04-29-2003, 11:35 AM
What's the deal with this engine? Is it just not good to build or what? If not Why?

If you could get one free to replace a stock '94 Civic D15 would you get it and build it up a bit? I think I can get a close to free turbo for it too. Is it worth the hassle?


04-29-2003, 03:25 PM
First off you wouldn't want to put the whole B20 into your car in the first place it wouldn't be worth it. The only thing good about a B20 is if you put a VTEC head on it and there are a ton of sites that tell you how to do it. If you put the VTEC head on it then yes its worth it but theres a lot more to it than just slapping the head on the block do a search on CRVTEC and you'll find out how to do it. Yes its worth it if you know anything about engines and can do it yourself or find a shop that knows how to do it but it might cost you a little though. Good luck, O I'm not real up on the whole B20 thing so I don't know if theres different B20's or not mabey someone else can help in that area

04-29-2003, 05:01 PM
well, I heard that B20A5 was not good for crvtec, why? I have no idea.

I am putting a B20b in my civic, and just B20(for now) but I bet even though it has not much top end goodness. I am sure it will be faster than my CX 70hp stock 1.5l

04-29-2003, 09:49 PM
ive been told if you make a CRVtec there is a valve-piston clearance problem, like if your head runs the vtec lobes... BANG?

04-29-2003, 11:03 PM
I think that aftermarket pistons have big enough valve clearances for the vtec head. at leats the ones I bought are intended for the B20b4 w/ b16 head, so im guessing mine ae gonan be safe when i go crvtec later on.

05-01-2003, 04:41 PM
A B20A5 is the 88-91 Prelude Si Engine. It has a R/S of 1.49. The D15 you're replacing had a 1.62 R/S. Plus the B20A5 sits like the H22A and H23A1, it tilts backwards. You don't want this engine and it would require custom mounts, because no one has wasted there time making any.
The engine is rated from 135-140 hp depending on the year of production.

05-07-2003, 05:19 AM
Yup... B20a5 is a piece of crap - dont waste your money OR your time with it just because you see them cheap.

06-03-2003, 01:41 AM
B20a5 not good to build up, but it would definetly give you a power boost. My 89 Lude has 325k miles, hard miles too. If the r/s is so bad on this car, then i guess the other engines will run for a million miles.

06-03-2003, 03:20 AM
325K my god thats amazing, HONDA'S RULE!!!! Ha hope all you VWer's out there read this and kiss are happy AZZZZZ's lol jk. Sorry most my friends have VW's so I have to rub it in, they think there hot S#$T because they can beat me after 110mph, who needs to go that fast anyway???

06-03-2003, 11:35 AM
Thats nothing, my mechanic works on a 500k mile 87 Lude, not the same engine I think though. Also, a B16 would definetly be worth more swapping in a civic. A b20a5 WOULD be a painfull install where the b16 is meant for the civic, if you get the right one. Leave the B20A5's to us Lude owners waiting for are engines to die! (even though Ill probably get an integra when it dies, hehehe)

06-05-2003, 09:52 PM
hey b20s are good motors!just gotta add the right parts

06-25-2003, 12:17 AM
I agree with PreludeX,
The b20a5 is a better turbo motor it has a low 9:1 C/R wich is far better then watising your money on a n/a 2.0 or even opting for a vtec b16. You Honda guys have to stop obsesing about vetc. Its a great system for small n/a motors to get more torque, but vetc isnt as needed with the extra cubes and turbos.

A well tuned turbo 2.0 will have a much better powerband with just 5 lbs of boost with no intecrooler, then any vtec b18 tuned, ported, camed, with race headers can have. Im not saying the 2.0 is the greatest stock turbo platform ever and it can handle 15 lbs, but if you can have some self control and leave the boost at 5lbs it should be a reliable engine, or mabey sneak it to 8 lbs ;). adn if you like teh engine and realize its potential you can get some forged low c/r pistons, rods, do some port work, a good turbo cam, and youd have a 400+hp engine on pump gas, if you build it right with a low 8:1 c/r and a well matched turbo or turbos(?)

(btw. why dont i ever see any twin turbo hondas? There are a few turbos small enough to accieve this, one i beleive is a garret t2. Ive never seen one on eaby but i bet there isa bunch of turbos small enough in a turbo shop, if you look around.)

Once you put a turbo on a vtek engine, the extra duration and overlap from vetc only increases reversion. This is my theory of why so much extra midrange power is made with the vetc turned at a higher rpm for turbo vect engines. That means the vect isnt as important as you guys dream.

This is why turbo eclipses and talons are so much faster, they have more displacment and a turbo. Midsubishi could have designed a turbo engine for there eclipses with some type of variable cam system but the engineers know its not worth it with turbos. Turbos already increase and strech the powerband far past any variable system would be worth to improve on.

06-25-2003, 02:28 AM
After running into more info on the idea of Turboing a B20A5, I would tend to agree that it would make a potent combo. I always here about the bad "r/s ratio" on B20A's, but yet mine has made it over 300k EASY! It definetly sounds like it could handle a low boost turbo would still be pretty reliable and I am going to look into it more. I think one issue with the original post 94 Civic is the legal issue of putting an older model year engine in your car.

06-25-2003, 03:27 PM
Turbo motors like short r/s ratios anyways. It reduces the effects of reversion. i cant find any technical info on the b20 but i believe it has small bore/stroke ratio so the smaller bore would bre more resistant toi detonation and will allow for some extra boost. I was loking on ebay for a b20 for my friends crx and found a guy thet swaped a b20 into his crx put a y28 turbo on and with only 6 lbs of intercooled boost 210 hp/190 tq. The intercooler probably only make around an extra 5 hp or so because the charge temps arent high with only 6 lbs. check it out yourself,


06-25-2003, 06:01 PM

This car has a transplanted B20B engine.

ITS NOT A B20a5...

06-25-2003, 07:29 PM
its not just the r/s ratrio that is bad on the b20a5 guys you keep forgetting the mounting position. it would requier custom mounts. and the r/s ratio really only matters when the engine is revved high. at low rpm it makes almost no difference.

06-26-2003, 12:18 AM
whats the diff?

Add your comment to this topic!