Feeling brave?

[cardiffrob]

Kemppi. Looking at the bolt pattern they were Franklin engine props. I was planning one day to clean them up and varnish them but they've stayed in a cardboard box for the last 10 years. No point leaving them outside to get damp and warp.

New thread?? "Things I have managed to slip into the house"

 

[KemppiFrog]

Kemppi. Looking at the bolt pattern they were Franklin engine props. I was planning one day to clean them up and varnish them but they've stayed in a cardboard box for the last 10 years. No point leaving them outside to get damp and warp.

New thread?? "Things I have managed to slip into the house"

The only Franklin I delt with was on one of Ken Wallis's autogyros. Used it to get the distance record.

 

[gordon stephenson]

The ladies will literally bend over backwards for anything horsey, While you have to look after yourself!! Not only wired differently they are completely the wrong voltage,

 

[Cobbler]

The ladies will literally bend over backwards for anything horsey, While you have to look after yourself!! Not only wired differently they are completely the wrong voltage,

Most have the wrong fuse as well ........ But we love them just the same

 

[8ob]

The ladies will literally bend over backwards for anything horsey, While you have to look after yourself!! Not only wired differently they are completely the wrong voltage,

They have just pulled in after doing an eighteen hour stint, they are getting another six ready to go at 3am again and I was wondering if I should ask if they are cooking any supper tonight

Five minutes ago

 

[cardiffrob]

I was thinking of putting the Franklin in the FRED but it was maybe a little large. Still, 125hp would have been nice. Might have gone well in a VW Beetle, too

 

[cardiffrob]

Head number 2 has been given the 'treatment', with management approval. Sadly, I think is a bit worse than my own one.
Pics from just before the wash. Valves in an old Sieve, not the cutlery tray (Good tip!)

 

[cardiffrob]

Should I try to bend the valves straight to get them out or just Dremel them off to get at the guides?

 

[Wedg1e]

I was thinking of putting the Franklin in the FRED but it was maybe a little large. Still, 125hp would have been nice. Might have gone well in a VW Beetle, tooView attachment 107151

Out of interest, what's the servicing/overhaul regime on a light aircraft/ microlight engine? I know that with gas turbines they get a complete strip, inspection and rebuild after so many full-power cycles (some of our customers do exactly that work) but it must be a hellish expense to do that with a flat-4 for a plane that might only be worth what, £20 grand?

I'm off microlighting in a couple of weeks, will ask to see records

 

[Wedg1e]

Should I try to bend the valves straight to get them out or just Dremel them off to get at the guides?

Depends where they're bent? Could do more damage to the guides getting them out; cutting might be the best option.

 

[KemppiFrog]

Wedgie
Often around 2000hrs for a complete overhaul. A cylinders off top O/H might be done at half life. Things have changed a bit since I was doing it, some discretion is allowed by the engineer now, depending on condition.
Microlight engines are often 2-strokes and I am not sure I would fly with an overhauled one.... Life might be 500hrs or less.

CRob, I would cut them out, less chance of doing more damage to the head and I assume if bent, of no further use.

 

[Bill Edwards]

Should I try to bend the valves straight to get them out or just Dremel them off to get at the guides?

What I would not do it cut them off.
I think that if you do that you'll end up with it still bent below where you cut it and that bit won't want to come out. You'll then have no option but to hammer it out using nothing but brute force.
I'd bend them straight first making sure they bend low enough so it'll go through the guide. Then chop off the top if it's mangled or not straight by all means, but be sure that the remainder is straight first.

 

[cardiffrob]

I did what Bill suggested and managed to drill a steel rod oversize and slip it over the stem. A bit of levering and the stems were straight enough to be tapped out. Looking at them, the stems had bent in just one place a few mm below the top of the guide, splitting it in the process. My money is on something being tied round the head when the engine came out.

The guides are 0.5 inch OD, 7mm ID (+ a bit but less that 9/32) and they ahve a retaining collar half way down. I looked for a suitable guide and the VW Passat just failed on insufficient OD but I think the 13mm OD bronze guide from the 2.0 16V Vauxhall (C20XE???) might be a candidate, unless anyone has any other suggestions? Can they be home made from scratch with any success?

 

[cardiffrob]

Oh. Any ideas why this happened? The inner springs are all OK/unbent/equal height.

 

[Gareth_16V]

It looks as if have either stress relieved to that shape, or have taken a set.
To me the the most serious part is the corrosion on them looks to be getting pretty severe so I would hesitate to put them back into service, due to the pitting present on the coils being a good initiation point for a stress failure.
Do you know if these are standard valve springs, or were they specials made for the head?
A company such as Piper Cams could probably measure the cam and advise the strength and type of valve spring you'd need if they are a non-standard.

 

[cardiffrob]

All the parts were custom so it is a case of finding a suitable alternative. For the damaged guides I have a suspicion that Vauxhall did a 13mm OD bronze guide for the 2.0 16v engine (C20XE?) that might be a suitable donor.
The 100e people might be a source of valve springs for me. I agree that they are unuseable, Gareth.

 

[Shox Dr]

View attachment 107209
Oh. Any ideas why this happened? The inner springs are all OK/unbent/equal height.

Even a good quality new spring can take a 'set' when new of around 3-5% of it's unsprung length. But they shouldn't bend like that. They may well be too long and have been under too much preload as well as binding on compression.
Do they show signs of the coils touching each other?

 

[cardiffrob]

I'll have a look and compare them to the other head. It has certainly sat for 1/4 century or more in the same position. Could that be it?