11:1 CR Race/Street Engine build - Page 18

SVXRide · #**256** 05-18-2010, 08:19 PM

Debris = fall out from the cam breaking?

-Bill

TomsSVX · #**257** 05-18-2010, 08:26 PM

Quote:

Originally Posted by SVXRide

Debris = fall out from the cam breaking?

-Bill

Thats my guess... the pump inlet is not filtered from the sump...

Tom

Boxersix · #**258** 05-18-2010, 09:14 PM

I should data log the oil temps on my car one day and get that info to you. It's remarkable how hot my cooler actually gets regardless of the fact that it's mounted and fed cool air just like the TMIC on the WRX/Sti.

SilverSpear · #**259** 05-19-2010, 12:02 AM

Quote:

Originally Posted by SVXRide

Debris = fall out from the cam breaking?

-Bill

Bummer.... hate to face unexpected issues.

Was it because they are welded/reground?

shotgunslade · #**260** 05-19-2010, 05:48 AM

Tom:

If you kept the oil filter, we should cut it open. That should reveal exactly what kind of debris did the damage to the pump.

It pains me to think that all the time I was enjoying that glorious engine at the Glen, it was self-destructing.

I really look forward to getting it back on the track. It is really sweet. It was also nice passing some people for a change, even though there was some seriously expensive iron out there with me.

longassname · #**261** 05-19-2010, 09:10 AM

I missed something...Shotgun's 11:1 engine broke a cam and then blew a rod bearing?

shotgunslade · #**262** 05-19-2010, 10:06 AM

Yes, but there was about 1200 miles of street and highway driving and about 100 miles of track driving between the 2 incidents.

Tom was driving the car home from the dyno shop, after tuning, when one cam broke in two. Suspicion was that the cam may have had an imperfection and the weld/regrind process may have caused a crack to develop. The ultra high lift and acceleration profile of the cam caused torque forces that shortly twisted it in two. He got Web to make a replacement and put it in the motor. I continued the break-in process, including a trip down to visit Old Tom in WV, and the trip up to Watkins Glen. About 20 minutes into my third track session, I experienced a sudden engine drop-out which we think was the knock sensor cutting fuel and advance in response to the bearing coming apart.

But, I don't know if Tom has verified that the debris found in the oil pump was from the cam, or some other source.

Cam · #**263** 05-19-2010, 10:10 AM

That is truly unfortunate. Hopefully all is well with the system cleaned out and a new oil pump. Do you suspect there to be debris in the cylinders? I am crossing my fingers that I wont have to deal with a similar problem in my build.

Johnybeas · #**264** 05-19-2010, 01:30 PM

dang... well at least the problem is found, I hope that in fixing this problem and getting it back on the road you don't run into anything else! Good luck!

Nomad · #**265** 05-19-2010, 01:59 PM

I have at home a broken cam...it broke in two one day like that. I don'T use special cams, pistons..... only a chip, intake from tom, ....

TomsSVX · #**266** 05-19-2010, 04:36 PM

Yea Mike... Still kinda dumbfounded by the cam shearing... L/S intake sheared like I have never seen before... No evidence of clearance issues, no bucket failures... Just a freak thing... This was after about 200 miles of break-in and a full dyno tune session.

This engine has proven to be the biggest pain in the ass I have ever dealt with. Between the insane amount of fab time and assembly for all the little custom bits and pieces and the crazy **** that has happened with this thing.... I can honestly say, I am looking forward to not dealing with another one like it

Tom

NeedForSpeed · #**267** 05-19-2010, 04:46 PM

Maybe a good idea to magnaflux all welded or performance cams before installing? Crankshafts are routinely magnafluxed in performance builds.

Mis-handling or dropping a cam may result in a break that wouldn't be noticed before assembly, but result in total failure in a running engine.

Any pictures of the broken cams, or did I miss that?

TomsSVX · #**268** 05-19-2010, 05:06 PM

Quote:

Originally Posted by NeedForSpeed

Maybe a good idea to magnaflux all welded or performance cams before installing? Crankshafts are routinely magnafluxed in performance builds.

Mis-handling or dropping a cam may result in a break that wouldn't be noticed before assembly, but result in total failure in a running engine.

Any pictures of the broken cams, or did I miss that?

Didn't really chat about it on the forums because it all happened in the ****storm of closing up the shop. I cannot remember if I have pics of the cam... I know they were handled by me with a feather fingered touch and the packaging left nothing to be desired so unless something like that happened at their shop I don't see that as a possibility.

Tom

NeedForSpeed · #**269** 05-19-2010, 05:22 PM

Quote:

Originally Posted by TomsSVX

Didn't really chat about it on the forums because it all happened in the ****storm of closing up the shop. I cannot remember if I have pics of the cam... I know they were handled by me with a feather fingered touch and the packaging left nothing to be desired so unless something like that happened at their shop I don't see that as a possibility.

Tom

Could happen during manufacturing, well before you got your hands on the cam.
Throw some weld, higher pressures, severe duty, bang

.

I've seen factory rods and cranks with cracks, both gas and diesel, no known reason for these fine cracks, but such can lead to failure. Welded cranks are always magnafluxed, maybe its not routine for cams?

TomsSVX · #**270** 05-19-2010, 06:08 PM

Quote:

Originally Posted by NeedForSpeed

Could happen during manufacturing, well before you got your hands on the cam.
Throw some weld, higher pressures, severe duty, bang

.

I've seen factory rods and cranks with cracks, both gas and diesel, no known reason for these fine cracks, but such can lead to failure. Welded cranks are always magnafluxed, maybe its not routine for cams?

Don't know for sure... Could have even been an inherent flaw from the factory, just never saw the extra stress that the new grind put them through... Either way... They are cast iron and they don't break "clean" so the shrapnel from the break more than likely found its way to the pump... I did do an oil change as soon as I got it back to the shop (drove it 10 miles w/ 2 cyl missing). At the time I thought I dropped a coil or something of that nature... After trouble shooting (passed a leakdown) for a couple hours finally pulled the valve cover to find it busted...

Like I said, it will be too soon before I do another one of these

Tom