I killed an LT4
Melting Slicks
Joined: Jun 2001
Posts: 2,525
Likes: 1
From: Sarasota, FL
Re: I killed an LT4 (Charles Klein)
On the bright side, I might never have chosen to build a stroker motor, but now it's the rational thing to do. I am going to a solid roller 396, built by Speed Demon Motorsports.
[Modified by Charles Klein, 9:22 PM 1/10/2002]
[Modified by Charles Klein, 9:22 PM 1/10/2002]
Le Mans Master
Joined: Jun 2001
Posts: 9,117
Likes: 1
From: 7th Floor Crew
Re: I killed an LT4 (jackyl)
Yup, sounds just the same!! here's Randy's email, maybe he can help ya out!! grandsport267@msn.com
He was driving along then outta no where it was like someone beat the hell outta the motor w/ a ball bat. Warranty bought him a whole new engine!! :yesnod: And he bought the old one back for like core of $400 or something. Hope this helps, sorry about your car!!
He was driving along then outta no where it was like someone beat the hell outta the motor w/ a ball bat. Warranty bought him a whole new engine!! :yesnod: And he bought the old one back for like core of $400 or something. Hope this helps, sorry about your car!!
Race Director
Joined: May 2000
Posts: 17,101
Likes: 4
From: No more yankee my wankee, the Donger is tired!
Re: I killed an LT4 (Hurricane_777)
Wasn't he the one who racing and oval track and doing like 160mph when it spun? I thought I remembered reading something about a GS owner who did this and got another motor on the warranty. I remember the problem as having something to do with the high speed + oval track and oil not getting out of the pan and through the motor. I could be completely wrong on this one though :crazy:
I even had the problem with my LT1. Blew out the number 6. Powdered rod blew and sent metal through the whole engine. Saw the oil pan after it was dropped, almost looked like a mirror due to the shiny metal being in there. It is an oil pick up problem. I was driving on the highway when mine happened. Not fun 58k on the clock and no NOS either.
Racer
Joined: Mar 1999
Posts: 423
Likes: 0
From: Austin Texas
Re: I killed an LT4 (Charles Klein)
Sorry to hear about the engine. Pretty scary since I just
crossed 36K with mine. I was watching your post about
headers recently with great interest since I plan the same
thing for mine by the end of this year. I've had mine
dyno'ed at Colvin's with a group and it sure seemed like
that put some strain on it. Don't suppose something
happened then do you?
Anyway, good luck with new power plant.
crossed 36K with mine. I was watching your post about
headers recently with great interest since I plan the same
thing for mine by the end of this year. I've had mine
dyno'ed at Colvin's with a group and it sure seemed like
that put some strain on it. Don't suppose something
happened then do you?
Anyway, good luck with new power plant.
Racer
Joined: Feb 2001
Posts: 480
Likes: 1
From: Ham Lake, MN
Re: I killed an LT4 (Hurricane_777)
Wasn't he the one who racing and oval track and doing like 160mph when it spun? I thought I remembered reading something about a GS owner who did this and got another motor on the warranty. I remember the problem as having something to do with the high speed + oval track and oil not getting out of the pan and through the motor. I could be completely wrong on this one though :crazy:
I've got about 36K on mine now. I hope I've got more than another 3K miles left in it. :eek:
[Modified by GS470, 9:09 AM 1/11/2002]
Thread Starter
Instructor
Joined: Oct 2000
Posts: 221
Likes: 0
From: Austin, TX
Re: I killed an LT4 (Micky Davis)
Mickey,
I actually did dyno it just that day, also at Colvin automotive. But I don't worry about strain from the dyno. I see it basically as one rev to the rev limit but with a lighter load on the engine than when actually driving.
I actually did dyno it just that day, also at Colvin automotive. But I don't worry about strain from the dyno. I see it basically as one rev to the rev limit but with a lighter load on the engine than when actually driving.
Team Owner
Joined: Aug 2000
Posts: 32,844
Likes: 0
From: Looking California Feeling Minnesota
St. Jude Donor '03-'04-'05-'06-'07'-08
Re: I killed an LT4 (Hurricane_777)
Wasn't he the one who racing and oval track and doing like 160mph when it spun? I thought I remembered reading something about a GS owner who did this and got another motor on the warranty. I remember the problem as having something to do with the high speed + oval track and oil not getting out of the pan and through the motor. I could be completely wrong on this one though :crazy:
Pro
Joined: Dec 2000
Posts: 666
Likes: 1
From: Salt Lake City UT
Re: I killed an LT4 (Charles Klein)
Sorry you have to go through this. The new one will be sweet.
Any preventive tips from anybody? My LT4 has almost six thousand miles and really don't want to loose it. My 65 vette put a rod through the block after a custom rebuild years ago and that was not a good time.
Any preventive tips from anybody? My LT4 has almost six thousand miles and really don't want to loose it. My 65 vette put a rod through the block after a custom rebuild years ago and that was not a good time.
Drifting
Joined: Aug 2000
Posts: 1,614
Likes: 0
From: Colleyville Texas
Re: I killed an LT4 (Charles Klein)
Had 45,000 miles on my LT-1 and did the same thing. Really surprised it did not happen earlier. My friend did the same thing with his Grandsport. The 396 will help ease your pain and remember to tell your wife it is a repair and maintenance expense not a mod. :)
[Modified by Red Rocket, 10:13 AM 1/11/2002]
[Modified by Red Rocket, 10:13 AM 1/11/2002]
Pro
Joined: Aug 2000
Posts: 700
Likes: 1
From: Florida
Re: I killed an LT4 (markmaz)
My LT1 spun the #1 rod bearing. Only 70K miles. Never obused, always
changed oil with mobil synth at 3k miles. I wonder if GM had a few bad
oil pumps, or oil circulation is just not what it should be.. Sorry to hear about the bearing... 396 is definitly the way to go..
Hank
changed oil with mobil synth at 3k miles. I wonder if GM had a few bad
oil pumps, or oil circulation is just not what it should be.. Sorry to hear about the bearing... 396 is definitly the way to go..
Hank
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Re: I killed an LT4 (jsaunde2)
OUCH! :(
I keep posting this as a warning.
LT4's have better rods, but ...
http://vette.ohioracing.com/majmods.html
I keep posting this as a warning.
LT4's have better rods, but ...
Gee what's that knocking noise?. The motor blew right at the finish line of an autocross event in the middle of nowhere Michigan. Of course right at the height of race season and one day after I had just spent big bucks on 4.09 gears. I broke my vette and Al Murrel, a fellow competitor, hauled me home. Thanks Al! You have an invitation to co-drive my car! Also, I owe thanks to John & Debbie Fessler, and Paul Wines for hauling my tire trailer home.
A word of warning, 6200 RPM is the Limit for a stock LT1. I set my rev limiter to 6400 RPM against the advice of Justin Vandersall (Superman Vette Mechanic). The motor lasted for maybe 10 revs at that limit. The LT1 rod caps can not take high RPMs. The cap on the number six cylinder stretched. The piston began to slap against the head when down revving. As soon as the engine cooled the bearing spun
A word of warning, 6200 RPM is the Limit for a stock LT1. I set my rev limiter to 6400 RPM against the advice of Justin Vandersall (Superman Vette Mechanic). The motor lasted for maybe 10 revs at that limit. The LT1 rod caps can not take high RPMs. The cap on the number six cylinder stretched. The piston began to slap against the head when down revving. As soon as the engine cooled the bearing spun
Drifting
Joined: Jul 2000
Posts: 1,661
Likes: 4
From: Phoenix, Arizona
Re: I killed an LT4 (Charles Klein)
Wow, sorry to hear of your pain. I run mine to the limit & back down constantly in auto-x. If anything, I overdo it on maintenance and oil changes, but I still run it hard all the time. It has 72K on it now and I keep waiting for the sound of doom. All you 396 guys, how would that fare for high revs & heavy backoffs in auto-x? I think I need to start planning for the future - it's inevitible.
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Re: I killed an LT4 (Red Rocket)
MTI said I could run my 396 up to 7,000RPM's with no problems. Also put on the Canton 7.5QT Race Oil Pan with the 396.
And how did the prep them?
BTW I know the LT4 rods are better.
Pro
Joined: Dec 2000
Posts: 666
Likes: 1
From: Salt Lake City UT
Re: I killed an LT4 (93LT1)
Is there anything we can do so we don't kill these motors? I guess I could keep it to 5000 rpm's or less, but I won't go as fast. With all the post and knowing two people who have been through this I am concerned. The post brought back the previous problems I had heard of. Up til now I had not thought about it. Is this a cronic problem like the rockers where on the early LT4's?
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Re: I killed an LT4 (Red Rocket)
Lunati 5.850 Billet Rods. Prepped with Clevite assembly lube compound. Engine warranty of one year. Voided if you use Nitrous. :)
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: I killed an LT4 (BrianCunningham)
[QUOTE]OUCH! :(
I keep posting this as a warning.
LT4's have better rods, but ...
[QUOTE]
I think the powdered metal rods were standard on 95 and later LT1 motors also but the crankshaft in LT1s is not as strong as the LT4 crank.
What exactly happened to the motor ? Did a rod let go, bearing insert spin, or was it the crankshaft journal ?
Smokey Yunick found that rotating assy failures that occurred even when rev limits were observed are caused by detonation or ignition crossfiring. The #5 and #7 and #4 and #6 can cross fire if the ignition wires are close together and cause problems. At high rpm you might not notice the cross firing or detonation occurring. He recommended keeping at least 1 inch center to center between the plug wires to prevent the crossfire problem.
I keep posting this as a warning.
LT4's have better rods, but ...
[QUOTE]
I think the powdered metal rods were standard on 95 and later LT1 motors also but the crankshaft in LT1s is not as strong as the LT4 crank.
What exactly happened to the motor ? Did a rod let go, bearing insert spin, or was it the crankshaft journal ?
Smokey Yunick found that rotating assy failures that occurred even when rev limits were observed are caused by detonation or ignition crossfiring. The #5 and #7 and #4 and #6 can cross fire if the ignition wires are close together and cause problems. At high rpm you might not notice the cross firing or detonation occurring. He recommended keeping at least 1 inch center to center between the plug wires to prevent the crossfire problem.