It is an interference engine.

 

i had a 90 prelude si with a b20aX in it i think it was b20a5, either way, im not sure if they are the same engine, but i broke the t-belt also and it was a bitch, didnt make any crunching noises either, maybe the key on the crank cracked in half on your motor.

either way, im pretty sure its interference and you are probably screwed if you cant fix the head yourself, cause they nail ppl for that. best bet is to buy a used motor for like 700 or a head if possible.

 

The B20a5 is a very diff motor. Almost nothing is interchangeable with other B series motors.
I only paid 750 for this motor 20k ago.
I can pull the head but of course a shop will have to repair the damage if any.

gtiger...how sure are you on the interference info? My normal site is down and they have lots of B20 info but of course I cant go check.

 

The vast majority of Honda engines are interference engines, the B20B/Z definately is.

 

I totally forgot about the keys. h: I posted really late at night and I was really tired, never will I do that again.

But yeah what you said is totally possible.

Do the b20b pistons have the cut out for the valves? If it does then you maybe in luck. If you have a hand vaccum pump with a gauge, you can use it to see if the head is leaking with the valves closed on the intake and exhaust port side.

I can't think of a Honda engine that isn't interference, maybe the older ones like from the 70's or something.

 

yea any overhead cam honda is probably interference, by nature

rotate the cams to TDC for each cylinder. then crank the engine. probably get a decent compression psi that way.

of course you will also be mashing the remaining valves that werent already broken when doing this

so do you feel lucky

~boom

 

Seen it happen.

Also, nearly every Honda engine made since '84 has been an interference engine.

 

Ok to start with I have verified that even the low comp B20b is an interference motor.

When I pulled the valve cover the two cams were 180 degrees off. The stripped belt was at the crank.

As near as I can figure (meaning this is my best guess) I think I know what happened. When I installed this motor I used a cap and rotor from Shucks (Checker/Kragen your choice.) When I had this problem I pulled the cap and the rotor was hanging loose even though the screw was still tight. The plastic had separated from the metal that screws on. This allowed the rotor to swing in a large arc. There is a plastic ridge inside the cap that has a chunk out of it. I assume the rotor swung and caught on the ridge and stopped the cam. The cam stopped but the crank was turning the belt so the belt stripped. The rotor then let go so the cam could turn again.
The crank continued to turn the belt until the stripped part got to the crank. Then of course it could go no farther. This loosed the cams and they settled at a closed position because of the valve spring pressure.

I checked the valve clearance and all were in spec so I chanced it and installed a new belt. And of course a cap and rotor. Also of course this time I used quality Acura parts. The diff in the Shucks rotor and the Acura rotor is noticeable. Both visible and the Acura part is heavier.

Now the car is running good and has no noises. It also runs better than before due to the bad cap and rotor before.

Moral of the story?
ALWAYS USE QUALITY PARTS!!!!!

 

so you didnt bend valves?

~boom

 

Aparently not... car is up and running good.