3 questions...


one what would happen if an S4 and S5 rotor housing were used in the same engine? (primarily regarding the spark plug position for timing)


secondly, what are the symptoms of a crushed needle bearing? would it make a noise with the clutch depressed?


thirdly...hot start issues...motor is making 90psi on each rotor when HOT, but still will not start easily like it does when cold. acts like flooding..but turning off the fuel pump just makes it ACT likes its going to start, then back to just cranking...sometimes it takes 5 minutes of fiddling with the fuel pump switch and modulating the throttle to get it to finally start. this motor has around 1,000 miles on it so far.

 

Since you mentioned the noise occurs when the clutch is depressed, I'll ventutre a guess that it's the pilot bearing and not one of the torrington bearings. When the pilot bearing goes, it sounds like sand being ground between steel rollers, very distinctive noise.

S4 and S5 housings should not be mixed due to a slight variation in plug position and timing.

90 psi is nothing to write home about, assuming this is a fresh rebuild with only 1k miles, pull, inspect and clean all 4 plugs. If they are good, you may neeed to pull the engine down and match the housings. Your psi should be at 100+ psi by now. While you have it apart, check all of clearance speds.

 

One of the local builders here in Toronto had no idea that there was a plug timing difference between S4 and S5 housings and had interchanged them for years. I pointed it out to them after I had opened one of their engines. The spark plug spread difference is subtle and in most cases it would actually go unnoticed. This is not to say that it's Ok to interchange them. They should always be used in correct pairs and ideally per correct generation application.

To set your mind at ease about the needle bearing, in addition to what trochoid described in terms of noise, you should also be able to pull the pulleys back and forth and feel a small amount of play.

Regarding your starting problems, if 1000 miles didn't break the engine in, I'd say the rotor housings may not be in the best of shape. Compare your compression to a cold reading. There is also a relationship between cranking speed and compression, so make sure your battery is in tip top shape and that your cranking speed is high enough. Also check your fuel pressure.

 

Timing is probably a little off. Did you stab the CAS correctly?

 

ive stabbed the cas many times haha. timing is pretty dead on...unless my pulley marks are wrong, but i believe the pulley and shaft are from the same engine.

 

Can you advance it a little? That might be all it takes to make starts easier.

 

ive tried this in the past...advancing much from my current position tends to make the motor ping under loads.

i currently run 89 in it...guess ill try 93 and some more timing.

 

gave it a few degrees, and just barely being warm gave it problems starting :[

took it for a drive..no pinging, but still horrible starting characteristics. i feel like 90psi is enough for a motor to crank easily when hot, but ill get some cold compression readings.

i dont know if my problem is compression/not enough fuel/too much fuel.

modulating the pedal while cranking makes it TRY to catch.

but still...have only had these problems on THIS engine..not these electronics(rtek 1.8, 720/880, s-afc)

 

Leaky injectors? You could have a small drip or something causing the fuel to pool a little in the motor when it sits until cold. I dont think its compression since you dont have the issue when hot starting (and the injectors havent had time to leak a bunch into your motor). There is a way to tell if you dropped a torrington bearing if you look straight down at the grooves on the water pump pulley you can tell somethings wrong if it looks misaligned (the crank pulley grooves are farther foward than the water pump grooves). Id imagine you would also be chewing up belts...

 

i ONLY have the issue when hot starting.

ive tried turning off the fuel pump before shutdown, or even during starting to try to get it to catch...most of the time it takes a lot of juggling back and forth.

injectors have been cleaned.

 

well then....made a little vid of the starting issues.

afterward i swapped out my battery for a larger one with more CCA...and sure enough the motor is turning faster and much easier to get started.

heres the video anyway.

http://www.youtube.com/watch?v=5ARKisxrf9Q

 

haha..put it to a real test today..and it failed. ended up having to coast backwards and push start it.

it does indeed spin faster but acts virtually the same as it does in the video :[