Is there any approval for 165 valves in a 150?

G

gjordan

New member
Does anyone have a 337 or STC to show approval for 165 valves in a Franklin 150? The 150 exhaust valves are unobtainable and I have enough 165 valves to do the job. I understand that it requires both intake and exhaust valves and the correct guides and the 165 rocker stands (springs also). I know it has been done many times before, but I have never seen documentation on it. My IA wants something to show the feds before we continue. Any help would be appreciated!_____Grant.
 
STC arrived and it allows almost the whole valve train from a 165 to be used in a 150. This includes splitting the case and putting in a 165 cam. We only want to do a top using 165 valves so we think we will submit it with a 337 to just use part of the info.The second problem is that the parts listed are all 165 except the exhaust valves,which are from an early helicopter engine. They most likely could not find 150 valves or 165 valves at the time. I posted more info on the Heavy Vs Light case 150 thread. I will let you know how this comes out.____Grant.
 
If you use the helicopter valve and they are sodium filled they will coke up and stick, unless you use 100LL. Check the part number a see what they really are. The 200 hp heli valve had a flat face......Greg
 
Greg,the helicopter valve listed in the STC is #19326 which is the valve that was removed by Franklin service letter N-43 when they changed to a sodium cooled valve. I suspect it is as unobtainable as the original 150 exhaust valve. I just talked to my partner and he said our IA didnt like the STC anyway so we will move on to plan C or D or whatever it is now. Do you know if there is any other previous approval for actual 165 valves? I agree about the sodium cooled valves. A friend ran them in a 150 for 800 hours back when 80 octane was available and he had to decoke them way too often. When removed at 800 hours they showed zero wear because of the rotators , and went into a 165 that only burns 100LL and have givin no trouble. OH WELL, the saga continues _____Grant.
 
All these valves will eventually go away. "Someone has 150 valves, someone has a few 165 valves." A few years ago, Russ Williams had Ferrea in Florida made new Ken Royce valves from prints that are available. I bought two sets of these from the very short production run and they weren't too expensive. As I remember, they were $65/ea. Believe me, the valves for the Ken Royce/LeBlond engines are rarer than Franklin 150/165 valves! Anyone want to make this project your baby? I think I'd copy the later 150 valve. It is beefier than the 165 valve. Ask Greg for his opinion. Over to you.............Dan
 
Grant, I also wonder about cutting away adequate clearance in the case for the cam. Do you create the equivalent of a 165 light case problem...just in a different part of the case?
Hmmm, maybe it is time for TOM to put in a 165? I know where he can get one...or two.
Larry
 
We have no plans to put the 165 cam in the 150. I dont know how much metal would have to be removed, but I doubt it would effect the main bearing journals. All we want to do is put 165 valves in a 150. It has been done before, but no one seems to have the paperwork to back it up. The sodium filled valves in the 150 previously mentioned worked perfectly (other than the coking) for many years and they are dimensionally the same as 165 valves. They came in overhauled cylinders from a reputable Franklin builder(25 years ago) and worked fine, but no paperwork. We were hoping to use the STC but the IA didnt like it. This will all work out in the end and we wont weaken and think about brand X engines like some people we know.____Grant.
 
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