mikes98z

Hey guys,

My 97 T/A is starting to get some lifter "chatter". I checked the rockers and they all seem to be ok. Basically a bolt on car and the short block is in great shape and very clean.

I was thinking of swapping to a 503CC cam, 918 springs, hardened pushrods, some RR's, and a new double row timing set.

My question is the bearings...the short block has a 145K on it but it still runs perfect and has good compression in all cylinders.

Would it be wise to go ahead and upgrade or risk spinning a bearing? Is it common to destroy a bearing when swapping a cam in a high mile block?

Thanks!
Mike

Z-RATED94

Spin a bearing? Everyone takes that chance when spinning higher rpms. But if your motor is healthy, as you mentioned, go for it. Just try and keep the install as clean as you can.
Seems like you have a good list of parts. You'll like the outcome.

2QUIK6

I'd say most spin a bearing because after the cam install they have a sense of "lead foot" and probably push the car harder than before because of the added power. The stock rotating assembly wasn't meant to spin much past 6k rpms so it you keep within those limits most of the time it should be fine. The 503 may require you to spin it a bit higher for max power depending on the heads you use, I know the specs say upto 5800 but with that duration I bet its a bit higher.

mikes98z

Thanks for the advice. It is basically a street/strip car and I rarely push it bast 5-5500. I ususally let about 2K miles go by for a break in period before starting to push it some.

ricehammer

Cleanliness is godlyness when it comes to cam swaps. Make good and sure that nothing foreign makes it into your motor. As a precaution you might want to install one of these

http://www.jegs.com/webapp/wcs/store...10002_94538_-1

as well as a Wix oil filter when you do the swap. The stock oil filter adapter has a bypass valve in it that allows oil past the filter. Some oil filters also have bypass valves designed in (don't remember which). This will ensure that all the oil, as well as any junk that may have made it into your oil pan, will have to go through the oil filter. Just another step you can take to prevent spinning a bearing.

wrd1972

I plugged the bypass valve in my stock adapter for less than a dollar.

JoeliusZ28

bringing this back up, but i didnt think bypass valves were an issue on a vertical oil filter.