Cam in LT1 Good or Bad???
07-04-2007, 02:03 PM
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Cam in LT1 Good or Bad??? Has anyone heard of things going wrong with a cam in an lt1? I put a comp cam 07-467-8 in my lt1 and have been told cams in lt1's lead to lower end problems only months after install? Anyone hear anything like that? How long have the LT1 guys had a cam like this in theirs with no problems?
cam is 230/236 with 1.6 rockers
cam is 230/236 with 1.6 rockers
07-04-2007, 02:25 PM
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okay so tell me if this will work well together and what numbers i should see:
97 lt1block in 95 car with pcm4less tune
mild ported heads
stock bottom end
cc467 cam 230/236
1.6 rr
ls1 springs
comp lifters
longtubes
ory
no cats
and cold air intake
52mm lingenfelter tb
intake match ported to heads
97 lt1block in 95 car with pcm4less tune
mild ported heads
stock bottom end
cc467 cam 230/236
1.6 rr
ls1 springs
comp lifters
longtubes
ory
no cats
and cold air intake
52mm lingenfelter tb
intake match ported to heads
07-04-2007, 03:19 PM
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Moving to LT1 section.....
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07-05-2007, 12:20 AM
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what kind of ls1 spring? you may want to get some better springs, little things like that can lead to big trouble. the valvetrain is VERY important when talking about reliability in cam only LT1's (or any car for that matter).
07-05-2007, 03:20 AM
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Originally Posted by str8rpn
there the 26918-16 high performance ls1 valve springs by comp cams
good deal, disregard what I said earlier those will work well.
07-05-2007, 04:28 AM
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Originally Posted by str8rpn
Has anyone heard of things going wrong with a cam in an lt1? I put a comp cam 07-467-8 in my lt1 and have been told cams in lt1's lead to lower end problems only months after install? Anyone hear anything like that? How long have the LT1 guys had a cam like this in theirs with no problems?
cam is 230/236 with 1.6 rockers
cam is 230/236 with 1.6 rockers
07-05-2007, 01:28 PM
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It does happen but exactly why seems to differ by opinion.
1) Higher milage engine + big cam = higher cylinder pressure = Bearing failure
2) Installing crank hub using Big Fing Hammer = Bearing failure
3) Getting junk in the oil and not changing it often after the install.
3) ( and my opinion ). Again higher milage engine + big cam AND spinnning a stock bottom end over 6600 RPMs.
I done a bunch of cam installs over the past 10 years on LT1s. I am very carefull about keepeing everything clean. 1st start up 15 minutes, change oil, 100 mile of easy driving - change oil. another 400 miles easy - change oil, then beat it like you hate it! I always say to never spin above 6600 and every one has lasted.
1) Higher milage engine + big cam = higher cylinder pressure = Bearing failure
2) Installing crank hub using Big Fing Hammer = Bearing failure
3) Getting junk in the oil and not changing it often after the install.
3) ( and my opinion ). Again higher milage engine + big cam AND spinnning a stock bottom end over 6600 RPMs.
I done a bunch of cam installs over the past 10 years on LT1s. I am very carefull about keepeing everything clean. 1st start up 15 minutes, change oil, 100 mile of easy driving - change oil. another 400 miles easy - change oil, then beat it like you hate it! I always say to never spin above 6600 and every one has lasted.
07-05-2007, 03:25 PM
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yes thats what he said, spun bearings...here is why i ask.
I bought the car with a rebuilt engine by jasper that was just put in...idiot that put the heads on didnt use the right head bolts so antifreeze was pissing everywhere after about 40 miles. I then pulled the engine and sent the heads to be machined and replaced the lifters/springs/rr's/pushrods/valve covers and the cam. Motor went back in and ran awesome for approx 600 miles maybe a little more. And now she is smoking white, lifter tap on one side, and overheating (past half way and it wants to keep going but i shut it off)when car is idling or not moving. Why would this happen? Was the one head gasket bad? Do you think any bottom end breakage? And what is with the tapping from the drivers side? Any help would be great
I bought the car with a rebuilt engine by jasper that was just put in...idiot that put the heads on didnt use the right head bolts so antifreeze was pissing everywhere after about 40 miles. I then pulled the engine and sent the heads to be machined and replaced the lifters/springs/rr's/pushrods/valve covers and the cam. Motor went back in and ran awesome for approx 600 miles maybe a little more. And now she is smoking white, lifter tap on one side, and overheating (past half way and it wants to keep going but i shut it off)when car is idling or not moving. Why would this happen? Was the one head gasket bad? Do you think any bottom end breakage? And what is with the tapping from the drivers side? Any help would be great
07-05-2007, 05:05 PM
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I think you have to start tearing it down to see what you have. Foremost you have to determine if you have coolant mixed with your motor oil. If it's there then you will be replacing bearings.
As for the leaking coolant, lets hope it is a head gasket and by some pure luck it is moving into the exhaust and not filling the crankcase.
One more thing about spinning bearings. People want to use heavier oil to boost pressure but in a stock motor this is truly a bad idea. The clearance is so small in modern engines that the lighter the oil the better. That's where synthetics shine because of the smaller round molecule. Correctly built engines have more bearing clearance from the git and a heavier oil can more easily make its way through those clearances. Pampered-Z nailed it with the RPM issue. It's rare to read about spun bearings with the factory rev limiter. It usually happens at those higher than normal revs.
As for the leaking coolant, lets hope it is a head gasket and by some pure luck it is moving into the exhaust and not filling the crankcase.
One more thing about spinning bearings. People want to use heavier oil to boost pressure but in a stock motor this is truly a bad idea. The clearance is so small in modern engines that the lighter the oil the better. That's where synthetics shine because of the smaller round molecule. Correctly built engines have more bearing clearance from the git and a heavier oil can more easily make its way through those clearances. Pampered-Z nailed it with the RPM issue. It's rare to read about spun bearings with the factory rev limiter. It usually happens at those higher than normal revs.
07-06-2007, 08:02 AM
#18
Bearing failure can happen on any engine, not just LT1's. When any given motor has high miles then the bearings are going to "wear in" to a particular RPM range and be subjected to a particular amount of power. They will simply just be used to their current environment and conditions.
When a bigger cam is installed then the bearings are subjected to hopefully higher RPM's and hopefully higher amounts of power. If the bearings are on or near the fine line of failure then the cam will be the nail in the coffin for those bearings and they will start to knock which means the engine is coming out.
This is obviously less of an issue on lower mile well taken care of motors, installing a cam in a higher mile engine is a crap shoot. I think it is safe to say that half of the people that install bigger cams end up spinning rod bearings and sometimes main bearings too. Others get lucky.
When a bigger cam is installed then the bearings are subjected to hopefully higher RPM's and hopefully higher amounts of power. If the bearings are on or near the fine line of failure then the cam will be the nail in the coffin for those bearings and they will start to knock which means the engine is coming out.
This is obviously less of an issue on lower mile well taken care of motors, installing a cam in a higher mile engine is a crap shoot. I think it is safe to say that half of the people that install bigger cams end up spinning rod bearings and sometimes main bearings too. Others get lucky.
07-06-2007, 08:18 AM
#19
Most Cams Bearings come with a procedure to break them in. I am about to build my Engine here soon, and when I do, I have to run it at 2000RPM's for 20 min to break in the Cam and the Bearings. Then you got to seat the Rings, which involves getting some miles on it, and getting on it a little bit, bring the Cylinder Temps up a little.