Finally...track times
10-31-2007, 02:09 PM
#76
Registered User
Thread Starter
Join Date: Dec 2004
Location: Wichita, KS
Posts: 968
Houston....we may have a problem 
I was driving it on my lunch break, and I rolled into the throttle in 1st....and it started poping pretty loud out of the exhaust. Of course, I let out of it....then tried it again to see what RPM this was occuring at, it was at 5800...
I don't even wanna say what I think it sounds like....but I will say that I'll be driving it home very gently and pulling the valve covers tonight to give my 918s a close inspection.......
This may put a damper on my Sunday
I was driving it on my lunch break, and I rolled into the throttle in 1st....and it started poping pretty loud out of the exhaust. Of course, I let out of it....then tried it again to see what RPM this was occuring at, it was at 5800...
I don't even wanna say what I think it sounds like....but I will say that I'll be driving it home very gently and pulling the valve covers tonight to give my 918s a close inspection.......
This may put a damper on my Sunday
10-31-2007, 03:21 PM
#78
Registered User
Thread Starter
Join Date: Dec 2004
Location: Wichita, KS
Posts: 968
It's not making any abnormal valvetrain noise at idle or anything....just the loud popping at ~5800ish....kinda sounds like it's valve floating very badly 
Who knows, I'll yank the valve covers tonight and report what I find. I guess if the valvetrain looks ok, I should probably look at the ignition?
If the springs ARE bad though....they'll be replaced with PACs. If thats the case, hopefully Comp will give me a refund rather than a new set of springs.
Who knows, I'll yank the valve covers tonight and report what I find. I guess if the valvetrain looks ok, I should probably look at the ignition?
If the springs ARE bad though....they'll be replaced with PACs. If thats the case, hopefully Comp will give me a refund rather than a new set of springs.
Last edited by Colin91Z; 10-31-2007 at 03:38 PM.
10-31-2007, 03:55 PM
#79
Registered User
Join Date: Oct 2001
Location: SoCal
Posts: 2,525
so the other 7 cylinders notice that the spring on one is broken? it will drive, but can exhibit the exact same symptoms as described.
does this cam have the 3192 and/or 3122 lobes too? cast core too?
10-31-2007, 04:43 PM
#82
Registered User
Thread Starter
Join Date: Dec 2004
Location: Wichita, KS
Posts: 968
but the wires and everything are brand new, and it ran fine...it just started doing this today.....I might pull all the plugs and see what they look like...
10-31-2007, 05:26 PM
#85
Banned
Join Date: Oct 2002
Posts: 6,518
Then again you would have to be around motors not drafting boards and CAD programs all day to know what happens in the real world.
Bret
10-31-2007, 05:28 PM
#86
Banned
Join Date: Oct 2002
Posts: 6,518
Colin,
The only thing that semi worries me is that they are Comp 918's not PAC ones. The only reason is that I have only had issues and bent springs out of the new Comp versions, where none with the PAC's on a hyd roller application.
If you broke a spring it would make a HUGE racket. The wires and rockers would be the first things I would check. Especially if all you have is a problem at a high RPM not all the time.
Bret
The only thing that semi worries me is that they are Comp 918's not PAC ones. The only reason is that I have only had issues and bent springs out of the new Comp versions, where none with the PAC's on a hyd roller application.
If you broke a spring it would make a HUGE racket. The wires and rockers would be the first things I would check. Especially if all you have is a problem at a high RPM not all the time.
Bret
Last edited by SStrokerAce; 10-31-2007 at 06:14 PM.
10-31-2007, 06:49 PM
#88
Banned
Join Date: Oct 2002
Posts: 6,518
Yeah, I undstand that I have some of those 918's from the other supplier and they are at PAC for them to look over and see the cause of the failure. Most times that's where they broke is the top coil. Either way you most likely drop a valve.... odd thing is that this doesn't happen on PAC's 1218's... hmmmm.
I'm glad your the expert on them now though... funny that your beehives didn't break from the cam I gave ya.
Bret
I'm glad your the expert on them now though... funny that your beehives didn't break from the cam I gave ya.
Bret
Last edited by SStrokerAce; 10-31-2007 at 06:51 PM.
10-31-2007, 07:00 PM
#89
Registered User
Join Date: Oct 1998
Location: Jackstandican
Posts: 3,144
10-31-2007, 07:28 PM
#90
Registered User
Join Date: Mar 2002
Location: Ocala, Florida
Posts: 3,245
Yeah, I undstand that I have some of those 918's from the other supplier and they are at PAC for them to look over and see the cause of the failure. Most times that's where they broke is the top coil. Either way you most likely drop a valve.... odd thing is that this doesn't happen on PAC's 1218's... hmmmm.
I'm glad your the expert on them now though... funny that your beehives didn't break from the cam I gave ya.
Bret
I'm glad your the expert on them now though... funny that your beehives didn't break from the cam I gave ya.
Bret