Valve guides

[furiousgeorge]

Hello, I've recently got a 251 from a '50 Chrysler for my '49 1/2 ton. It had been rebuilt and overbored, then left to sit and dry seize. The fellow I got it from got it all apart, got new pistons and rings, then sold it to me. My issue is that he had broken some valves getting them out, and the top of a couple guides are chipped or have a piece broken off. Can a guy change those at home? Or are special tools required? Also, how difficult is it to drive out the wrist pins to change pistons? I've rebuild a few 360's, but they didn't need these jobs done, so new territory for me.

Thanks!

[wallytoo]

the wrist pins shouldn't be very difficult to remove/install. they are supposed to be a "thumb" press fit.

[John-T-53]

To drive out and install the guides, you need an appropriately sized driver and a big hammer. Then you'll need a mic, depth guage, valve guide hone, and dial bore guage to size the guides to your valve stems. Then you need a seat cutter (stone) or better yet a valve guide and seat machine to cut the seats. Then finally, lapping compound.

http://www.cylinderheadsupply.com/valve-guide-tools.html

360's have hot press pins, but these flatties have floating pins - thumb press as stated by wally below.

[NiftyFifty]

Guides are something best left to a really good engine shop with all the machines to do the work. I'm guessing your getting all new valves, so they would want the block to check the valve seats anyway and then they can do the guides which on a rusty block can be a big chore as the shop that did mine found out.

Also if yours was siezed their may be some pitting in the seats and best to have those ground so your not loosing anything with bad valve contact