Cam Install Question

[JerzNick]

Just curious - How many miles is too many on a 3800 block to install a cam without redoing the bearings/rings etc...


I'm asking because I have an extra XP cam and a motor with 130k on it... would it be a waste of time?

[Fivefingerdeathpunch]

130k is nothing, I bet you the avg modded motor has well over 120,000 miles on it, and are still running past 200k is many cases.

[JerzNick]

130k is nothing, I bet you the avg modded motor has well over 120,000 miles on it, and are still running past 200k is many cases.

Thanks, Good to know. When I cammed(XP) my last motor(110k), I got 90 miles out of it and spun a bearing... the machine shop told me the cam was too aggressive with that many miles lol

[Schwuppes]

The problem with these engines is cam bearings...I wouldnt go so far as to say its "common" for them to spin a cam bearing after a cam swap... but its certainly a weak point.... more than anything else on these motors.

If the engine has been serviced correctly with the right oils there should be very little wear on the cam bearings and no problems, provided you dont scratch the bearing during the cam install.

.... a poorly serviced engine (even if its relatively low miles) is much more likely to spin a cam bearing when installing a fresh cam onto those old bearings.

I'd check the old cam journals and bearings for excessive brass showing and wear before putting the new cam in.

[dsmuts]

I'd cam a motor regardless of mileage if it runs fine.

[JerzNick]

Thanks for the input guys... I used assembly lube on the cam bearings(which looked fine to me) and pretty much drenched the cam with vaseline. Fingers crossed! If I spin another bearing I will drive this thing off the nearest cliff.

[GTPpower]

The problem with these engines is cam bearings...I wouldnt go so far as to say its "common" for them to spin a cam bearing after a cam swap... but its certainly a weak point.... more than anything else on these motors.

If the engine has been serviced correctly with the right oils there should be very little wear on the cam bearings and no problems, provided you dont scratch the bearing during the cam install.

.... a poorly serviced engine (even if its relatively low miles) is much more likely to spin a cam bearing when installing a fresh cam onto those old bearings.

I'd check the old cam journals and bearings for excessive brass showing and wear before putting the new cam in.

Maybe in AU...here in the states, I've never seen one with spun cam bearings.

[Bio248]

yeah, i've seen lots of crank bearings, not so much cam bearing action.

[BillBoost37]

I've seen a couple cam bearings spin. It's not super common. But then who takes the motor down far enough for see if the failure was truly a cam bearing that led to a crank bearing.

[Bio248]

i opened mine up before i threw it away.

[darkhorizon]

The problem with these engines is cam bearings...I wouldnt go so far as to say its "common" for them to spin a cam bearing after a cam swap... but its certainly a weak point.... more than anything else on these motors.

If the engine has been serviced correctly with the right oils there should be very little wear on the cam bearings and no problems, provided you dont scratch the bearing during the cam install.

.... a poorly serviced engine (even if its relatively low miles) is much more likely to spin a cam bearing when installing a fresh cam onto those old bearings.

I'd check the old cam journals and bearings for excessive brass showing and wear before putting the new cam in.

must be an AUS thing, because we have never had cam bearing issues up here. Spinning main/rod bearings after cam installs here in the states is 100% the fault of the cam installer every time.

[Wotgtp]

X2. Use plenty of lube(giggity) and as long as the engine is running good and you are careful about swapping the cams you should be fine. I did my NIC install around 120k and it runs great.