Low profile rocker covers?

Gonzo24 · #1 11-19-2011, 06:02 PM

I am trying to minimize rocker cover to cowl contact on my set up on #1 and #2 cylinder.

Is there such a beast as low profile rocker covers? My ECI covers (IO-375) are square on the top edge and appear to be high relative to what's needed.

I have maybe 3/8" at the top front corner of the cylinder to the cowl. during start up and shut down I anticipate it will hit the cowl with the current covers. Curious if lycoming rockers fit and are less obtrusive among other options?

thanks,

rocketbob · #2 11-19-2011, 07:19 PM

Not enough room inside the rocker covers to make them any smaller.

FORANE · #3 11-20-2011, 05:10 AM

Have you removed the cover and measures the clearance? I am not familiar with the ECI.
When I purchased my plane with lycoming o-320 the builder had a similar clearance problem. He had actually tapped in the cover to increase the clearance between the cowling and cover. He then put indicator tape on the cover to show if it was rubbing. It ran fine this way for a few hundred hours. It still had enough clearance inside the rocker.

Gonzo24 · #4 11-20-2011, 10:21 AM

Engine is still in preserved state. don't want to rotate the prop and wipe the preservative oil at this stage. There has to be a happy medium given the valve lift on these engines... the search goes on. does anyone know if the valve lift on a 375 is the same as a 360. guessing it is not more than .500"?
Lycoming's traditional rockers appear to have a lower height just from a visual glance at engine pics. may pick up some cheap rocker covers on ebay and experiment...

rocketbob · #5 11-20-2011, 10:47 AM

Lycoming covers have a larger radius at the top. Doubt it helps much. My rocket has the same problem and I've seen where some builders have bonded with RTV a piece of rubber baffle to keep the rocker cover from bumping.

I've been working on some roller rockers so I've checked the clearances inside the covers...there's just not much room between the pushrod end of the rocker and the cover when the valve is fully open.

jrs14855 · #6 11-20-2011, 11:27 AM

I built a 180 Pitts that had a custom cowl. Clearance on one rocker cover was approx 1/8". I bonded a piece of 1/8" thick hard rubber(not baffle material) to the inside of the cowl. It worked just fine for 1000 hours. Pitts had the aerobatic mount rubbers so not quite as much movement as non acro mounts.

Gonzo24 · #7 11-20-2011, 06:54 PM

thanks for the info guys