end power the hybrids just havent yet been able to keep up with the f.i. vtecs but some built na hybrids have been able to beat some built na vtecs in terms of their et's but have yet to beat the built nas trap speed, this is mostly due to the hybrids's much better torque curve.

So what happened to the two afformentioned crvtec motors. Unfortunately both motors failed. The lower horsepower motor failed first with 25k miles on it. It melted a plug and put a large hole in piston 1 also all the pistons were chipped and so were the valves. The second crvtec motor failed at 30K miles with all of the cylinder sleeves cracking but there was not warping yet. It does seem that the sleeves are cracking first before they are warping i have not heard any reasons why though they are cracking first. The second motor also had chipped pistons and valves.

My point for this post is not to say that the crvtec is not a good motor cause it is. My point is that there are alternatives (f.i. b series vtec motors) that have historically made more power and have had more reliability than the hybrid motors have. Where the advantage of the hybrid comes is in cost of na hybrid vs cost of na b series vtec. With out a doubt the na hybrid will always make more torque than a built na vtec. Both of the crvtecs i have seen have had usable torque from 2000 to 7000 rpm which is very impressive and something you cannot get in a built na vtec motor. A b series vtec motor can though approach the levels of torque that can be made with a built na hybrid. This has been accomplished by people building vtec motors with sleeves of the same bore as the hybrid blocks. Unfortunately they have not fully approached the torque levels yet due to keeping the stock stroke. They keep the stock stroke though for a reason, which is to maintain the vtec motors better rod ratio length therefore retaining better reliabilty. Poor reliabilty though is not uncommon just to the hybrid world it is something that is experienced in the f.i. world to. We all do what we do to make more power and we all have different styles the point was not to say the crvtec was a crappy motor it was to say that it has had consideralble reliability issues. This is heavily documentated on the web and on many forums. I wish you the best of luck with your setup and hope you found some of this helpful. I look forward to your reply and hope you have some of your own info that you could bring to this discussion since no one is truly wrong or right.

tony1

Well, that last post was entirely too long so I didn't read it all. It this has anything to do with it, it is unintentional.

A motor is a motor, there are many physics behind it. The head doesn't know what block it's mated to. With the block there is bore, stroke, and rod length as major factors. Increase stroke and you will make more torque and usually have a lower redline. I have had very good results from ls/vtec swaps and when done right they are pretty reliable. There is no doubt that the ls/vtec will make more power than an ls. It will not be any less reliable either, as the stroke is the same. 8k rpm isn't too much for a properly assembled ls block. The whole unreliable thing comes from incorrectly assembled motors. This is my view on the matter...

abraunb16

I agree that the post is to long. The other thing that got me was the author of the CRVTEC post was comparing B20/VTEC NA setups to GSR/JRSC setups. What a dink! No kidding the JRSC should make more power. The B20's making 180 whp is nothing, a kid in town built a 210 whp and 158 ft lbs B20/VTEC in a coupe. Also was running 12.9's on DR's. Just goes to show that proper building and somewhat tuned setups do make power.

Anyway back to LS/LS VTEC turbo question. I wanted to be different also so I built an LS turbo setup. The thing screamed with low boost, never got a chance to get nasty with the boost, timing belt failure smoked my valves. Now I'm going LS VTEC turbo so if you can wait a couple more weeks I could give you some feed back on the gains if any. As a reference point, I compared my dyno's against a buddies piston/rod 9:1 GSR and made more horsepower and torque up to 6k rpm. Then his larger housing turbo would put a few on me from 6 to 8k. I can't say he would have made more power if he had the same turbo as mine. It still a little unfair since my motor was fully built and his wasn't. Powers, Power though and I made more up to a certain point. Oh well, best of luck. Later Allen

LsVTeCTuRBo17

BRO I don't know if you were aware of it or not BUT the B20 Crank and an LS Crank ARE EXACTLY identical (89mm). My Ls/Vtec has never had any problems with a "Vibrating Crank". I don't know who builds those engines down their, but I know guys who have had their ls/vtec engine last over 60k already. Maybe you should do some more reading up http://www.hondatuningmagazine.com/tech/0203ht_killerb/

ahobbs

Tony knows his S##T. trust me he was doing everything to my car until i totalled it. This guy looks cool but has a nerd brain. "MAD SCIENTIST". J/K he knows his stuff. and has built lots of cars.

turbopanda

I plan on destroking my B20B with a B18C crankshaft, B18C forged rods + 84mm JE's (saving up for the JE's now.. then i'll be doing it) - hope it will prove more reliable than my current setup: stock B20B pistons and rods

DIRep972

iTrader: (1)

jason hunt has the fastest fwd street class honda running 9.8 @ 150 and he runs an LS/vtec turbo. food for thought.