Ok I'm picking up a B21A1 and cable tranny that it's hooked to. I'm told it was pulled from an Integra. When I got there to see the engine I realized it wasn't a B18 that I was expecting but a B21A1 which I'd never heard of before. After a little research finding that it was the 91 Prelude engine. Now since the engine was free it's not a big deal but will it really fit in an Integra? Did the 91 Prelude have a cable tranny? What's the redline on that like maybe 6200. What to look out for if I put it into my 1990 Integra that might need a new engine. Assuming the engines good as I havn't done a compression test yet is it worth using or say don't waste my time?

 

hmm.....I can't tell you anything about it fitting or not, which I'm sure can be done, but I can tell you a little bit about as I have one in my 91 prelude Si.


B21A1 2.1 liter non-vtec

DOHC 16 Valve PGM-FI

Horsepower@rpm: 140@5800
Torque (lb.ft. @ rpm): 135@5000
Compression Ratio: 9.4:1
Redline: 6400

It takes pretty well to bolt ons too... some of the dyno proven results were:

DC Sports CC 4-2-1 header.........11.68whp / 9.8wtq
AEM Cam gears.........................-2I/-4E netted 7.1whp and 4.3wtq
Thermal R&D catback:................ 4.5whp / 3.01wtq

These are just some of the bolt ons, also, the final drive ratio of the DJ25 tranny that comes with B21A1 is a 4.27, short gearing much like that of a gsr tranny.

 

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But I can! It won't fit in anyother car without custom mounts except for another 88-91 prelude. It's a strong engine also unless it's rings are shot as many of them were when Honda was experimenting with FRM sleeves which chewed up the piston rings in there. Also its cams and head don't really match each other very well. If you want to sell it I bet you could get a little more money than you bought if for (lol) at http://www.preludepower.com

 

Cool thanks. So the prelude engines really were the bastard B series. I was hoping that even though is was old a B18 head might fit on the block. I guess kinda like the old D16 Integra engine woulnd't fit anything newer and nothing interchangable. Was the 91 Prelude tranny cable? Cause the mounts are still on the engine, the one on the engine is kinda weird has a big cylinder looking thing on it I don't remember seeing on other hondas.

 

i just know that the b21's were more known for bad rings.. then the b20's i have a b20a5 mine burns oil real bad as well... but bastard b series is right IMO they suck ***... all kinds of bullshit vacum lines and hoses and ****.. i'm sick of it... i wanna JDM B20 bad.. one in better condish..

 

I have a 91 honda Prelude with a b21a1 with 144 thousand on it and to tell the truth the b21a1 engine is realy relieable and has alot of get up and go for a 4 banger. it's all stock and runs strong. 3 gen prelude's are fun cars

 

This motor is a good motor when it does not burn up its ring lands and then blows through oil like a quart a week. It was the first generation FRM technology before Honda was able to fine tune it a little better for the H22 and other Honda motors.

But, unfortunately you will run into that oil burning problem soon enough. At which point you can rebuild and and re-ring the pistons but run into the same issue down the road again or change out the long block to the B20a(JDM) or B20a5(USDM) 1988-89 Prelude motors of that year. And get a more reliable motor that is ready for turbocharging due to the iron sleeves that come stock in the B20a5 blocks.

Or you can swap to the H22 motor and join the growing number of 3rd genners that have swapped including myself to the H with more power and aftermarket potential.

Either way is up to you, but should you have questions about what can be done to this chassis then email me at: 1funryd@comcast.net

I support this chassis by selling and creating aftermarket parts for it and know where to get the existing aftermarket parts for it as well.

And for your information, you will get more support for this chassis at: www.p r e l u d e p o w e r.com(minus the spaces)

Sean

 

where did you get your cams from for your b21a1? i cant find any that are cheap. and i cant find any motors that are compatible. i need help please. my cams are screwed and my rockers are shaking and i need them replaced ASAP.. please help

 

I ran into the same problem about 5 years ago the b21 is truly the bastard B. we couldn't get it into anything else tried an EF and an EG we just ended up using the engine as target practice lol

 

There are no cheap options for anything 3rd gen related.

If you are looking for OEM new, then you are out of luck, they dont make them.

You can call the big name cam makers and then can do cam regrinds for you which is no cheap option, but it should help you out of your situation.

Other that, you will need to look at buying a JDM B21a(Rare) or swap over to the B20a(JDM).

Or look around junkyards for spare parts, and there is a seller on ebay called hondapartsunlimited and they are a junkyard out of California that sell and ship(only) all their parts. They usually have a good selection of stuff for the 88-91 ludes. I know I purchase many parts from them.

 

there aight

 

it will fit might take a lil work but it can be done and the prelude has a hydraulic clutch and redline is about 6500

 

NO its not a drop in.

You will need to make custom mounts to make it work, which I do not think you will want to do especially since there is no real aftermarket for the B21a1.

It was the first Prelude motor to come with FRM sleeves(google FRM sleeves) and there was no solution to resolve the buring of oil after so many thousands of miles.

Honda got better in the H22/23 motors, but they did not do anything for the B21a1.

There are only 2 header's that are still in production, one is the OBX replica and another is Pacesetter. Everything else is discontinued.

So at this point from start to finish everything you do will be custom, and you will have to do a wire conversion as well, because the engine harness does not plug and play with any civic/integra engine harness.

The motor is slanted at 18 degrees from the factory so it does not sit up right and the intake manifold sits real close to the rear subframe on the 90-91 Prelude engine bay.

Good luck, because those motors are notorious for throwing the number 3 rod when oil starvation occurs due to burning of oil much more than the H22/23 motors do.

I personally would walk away from that motor, so don't say you werent warned.

 

Hydro trans with shifter cables. Dont bother with this motor. It is a downgrade.