Replace Pushrods + Lifters @ 150K ?
Thread Starter
Drifting
Joined: Nov 2002
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From: East TN
Replace Pushrods + Lifters @ 150K ?
I've been reading posts on here about replacing the pushrods and lifters when doing the hot cam upgrade on an LT1 but haven't found any info on a higher mileage cars like mine.
At 150k miles would it be a good idea to replace the pushrods and lifters? This is for a daily driver and I want reliability.. dont want to be replacing stuff again in a few years. I'd rather pay for it now if its likely to fail in the near future.
If I do get new pushrods should I get the harderened kind or is that a waste since they wont be touching the factoy guideplates? Also does anyone know the difference between the high energy and pro mag comp cam lifters? I don't want to spend money needlessly but dont want stuff breaking down on me either.
At 150k miles would it be a good idea to replace the pushrods and lifters? This is for a daily driver and I want reliability.. dont want to be replacing stuff again in a few years. I'd rather pay for it now if its likely to fail in the near future.
If I do get new pushrods should I get the harderened kind or is that a waste since they wont be touching the factoy guideplates? Also does anyone know the difference between the high energy and pro mag comp cam lifters? I don't want to spend money needlessly but dont want stuff breaking down on me either.
Race Director
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Technically for a hydraulic roller cam there will be minimal wear on the lifters so there is no reall NEED to change them, especially if you've run synthetic oil all it's life like you're supposed to. Now that being said to some degree your pushrods do wear into the lifters and the rockers. If you do use the same pushrods you are technically supposed to use them with the same lifters that they were in previously.
Personally I would replace them for no other reason than to just have a basically new valvetrain. Trick Flow makes some very nice single piece pushrods and I like the comp cams pro magnum lifters.
The difference in the lifters is that the Pro Magnum series is supposed to be slightly modified inside to provide a more stable platform for high RPM operations. A stock hydraulic lifter tends to "pump up" at high RPM's which leads to incorrect valve positioning. With the pro magnums you can easily spin 7000-7500 RPM's without any trouble. This is overkill for my application, but overkill is good.
Personally I would replace them for no other reason than to just have a basically new valvetrain. Trick Flow makes some very nice single piece pushrods and I like the comp cams pro magnum lifters.
The difference in the lifters is that the Pro Magnum series is supposed to be slightly modified inside to provide a more stable platform for high RPM operations. A stock hydraulic lifter tends to "pump up" at high RPM's which leads to incorrect valve positioning. With the pro magnums you can easily spin 7000-7500 RPM's without any trouble. This is overkill for my application, but overkill is good.
Team Owner
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From: OBAMA IS HITLER
I agree, now's the time for new lifters and pushrods to go with the new roller rockers and HOT cam.
if you're going with self-adjusting RR's, you DON"T need hardened chrome-oly pushrods. if you're using the HOT cam kit, you're getting self-adjusting 1.6 RR.s.
www.compcams.com provides great info on the differences between the roller rockers vs. non roller.
if you're going with self-adjusting RR's, you DON"T need hardened chrome-oly pushrods. if you're using the HOT cam kit, you're getting self-adjusting 1.6 RR.s.
www.compcams.com provides great info on the differences between the roller rockers vs. non roller.
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From: The Top of Utah
Originally Posted by dan6712cc
I've been reading posts on here about replacing the pushrods and lifters when doing the hot cam upgrade on an LT1 but haven't found any info on a higher mileage cars like mine.
RACE ON!!!
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
My 87 gets driven every day and has 198k miles. The heads have been overhauled twice and the lifters and push rods are original with nothing wrong with them. If it ain't broke, don't fix it!
Team Owner
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From: OBAMA IS HITLER
i guess this proves there's all kinds of opinions......when i had my engine rebuild done, my mechanic looked at me square in the eye and said it was a very good idea to replace the lifters since the LPE 219 cam, etc. is being installed and everything will be apart, and he further wnt on to say this is a good idea to do at about 80k miles. i had 67k miles on it at the time.
for about $240 you can get a new set of comp cams hydraulic roller lifters. with 150k on the engine -- and since its going to apart anyway -- i would do it for peace of mind. but hey, thats just me!
for about $240 you can get a new set of comp cams hydraulic roller lifters. with 150k on the engine -- and since its going to apart anyway -- i would do it for peace of mind. but hey, thats just me!
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Safety Car
Joined: Apr 2003
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From: VA
It's not clear from your post, but if you're considering a cam change in an original 150k bottom end you need to think about freshening the bottom end.
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
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Originally Posted by steve9899
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
There's not a lot of proof that spinning the bearings in an LT1 after a cam swap is any more common than any other SBC. Follow very good shop practices and drive the car easy while you break in the new parts and you'll be fine.
Thread Starter
Drifting
Joined: Nov 2002
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From: East TN
Originally Posted by steve9899
It's not clear from your post, but if you're considering a cam change in an original 150k bottom end you need to think about freshening the bottom end.
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
Yes I'm planning on putting in a hot cam kit in an LT1 engine with 150k on it but it had a new oem tranny put on a few years ago.... what needs to be done to the bottom end to get it in shape for the cam?
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From: VA
Originally Posted by Nathan Plemons
Follow very good shop practices and drive the car easy while you break in the new parts and you'll be fine.
I would agree with "should be" "ought to be" but definitely not "will be"
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From: VA
Originally Posted by dan6712cc
Yes I'm planning on putting in a hot cam kit in an LT1 engine with 150k on it but it had a new oem tranny put on a few years ago.... what needs to be done to the bottom end to get it in shape for the cam?
Myself I'd pull it out and at least replace rings and bearings. But then of course at 150k that probably leads to an overbore, and then you gotta think about a stroker, and cost just keeps escalating...
Go search the LT1 forum at camaroz28.com for spun bearings or cam install and you'll find more info.
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From: Maryland
Originally Posted by steve9899
It's not clear from your post, but if you're considering a cam change in an original 150k bottom end you need to think about freshening the bottom end.
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
There's a pretty high incidence of spinning bearings after cam changes on high-mileage LT1s, and when people talk about this they usually mean 75k as high mileage.
I replaced lifters, pushrods, and I drove it like a Grandmother for 500 miles or so, as recommended by my head porter.
So maybe break-in is the key?
Thread Starter
Drifting
Joined: Nov 2002
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From: East TN
Originally Posted by sothpaw2
I did my cam install at precisely 75 k mi and I had no problems.
I replaced lifters, pushrods, and I drove it like a Grandmother for 500 miles or so, as recommended by my head porter.
So maybe break-in is the key?
I replaced lifters, pushrods, and I drove it like a Grandmother for 500 miles or so, as recommended by my head porter.
So maybe break-in is the key?
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From: The Top of Utah
Originally Posted by dan6712cc
Did you also keep it at 1500-2000 rpm for the first 20 minutes after the cam install?
At 150,000 miles, I would replace the lifters at the same time, along with the timing set. If ALL you're changing is the cam, there should be no need to change the push rods.
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Race Director
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Originally Posted by steve9899
You guarantee?
You see the problem is that people think they can just go throw a cam in in a dirty garage, start the car up and fire down on it. Although you might get away with this every now and then it's terrible practice. A new cam should be very generously coated with assembly lube, which needs to be flushed out of the engine carefully after initial startup. Drive it easy for a little while and give the parts a chance to "settle" for a lack of a better word. Driving it easy for a little while also ensures that your oil gets filtered better before you hammer down on it. You see as your oil pressure climbs more and more of it actually bypasses your filter! So if you've got some small amount of trash in the oil and you go wide open throttle immediately that garbage is a lot more likely to end up in your bearings than in the filter.
Thread Starter
Drifting
Joined: Nov 2002
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From: East TN
Originally Posted by Nathan Plemons
A new cam should be very generously coated with assembly lube, which needs to be flushed out of the engine carefully after initial startup. Drive it easy for a little while and give the parts a chance to "settle" for a lack of a better word. Driving it easy for a little while also ensures that your oil gets filtered better before you hammer down on it.
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From: OBAMA IS HITLER
drive 500 miles in an "around town" enviornment. try not to exceed 4,000 rpms; vary your speed within this range, off and on - this is the whole key. stop lights are no problem.
i would use regular dino oil (not synthetic) during this break-in period, changing it (oil AND filter) after the intial run (about 30 mins.), 100 miles, 500 miles, then later on at 3000 miles.
i would use regular dino oil (not synthetic) during this break-in period, changing it (oil AND filter) after the intial run (about 30 mins.), 100 miles, 500 miles, then later on at 3000 miles.
