Its been 2500 miles since my build

GSR
PNP head
skunk IM portmatched
68mm tb
pro1 cams
supertech sp&ret
NSX LMA
golden eagle cam gears
pr3 pistons 81mm
stock rods
acl bearings
ebay header
2.5 exhaust no cat
s300

anywayz drivin today to go change my water pump cause saw water from lower timing cover, and SNAP!!! I immediatly killed the power and pulled over, sure enough the belt T-belt snapped... I have no clue why, been drivin for 4 months or so, hit the track once, street, etc... WTF? rev set to 8750 and hardly see Vtec on the daily...I got gates OEM... There are a couple rubs on the cover like the belt was dancin around a little, but still IT SNAPPED!!! My keepers on the crank gear are on there right, tension was good too... Any ideals?? Thinkin bout Different belt, but keep readin mixed emotions on OEM, Greddy, etc...Hopefully no damage, i looked down the plug holes, and saw no damage..hope i still got compression... Any ideals why the belt snapped, and what belt to get??? BullSh**!!!

 

pics of belt and where it snapped please ... and it is possible that you had the belt so tight that it was pullin up on the water pump causing it to leak then finaly the belt gave out

 

I've seen this several times, some people think that tightening the tension as much as possible will be better.

OP, do you seen any other signs of wear on the covers? The belt shouldn't make contact with the covers if everything is installed properly. I've never had any problems with Gates belts, or OEM.

Is there any wear on the inside of the timing belt? Perhaps a bur or sharp edge on the cam gears.

 

there is no marks on the teath, they still look new...I dont think the belt was too tight cause I was worried bout it bein loose when i put it together, play from ex to crank...no jumpin teeth, its a mystery...gonna check for head oil starvation, the cams were always hard to turn, but i figure thats from the valvetrain and those pro1's...the tensioner is new and spinnin freely, water pump has no hesitation...Gotta go do some investigatin, ill snap some flix and post em later...car is at my buddys shop and im goin there now...Thanx for the replies and hopefully NO DAMAGE!!!

 

Did you notice if there was a slight whine at all coming from the motor? I had the same problem but the belt didn't snap, the woodruff kry just gave out.

 

Did the belt have any cuts in it that you didn't know about? I've only seen a belt do this once before but it was oil soaked.

 

I've actually never seen a gates/greddy or toda belt snap..ever..lol

 

here are the flix...there was no whining, done that before and didnt like it...even though it sounded like a mini supercharger... if there was any noise, i couldnt hear it over exhaust and valvetrain (even when listening w/stethescope after 1st start) Anywayz, could be possible too tight cause i did a pressure test and the water leakin from the water pump shaft, and as dude said "could be tight pullin up on the pump causing it to leak." I also stuck a camera in the cyllinders and NO SIGN OF CONTACT!!! so, so far so good... will get the belt tomorrow and do a compression test, then fire up.... we'll see what happens....oh yeah i dont think the head is starvin for oil cause i have a old belt i put on to set TDC and seems to be spinnin freely(considering spring and high lift) and there was fresh oil on the lobes...

 

that's weird. hopefully it starts up man!

 

that is not a gates belt where did you buy it from ?

 

looks like it may have been rubbing? the edges look a little frayed...

 

pictures are a lil out of focus but the water pump bearings probably went bad while letting the gear to work at an angle which may have let the belt walk. how many miles where on that pump?

 

well i could be wrong sorry .. just thought all gates belts the back of them where blue

 

they are, that isn't a gates, thats probably some felpro ****.

 

Along with pump and belt, I'ld be inclined to change the idler pulley also.

 

The logo resembles Gates'

 

The logo looks like a worn belt that was stretched over a period of time but only 2,500 on it...wondering if the valvetrain tension could have been the reason for that...but maybe it was too tight? well see tomorrow if she's gonna run w/good compression....I changed tensioner and spring when i built it, and it still seems ok...It was rubbin, the inside cover has marks, still tryn to figure that out...Belt didnt look like that one, but Trust me, GATES logo right on the top, and obviously all gates are not blue...

 

Could be anything. A strap wrench works good for turning over the cam - make sure #1 is mid stroke if ya do it. A 3/8" long extension dropped into the plug hole is a good way to ensure it is.

 

HUH...Im not quite understanding what ur saying to do or ensure?

 

If you want to turn over the top end, Putting #1 mid stroke, will also put #2 3, & 4 at mid stroke. A strap wrench around the cam pulley works real nice to turn it over - pistons mid stroke will ensure no valve/piston interference.

Just offering possibilities for diagnosis. Not sure where this will end up. But, it's a limited set of options for the cause - yet, still a pretty long list.

Cam bearing could be hosed up thus binding camshaft rotation.

Idler could be trashed up. If the bearing is hosed, then heat and friction would ensue. Didn't look like it was dragging at the idler based upon the picture on the back side of the belt. However, if the idler was not tracking straight, then it could misalign the belt travel.

My first thought was the water pump binding - I know you checked it via turning it by hand - still could be the cause. Maybe when it's warmed up to operating temperature, and with the side load from the belt, it drags.

Food for thought bro. Good luck with it.

 

right on...I already put the pistons at mid and turned over the cams, little hard to turn when lobes on rockers, but as soon as they ride off, they spin freely...still thinkin its pump related cause what it was the 1st sign, (leaking) never to expect a belt to snap huh...sucks, but everything else looks good...i should be done today, gotta wait till the lady gets off work and frees me of baby duty...ill post as soon as its runnin(hopefully)...

 

Wrong, not all gates are blue, just their racing series. OEM series is black

 

well is the motor okay? Thats what matters.

 

Agreed on suspecting the pump. While in the top end, I'd probably pull the cam bearing caps and have a look just to be sure. Re-torque and run the valves too.

Be sure and check the belt idler real good also.

An ounce of preventive is always worth a pound of cure.

Be sure and get a new belt too! ROFL

 

Drove it home today!!! Compression w/out adding oil in the cyllinders was 205,205,215,215...I left the top cover off to see if the belt was dancin back n forth and its not...I guess just a lucky ****...