Valve job, valve size question
- Thread starter jimlj66
- Start date
Howdy Jim:
That's is exactly what I did back in 2000 when I had my 250 engine built. A couple of things to note; (!.) That was prior to Classic Inline and easy availability of 1.5" SSI valves. If I were to do a head today, I'd use the 1.5" SS exhaust valves from Mike. A set of 144 vavles were hard to find in 2,000. Probably harder to find today and more expensive. (2) I have had no trouble with the 144 intake valves used as exhaust valves. One old engine builder commented, "Valves are valves. They don't know if they are exhaust or intake. They're just valves." I suspect that in extreme duty special valve material may be tougher, but in our engines it doesn't seem to matter. At least, so far. (3) depending on the head you are using, induction hardened seats got better and the hardening process got deeper, so you may not have to add a hardened seat. FYI going from a stock 1.38" valve to a 1.50" will only increase the radius by about .060". For a '78 and later casting I'd guess fine. For anything earlier, I'd check.
I should have ask first, what is the intended use for this engine? IF it will see alot of abuse then hardened seats are a good investment. If it will be a weekend toy, hardened seats won't be much of an issue.
Hope that is what you needed. Keep us posted on your process.
Adios, David
That's is exactly what I did back in 2000 when I had my 250 engine built. A couple of things to note; (!.) That was prior to Classic Inline and easy availability of 1.5" SSI valves. If I were to do a head today, I'd use the 1.5" SS exhaust valves from Mike. A set of 144 vavles were hard to find in 2,000. Probably harder to find today and more expensive. (2) I have had no trouble with the 144 intake valves used as exhaust valves. One old engine builder commented, "Valves are valves. They don't know if they are exhaust or intake. They're just valves." I suspect that in extreme duty special valve material may be tougher, but in our engines it doesn't seem to matter. At least, so far. (3) depending on the head you are using, induction hardened seats got better and the hardening process got deeper, so you may not have to add a hardened seat. FYI going from a stock 1.38" valve to a 1.50" will only increase the radius by about .060". For a '78 and later casting I'd guess fine. For anything earlier, I'd check.
I should have ask first, what is the intended use for this engine? IF it will see alot of abuse then hardened seats are a good investment. If it will be a weekend toy, hardened seats won't be much of an issue.
Hope that is what you needed. Keep us posted on your process.
Adios, David
The head I plan to use is out of a '82 Mercury Zephyr. It is still in the car and will be there for at least a few more weeks . My wife has put me on notice that I am not allowed to start this project untill her kitchen is finished. Sometimes I just don't understand women.
I am building an engine for my '66 Mustang. It only gets dirven in the summer, 3 or 4 thousand miles a year. The car is going to get a header and an aftermarket cam, Autolite 2100 (or Holley 5200, undecided here) I will stick with a C4 transmission. (Hey, I'm getting old and shifting is not as cool as it was 30 years ago)
I am building an engine for my '66 Mustang. It only gets dirven in the summer, 3 or 4 thousand miles a year. The car is going to get a header and an aftermarket cam, Autolite 2100 (or Holley 5200, undecided here) I will stick with a C4 transmission. (Hey, I'm getting old and shifting is not as cool as it was 30 years ago)
That head has the good seats so your good to go on that part
!
X2 :rolflmao:
X2 :rolflmao:
