Dang, I've been looking at putting a Hotcam in mine, but after what you guys have said...I don't know. I only have 58k on mine right now. What kind of precautions do you suggest before doing the cam swap to try to keep that from happening? I'm kinda skeered now!

 

This past January I talked to a "tech" at a speed shop in Huston,TX. about a cam change for my T/A. He advised me against any cam or head change on a LT1 with over 40,000 miles on it. He claimed that the LT1 is a very close tolrace motor & that it takes a "set" over time. Disassebling & reassembling it would "disturbe" this set. The result would be that the bottom end would go out , read bearings in short order. Belive the name of the shop is MTI....

 

lots of people on here say, "its alright, right when youre done with the install. romp on it". one of the members on here, was telling me to take it slow for the first couple thousand kilometers, whcih i did. he was telling me, some guys put in a new cam, and right away head to the dyno, track, or just beat on it. makes sense, even if its "alright" to romp it right away. i took it real easy the first few weeks. cars running great (knock on wood). sorry bout your luck though

 

Man i had guy here close to me install my LT4 hot cam kit with 65XXX miles and i broke her in for the first bit just to clean the oil out and let the new springs adjust, and holy crap i never regret it a single bit. It runs absolutely beautiful.

 

put a cam in my car a few weeks ago with 80k on the clock and it runs like a champ. its always a risk when you dig into your motor like that but people think they are more fragile than they really are. miles mean nothing to a motor.... its all about RPMs. if a guy drives from home to work every day and its about 95% highway miles with 100k on the clock.. i would be willing to bet his motor is in better shape than someone who idles thru heavy city traffic 5 days a week with only 50k on the clock.

installing a cam isnt a crap shoot.. if you take your time pulling out the old cam and installing the new one then you really have nothing to worry about except for an intake leak or loose rocker.

 

The world is full of hack techs and having an engine failure after a cam swap at less than 50,000 miles is a huge red flag that some hack has worked on your car.

An LT1 is just like any SBC when it comes to changing the cam. There isn't anything special as far as tolerances and "sets" vs. any 350.

A common screw-up is the use of abrasive pads or disks on the intake surfaces and the front/rear "china walls" at the front and back of the intake. (3M Roloc, Scotchbrite, and similar products)

These pads clean things up really nice but they leave behind tons of micro-particles of aluminum oxide that are about 5 microns in diameter. They go right through the media in the oil filter and basically wreck the engine within a few hundred miles. These pads have been agressively marketed for gasket removal by 3M and other companies These abrasive pads/disks etc. are responsible for more post-repair engine failures than can be counted. They are ok for some parts when used properly off the vehicle where the parts can be properly flushed and cleaned before being reinstalled.

Often techs will scrape and clean the intake surfaces and over-use new RTV or leave strings and bits of RTV in the intake valley. This will eventually work its way down to the oil pan and cover the pickup cutting off oil flow to the engine. Another 100% kill.

Dirt, crud, and debris are the enemy of the engine and dumping a bunch of abrasive into it is absolutely a no-no. Having an infant mortality issue after having parts installed in the engine is a sign of poor workmanship in about 98% of the cases if the engine was properly cared for beforehand. A competent tech will contact the owner if the inside of the engine is a skank-pit and will tell them that there may be some risk of problems after the job is completed based on the condition of the engine. If the engine was fine and had regular maintenance up until the modification or repair was done and then "poof!" it just fails, something is up.


Take an oil sample from the failed engine and send it to Blackstone labs and have them look for contaminants such as Aluminum Oxide and Silica. What you do with the results after that is entirely up to you but you might want to bring them to the shop that did the work and see if they have some kind of remedy for sloppy work.

I have seen shop rags, gloves, massive amounts of RTV, scrapings and abrasives ruin hundreds of engines. In my regular day job, I have been tasked with inspecting failed engines and trying to determine what the failure mode was. In the majority of the cases it was sloppy work by a tech who left behind a trash pit in the engine when he closed it up. Another killer of Small-Block style engines that people don't often notice is that they are very sensitive to intake manifold bolt torque. Over-torquing or uneven torquing of the intake will distort the block often to the point that the cam bearing and main bearing bores aren't round anymore. - This is usually in the extreme case of the tech who uses an impact to run down the intake manifold bolts.

I have I have been doing engine repair work on the side for almost 20 years and have never had an engine just "fail" that didn't look like it was on its last legs when I opened it up. In all of those cases, the person who owned the car was summoned and the situation was explained that the car was not and had not been properly maintained so there wouldn't be any kind of warranty on the work.

 

Umm... the issue here is poor workmanship, not the cams themselves, right?

What makes the install so difficult?

If you're going to trust a shop with an lt1 rebuild, can I assume they'll pull off a hotter cam install properly? This shop said they'd give me a nicer cam along with my low comp pistons, et-al..

I cannot afford to have a money pit...

 

Then dont go internal or use a power adder. plain and simple.

 

I agree with Dave1w41's assessment of cam failures - I have heard so many people complaining of cam bearings going out etc. in LT1s it makes me wonder what is so different about these engines. Not much - there's the chance that the original bearings were not put in correctly with respect to the oil hole alignment and that can come back to haunt you, and the possibility that the new cam's journals are a poor match for the used bearings, but the overwhelming factor in the success of a cam swap is care and cleanliness followed by a breakin period and readjustment of the rockers. If you talk to enough car crafters, you find out that the majority of us who choose to work on our own cars chose to do so not only because of the cost and convenience factors, but because we do not trust the skills and workmanship of the tech that might draw the short straw to work on the F-body. There's no magical reason why an LT1 cam swap should go bad...

 

I agree 100% as well. Funny how nearly every time you hear about a quick engine failure after a cam swap the case involved a "professional" doing the work. I would say that the chances of having a problem are much greater with a shop than working on your own with the help of an experienced and knowledgeable f-bud.

I've got 17K trouble free miles on my head/cam swap with lots of
hard driving on road courses, autox courses and drag passes.

 

Forgive my ignorance, but is it even POSSIBLE to CHANGE the cam bearings in a typical cam install? Doesn't that require complete engine disassembly? That's way beyond a typical in-car cam install.

I just put in my Hotcam and I haven't put it all back together yet.... I have tons of oil sludge on the outside of the motor (not inside) and I'm trying to keep it FAIRLY clean inside, but occasionally dirt is falling into the motor. No RTV has fallen in though, since the factory didn't use any (some say on their cars they do, but mine had NO RTV on the intake, just rubber gaskets, including the front & rear).......

Problem is I know I scored the bearings when pulling the old cam out, because I got some metallic slivers...

I guess at this point, all I can really do is put it back together and hope for the best... I am hoping to get 20k miles out of the motor before a rebuild.... I plan to take it easy at first, run it 20 minutes, drain the oil, change filter.... run 50 or so miles, drain oil & change filter, then drain it again in 100 miles or so and keep checking the filter, etc, for bearing material... then drive the bajeezus out of it and pray for the best..

What do you guys think??

-Michael

 

It is possible to change the cam bearings with the engine in the car - you just need the right tools. Tools that only an engine shop or dealership would have, although there might be a way to rent them, but I'm just guessing. It would also be tougher to do with the engine in the car, and the alignment is critical. If you scored the bearings - that's not good.

And if you have a filthy engine that is going to be opened up, the only thing to do is clean it as much as possible BEFORE pulling it apart. Granted, the opti makes it tougher to steam clean or pressure wash.

 

That sucks bro. I spun a rod bearing a couple months ago myself That knocking sound is your piston slapping your head

Check out these pics: http://paradox.shacknet.nu/dave88lx/formula/knock

Check out the video's too.

Hosed my rod, crank, camshaft (could have been previous), lifters, gouged my cylinder wall....

OH, whoever said they don't want their LT1 to be a money pit, too late. Look how much the prices are JACKED UP on LT1 **** compared to a regular chevy or other engine. Hell, even the BOLTS cost double

****ing aftermarket!

 

My car runs like crap in the rain when the O2 wires get wet.

 

I've got a cam bearing tool, cost about $45, only works on SBC and 90 degree V6 though. Unless you have a ton of room to work with, you need to remove the block to get the bearings aligned correctly. The rear cam bearing has to have the tranny removed to be taken out or installed. It's simple as hell, but now if you have shavings or metal in the engine, it's time for a rebuild with a new oil pump and hot tanking to remove the extra debris.

-Shannon