i want to do a ls/vtec conversion, but i'm worried about the block not holding the high rpms.

can i do the ls/vtec and limit the car to 7000 rpm? or is it not worth?

 

The problem with LS-Vtecs is the rod to stroke ratio. The speed of the pistons is too high when you rev it above 8000, that is on stock rods and rod bolts the tencil strength is not high enough for the speed. If the rods are replaced with better than stock and you put ARP rod bolts in the rods then you will have no problem reving above 8000 or even 9000. and by the way it is defantly worth making an LS-Vtec

 

i take my ls vtec to 8300

 

a block girdle helps too right?

 

I have a 95 Ls and want to do a Vtec head swap. any idea where i can get a vtec head and about how much it would be?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsmenaceteg &raquo;</TD></TR><TR><TD CLASS="quote">I have a 95 Ls and want to do a Vtec head swap. any idea where i can get a vtec head and about how much it would be? </TD></TR></TABLE>

there are lots of b16 and b18 heads, harnesses etc in the classifieds

 

mine is holding... i don't beat on it everyday to 8k but it holds stock lsvtec 8k here and there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Phatch99 &raquo;</TD></TR><TR><TD CLASS="quote">mine is holding... i don't beat on it everyday to 8k but it holds stock lsvtec 8k here and there.</TD></TR></TABLE>
same here

 

well i have 145k on the stock motor now. would u recommend a rebuild before the head swap or do u think it would be ok. I planned on rebuilding the bottom end anyways but do u think it would be a must before the head swap. and what all is envolved with the head swap like other parts that need to be replaced or bought?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Electron_LS-Vtec &raquo;</TD></TR><TR><TD CLASS="quote">If the rods are replaced with better than stock and you put ARP rod bolts in the rods then you will have no problem reving above 8000 or even 9000.</TD></TR></TABLE>

Ls blocks with ARP rods bolts using ARP headbolts can take 8000rpm without much of a fuss. Keep in mind that it's USELESS to rev your motor (whatever it may be) past 8000-9000rpm unless your camshafts are making power up in those ranges. Stock B16 cams don't make power past 7600-7800 no matter how high you rev it. It's a common misconception...get cams or go home with your 9000rpm

 

Im sorry i didnt clear my self up i was just talking about the rods taking the punishment at that high of rpm. I thought that cams were a given. When you are making the engine rev higher there are a few things to concider. The rod strength and the piston speed and the durration that the cams have in high cam. If you have the stock b16 cams with the stock block dont rev it past 8200....Thats when it gets dangerous... I have 200000 on mine for the time being and i have no problem taking it to 8000 but thats where i stop. If you get a cam with a higher durration and lift you will be able to rev it higher as long as you upgrade the rods. B16 cams i think only have a durration of 160 to 180 or something like that, which will cause the power to drop off at around 7800 to 8000. If you upgrade to gsr or type r cams (watch the clearences) you will be able to make power up to 8000 to 8300 and the type r cams will make power to 8500 with a durration of 305 degrees. If you are planning to go turbo you shouldnt get type r cams because there is too much overlap and you will loose boost when both sides are open. You can get some even higher durration cams being Dynamics cams that have a durration of 324 degrees you will be able to make power even higher but now you need to upgrade the valve train. Have fun and good luck

 

Build it, put it in your car, and the motor can hold 9k all day long. An lS/v is a strong motor, everyone underestimates. I have had one for 2 years and have rodded the living hell out of it. It is now torn down for boost, but i know for a fact that the motor would of kept strong for a long time.

 

i take my ls/vtech to 8,500

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1994typeR &raquo;</TD></TR><TR><TD CLASS="quote">i take my ls/vtech to 8,500</TD></TR></TABLE>


haha,dam cant you get it straight by now vtec.....

For you question do some more research,cant just ask people this few questions you need more knowlodge

 

I also take mine past 8 k at the track and its holding fine, there is almost 200 k on the bottom end. what do your guys sl/vtec set ups run? If you dont mind me asking in this thread? I run high 14s to low 15s all stock innards.

 

i take mine to 9200

 

x3, stock lsvtec to 8k. since june of last year.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Electron_LS-Vtec &raquo;</TD></TR><TR><TD CLASS="quote">The problem with LS-Vtecs is the rod to stroke ratio. </TD></TR></TABLE>
NO, IT'S NOT! it is the rodbolts. there's nothing wrong with the ls rod stroke ratio. granted, it isn't the best, but if you're that worried about it, buy a blockguard and call it a day.
when will people quit posting b.s. they don't understand...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LSvtec03 &raquo;</TD></TR><TR><TD CLASS="quote">x3, stock lsvtec to 8k. since june of last year.


NO, IT'S NOT! it is the rodbolts. there's nothing wrong with the ls rod stroke ratio. granted, it isn't the best, but if you're that worried about it, buy a blockguard and call it a day.
when will people quit posting b.s. they don't understand...</TD></TR></TABLE>

The rod bolts wont solve all of your problems buddy......when you rev a motor with arp rod bolts in ls rods, the tencil strngth of the metal that the rods are made out of is in question...... the rod to stroke ratio will directly effect the piston speed, which is the only thing you should be worried about...when the piston speed gets higher there is a great amount of force on the rods when they apex and are pulled back down by the crank.....this is when they snap...not at the rod bolts, but at the top of the rods by the wrist pin.....a block guard wont help any thing except for top cylinder movement....which has nothing to do with the rod to stroke ratio.....you should learn what you are talking about before you start talking **** to people.....sorry i didnt explain myself better.....

 

the problem with an LS not being able to rev past 7k does not have anything to do with the block but more so with the valve train. an LS/Vtec should rev up to 8k with no problems what-so-ever. hell i rev my boosted LS to 8.5k...but it's fully built though.

oh and i've never heard or seen anyone snap an LS rod because they revved past 7k. a GSR 87.2 stroke compared to an LS 89 isn't an insane jump. if you're comparing the B16 stroke of 77 vs. the LS 89 then yes that's a pretty big jump.


Modified by shermanyang at 5:28 AM 10/27/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shermanyang &raquo;</TD></TR><TR><TD CLASS="quote">the problem with an LS not being able to rev past 7k does not have anything to do with the block but more so with the valve train. an LS/Vtec should rev up to 8k with no problems what-so-ever. hell i rev my boosted LS to 8.5k...but it's fully built though.

oh and i've never heard or seen anyone snap an LS rod because they revved past 7k. a GSR 87.2 stroke compared to an LS 89 isn't an insane jump. if you're comparing the B16 stroke of 77 vs. the LS 89 then yes that's a pretty big jump.</TD></TR></TABLE>

Look at the name of the thread.....we are talking about LS-Vtecs....that is defantly the problem with an ls reving high, but that has nothing to do with what we are talking about.... we are also talking about reving ls rods much higher than 7000.....thanks for the input...read the posts more closely next time.....

 

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

Look at the name of the thread.....we are talking about LS-Vtecs....that is defantly the problem with an ls reving high, but that has nothing to do with what we are talking about.... we are also talking about reving ls rods much higher than 7000.....thanks for the input...read the posts more closely next time.....</TD></TR></TABLE>

i did read it closely and what i was trying inform you was the fact that LS rods do not limit the revs on an LS/Vtec setup. i have personnally built a few LS/Vtec's that rev to 9k with no problems. you'd have to really screw something up or have insane FI to break those rods. and honestly, do you really think that the difference of the LS' 89 stroke vs. the GSR's 87.2 stroke is so great that you'd snap a rod? i would think not.


another thing for you to think about as well...FI LS motors accelerate about 3-4 times as fast as a normal LS motor would. don't you think this increased power and acceleration would cause more stress on the LS rods than the slowly increasing speed of LS/Vtec? honestly, think about it.

 

I've taken my friend's B20/VTEC to 8000 safely. He says he shifts at 8500. The thing revs up so fast and makes power all the way to 8000. Maybe even 8500.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shermanyang &raquo;</TD></TR><TR><TD CLASS="quote">i did read it closely and what i was trying inform you was the fact that LS rods do not limit the revs on an LS/Vtec setup. i have personnally built a few LS/Vtec's that rev to 9k with no problems. you'd have to really screw something up or have insane FI to break those rods. and honestly, do you really think that the difference of the LS' 89 stroke vs. the GSR's 87.2 stroke is so great that you'd snap a rod? i would think not.


another thing for you to think about as well...FI LS motors accelerate about 3-4 times as fast as a normal LS motor would. don't you think this increased power and acceleration would cause more stress on the LS rods than the slowly increasing speed of LS/Vtec? honestly, think about it.</TD></TR></TABLE>

Ls rods are the only thing that does limit the set up......you are playing with the devil if you are reving the ls rods to 9000.....think about how many times the engine is rotating the difference in 1.8mm is huge when you think about the distance compaired to how many times you rotate the engine.....you dont know what you are talking about....you are just talking from expirences...you need to read up and look at the formulas for piston speed compaired to stroke.....and about the more stress on the rods....that makes you look even more like an idiot....i hate it when people insult my intelligence....you dont know what you are talking about...more power will not even phase the rods....that might make the fatiegue factors of the material that the rods are made out of less, but it will for no means hurt the rods....i have seen countless turboed b-series engines that are useing stock rods that are putting well over 300 to the wheeles....wouldnt that put more stress than a vtec head on a stock bottom end...... go and get the bosch complete manual of engines and cars....read the whole thing on piston speed rod to stroke ratios and tencil strength of metals and fatiegue factors..... then come and tell me that i am wrong...sorry for the strong worded post but you need to do some more reading.....

 

okay...here's what you don't understand. i speak from experience and knowledge. you're only partially correct from where you stand. yes that 1.8mm will make a difference but not enough to actually limit or snap a rod.

what you don't understand is the fact that extreme acceleration WILL cause more damage to the rods than having moderate power and accelerating at a steady rate. just an example for you...what do you think would snap or stretch a timing belt at a quicker rate?

a) revving to 9k with moderate power?
or
b) revving to 7k with 3x the power?

obviously having 3x the power and accelerating at 3x the speed will create more stress on the timing belt. this goes the same for the rods as well. why do you think more people snap stock rods when boosted compared to when they're N/A?

if you don't want to take my word for it, i could really careless. books don't tell you everything...and just because you read it, doesn't mean it applies to everything. just because you read a book doesn't mean you know it all. hell if you don't believe me ask anyone else who's knowledgeble about this situation and they'll tell you the same exact thing i'm telling you. i didn't want to point this out but experience is a whole lot better than any one book.


oh...and one more thing, there is only a .9mm difference in length from the LS to GSR rods while the rod ratios are 1.54 on the LS to the GSR's 1.58.

 

all is true ,
but one thing if you are going to d a ls-vtec to it right , build it , don't just use al stock stuff

o and , i can take my motor to 10000rpm , but never do , for 1 i start loosing power at 9600 and for another i don't want any thing to happen , its not cheap to brake part, and + its daily driven and almost never take it past 4000rpm ,
the on time i took it to 10000rpm was on the dyno table thats it and also , 3 times at the street races

sorry if i have no point