Eating Cylinders on 414 Ram IV

Home 2024 Forums Opening Section Maintenance Issues Eating Cylinders on 414 Ram IV

Viewing 15 posts - 1 through 15 (of 27 total)
  • Author
    Posts
  • #83513

    Hi everyone,
    I need some input from other owners. I have a 414 with Ram IV. I go through new cylinders like crazy. I have to replace at least one cylinder every year. I either have cracked cylinders or burnt exhaust valves. My mechanic says that I just have bad luck. All of my cylinders are recent (last 5 years, under 300 hrs) Ram/ECI cylinders. I typically fly at 50-55% cruise power at FL150, 28in/2300. I usually fly slightly rich of Rams settings 31-32 gal/hr.
    What are other owners seeing?

    #94826

    ok, what was tony’s technique? It does no good to post a response without the info. Tony and i go back to the early 90’s
    when larry ball was the “guru” and i found him lacking then.

    #94827
    quote SGERBER:

    … I typically fly at 50-55% cruise power at FL150, 28in/2300. I usually fly slightly rich of Rams settings 31-32 gal/hr.

    Questions:
    1. What is your full power (takeoff) fuel flow?
    2. What do you set for climb power, what is the fuel flow, and what are the max CHT and EGT / TIT numbers?
    3. What are the numbers (CHT and EGT / TIT) during cruise?

    I don’t have a RAM IV recommended power setting card but 28″ / 2300 RPM seems like it should be producing more than 50 – 55% power and therefore require more fuel flow ROP. I think it is unusual to be losing cylinders the way you are. Failures like that are generally caused by inadequate fuel flow during high power operation. For reference, my full-power fuel flow is 38GPH (RAM VII / 335 HP).

    #94829

    As a member of the CPA and TCF my dues should allow me to have this info. That’s what this forum is all about. Twin cessna flyers helping other
    twin cesna flyers. Perhaps the administrator should clarify the “mission”
    of this ” type club” and if it’s to sell tony’s seminairs and the monthly mag i’ll pass on the the membership because it’s a waste of toime and money.

    #94830

    Ram setting for take-off is 41″ full rich. I climb at 34″ 2500 54gph. Lately I’ve been using 39″ full rich for take-off. cht’s are always in the green and I think my egt’s are 1500-1525 during the climb. I keep everything under the Ram settings.

    I agree that this forum is to assist other members. Just another point. I’m also a member of the Aerostar Owners Association which has a blog/forum. Their forum is very active and every member makes an effort to help other owners with ownership issues. There group includes members that are in the Aerostar business and that never impedes their effort to provide assistance. This is not the first time that I have asked the membership for assistance and I must say that so far the membership has not put forth an effort to provide such aide. I certainly hope that attitude changes here forward.
    Thanks
    Sandy

    #94831
    quote SGERBER:

    Ram setting for take-off is 41″ full rich. I climb at 34″ 2500 54gph. Lately I’ve been using 39″ full rich for take-off. cht’s are always in the green and I think my egt’s are 1500-1525 during the climb. I keep everything under the Ram settings.

    Your climb setting of 34″ / 2500 @54 GPH sounds OK / maybe a little on the low side. My engines are setup (335hp) for 33″/2500RPM @ 56 GPH. During initial climb I see 28GPH left and 29.5 GPH right; it then settles down to 28/28 by about 8,000′. That is the full rich setting. Your EGTs seem high or very high – I don’t have my logs with me but I believe my EGTs are in the high 1300s during climb (CHTs run in the 330 – 350 range). I am sure that the climb TIT number is around 1440 and a cruise value of 1530 on the right and 1540 on the left. Those are reported from a JPI engine analyzer. I will lookup the exact numbers for takeoff, climb and cruise and report those later.

    As far as the RAM settings go, I have found that even RAM is on the light side when it comes to fuel flows and performance. I find that I need to add 0.5 – 1.0 GPH per side to RAM’s cruise figures when operating ROP. I have no experience operating LOP. While I am no expert on engine operations, one thing that is clear to me is that if you are burning valves it is most likely due to lack of fuel flow at high engine power settings. For reference, I have 800 hours on ECI cylinders and my compressions are 75 – 78 psi and am therefore happy with their performance to-date. I am concerned about the cracking issue however.

    I don’t recall whether you posted it or not – who is performing your maintenance / engine setup and do they have all of the proper equipment & Continental / RAM procedures? If I were having these problems I would go get a second opinion and engine setup evaluation from another well known shop.

    With respect to the comment on Tony’s procedures, if he considers that to be copyright material then I can understand and support not posting it. But, like you, I would like to see more participation and sharing of what works for everyone else. Departure to cruise engine management should be well established and published, certainly by this organization. In fact, all standard operating procedures that could enhance operations, reduce costs or improve safety should be available on this website. Bob, I’d like to hear your opinion on this.

    #94832
    quote SGERBER:

    Ram setting for take-off is 41″ full rich. I climb at 34″ 2500 54gph. Lately I’ve been using 39″ full rich for take-off. cht’s are always in the green and I think my egt’s are 1500-1525 during the climb. I keep everything under the Ram settings.

    Sandy – Do you have an engine monitor?

    The factory CHT redline for these engines is in the 460 range which is generally considered WAY too hot. I prefer keeping my cylinders below 400, and running them at a much hotter setting can cause premature cylinder failure.

    Also, EGTs in the 1500+ range for climb seems very high to me. I want to see 1300’s on takeoff and through the climb.

    It’s very hard to really tell what these engines are doing without a monitor… The factory gauges are woefully inadequate.

    Mike Busch has written a lot about both temperatures and using an engine monitor, as have the Tornado Alley Turbo guys (John Deacon, especially, has a great series that ran on AvWeb – I consider this mandatory reading: http://www.avweb.com/news/pelican/182544-1.html)

    Personally, I am NOT a fan of partial power takeoffs – I don’t think taking off at 39″ is going to help with your cylinders and it increases the time you are close to the ground…

    Robert

    P.S. With the above all said, sometimes you just have bad luck. I had to replace a 400 hour ECi cylinder in my T210 this annual, and if it spent 15 minutes over 400 degrees its entire life I’d be shocked. To some extent cylinders are consumables.

    #94833

    If your RAM IV has AA Intercoolers added, 41′ at takeoff will produce 365 hp. RAM issued a bulletin on this issue in the late 1990’s and recommended 39′ as a max for takeoff, which according to their charts produces 339 hp. The point is that 365 hp may very well be what is causing your cylinder problems.

    The bulletin I’m referring to can be viewed at RAM’s website, just click on “Service Bulletins & A.D.s” which appears on the left margin of its home page. It’s interesting reading.

    Hope this helps.

    #94834

    Thanks for the comments. I do not have an engine analyzer. I just have the basic Alcor egt and Cessna/Ram 3in1 gauge for cht. The Ram IV has the Ram intercooler but not the intercoolers that have the air scoop like AA’s or Ram VI or VIIs. Since I don’t have an engine analyzer I have been relying on the fuel flow settings provided by Ram and then I add .5-1 gph/side to the rich side just to be safe. It has been my understanding that at 50-55% power settings if you ran the engines at peak lean you won’t damage the engines. Therefore, I would guess that the exhaust valve burning must be occurring during take-off or climb. On take-off when I use 41/2600 at full rich I’m burning around 35gph/side. This is only for the first minute/1000ft of the flight. Ram’s cruise climb for the Ram IV is 35/2500 and 26.5gph/side and I usually climb at 34/2450 and 27gph/side. Maybe I need to climb a little richer? BTW, my maintenance is performed by Jimmy Garland at S&S Aviation. Twin Cessnas, more specifically 414,421 and 340s, are their specialty.

    #94835

    Apparently, the person that made the post about Tony’s methods did not want any negative commentary. So he deleted it. Frankly, the negative comments might get this association to be more active in meeting its purpose of supporting twin Cessna owners and pilots.

    #94836
    rwelsh
    Participant
      quote :

      ok, what was tony’s technique? It does no good to post a response without the info. Tony and i go back to the early 90’s
      when larry ball was the “guru” and i found him lacking then.

      Well, you got me confused how Tony got in this conversation on this subject. If you have a beef with the forum, talk to Bob about it.

      As to the engine problem on this thread, I think one should be talking about how many GPH per engine, not total GPM on both as it can be confusing. On my 310 HPs on the 340, I use 37 GPH on takeoff and 29 GPH on climb at 2600 and 32 inches. My EGTs are in the 1300 range at TO and climb. The CHTs run around 350 until above FL180 then they run up to 380 to FL250. I cruise at 2350, 34 inches and 15.5 GPH at 204 KTAS running LOP above FL180. I had ECI give me 12 new cylinders due to their recall. Before returning the cylinders to ECI, I removed the valves and checked the valve guide condition. On 8 out of 12 cylinders, the valve guides were out of round with the valve seats; in other words, ECI had bad tooling when reaming the guides and or grinding the new valve seats. 7 of the 8 exhaust valves had some kind of valve burning which showed up in my initial borescope of the cylinders. I believe that ECI had very bad cylinder manufacturing in the 2003 to 2009 period–lots of problems and recalls and service letters. Hopefully Superior will do a better job with the Chinese running the new show.

      I think you are not running enough fuel flow for takeoff and climb. Too much is better then too little. Also I was puzzled when you said your CHTs were running in the green. That tells me you do not have an engine monitor. To keep these engines running for longevity, I believe an engine monitor is crucial to prolonged cylinder life. As I have said many times before on both Forums, the baffle system has to be the tightest as can be all around the engine, not just the side baffles. You can search through my previous posts on the baffle cooling issue.

      You should be borescoping your cylinders every 100 hours or sooner. A few articles have been written by Mike Busch about what to look for on the exhaust valves during borescoping. In fact, Mike wrote an article last month in the CPA mag with color photos of good and bad exhaust valves. You also might think of changing mechanics if he/she is not borescoping your cylinders. If you remember, it wasn’t too long ago we were lucky to get 600 hours on the top end of these TCM, soon to be Chinese, engines. Now I complain if I can’t get 1600 hours out of a cylinder.

      #94837
      bthomason
      Participant

        [/quote] With respect to the comment on Tony’s procedures, if he considers that to be copyright material then I can understand and support not posting it. But, like you, I would like to see more participation and sharing of what works for everyone else. Departure to cruise engine management should be well established and published, certainly by this organization. In fact, all standard operating procedures that could enhance operations, reduce costs or improve safety should be available on this website. Bob, I’d like to hear your opinion on this.[/quote]

        While the poster’s cautious assumption that TTCF might not want information from a seminar shared on the Forum was reasonable, it is not correct. TTCF will answer any technical question a member may have, whether we cover the subject in a Seminar or not.

        Below are Tony’s “cylinder-saving” tips for both normally aspirated and turbocharged engines:

        “The “technique” mentioned is for normally aspirated aircraft engines only and simplistically is that the first power reduction is with RPM (prop control) thus leaving the throttle full forward, and as the aircraft climbs the MAP naturally drops, yet leaves the mechanical connection to the fuel at its richest possible setting. This procedure is not “mine” but is well defined in various TCM manuals and some aircraft POH primarily newer Beech and Cirrus. However this does not apply to the turbocharged aircraft, which is the heart of the Forum conversation.

        My comments on the Turbo models is rather simplistic.
        Set the T.O. fuel to the higher part of the allowable range. Use full travel on the throttle for T.O.
        Set climb setting fuel to the specified settings and use that power setting for climb.

        And lastly accept the fact that cylinders are somewhat sacrificial. Starting at around 500 hr. and on most operators will see a need for cylinder replacement due to the started reasons for 1/2 to 2/3 of the cylinders by the TBO.”…….Tony

        #94838

        I guess I’m lucky πŸ™‚ Mine are TSIO-520’s, RAM 1, Millenium cyls. 1400 TBO. They’re over 1200 hrs now. I’ve flown only the last 400. According to the engine logs none of the cylinders have ever been removed/replaced.

        Here is some interesting (to me), reading:

        http://www.buy-ei.com/Information/Pilots%20Manual.pdf

        See “Leaning Methods”, “Takeoff and Climb”. We all know EGT is relative, probe placement, etc., but climb power (75 percent), EGT’s of around 1300 is what I routinely see.

        #94839
        rwelsh
        Participant

          Rich, that was an interesting article by E.I. on engine management. Assuming what they say is true, then the original poster on this thread is operating in the detonation range at takeoff power if his takeoff EGTs are actually 1500dF. The article, on page 16 and figure 13, shows at least 200 dF less then peak EGT to be out of the detonation range. Assuming the peak EGT for properly placed EGT probes is around 1625dF, then a takeoff EGT of around 1400dF would be the max. I actually prefer 300dF difference on my engines by increasing the fuel flow 2 more GPH over recommended for a maximum takeoff EGT of 1300dF.

          I would be interesting to see if the edges of his pistons are slightly eroded from excess temps at takeoff. But as I mentioned in an earlier post, he may not have an engine monitor and his EGT probes may be too close to the exhaust flange giving a temp reading too high.

          I am going to ask George Braly of GAMI to respond to the issues presented in the E.I. article.
          Dick Welsh

          #94840

          Thx, Dick. I found it educational. George likely won’t agree with certain points, I think.

          My own engines aren’t GAMI equipped and run EGT spreads of near 100 deg. First to peak cylinders are consistent and peak at 1520-1550 at 61 percent cruise power. I’m a ROP, “best power” operator so I lean to run close to 1400.

          My takeoff EGT’s typically run high 1200- low 1300’s.

          I think there is a fuel flow issue for the OP. I, for one, lean according to EGT. My factory FF Gage has been overhauled, but if I used it for primary mixture setting I’d be running way to rich πŸ™‚

          Ps My turbos are about 600 SOH with no problems … Yet 8)

        Viewing 15 posts - 1 through 15 (of 27 total)
        • You must be logged in to reply to this topic.