LS Vtec understanding/questions
11-15-2005, 11:43 AM
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LS Vtec understanding/questions
So I don't really want to build an LS Vtec, but just to get a better understanding of how/why, and try to figure out if it's possible to build a GSR motor basically out of an LS block, and a B16 head. Please read on. I've done some research but still have questions.
OK, so I beleive what most people do with an LS Vtec is to use the entire LS bottom end, crank, rods, and pistons, and then slap the vtec head on it with the extra oil lines.
What I've also heard is that what makes the power/causes the problems is an odd rod/stroke ratio. Basically that the LS motor strokes further than the GSR or B16 motors do? and that the fix is to balance the crank and sometimes use stronger rods/rod bolts. I beleive this is because the odd length of stroke puts sideways pressure on the whole setup and at the high RPM's needed for vtec, this causes extra stress that a GSR/B16 motor are not under, and can cause the motor to come unglued unless strengthened.
So what I'm wondering, is can an LS block be combined with a B16 crank to creat a Vtec engine (as opposed to an LS-Vtec engine), to my thinking it would creat a GSR engine? Will doing this eliminate the side stress on the bottom end? if so, what would one use in the way of pistons/rods to create a workable setup?
Theory's are nice, but actual experience is priceless. Thanks, Ben Inglis
OK, so I beleive what most people do with an LS Vtec is to use the entire LS bottom end, crank, rods, and pistons, and then slap the vtec head on it with the extra oil lines.
What I've also heard is that what makes the power/causes the problems is an odd rod/stroke ratio. Basically that the LS motor strokes further than the GSR or B16 motors do? and that the fix is to balance the crank and sometimes use stronger rods/rod bolts. I beleive this is because the odd length of stroke puts sideways pressure on the whole setup and at the high RPM's needed for vtec, this causes extra stress that a GSR/B16 motor are not under, and can cause the motor to come unglued unless strengthened.
So what I'm wondering, is can an LS block be combined with a B16 crank to creat a Vtec engine (as opposed to an LS-Vtec engine), to my thinking it would creat a GSR engine? Will doing this eliminate the side stress on the bottom end? if so, what would one use in the way of pistons/rods to create a workable setup?
Theory's are nice, but actual experience is priceless. Thanks, Ben Inglis
11-15-2005, 12:42 PM
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Sounds like the research you've uncovered has been posts/info from people who don't know much on the subject.
A lot of hear say...A friend of a friend's sister says this will happen you do this without doing this or that....get my point...
yes you can put a b16 crank into an ls block but you will need longer rods.
Deck height is still the same...
It won't be the same as a vtec block, they still have oile squirters, block girdle (b18c) diff oil pump..etc..
Changing rod bolts is to make them stronger, the ls bolts aren't meant to withstand the high rpm that the vtec engines run, the stock bolts can stretch and then you spin a rod bearing....
The ls/vtec makes more power due to the higher compression and the longer stroke.
A lot of hear say...A friend of a friend's sister says this will happen you do this without doing this or that....get my point...
yes you can put a b16 crank into an ls block but you will need longer rods.
Deck height is still the same...
It won't be the same as a vtec block, they still have oile squirters, block girdle (b18c) diff oil pump..etc..
Changing rod bolts is to make them stronger, the ls bolts aren't meant to withstand the high rpm that the vtec engines run, the stock bolts can stretch and then you spin a rod bearing....
The ls/vtec makes more power due to the higher compression and the longer stroke.
11-15-2005, 01:35 PM
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any idea what rods I would go to? LS rods? GSR rods? if/when I do this it will be forged rods and pistons of course, and probably sleeved and an after market block girdle etc, but just trying to get an idea so when I DO do it, I can order the correct parts and get what I need.
I know it's hear say :-) that was kinda the point of the whole thread. Thus the "Theory's are nice, but actual experience is priceless." part...
So the longer stroke is created by the combo of the longer rods AND the taller "throw" so to speak of the LS crank? is that right? or is it more one than the other?
Are you saying the LS motor doesn't have oil squirters? cuz I know the B16 does...and we're talking about the deals inside the lower end of each piston bore that squirts oil onto the under side of the pistons right? I beleive to lube the wrist pin?
I know it's hear say :-) that was kinda the point of the whole thread. Thus the "Theory's are nice, but actual experience is priceless." part...
So the longer stroke is created by the combo of the longer rods AND the taller "throw" so to speak of the LS crank? is that right? or is it more one than the other?
Are you saying the LS motor doesn't have oil squirters? cuz I know the B16 does...and we're talking about the deals inside the lower end of each piston bore that squirts oil onto the under side of the pistons right? I beleive to lube the wrist pin?
11-15-2005, 04:12 PM
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Yeah only the dohc vtec engines (h22, b18c,b16a) have oil squirters. The ls has a hole in the rod that allows oil to lube the wrist pin, along with the oil the rings scrape down the cylinder and into the holes in the side of the piston.I'm sure some oil splashes up to the bottom of the pistons, the ls doesn't have the windage tray like the gs-r..
11-15-2005, 05:44 PM
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the rod length only moves the piston position up and down in the chamber. the stroke is determined strictly by the crank.
the b16 head is not the same as the gsr head, the b16 head is from the same mold as the type-r head. the gsr head yields a higher compression. the same internals with the gsr head should give better results, that being said if you use every gsr part and the b16 head you wont have the performance of a gsr.
the ls doesnt have oil squirters. like said above
may i ask why you are doing this?
the b16 head is not the same as the gsr head, the b16 head is from the same mold as the type-r head. the gsr head yields a higher compression. the same internals with the gsr head should give better results, that being said if you use every gsr part and the b16 head you wont have the performance of a gsr.
the ls doesnt have oil squirters. like said above
may i ask why you are doing this?
11-16-2005, 06:09 AM
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Originally Posted by sherwood
the rod length only moves the piston position up and down in the chamber. the stroke is determined strictly by the crank.
the b16 head is not the same as the gsr head, the b16 head is from the same mold as the type-r head. the gsr head yields a higher compression. the same internals with the gsr head should give better results, that being said if you use every gsr part and the b16 head you wont have the performance of a gsr.
the ls doesnt have oil squirters. like said above
may i ask why you are doing this?
the b16 head is not the same as the gsr head, the b16 head is from the same mold as the type-r head. the gsr head yields a higher compression. the same internals with the gsr head should give better results, that being said if you use every gsr part and the b16 head you wont have the performance of a gsr.
the ls doesnt have oil squirters. like said above
may i ask why you are doing this?
As for why i'm doing this...
I currently have a B16 in my hatchback, turbo charged with a super mild "build" on the motor, just new rings and lower compression pistons. It runs great and makes 297 at the wheels, but smokes a little and my wish is to build a stronger motor, to handle more boost etc. I have an LS motor I pulled out of my brother-in-laws car when we did a B16 swap in it. So I was hoping, that it would be possible to have that block sleaved, and all the machineing/hard work done to it, allowing me to do final assymbly myself with the correct parts. Allowing for a shorter amount of down time as I have a local shop I would trust with the crank balancing.
The end goal not being to have a turboed LS-vtec (wich I think would be over kill, and prematurely end the life of my motor) but to have a bored out vtec motor to turbo charge, and to not have a lot of down time.
Thanks for the posts so far.
11-16-2005, 06:47 AM
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LS motors do have windage trays, just not EXACTLY the same design due to differences in clearances needed in the gs-r and type r for the girdle.
LS/VTEC is a great thought if done right. It took me about 6k from start to finish to build one to satisfy me, pm me if you have any other direct questions, go to honda-tech.com and research some more there.
LS/VTEC is a great thought if done right. It took me about 6k from start to finish to build one to satisfy me, pm me if you have any other direct questions, go to honda-tech.com and research some more there.
11-16-2005, 07:38 AM
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no it wouldnt fix the r/s ratio as to get the same compression you'd need longer rods
the problem here is that if you use the b16 crank you will end up with the stroke displacement of a b16. the stroke is where you get the extra displacement vs the b18's seeing as the bore is the same.
you NEED the longer stroke for the extra displacement. and you will not overcome the R/S ratio by doing what you are doing.
the main difference between a type-r engine and a b16a is the fact that the block is physically taller and it has a longer stroke.
the rod stroke ratio bull isnt all it's cracked up to be, if an engines built enough it can handle it. hell even if they arent they can usually handle it.
if you are serious about this and want to make some power goto http://www.c-speedracing.com and look at their ls/vtec build up. do the same thing, only with a b20 and i will personally garuntee if done right and you make your tolerances VERY TIGHT you will see over 200whp and a whole lotta torque.
the problem here is that if you use the b16 crank you will end up with the stroke displacement of a b16. the stroke is where you get the extra displacement vs the b18's seeing as the bore is the same.
you NEED the longer stroke for the extra displacement. and you will not overcome the R/S ratio by doing what you are doing.
the main difference between a type-r engine and a b16a is the fact that the block is physically taller and it has a longer stroke.
the rod stroke ratio bull isnt all it's cracked up to be, if an engines built enough it can handle it. hell even if they arent they can usually handle it.
if you are serious about this and want to make some power goto http://www.c-speedracing.com and look at their ls/vtec build up. do the same thing, only with a b20 and i will personally garuntee if done right and you make your tolerances VERY TIGHT you will see over 200whp and a whole lotta torque.
11-16-2005, 01:01 PM
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[QUOTE=kornycivic]So what your saying is if I use my b16 crank i bypass the odd rod/stroke ratio problem? QUOTE]
No, forget that....there is no "odd R/S problem....it is fine, if there was a problem honda wouldn't have developed that motor and produced it for 12+ years....
Overkill? why would it prematurely end the life of your motor?
If your dead set against a ls/vtec then sell the b18b block and buy a gsr block, thats the only way around a ls/vtec....
No, forget that....there is no "odd R/S problem....it is fine, if there was a problem honda wouldn't have developed that motor and produced it for 12+ years....
Originally Posted by kornycivic
The end goal not being to have a turboed LS-vtec (wich I think would be over kill, and prematurely end the life of my motor) but to have a bored out vtec motor to turbo charge, and to not have a lot of down time.
Thanks for the posts so far.
Thanks for the posts so far.
If your dead set against a ls/vtec then sell the b18b block and buy a gsr block, thats the only way around a ls/vtec....