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My current A&P seems to think he did all he can do.

I have a grumman cheetah with a HC STC. The #4 cylinder is running really hot (it did before the STC as well)

Can anyone recommend a good A&P for this kind of thing in the NY/CT area?

asked Apr 20 '10 at 18:52

Tim's gravatar image

Tim
811210

edited Jul 23 '10 at 16:09

Patrick%20Pohler's gravatar image

Patrick Pohler ♦♦
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1

Silly but required question:

You've swapped the probes, right? Both at the engine and at the monitor? Do you have any evidence of overheating besides the monitor?

(Apr 22 '10 at 17:59) Jim C Jim%20C's gravatar image

@Jim Those are great questions. No, I have not swapped probes. I will do that and check again. I am not sure what other evidence there can be - any ideas?

(Apr 25 '10 at 06:08) Tim Tim's gravatar image

Tim/Jim Hi We have a Cheetah with #3 and #4 running too hot 450 on #3 briefly during climbs, David Fletchair mentioned that there are fiberglass augmenters (collect and organize cowling air flow prior to dumping into airstream) which can distort with heat that would be a place to look. I havent looked at ours yet..

Any luck wiht your issue?

answered Mar 17 '11 at 23:58

Tunahawk's gravatar image

Tunahawk
511

I recently read an article emphasizing the importance of the plastic cowling baflfing that directs the airflow around the engine. In the Cessna type airplanes, they are usually orange. I once flew a 172H with these dangling and the engine always seemed to run hot. It wasn't till reading that article that I put two and two together. Great post.

(Mar 18 '11 at 00:20) wbeard52 wbeard52's gravatar image

To all Hi,

Recieved some other info re baffling and exit ramps for a Cheetah

Where are you located? Dave is speaking about the exit ramps in the bottom cowl. My 78 Cheetah has metal exit ramps I believe the earlier ones have fiberglass ramps. The heat and time can weaken the exits and the center of it sags down narrowing the exit opening.

http://www.bondline.org/wiki/Lower_Cowling_Split

http://www.bondline.org/wiki/Engine_Baffles

These are some links that also

might help.

Some other factors are: -Replacement lightweight starters are often installed poorly. The front metal baffle has to be trimmed and flexible baffle material installed around it. Many mechanics don't take the time to do this. -The flexible baffle material that seals between the nosecowl and the fixed metal front baffle have to be in GREAT shape. There are many places where cooling air can be lost. These cant be seen without removing the fiberglass nosecowl. If you have the split cowl then you don't need to take the prop off otherwise you do. -Top baffles have to be in GREAT shape, essentially all baffles have to be in great shape. -What CHT gauge do you have? JPI reads higher that EI and is more accurate in my opinion. So if you have a temp of 454 with a EI (Electronic International) your temp may actually be higher. The JPI CHT probe is spring loaded and actually touches the cyl head. The EI CHT probe screws into the cyl assy but doesn't actually touch the cyl except where the threads are.

My HC Cheetah can get into the 420s while climbing with a JPI probe. It used to be worse. I have great baffles, rebuilt the exit ramps and made them larger. I also have sealed the space between the prop spinner and the nosecowl. I agree that your 454 is to high.

answered Mar 18 '11 at 10:36

Tunahawk's gravatar image

Tunahawk
511

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Asked: Apr 20 '10 at 18:52

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Last updated: Mar 18 '11 at 10:36

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