Gami Injectors

[J-nut]

Hi Guys,

I'm looking at putting a set of Gami injectors on my machine. I've talked with the folks at Gami and they have the STC for the B2b but they tell me they've never sold a set.

I've known guys who ran them on their 300Cs and have had great results - smoother running, cooler running and reduced fuel consumption. One guy I know claimed 1-2 gal/hr fuel drop depending on what he was doing. Looking at the B2B induction system it seems like it would be even more inefficient than the 300C.

Before I drop the money for the injectors I wanted to see if anyone is running an engine monitor. The rep at Gami tells me if you see pretty even temps across the board, the injectors won't make much difference but if the cylinders show an inbalance if can make a BIG difference.

Anybody out there have an engine monitor and could shed some light on this for me?

[seneca2e]

I personally don't think the Gami injectors are worth it. You're not going to run a helicopter lean of peak! I don't think you're going to see a difference in fuel efficiency at all.

[J-nut]

Running engines lean of peak is only one perk of the Gami's. Like I mentioned I've seen BIG differences in the Hughes 300's. Added power, cooler, smoother running and lower fuel consumption are all traits of the 300's with the Gami's. The Gami's help match the fuel/air ratios for all the cylinders. Looking at that octopuss of an intake manifold on the Brantly I have a strong suspicion there is a large imbalance of air/fuel ratios across the cylinders. An engine monitor would tell the tale though. I know Bryan Cobb had one on his ship but he's sold it and I'm not sure who has it now but they could probably answer that question.

[senglish]

Did you ever try these injectors?

[J-nut]

No, but I have plans to once the engine is rebuilt. I'll post results once I do.

[bryancobb]

Hey J-Nut!
Bang-for-the-buck... PUT THE GEM-602 OR SIMILAR IN AND FORGET THE GAMI'S.
I flew N2175U for about 200 hrs without the engine monitor, and 150 after.
I experienced a verifyable documented reduction in ave. fuel consumption from 11.5 gal/hr in cruise, down to 9.5 gal/hr in cruise.

I let the 1-cylinder CHT gauge in place, but the 602 still required field approval. I put in line a cannon-type plug with ALL probe wires on it so engine removal/installation is easy.

I got the GEM-602 off Ebay for 125.00 an the probes from INSIGHT were another 450.00.

A lot cheaper than GAMI's.

I checked the probes for equal sensitivity before installation, using a hand held propane torch.
After installation, the CHT's and EGT's were all within 1 bar of each other on the scale.

After you put a monitor in, if you feel GAMI's are needed, you can then order the correct ones by giving them the readings you are getting.

Bryan Cobb

[J-nut]

Bryan,

According to the guys at Gami an engine monitor is a necessary first step like you said. If you have equal temps across the board the Gami's won't help since the fuel mixture is already balanced. Do you know what your resolution was for each bar? If I remmeber correctly the insight had a pretty wide range for each bar.

How did you manage to get the cruise fuel burn down? Were you leaning in cruise? That's an awesome fuel reduction!!

[bryancobb]

Hey J-Nut:

On the GEM-602, each bar represented 25 DegF. The manufacturer emphasizes that there is NO VALUE in knowing the numerical value of EGT/CHT's. They say not to even try to interpret the instrument as numerical values. They say to just "get the picture," compare for uniformity, and go on.

My fuel consumption reduction was large because before I installed the monitor, I flew around "full-rich" all the time. I really didn't feel I had a reliable way to lean.

After the engine monitor was put in, I leaned AGGRESSIVELY!

The monitor scans all cyl's several times/sec. and displays 4 EGT's and 4CHT's. It also has a button to push that puts the computer in search mode. When I leveled off in cruise, I pushed that button and started leaning. The monitor is then looking closely for which cylinder's EGT reaches its' peak first. As you lean ... when ONE cyl. starts getting cooler as you twist the vernier out, this means that cyl. has peaked and that WHOLE COLUMN of bars for THAT cylinder would begin to flash. Then I'd look at the Brantly fuel flow gauge and richen the mixture a smidge.

Best I can remember... one cylinder would usually start flashing when the Brantly fuel flow gauge showed between 9 and 9.5 GPH.

BC