B20 vs B18cR crank
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From: Durban, South Africa
B20 vs B18cR crank
I want to mod my 98 spec JDM ITR, but I'd prefer to leave the
originl sub untouched.
So I have managed to get my hands on a second b18c block.
My dilemma is:
1- Do I go Darton dry liners, 84mm pistons, B20 crank & rods, & deck the block to B20 height, so effectively a proper Vtec B20?
or
2- Do I go Darton dry liners, 84mm pistons, b18cR crank & rods. Here I will lose capacity vs a B20, around 1930cc if I recall correctly, but I will maintain
a better rev range, rod/stroke ratio, & better power band., but less torque.
or
3- Do I go Darton dry liners, 85mm pistons, b18cR crank & rods. Here I will regain capacity, around the same as a B20, but still maintain revability
with a better rod/stroke ratio & power band. Only problem is if things go wrong, there isn't allot of room for reboring.
When I refer to rods, I mean I have a set of Manley B20's & Eagle B18C's.
Head I will utilize off my b18cR, but I have a Skunk2 valve train, & Blox P1 cams.
Pistons will obviously be forged.
Another question: Do I keep my standard valves on the B18cR head or do I use the 1mm OS oem style Ferrea valves I have?
Opinions please...
originl sub untouched.
So I have managed to get my hands on a second b18c block.
My dilemma is:
1- Do I go Darton dry liners, 84mm pistons, B20 crank & rods, & deck the block to B20 height, so effectively a proper Vtec B20?
or
2- Do I go Darton dry liners, 84mm pistons, b18cR crank & rods. Here I will lose capacity vs a B20, around 1930cc if I recall correctly, but I will maintain
a better rev range, rod/stroke ratio, & better power band., but less torque.
or
3- Do I go Darton dry liners, 85mm pistons, b18cR crank & rods. Here I will regain capacity, around the same as a B20, but still maintain revability
with a better rod/stroke ratio & power band. Only problem is if things go wrong, there isn't allot of room for reboring.
When I refer to rods, I mean I have a set of Manley B20's & Eagle B18C's.
Head I will utilize off my b18cR, but I have a Skunk2 valve train, & Blox P1 cams.
Pistons will obviously be forged.
Another question: Do I keep my standard valves on the B18cR head or do I use the 1mm OS oem style Ferrea valves I have?
Opinions please...
Re: B20 vs B18cR crank
Honestly this is too opinionative.. What are you final goals? I prefer more top end power and higher Redline so I'd go with the R setup. I believe the deck height of the B20 motor and the B18C are the same as well, correct me if I'm wrong. Either way Rod/stroke ratio of the R motor is more reliable than the B20 in the end.
Thread Starter
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Joined: Apr 2009
Posts: 247
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From: Durban, South Africa
Re: B20 vs B18cR crank
Honestly this is too opinionative.. What are you final goals? I prefer more top end power and higher Redline so I'd go with the R setup. I believe the deck height of the B20 motor and the B18C are the same as well, correct me if I'm wrong. Either way Rod/stroke ratio of the R motor is more reliable than the B20 in the end.
The B20 deck height is a little over 1mm shorter I believe. Not dramatic, but
enough to impact on cr & squish area.
Im also inclined towards the R setup, but I'd like to hear from those who have
experience with all these setups, particularly the R setup with 84 vs 85mm, &
both power & torque of these vs the B20 setup.
With the B20, I'm not referring to a stock bottom, I'm instead referring to
mod for mod vs a b18cR, with 84 or 85mm.
Re: B20 vs B18cR crank
i'll give it a shot.
So I have managed to get my hands on a second b18c block.
1- Do I go Darton dry liners, 84mm pistons, B20 crank & rods, & deck the block to B20 height, so effectively a proper Vtec B20?
Darton Dry sleeves will only be for 81-82mm max. Maybe your referring to darton "wet" sleeves which are also called M.I.D. sleeves? because those you can order in 84mm. There his a HUGE price difference in the 2 sleeves & the install process of 2 types of sleeves.
or
2- Do I go Darton dry liners, 84mm pistons, b18cR crank & rods. Here I will lose capacity vs a B20, around 1930cc if I recall correctly, but I will maintain
a better rev range, rod/stroke ratio, & better power band., but less torque.
^^ see comment above....I think you have the dry vs. wet sleeves mixed up.
Find out if you want to get WET sleeves or Dry Sleeves.
Find out if you want to use B18c 81mm block or B20 84mm block
once you knows those 2 then i can help you out.
or
3- Do I go Darton dry liners, 85mm pistons, b18cR crank & rods. Here I will regain capacity, around the same as a B20, but still maintain revability
with a better rod/stroke ratio & power band. Only problem is if things go wrong, there isn't allot of room for reboring.
Revability?
There is zero reason why you cannot safely rev a LS crank 89mm stroke to the same rpm as a gsr/itr 87mm stroke. Do more homework on this. Maybe 10yrs ago people would get hung up on the "r/s ratio" argument but not anymore. Countelss engines with 89mm stroke rev to +9000rpms.
Another question: Do I keep my standard valves on the B18cR head or do I use the 1mm OS oem style Ferrea valves I have?
stock size are fine.
Bigger valves doesn't always mean more power.
Also bigger you will want to recheck all your p2h and p2p clearances or else as soon as you go into vtec you could gernade your new engine.
if your rebuilidng your head and want new valves, the ferrea 6000 series valves are nice and worth the extra money if your already looking at the cheaper 5000 series.
if your on a budget, just get your current valves checked & re-faced while you rebuild the head and get a valve job.
Opinions please...
Here's my opinion in terms of what i'd reccomend in different combiniations for block setup:
a) gsr/itr stock sleeves 81.5-82mm bore higher compression pistons (base on fuel type)
LS 89mm crank
LS spec rods
make more power/tq throught entire power band and carry power 200-350ish rpms longer before power starts dropping off.
200-225whp while still keeping things very streetable.
b) sell the b18c block
go buy a b20 block
stock sleeves bore to 84.5 & higher cr pistons
LS crank & LS rods
night and day differnece in power compared to stock itr motor.
220-240whp while still keeping things very streetable.
lastly, if you had to pick between bigger bore or longer stroke, I'd go with longer stroke.
That's just me.
So I have managed to get my hands on a second b18c block.
1- Do I go Darton dry liners, 84mm pistons, B20 crank & rods, & deck the block to B20 height, so effectively a proper Vtec B20?
Darton Dry sleeves will only be for 81-82mm max. Maybe your referring to darton "wet" sleeves which are also called M.I.D. sleeves? because those you can order in 84mm. There his a HUGE price difference in the 2 sleeves & the install process of 2 types of sleeves.
or
2- Do I go Darton dry liners, 84mm pistons, b18cR crank & rods. Here I will lose capacity vs a B20, around 1930cc if I recall correctly, but I will maintain
a better rev range, rod/stroke ratio, & better power band., but less torque.
^^ see comment above....I think you have the dry vs. wet sleeves mixed up.
Find out if you want to get WET sleeves or Dry Sleeves.
Find out if you want to use B18c 81mm block or B20 84mm block
once you knows those 2 then i can help you out.
or
3- Do I go Darton dry liners, 85mm pistons, b18cR crank & rods. Here I will regain capacity, around the same as a B20, but still maintain revability
with a better rod/stroke ratio & power band. Only problem is if things go wrong, there isn't allot of room for reboring.
Revability?
There is zero reason why you cannot safely rev a LS crank 89mm stroke to the same rpm as a gsr/itr 87mm stroke. Do more homework on this. Maybe 10yrs ago people would get hung up on the "r/s ratio" argument but not anymore. Countelss engines with 89mm stroke rev to +9000rpms.
Another question: Do I keep my standard valves on the B18cR head or do I use the 1mm OS oem style Ferrea valves I have?
stock size are fine.
Bigger valves doesn't always mean more power.
Also bigger you will want to recheck all your p2h and p2p clearances or else as soon as you go into vtec you could gernade your new engine.
if your rebuilidng your head and want new valves, the ferrea 6000 series valves are nice and worth the extra money if your already looking at the cheaper 5000 series.
if your on a budget, just get your current valves checked & re-faced while you rebuild the head and get a valve job.
Opinions please...
Here's my opinion in terms of what i'd reccomend in different combiniations for block setup:
a) gsr/itr stock sleeves 81.5-82mm bore higher compression pistons (base on fuel type)
LS 89mm crank
LS spec rods
make more power/tq throught entire power band and carry power 200-350ish rpms longer before power starts dropping off.
200-225whp while still keeping things very streetable.
b) sell the b18c block
go buy a b20 block
stock sleeves bore to 84.5 & higher cr pistons
LS crank & LS rods
night and day differnece in power compared to stock itr motor.
220-240whp while still keeping things very streetable.
lastly, if you had to pick between bigger bore or longer stroke, I'd go with longer stroke.
That's just me.
Thread Starter
Honda-Tech Member
Joined: Apr 2009
Posts: 247
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From: Durban, South Africa
Re: B20 vs B18cR crank
Tnx for the info.
Yes, I do know the difference between the MID's and dry liners, it's just that I was told the dry liners can go to 84, even 85mm.
This does throw a spanner in the works...
Yes, I do know the difference between the MID's and dry liners, it's just that I was told the dry liners can go to 84, even 85mm.
This does throw a spanner in the works...
Re: B20 vs B18cR crank
i don't think darton even makes dry liner sleeves for the b20 engine due to it's singular piece design.
yes the rule of thumb is you can go up to +1mm overbore on dry sleeves.
so if you bought 81mm you can overbore to 82mm, 84mm to 85mm.
so now you have to look at if you want to keep that gsr or find a b20 block.
btw i have a b20 block for sale... hehe crank & rods too. lol
also if you haven't bought rods yet, just use stock LS rods with arp rod bolts.
yes the rule of thumb is you can go up to +1mm overbore on dry sleeves.
so if you bought 81mm you can overbore to 82mm, 84mm to 85mm.
so now you have to look at if you want to keep that gsr or find a b20 block.
btw i have a b20 block for sale... hehe crank & rods too. lol
also if you haven't bought rods yet, just use stock LS rods with arp rod bolts.
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Thread Starter
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Joined: Apr 2009
Posts: 247
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From: Durban, South Africa
Re: B20 vs B18cR crank
Lol, I'm in South Africa.
Here, B20 is the choice for most, along with the s4c box with a 4.7/4.9 fd, mainly because of availability. A b18cR and n3e can set you back around $4/5000 in SA.
I've always been a b18cR fan, so I managed to, entirely by luck, procure a 98 spec ITR. One of just 3 legally registered in the country, that I'm aware of.
I had planned on a turbo build and an 84mm MID sleeved b18c, and over a period of time accumulated almost everything for a 550/600hp build, bar just sleeving the block, an exhaust manifold and some minor odds and ends. All this was meant for my EK Civic sedan.
Then I acquired the ITR and instead decided to build a strong na engine first, based on an 84mm b18c build, which it seems isn't possible, without mid's. Obviously building something inferior to a b20 is pointless.
This is what I have:
-My 98 spec b18cR with n3e box, that's in the itr obviously.
-A b16b bare block.
-A b18cR block with a cracked sleeve but clean crank.
-A gsr motor with a slightly scored crank.
-A B20 crank.
-A set of eagle b18c rods.
-A set of Manley b20 rods.
The idea had been to sell the b16b, use the gsr block with 84mm dry sleeves, and itr crank with eagle rods for the na build, or the b20 crank with its b20 rods.
Then use the itr block with the cracked sleeve for mid sleeving and turbo. Along with the gsr head.
Now though, I'm not so sure.
Here, B20 is the choice for most, along with the s4c box with a 4.7/4.9 fd, mainly because of availability. A b18cR and n3e can set you back around $4/5000 in SA.
I've always been a b18cR fan, so I managed to, entirely by luck, procure a 98 spec ITR. One of just 3 legally registered in the country, that I'm aware of.
I had planned on a turbo build and an 84mm MID sleeved b18c, and over a period of time accumulated almost everything for a 550/600hp build, bar just sleeving the block, an exhaust manifold and some minor odds and ends. All this was meant for my EK Civic sedan.
Then I acquired the ITR and instead decided to build a strong na engine first, based on an 84mm b18c build, which it seems isn't possible, without mid's. Obviously building something inferior to a b20 is pointless.
This is what I have:
-My 98 spec b18cR with n3e box, that's in the itr obviously.
-A b16b bare block.
-A b18cR block with a cracked sleeve but clean crank.
-A gsr motor with a slightly scored crank.
-A B20 crank.
-A set of eagle b18c rods.
-A set of Manley b20 rods.
The idea had been to sell the b16b, use the gsr block with 84mm dry sleeves, and itr crank with eagle rods for the na build, or the b20 crank with its b20 rods.
Then use the itr block with the cracked sleeve for mid sleeving and turbo. Along with the gsr head.
Now though, I'm not so sure.
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From: san diego, ca, USA
Re: B20 vs B18cR crank
its actually easy to answer
long stroke short rods , you MUST have strong strong rods and sleeves = high piston speed lower r:s number but better air turbulence
short stroke long rods ,will require maximum bore which will have to be sleeved
long stroke long rods will net you the best of all worlds to offset the r:s problems but normally needs a custom piston and a deck plate to offset everything else
for the o/s valves you wont see much gain in cfm unless , you must do an aggressive port work, back cut the valves and do a 5 angle valve job , now your pistons will rely on this first .. if you go O/s valves make sure to accommodate the valve relief , or you wont have must timing to play with
i say stroker also
long stroke short rods , you MUST have strong strong rods and sleeves = high piston speed lower r:s number but better air turbulence
short stroke long rods ,will require maximum bore which will have to be sleeved
long stroke long rods will net you the best of all worlds to offset the r:s problems but normally needs a custom piston and a deck plate to offset everything else
for the o/s valves you wont see much gain in cfm unless , you must do an aggressive port work, back cut the valves and do a 5 angle valve job , now your pistons will rely on this first .. if you go O/s valves make sure to accommodate the valve relief , or you wont have must timing to play with
i say stroker also
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Joined: Feb 2003
Posts: 9,820
Likes: 12
From: schooling kids in ny, usa
Re: B20 vs B18cR crank
my 89mm crank/benson 84.5mm sleeved block goes between 9000-9300 rpm at the track depending on how many times i hit the limiter in 1st and 2nd gear. on the street its revs up to 8600 i dont have any problems.
going motor vs. turbo on an 84+mm block is going to be a tremendous difference in power so what are you going to use the car for i guess is the next question. something more fun to drive around in, or something to make that 10 second pass in? sounds like you want the drag motor instead.
i would take all your turbo parts and toss them in a 84mm sleeved b18cR block you have with the eagle rods. for pistons i would try and get something around 10:1 compression.
i would not use oversized valves i dont think its necessary and more hassle then its worth for 500-600hp.
what kind of octane/fuel do you have access to over there?
going motor vs. turbo on an 84+mm block is going to be a tremendous difference in power so what are you going to use the car for i guess is the next question. something more fun to drive around in, or something to make that 10 second pass in? sounds like you want the drag motor instead.
i would take all your turbo parts and toss them in a 84mm sleeved b18cR block you have with the eagle rods. for pistons i would try and get something around 10:1 compression.
i would not use oversized valves i dont think its necessary and more hassle then its worth for 500-600hp.
what kind of octane/fuel do you have access to over there?
Re: B20 vs B18cR crank
https://honda-tech.com/forums/hybrid-engine-swaps-18/deck-height-b20b-%60%60-176225/
Just wondering if it's 100% sure the B20/B18 has a .5mm smaller deckheight?
Just wondering if it's 100% sure the B20/B18 has a .5mm smaller deckheight?
Thread Starter
Honda-Tech Member
Joined: Apr 2009
Posts: 247
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From: Durban, South Africa
Re: B20 vs B18cR crank
its actually easy to answer
long stroke short rods , you MUST have strong strong rods and sleeves = high piston speed lower r:s number but better air turbulence
short stroke long rods ,will require maximum bore which will have to be sleeved
long stroke long rods will net you the best of all worlds to offset the r:s problems but normally needs a custom piston and a deck plate to offset everything else
for the o/s valves you wont see much gain in cfm unless , you must do an aggressive port work, back cut the valves and do a 5 angle valve job , now your pistons will rely on this first .. if you go O/s valves make sure to accommodate the valve relief , or you wont have must timing to play with
i say stroker also
long stroke short rods , you MUST have strong strong rods and sleeves = high piston speed lower r:s number but better air turbulence
short stroke long rods ,will require maximum bore which will have to be sleeved
long stroke long rods will net you the best of all worlds to offset the r:s problems but normally needs a custom piston and a deck plate to offset everything else
for the o/s valves you wont see much gain in cfm unless , you must do an aggressive port work, back cut the valves and do a 5 angle valve job , now your pistons will rely on this first .. if you go O/s valves make sure to accommodate the valve relief , or you wont have must timing to play with
i say stroker also
When you say stroker, I assume you mean go with the B20 crank?
my 89mm crank/benson 84.5mm sleeved block goes between 9000-9300 rpm at the track depending on how many times i hit the limiter in 1st and 2nd gear. on the street its revs up to 8600 i dont have any problems.
going motor vs. turbo on an 84+mm block is going to be a tremendous difference in power so what are you going to use the car for i guess is the next question. something more fun to drive around in, or something to make that 10 second pass in? sounds like you want the drag motor instead.
i would take all your turbo parts and toss them in a 84mm sleeved b18cR block you have with the eagle rods. for pistons i would try and get something around 10:1 compression.
i would not use oversized valves i dont think its necessary and more hassle then its worth for 500-600hp.
what kind of octane/fuel do you have access to over there?
going motor vs. turbo on an 84+mm block is going to be a tremendous difference in power so what are you going to use the car for i guess is the next question. something more fun to drive around in, or something to make that 10 second pass in? sounds like you want the drag motor instead.
i would take all your turbo parts and toss them in a 84mm sleeved b18cR block you have with the eagle rods. for pistons i would try and get something around 10:1 compression.
i would not use oversized valves i dont think its necessary and more hassle then its worth for 500-600hp.
what kind of octane/fuel do you have access to over there?
I couldn't possibly go that high on cr. We have very low quality fuel in SA, 95 at the coast where I live. Currently, I have the 8.4-8.8 Wisecos, which I had planned on selling to get the 9 or so cr pistons, but in retrospect, I think maybe the 8.4-8.8 might still be safer for a built in buffer.
https://honda-tech.com/forums/showthread.php?t=176225
Just wondering if it's 100% sure the B20/B18 has a .5mm smaller deckheight?
Just wondering if it's 100% sure the B20/B18 has a .5mm smaller deckheight?
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Joined: Feb 2003
Posts: 9,820
Likes: 12
From: schooling kids in ny, usa
Re: B20 vs B18cR crank
so honestly 95 isnt that low of an octane, as long as its consistent so you dont get a good tank then a bad tank..
i think 8's is way to low for compression, you can really be closer to 10:1. it will make the engine more efficient, keeping boost pressure a bit lower to reach a certain power level. worst case is that it runs a few degrees less timing, oh well that will all be decided on a dyno
as for the all motor setup first, 84mm is a good starting point as it will allow you to go .020 over a few times in case of bad stuff happening. something with a compression of right about 12:1 and a good cam set will produce good numbers and a nice tq/powerband if it has the right header/other supporting components.
side note, you might want to look into the sk2 ultra manifold. you can run it with the smaller plenum for n/a and then use the spacers to increase plenum volume when u boost
i think 8's is way to low for compression, you can really be closer to 10:1. it will make the engine more efficient, keeping boost pressure a bit lower to reach a certain power level. worst case is that it runs a few degrees less timing, oh well that will all be decided on a dyno
as for the all motor setup first, 84mm is a good starting point as it will allow you to go .020 over a few times in case of bad stuff happening. something with a compression of right about 12:1 and a good cam set will produce good numbers and a nice tq/powerband if it has the right header/other supporting components.
side note, you might want to look into the sk2 ultra manifold. you can run it with the smaller plenum for n/a and then use the spacers to increase plenum volume when u boost
Thread Starter
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Joined: Apr 2009
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From: Durban, South Africa
Re: B20 vs B18cR crank
so honestly 95 isnt that low of an octane, as long as its consistent so you dont get a good tank then a bad tank..
i think 8's is way to low for compression, you can really be closer to 10:1. it will make the engine more efficient, keeping boost pressure a bit lower to reach a certain power level. worst case is that it runs a few degrees less timing, oh well that will all be decided on a dyno
as for the all motor setup first, 84mm is a good starting point as it will allow you to go .020 over a few times in case of bad stuff happening. something with a compression of right about 12:1 and a good cam set will produce good numbers and a nice tq/powerband if it has the right header/other supporting components.
side note, you might want to look into the sk2 ultra manifold. you can run it with the smaller plenum for n/a and then use the spacers to increase plenum volume when u boost
i think 8's is way to low for compression, you can really be closer to 10:1. it will make the engine more efficient, keeping boost pressure a bit lower to reach a certain power level. worst case is that it runs a few degrees less timing, oh well that will all be decided on a dyno
as for the all motor setup first, 84mm is a good starting point as it will allow you to go .020 over a few times in case of bad stuff happening. something with a compression of right about 12:1 and a good cam set will produce good numbers and a nice tq/powerband if it has the right header/other supporting components.
side note, you might want to look into the sk2 ultra manifold. you can run it with the smaller plenum for n/a and then use the spacers to increase plenum volume when u boost
I'm thinking around 9.5 at least for the turbo.
Again, I wouldn't go as high as 12. Its been tried locally on our pump gas, & 12 is borderline. We generally err on the side of caution & go around 11.7 or so.11.5 is more common.
I'd need to wait for the exchange rate to stabalze first, before even contemplating getting one of those. I think my brother bought one for his B20 setup a few months ago though.
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Aug 25, 2004 04:50 PM