The Stovebolt Site Forums The Shop Area Engine Shop 248 gmc engine Head

Does anybody have aor can give me a part# or NOS# for the intake valves and the exhaust valves. Tks. Mike 1951 248 engine.

Try NAPA if you have one. Egge in CA got me some 503 valves.

Ed

Our Napa can't get them.Tks Mike

https://www.ebay.com/itm/221663654720

I have ordered them and the specs. are correct. Tks. Mike

I should have answered sooner, 270 and 302 parts are readily available, next time might be worth while starting with rather, looks same, more HP, bolts right up.

Ed

Tks Ed, JusT LEARNING EVERYDAY and I thank you'll for it. Mike

These are. The wrong ones againv

Second vote for EGGE. Kits and individual parts. Call them and explain what you need with measurements.

https://egge.com/product/kits.php?a...kit_model=&kit_year=&kit_engine=

Before you deal with Egge, buy a quart of Vaseline- - - - -you'll need it!
Jerry

Ya......it's a lot cheaper and convenient to buy two or three sets off eBay that are not right.

EGGE Is not Rock auto but it found things for GMC that were not available else where. They were not cheap but priced fair or competive all things considered. Especially for pistons and valves especially when compared to those eBay prices.

I called them, spoke with Jim, sent them a detailed, full scale drawing, sent the correct parts. You will need a micrometer to get the shaft size, a vernier caliper for the rest. Probably should get new guides to go with new valves.

Ed

The 228-270 engines all used the same valves except some used a 30º degree seat and some used a 45º seat. And what the book calls for may not be right. It was common to retrofit 45º seats with 30º seats and of course then you need valves to match. It is possible to make 30º valves out of 45º, but not vice a versa. A 51 probably came with 45º but it may have 30º seats now. The valve stems are all the same. If you are familiar at all with valves, you can tell the difference in 30º and 45º at a glance.

The problem on this one is the number and placement of the keeper grooves, and a slight difference in the stem length. Rather than keep buying stuff that's not exactly right, Mike is about to bring me his parts to see if there's a possibility of doing a little adapting to make the new parts compatible with his springs, retainers, and keepers. Since the stem diameter and face angles match, the rest of the situation can probably be managed with a little tinkering. We live about 70 miles from each other.

The engine is a "256" which combines a 248 stroke with a 270 bore. The head casting number cross references to a 248 engine. No telling what's been done to it previously, as it's bored .030" oversize with domed pistons and has obviously been rebuilt one or more times.
Jerry

Finally got to order the right ones from Internal parts out of nvl. tn. Real good people and will get you what you want with no problem, thanks to hotrod. You'll have a good evening , Moonshine Mike