Ralf,
I do not have GAMI injectors in my IV-P. I do have GAMI’s in my Bonanza. My IV-P engine has 8.5 to 1 CR, an experimental camshaft, ceramic coatings in the exhaust, my own design intercoolers, and the larger turbo compressor used in some Malibu. All this piddling caused the stock wastegate to be inadequate and I had to install a larger wastegate in order to prevent an over boost condition. So yes….I would have to say my engine is different. I wouldn’t say it is significantly better…..but I had fun piddling. In my opinion it does not hurt anything to run 32 inHg at 2500 rpm and LOP. I do all the time. I have for years run my TNIO550 A36 Bonanza at 30 inHg and 2500 rpm and LOP. I do watch my TIT’s and CHT’s very close and my personal IV-P CHT limit is 385 degF and TIT is 1645 degF. A reduction of 0.1-0.2 gph will reduce CHT’s 5 degs or more. I don’t think CHT’s at 390 degF will hurt anything, I just like having a cushion before I see 400(+) degF. At 400 degF I am doing something significant to reduce CHT’s. I do believe this…..for any given engine at the same rpm and throttle setting, your CHT’s reflect peak cylinder pressure. If you are ROP and CHT’s are 395 degF and when you go LOP at the same settings and your CHT’s are 375 degF…..you are abusing your engine LESS when LOP. However you go faster ROP.
Craig
N7VG
Hello Craig,
Do you have the GAMI injectors or was your engine set up in a special way?
I thought that LOP operations are approved up to 28 inHG. I would like to run mine with 32 inHg but I am afraid to damage something.
Here is what I see so far:
Climb – full power – full rich (this gives me the coolest temps) – 160…170 IAS – CHT 380 – 390 – results in 1600 ft/min (beginning) 800 ft/min (end)
Level off at FL22, FL23 – full power – full rich – TAS 292…297 (on the bezel – I know this reads high) – #3+4 CHT 380 - 390
After this LOP at FL22, FL23 at 28 inHG, 16.1 gph – TAS 270…275 (on the bezel) – #1 CHT 360…375
Like I said I would like to run it at 32 inHg LOP but I am afraid I damage something.
Ralf