Red line on a Frankie 150

G

Gary Brink

New member
I put a new tach in my 1413 with a Franklin 150. In looking where to put the red line on the tach, I find differing numbers. One place says it should red line at 2500 rpm, another said 2550 and a third suggested 2600 is the correct red line. So I'm asking the experts: Where should I put the red line so that I don't over rev my new engine?
Thanks,
Gary
 
Gary,
The redline RPM for the 6A4-150B3 engine is 2600 RPM. It is in your engine manual.....you do have one, right.
Dan
 
Yes, however an on-line site said 2550 and another source said 2500. I will put the red line on the 2600 mark.
Thank you, Dan,
Gary
 
Gary,
Half the crap "online" is not true. Use the internet with a "jaundice eye."
That being said.....some of the pre-war Franklins did have a 2550 rpm redline.
This includes the 6AC-298F3 in the T14.
Dan
 
My red line is installed according to the book. I want to mention how impressed I am with my engine thus far. We still haven't flown it due to lousy weather but I have been taxiing it. I am impressed with how it starts.
When it is cold it takes two shots of primer and turns over two or three time before it fires. After it is warm I simply turn on the mags and hit the starter. It starts on the first time over nearly everytime. I recently sold the Cherokee but neither it nor any other airplane that I have ever flown has started like this. I guess with a new major and everything that can be replace or overhauled, I should maybe expect it but I am still surprised every time I hit the starter.
 
Franklin marries some modern design features :
oversquare bore and stroke... shorter stroke than bore dimension ( the heart of modern engine design ! )
Sodium Filled Valve Stems
No Lead Capable !

with some classic features of the best industrial designs :
replaceable cylinder liners

and some frankly "automotive" features:

removeable oil pan and top crankcase cover...
wet sump
"floto" oil pick up

The thing is hell for stout, and just runs so smoothly and nicely that the only
"advantage" of the 4 cyl Lycs is lower parts count and some lightness that comes from that.
put one in your bellanca and they look funny.

The metallurgy seems to be very good, and servicablity is great.. despite somewhat close quarters in the bellanca.

Only being out of production, rather than progressively improved hurts it today.


- not discussing the whole 80/87 , rich boys high test , no lead quandary -

I like flying behind it !
 
150 Franklins dont have sodium filled valves. Not if they were rebuilt according to the manual. A friend that had sodium filled valves in a 150 said that he had valve guide problems often, which is just what Greg Lucas said about them. They work better in a 165 (165 runs hotter) , but are probably still not legal. The higher HP Franklins, including Helos had the sodium filled valves. Just another little tidbit of info. _____Grant.
 
well, I'm just a running fountain of misinformation.. drink at your own risk.

I "thought" they all had sodium in the stems and blah blah blah.

There are 2 different valve stem diameters and guides.. one of which is for the 165 I guess.
surely not going to mix and match sizes, but I can't see any reason why either type won't work fine in the
150.. assuming they are matched, and machined accordingly. ( yeah 165's have higher lift cams, and different valve springs)
so maybe its better to say no reason the 165 cylinders wont work in the 150 ,.. assuming you are out of 47 chev parts.
 
We probably should start another thread, but I will continue here for the moment. There is actually an STC to use the whole 165 valve train in a 150 (except for the lifters which stay 150 parts). The amazing part is that the owner is still alive (rare for an STC for anything Bellanca related) and is willing to have it used. Mr Wirt, I dont recall his first name is a member of the Stinson club. I spoke with Mr Wirt in the last couple of years. The only difficulty is that you must use the 165 cam to be in compliance with the STC. That means you have to split the case, so it is only practical during a Major. I would think it would be simple to use the STC with a 337 to retain the original 150 cam, but two different IAs have just shaken their heads and said Good Luck getting any change approved. I follow the Stinson Yahoo group, just to get Franklin information. The Stinson group has many more users than we do, and even has its lovable old grump that is a wealth of information. Sort of like our group? _________Grant.
 
There are three different valve stem diameters depending on whether it is a 150 or 165. The early 150 had ~ .372 " dia stem. 150 x also had .4342-.4350" dia stems. 165 had .403" dia stems. See pg 25 of "the book". I have seen the latter used in 150 engines too.
 
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