building All Motor b21a1
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From: frederick, MD
building All Motor b21a1
this winter i am getting my engine rebuilt and am going to try to push as much power out of it as i can, how can i get the most power out of the engine? im looking for over 200 whp
***i know its hard with that engine, but thats half the reason i want to do it, there arent many else out there
***i know its hard with that engine, but thats half the reason i want to do it, there arent many else out there
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From: Corona, CA, USA
Re: building All Motor b21a1 (Mr Milano)
yeah...seriously, i mean...not to knock on your motor, buts its seriously the worst motor honda has ever made. probably one of the worst chassis too. you can't swap anything in there w/out a headache, can't fix up that motor, it has a horrible r/s ratio...the list goes on
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From: Orland Park, Il, USA
Re: building All Motor b21a1 (SimbaDogg)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SimbaDogg »</TD></TR><TR><TD CLASS="quote">yeah... probably one of the worst chassis too. you can't swap anything in there w/out a headache, </TD></TR></TABLE>
The motor is a peice of ****, but regarldess the car in general is badass. The h22 swap in that is just as easy as putting a h22 in a eg or ek. Place racing has the mounts, axles, and interface box you would need. You could aslo get a jdm b20a, and boost the hell out of it. The b21 is just a pain in the ***, no matter what you do its going to burn oil.
The motor is a peice of ****, but regarldess the car in general is badass. The h22 swap in that is just as easy as putting a h22 in a eg or ek. Place racing has the mounts, axles, and interface box you would need. You could aslo get a jdm b20a, and boost the hell out of it. The b21 is just a pain in the ***, no matter what you do its going to burn oil.
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From: Sacramento, CA, USA
Re: building All Motor b21a1 (Mr Milano)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr Milano »</TD></TR><TR><TD CLASS="quote">What is up with all these kids wanting to build old prelude motors latley. I'm not trying to discurage you but it aint gonna be cheap and it aint gonna be easy.</TD></TR></TABLE>
I think the whole reason why so many people have been considering this lately is the fact that these motors get you more displacement than a typical Honda motor AND they are dirt cheap. But people forget that bolting them into a Civic is not just a simple matter of giving Hasport a call. This motor is a cut and weld swap into ANY Civic. In fact, I would go so far as to say that unless you actually have a 1988-1991 Prelude, don't even consider using this motor. If you want big displacement, consider a B20B or B20Z. With the exception of price, this motor is superior in every way possible to the old 1988-1991 Prelude motors. Or consider an H22A swap.It bolts into 1992+ Civics with a kit, which is ALOT more than can be said about the old Prelude motors. And even though it is a cut and weld swap into a 1988-1991 Civic, so is a B20A/B21A swap. And the B209A/B21A won't produce nearly as much power as even the non-VTEC (and fairly cheap) H23A. It also next to no aftermarket support.
If you do have a 1988-1991 Prelude, I would consider the possibility of the H-swap that the other guy mentioned. As mentioned above, even the basic non-VTEC H23A produces ALOT more power and torque than the B21A. And aftermarket support is WAY better. As for the H22A, there is simply no comparison. But if you stick with the B21A, you are kind of on your own. There is little in the way of aftermarket support for this motor. The only positive thing I have heard about this motor is a rumor that you can slap a B16A VTEC head on it. But it's just that - a rumor.
I know you want to be different. But at some point you have to ask yourself if the costs of doing so and mediocre results are worth it. If you REALLY want to be different, you can do as Bisi has done and go with an F22A SOHC VTEC. At least that motor has potential.
I think the whole reason why so many people have been considering this lately is the fact that these motors get you more displacement than a typical Honda motor AND they are dirt cheap. But people forget that bolting them into a Civic is not just a simple matter of giving Hasport a call. This motor is a cut and weld swap into ANY Civic. In fact, I would go so far as to say that unless you actually have a 1988-1991 Prelude, don't even consider using this motor. If you want big displacement, consider a B20B or B20Z. With the exception of price, this motor is superior in every way possible to the old 1988-1991 Prelude motors. Or consider an H22A swap.It bolts into 1992+ Civics with a kit, which is ALOT more than can be said about the old Prelude motors. And even though it is a cut and weld swap into a 1988-1991 Civic, so is a B20A/B21A swap. And the B209A/B21A won't produce nearly as much power as even the non-VTEC (and fairly cheap) H23A. It also next to no aftermarket support.
If you do have a 1988-1991 Prelude, I would consider the possibility of the H-swap that the other guy mentioned. As mentioned above, even the basic non-VTEC H23A produces ALOT more power and torque than the B21A. And aftermarket support is WAY better. As for the H22A, there is simply no comparison. But if you stick with the B21A, you are kind of on your own. There is little in the way of aftermarket support for this motor. The only positive thing I have heard about this motor is a rumor that you can slap a B16A VTEC head on it. But it's just that - a rumor.
I know you want to be different. But at some point you have to ask yourself if the costs of doing so and mediocre results are worth it. If you REALLY want to be different, you can do as Bisi has done and go with an F22A SOHC VTEC. At least that motor has potential.
Joined: Feb 2002
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From: rigged and ready., WashingtonD.C./FlagstaffAZ/TempeAZ usa
Re: building All Motor b21a1 (StorminMatt)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StorminMatt »</TD></TR><TR><TD CLASS="quote">
I think the whole reason why so many people have been considering this lately is the fact that these motors get you more displacement than a typical Honda motor AND they are dirt cheap. But people forget that bolting them into a Civic is not just a simple matter of giving Hasport a call. This motor is a cut and weld swap into ANY Civic. In fact, I would go so far as to say that unless you actually have a 1988-1991 Prelude, don't even consider using this motor. If you want big displacement, consider a B20B or B20Z. With the exception of price, this motor is superior in every way possible to the old 1988-1991 Prelude motors. Or consider an H22A swap.It bolts into 1992+ Civics with a kit, which is ALOT more than can be said about the old Prelude motors. And even though it is a cut and weld swap into a 1988-1991 Civic, so is a B20A/B21A swap. And the B209A/B21A won't produce nearly as much power as even the non-VTEC (and fairly cheap) H23A. It also next to no aftermarket support.
If you do have a 1988-1991 Prelude, I would consider the possibility of the H-swap that the other guy mentioned. As mentioned above, even the basic non-VTEC H23A produces ALOT more power and torque than the B21A. And aftermarket support is WAY better. As for the H22A, there is simply no comparison. But if you stick with the B21A, you are kind of on your own. There is little in the way of aftermarket support for this motor. The only positive thing I have heard about this motor is a rumor that you can slap a B16A VTEC head on it. But it's just that - a rumor.
I know you want to be different. But at some point you have to ask yourself if the costs of doing so and mediocre results are worth it. If you REALLY want to be different, you can do as Bisi has done and go with an F22A SOHC VTEC. At least that motor has potential.</TD></TR></TABLE>
couldn't be said better, in bisi's case he weighed the costs and result, and while still being different, he managed to build an engine relativly cheaply and w/ out much trouble, and he has an amazing car that most everybody has the utmost respect for, even a lot of domestic guys
I think the whole reason why so many people have been considering this lately is the fact that these motors get you more displacement than a typical Honda motor AND they are dirt cheap. But people forget that bolting them into a Civic is not just a simple matter of giving Hasport a call. This motor is a cut and weld swap into ANY Civic. In fact, I would go so far as to say that unless you actually have a 1988-1991 Prelude, don't even consider using this motor. If you want big displacement, consider a B20B or B20Z. With the exception of price, this motor is superior in every way possible to the old 1988-1991 Prelude motors. Or consider an H22A swap.It bolts into 1992+ Civics with a kit, which is ALOT more than can be said about the old Prelude motors. And even though it is a cut and weld swap into a 1988-1991 Civic, so is a B20A/B21A swap. And the B209A/B21A won't produce nearly as much power as even the non-VTEC (and fairly cheap) H23A. It also next to no aftermarket support.
If you do have a 1988-1991 Prelude, I would consider the possibility of the H-swap that the other guy mentioned. As mentioned above, even the basic non-VTEC H23A produces ALOT more power and torque than the B21A. And aftermarket support is WAY better. As for the H22A, there is simply no comparison. But if you stick with the B21A, you are kind of on your own. There is little in the way of aftermarket support for this motor. The only positive thing I have heard about this motor is a rumor that you can slap a B16A VTEC head on it. But it's just that - a rumor.
I know you want to be different. But at some point you have to ask yourself if the costs of doing so and mediocre results are worth it. If you REALLY want to be different, you can do as Bisi has done and go with an F22A SOHC VTEC. At least that motor has potential.</TD></TR></TABLE>
couldn't be said better, in bisi's case he weighed the costs and result, and while still being different, he managed to build an engine relativly cheaply and w/ out much trouble, and he has an amazing car that most everybody has the utmost respect for, even a lot of domestic guys
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From: Orland Park, Il, USA
Re: building All Motor b21a1 (SimbaDogg)
One day when i get bored i want to do another the 3rdgen. The motor stock is gay, you cant really say there are no parts for it. Just cause apc didnt make some tail lights, and greddy doesnt have a turbo kit doesnt mean the car is a lost cause. The Motor can be built with h23 rods, bseries pistons, bseries non-vtec valvetrain, cams are available the list goes on....... The vtec head can also be put on, just a matter of moving the front head bolts up alittle bit.
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From: Miami, FL
Re: building All Motor b21a1 (dwn-shift)
I was thinking of running an crv block with a B21 crank, and throw a greddy kit on it for my daily driver motor. Redline would be like 6500 but it doesn't matter cus the motor's purpose would be low end torque to daily drive with. If I want to race, ill use my 240whp 10,000rpm motor...
Is there anything wrong with a setup like that?
B20b block
B21a crank (perhaps offset grinded a little big)
B16 stock rods (arp rod bolts)
Ported LS Head
Thicker Headgasket + ARP Head Bolts
Block Guard
B18c1 Greddy Turbo Kit
Hondata + 440cc injectors
I could throw that setup together for almost no money at all..probably less then 1500bux for the entire motor.
Is there anything wrong with a setup like that?
B20b block
B21a crank (perhaps offset grinded a little big)
B16 stock rods (arp rod bolts)
Ported LS Head
Thicker Headgasket + ARP Head Bolts
Block Guard
B18c1 Greddy Turbo Kit
Hondata + 440cc injectors
I could throw that setup together for almost no money at all..probably less then 1500bux for the entire motor.
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From: Winnipeg, MB, Canada
Re: building All Motor b21a1 (dwn-shift)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dwn-shift »</TD></TR><TR><TD CLASS="quote">The vtec head can also be put on, just a matter of moving the front head bolts up alittle bit. </TD></TR></TABLE>
What do you mean "up a little". Headbolts placement isn't something you can easily modify.
What do you mean "up a little". Headbolts placement isn't something you can easily modify.
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From: Wayland, MI, US
Re: building All Motor b21a1 (dwn-shift)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dwn-shift »</TD></TR><TR><TD CLASS="quote">One day when i get bored i want to do another the 3rdgen. The motor stock is gay, you cant really say there are no parts for it. Just cause apc didnt make some tail lights, and greddy doesnt have a turbo kit doesnt mean the car is a lost cause. The Motor can be built with h23 rods, bseries pistons, bseries non-vtec valvetrain, cams are available the list goes on....... The vtec head can also be put on, just a matter of moving the front head bolts up alittle bit. </TD></TR></TABLE>
The b21 lude motor will not take b series 81mm slugs. Unless you don't mind a couple extra mms of clearance. Maybe you could just move the bores up a bit to match the head bolts you just moved.
Modified by TimoneX at 7:11 PM 10/1/2003
The b21 lude motor will not take b series 81mm slugs. Unless you don't mind a couple extra mms of clearance. Maybe you could just move the bores up a bit to match the head bolts you just moved.
Modified by TimoneX at 7:11 PM 10/1/2003
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From: Orland Park, Il, USA
Re: building All Motor b21a1 (TimoneX)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TimoneX »</TD></TR><TR><TD CLASS="quote">
The b21 lude motor will not take b series 81mm slugs. Unless you don't mind a couple extra mms of clearance. Maybe you could just move the bores up a bit to match the head bolts you just moved.
Modified by TimoneX at 7:11 PM 10/1/2003</TD></TR></TABLE>
Well buddy the "ancient lude motors" are a 81mm bore, with a 95mm crank. Thats how you get the 2.0. Its amazing any machine shop can easily redo the bolt spacing.
Here is a quote from Tom colman who actually did the swap
""To make 200HP at the wheels, you will need to install VTEC pistons (PR3 B16, ITR, CTR). This involves taking the rods to a mchine shop and having them install bushings to accpet the smaller piston pin of the VTEC pistons. You will also need ITR or better (JUN or TODA) cams and some adjustable cam gears to make the power. Of course, the setup will have to be dyno tuned to get the most out of it. Please be aware that it is unsafe to rev the stock rods past 7500rpm. If you install Eagle H22 or H23 rods, then 8000rpm will be safe. """"
The b21 lude motor will not take b series 81mm slugs. Unless you don't mind a couple extra mms of clearance. Maybe you could just move the bores up a bit to match the head bolts you just moved.
Modified by TimoneX at 7:11 PM 10/1/2003</TD></TR></TABLE>
Well buddy the "ancient lude motors" are a 81mm bore, with a 95mm crank. Thats how you get the 2.0. Its amazing any machine shop can easily redo the bolt spacing.
Here is a quote from Tom colman who actually did the swap
""To make 200HP at the wheels, you will need to install VTEC pistons (PR3 B16, ITR, CTR). This involves taking the rods to a mchine shop and having them install bushings to accpet the smaller piston pin of the VTEC pistons. You will also need ITR or better (JUN or TODA) cams and some adjustable cam gears to make the power. Of course, the setup will have to be dyno tuned to get the most out of it. Please be aware that it is unsafe to rev the stock rods past 7500rpm. If you install Eagle H22 or H23 rods, then 8000rpm will be safe. """"
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From: Wayland, MI, US
Re: building All Motor b21a1 (dwn-shift)
I'm aware the b20a uses 81mm bore. The b21 does not, and it was the topic of this conversation. If you want to put that kind of work into what is after all a very unimpressive motor by Honda standards then be my guest.
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From: Orland Park, Il, USA
Re: building All Motor b21a1 (TimoneX)
.<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TimoneX »</TD></TR><TR><TD CLASS="quote">I'm aware the b20a uses 81mm bore. The b21 does not, and it was the topic of this conversation. If you want to put that kind of work into what is after all a very unimpressive motor by Honda standards then be my guest.</TD></TR></TABLE>
Great the b21a has a 83mm bore, companies do make 81-87mm bore pistons Some people like the old ludes, if you have driven and owned one you would understand. THe lude isnt a drag car, in stock form this car will kick major *** in any autoX event.
Great the b21a has a 83mm bore, companies do make 81-87mm bore pistons Some people like the old ludes, if you have driven and owned one you would understand. THe lude isnt a drag car, in stock form this car will kick major *** in any autoX event.
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From: Wayland, MI, US
Re: building All Motor b21a1 (dwn-shift)
I had 2 right in a row. The second one because the first got totalled. Both 88si w/o 4ws and have mentioned it numerous times here in the past. They were fine, but that was several years ago and I didn't think enough of the design to think it worthy of turning it into a money pit. There are much better platforms, but you do what you want with your $$$ and good luck.
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From: Sacramento, CA, USA
Re: building All Motor b21a1 (dwn-shift)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dwn-shift »</TD></TR><TR><TD CLASS="quote">Some people like the old ludes, if you have driven and owned one you would understand. THe lude isnt a drag car, in stock form this car will kick major *** in any autoX event. </TD></TR></TABLE>
If you like the 3G Prelude, fine. But what I think is really stupid is how people these days want to swap those crappy motors into Civics. I mean, why would you want one if you don;t have to use one?
If you like the 3G Prelude, fine. But what I think is really stupid is how people these days want to swap those crappy motors into Civics. I mean, why would you want one if you don;t have to use one?
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From: Import Builders, US
Re: building All Motor b21a1 (prdtr15)
If its something you want to do then go for it. You dont have to follow the pack on this one... I see some potential with this motor, some real potential but it aint going to be an inexpensive build by anymeans...
Before I go into detail about my ideas Id just like to say that Ive never put thought into building this motor until now... read my ideas and tell me what you think... I might suprise you a little
B21a1, Essentually the same block as the B20A1,3,5 with a slightly larger bore (83mm as apposed to 81mm). I say get a builder block to start with, a B20A5... Sleeves are a must (85mm) but I think you should take it a step further... Can you say... deck plate? run a 3/4 inch deck plate and taller stepped flange style sleeves to accomidate the new deck height... this will solve the engines poor geometry... I believe the stock rod length was 141.5??? Ok, Im going to use a guestimate that the deck height is 8.625... with a 3/4 inch deck plate viola! 9.375 of block to play with... This enables you to run a 160.5mm rod which will bring the rod/stroke ratio to 1.69... not too shabby... I recomend having the crank crio frozen for a little added strength and having the entire rotating assembly balanced...
Well, theres the block... we now have a 2.2L with a 1.69 r/s ratio
How about the head?
Well, unfortunately there arent any options for a VTEC head... been tried by a few and... nope, no worky. The stock head is going to have to be retained here. Some decent headwork will greatly benefit this head... from what I recall, its fairly similar to a LS head... Im not sure if you can run the LS cams or not but if you can cam set ups are endless, even if you cant use LS cams the possibilities for finding a decent cam grinder/maker is a sure bet.
IM...
eh, thats no fun... its a 91... Carbs, yeah... carbs are cool.
Weber 48 side drafts should do the trick
Well, thats my take on it...
Keep in mind the cost will be that of a B-series VTEC build but I think you can hit some 200+ WHP marks with the set up I described. Sure its not the popular choice but as everyone knows theres more than one way to make HP.
Whatchya guys think?
Before I go into detail about my ideas Id just like to say that Ive never put thought into building this motor until now... read my ideas and tell me what you think... I might suprise you a little
B21a1, Essentually the same block as the B20A1,3,5 with a slightly larger bore (83mm as apposed to 81mm). I say get a builder block to start with, a B20A5... Sleeves are a must (85mm) but I think you should take it a step further... Can you say... deck plate? run a 3/4 inch deck plate and taller stepped flange style sleeves to accomidate the new deck height... this will solve the engines poor geometry... I believe the stock rod length was 141.5??? Ok, Im going to use a guestimate that the deck height is 8.625... with a 3/4 inch deck plate viola! 9.375 of block to play with... This enables you to run a 160.5mm rod which will bring the rod/stroke ratio to 1.69... not too shabby
... I recomend having the crank crio frozen for a little added strength and having the entire rotating assembly balanced...Well, theres the block... we now have a 2.2L with a 1.69 r/s ratio
How about the head?
Well, unfortunately there arent any options for a VTEC head... been tried by a few and... nope, no worky. The stock head is going to have to be retained here. Some decent headwork will greatly benefit this head... from what I recall, its fairly similar to a LS head... Im not sure if you can run the LS cams or not but if you can cam set ups are endless, even if you cant use LS cams the possibilities for finding a decent cam grinder/maker is a sure bet.
IM...
eh, thats no fun... its a 91... Carbs, yeah... carbs are cool.
Weber 48 side drafts should do the trick
Well, thats my take on it...
Keep in mind the cost will be that of a B-series VTEC build but I think you can hit some 200+ WHP marks with the set up I described. Sure its not the popular choice but as everyone knows theres more than one way to make HP.
Whatchya guys think?
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87dxrex
Honda CRX / EF Civic (1988 - 1991)
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