Gipsy Major Fuel

[Wanderin_dave]

Hey guys and gals, i've only flown aluminium head Gypsies on AVGAS and remember years back being told that you should only run bronze headed Gypsies on unleaded with a valve lubricant. I was told this is due to the AVGAS burning too hot for the bronze.
Can anyone enlighten me on the best fuel for a bronze headed Gypsy in a Tiger Moth as i'll soon be flying one. Just for info it'll be doing aerobatic jollies, so she'll be working hard with lots of climbing.
While we're here, any other tips?

[OZBUSDRIVER]

I am absolutely amazed what can be trawled up on google-
accident report/G-ADGT

[Wanderin_dave]

You're not wrong! Some great stuff and more than covers what i was after.
Thanks very much OZBUSDRIVER

[Andy_RR]

Bronze heads in a 1F?

It's an odd conclusion in that AAIB report. The aircraft was fitted with a 1F engine, which according to the service manual has Aluminum cylinder heads with steel valve seat inserts.

Then they blame use of leaded fuel with bronze heads for a carbon deposit issue, when the lead-bronze incompatibility issue is about corrosion of the cylinder head.

Whatever the reality, it's not very well explained in the report.

A

[asw28-866]

Wanderin Dave,
Been doing it (Tiger Aero's) pretty full time for last 4 years, PM me if you want specific info (as long as you are not in the SE QLD area!).

Wouldn't have picked up the Tiger from YHBA recently?

Cheers

ASW28

[OZBUSDRIVER]

AndyRR, I think the carbon fouling is from running a cylinder too hot and carbonising the oil.

[Andy_RR]

I agree, OBD, but why all the horlicks about bronze cylinder heads and lead when it was neither directly stated that bronze cylinder heads were fitted, nor should they have been, given that it was a Gipsy Major 1F, which has aluminium heads - at least according to the dH/Rolls Royce service documents that I have.

[Wanderin_dave]

I read it to say about the same. I didn't pick anything about the engine running too hot, just that the carbon build up could occur. Which seems to say that it could happen during normal ops at normal temps.
I agree it's poorly worded and i'm thinking the last line of the 'Engineering Investigation' is trying to say that the aircraft involved had bronze heads. Though you say a 1F engine shouldn't have bronze heads. Wouldn't be the first mix and match Gypsy to take to the skies.....
Still some good info in there.
Makes me think unleaded is the way to go. Will run this past the boss.

ASW28 - PM sent. No, didn't pick up a Tiger from YHBA, but did say goodbye to one there recently.

[Bob Murphie]

The flight manual of my J1B said to use "any good quality standard automotive fuel". The "standard" being to differentiate with "super". Both of which were leaded.

At the time, you could still buy "super" and I used this strained through a chamois.

I understand problems with valves came about after "unleaded" came to be available. I gather the lead helped to lubricate the valves (especially the exhaust valves which had a tendency to "tulip".

I had two engines and sold the spare bronze headed one, so I assume the flight manual referred to the original engine. I had no problems with the aluminium heads fueled as I mentioned. This Gypsy was a Mk10.