Webley Rebel bolt seal question

[ratbuster2240]

A flat top piston (FTP) reduces the head space between piston and valve. The design is more efficient at compressing air and most are adjustable. I fitted one on a Crosman 1322 and it reduces the amount of pumps required.


Excellent read/info. Thanks. For my info. what's FTP please?[/QUOTE]

[deejayuu]

A flat top piston (FTP) reduces the head space between piston and valve. The design is more efficient at compressing air and most are adjustable. I fitted one on a Crosman 1322 and it reduces the amount of pumps required.

Ah yes. The cup always irritated me 'cos it lowers compression ratio. Another question I'm afraid. Is the exhaust valve held shut/sealed by contact with the sliding sear plate? If so I'm guessing the plate thickness/valve stem length are critical.

[kash2001]

Yes there is a shear plate that hold the pressure loaded pin in place, when the trigger is pulled the plate is moved and the pin fires out releasing the compressed air up into the chamber and air port to the barrel.

In days gone by this pin used to bend or the back plate damage as the pin fired back to hard and the gun wouldn't work.

I assume the length is critical but those with more knowledge than myself can advise better.

Atb

[ratbuster2240]

(Images from Louis Van Hovell)

My Innova's have always had the earlier block sear, the later type has the L sear. Does anyone know why they made the change?

The advantage of this design was that even if the rifle was misused and over pumped, the valve wouldn't lock and it could dump the air. Less of an issue in the UK but it would happen to the Sheridan's with a knock open valve.

[deejayuu]

ああ、ありがとう。私たちにはシム/微調整メチンクが必要です
Ā, arigatō. Watashitachi ni wa shimu/ bi chōsei mechinku ga hitsuyōdesu


Thanks. Ours needs a shim/tweak then methinks

[--ped--]

on the rebels which use the later l plate many had issues with the air bypassing the pin and the valve position had to be adjusted by use of the cylinder screw plug

[kash2001]

ああ、ありがとう。私たちにはシム/微調整メチンクが必要です
Ā, arigatō. Watashitachi ni wa shimu/ bi chōsei mechinku ga hitsuyōdesu


Thanks. Ours needs a shim/tweak then methinks

A Japanese speaker not that many around. I'll try to get the valve off to you for tomorrow all being well - Arigatōgozaimashita

ATB

[deejayuu]

Sumimasenga Nihongo wokaraimas.

Just to answer my own, careless, question earlier.
No. The stem/sear length is not critical 'cos the valve has to travel a few mm to clear the stem seal not shown in the excellent sketches.

[--ped--]

all repaired Paul i had to machine the old retainer out supply a new one
i also chased up the threads and cleaned up the adj plus i'll put one of my inlet seals in just in case the seal you got from Lawrie got damaged when you tried to fit it
the piston head imo has gone too hard to work efficently so i would recommend you swap it ,Steven the lad who has got the ally breech's also got a lot of piston heads sent over and i can put you in touch with him

[ratbuster2240]

Lovely Job Ped. The Innova/Rebel is a great design.

[--ped--]

cheers James with the ally breech's now available from Steve many more will be able to be saved

[ratbuster2240]

The ally breeches look really good and still look like the original plastic ones. A couple of plastic breeches I've had looked fine externally but internally several cracks.

cheers James with the ally breech's now available from Steve many more will be able to be saved

[kash2001]

Hi everyone apologies for the delay in responding, works been manic and I'm paying my sins off 😁 many thanks to Ped for his work snd shipping the parts back, just got to find time to reassemble and sort the pump head out.

Once done I'll report back on MV and pumps, hopefully I can crack the 10.5ftlb dream, keeping my fingers crossed.

One last thing Ped there was a red soft rubber cap in the packaging I assume this isn't used?

Atb

[ratbuster2240]

Great project Kash enjoy tinkering.

[--ped--]

it's not it was just packaging to prevent the pump rod from poking through the mail bag