Ok guys,i just traded a 2005 Ninja 636 for this 93 FD black on tan 5speed all stock.It had been setting in the guys yard for about 3years and he told me he worked on it for a while but never got it running,I towed it home and started messing around with it,He had the upper intake manifold and rats nest off the car and in the trunk.I put it back together and put new hoses on it and it fired up but ran like crap.I cleaned the plugs and air filter and still it would take 10-15 sec to start and if i dont give it some gas it will cut off.So i said F%$^ IT and i got a compression gauge and what i found was funny.Front rotor had about 45psi on bump test and 90 on hold test but the back rotor had nothing!0psi and with the spark plug out it has no wossh sound at all.I know its time for a rebuild but what i would like know is knowing the back rotor is shot,what are the chances that i will need new rotor housings?And would it better to just buy a motor?Any help you guys can give me would be great!

 

It's hard to say. If there's truly 0 compression on the back rotor, it's not just one seal that's blown.
It could be a number of things, but I'd plan on buying at least a good shortblock.

 

With zero compression on the rear it likely broke off a decent size piece of the apex seal and took out the other 2 seals or at least one of the other seals. You can pretty much gaurantee that one rotor housing and one rotor are toast. Depending on mileage you will likely need new bearings etc. I would expect to spend around $2k-$3k on the rebuild if you send it to a shop. Go back with stronger seals, ALS is all I recommend these days but there are also other options, replace the bearings, dont do some massive port unless you plan to shoot for 600+rwhp and in that case you will need to do a lot of other stuff while the engine is apart.

 

Well it has 72k on it and ill be doing the rebuild myself.Where is the best place to get housings and rotors?

 

New housings are around $800.00 a piece these days from Mazda. Just find a good used rotor and rotor housing on the forum and you will save a ton. Likely though your "good" rotor housing will have bad flaking on the edges, striations above the trailing spark plug hole and cracking arond both spark plug holes. Might as well find a good low mile set of housings and one good rotor. Building it yourself you will save a lot and be able to afford to do a lot of nice upgrades.

 

if it sat for a long period of time the seals could be carbon locked which can cause 0 compression also. you can try a water injection treatment but if it still doesn't show any compression then expect it to need at least a new rotor and housing.

 

Well im going to pull the motor as soon as i can,right now Ive been busy working the bugs out of my SC300 NA-T and 5speed swap.But if anyone has a rotor and housing they are selling cheap let me know,,,Ohh yeah one more thing when i rebuild the motor i was thinking of going single turbo but keeping it stock boost, will i really need to get a Power FC?Ive seen alot of people say yes and some say no.Im not looking for crazy power and my Apexi SAFC is doing great on my SC300 so could i just upgrade the injectors,FUEL PUMP and tune a SAFC and be ok @10-12 PSI?

 

Yes you'll need some kind of EMS, you can't directly change the tuning maps on stock ECU.

 

some guy was selling housings for cheap in the west forsale section

 

think you can make that sig any bigger?

 

I don'tknow how, I suck @ computers, can u help?