Retlas

[Chipmaster]

Hi Jason, I was alluding to a post by Graham early in this thread. I assumed this referred to two original engines that still exist. It would be good to see modern detailed pictures of these engines.

"...............two vertical Gardner engines have surfaced but due to the rarity the owners wish to remain anonymous."

Andy

[Chipmaster]

The rest of the work on the inlet valve chest was done using a pillar drill, the pictures aren't interesting, no fancy set ups just various drills disappearing into the casting.
Building Retlas 478 by Andy, on Flickr

Building Retlas 483 by Andy, on Flickr

Building Retlas 486 by Andy, on Flickr

Milling the inlet port which leads from the valve chest to the cylinder.
Building Retlas 488 by Andy, on Flickr

This is an extract from the cylinder drawing showing the cylinder from above with holes for the five studs and three water passages. Early on in this build when machining the cylinder I chose to move one water passage (arrowed ) because it was so close to the inlet port that there was a risk the holes breaking through. You can see on the next couple of pictures that there is plenty of scope to put the water passage in a less risky position.
Retlas Cylinder Liner Drawing by Andy, on Flickr

Building Retlas 491 by Andy, on Flickr

Building Retlas 490 by Andy, on Flickr

With both of the valve chest castings completed here are a few pictures of the engine so far. Blending these valve chests in with the cylinder casting would need a lot of grinding, filing and filling if I decide to attempt the challenge.

Building Retlas 494 by Andy, on Flickr
Building Retlas 495 by Andy, on Flickr
Building Retlas 496 by Andy, on Flickr
Building Retlas 498 by Andy, on Flickr
Building Retlas 499 by Andy, on Flickr
Building Retlas 503 by Andy, on Flickr
Building Retlas 506 by Andy, on Flickr
Building Retlas 507 by Andy, on Flickr
Building Retlas 504 by Andy, on Flickr

Andy

[Alyn Foundry]

Hello Andy.

Looking good !! 

I was a little puzzled to start with, regarding the cylinder pad discrepancy and then remembered you had taken a miss shape !! That casting had parted the boxes during the pour resulting in an oval shape and extra width to the pads. I assume you'll be at it with a die grinder?

When you think about the original what amazing dexterity those moulders had. As both the yoke, cylinder and head were one single casting with a core placed to provide a water jacket. Real craftsmen !!

Kind regards, Graham.

[Chipmaster]

Good afternoon Graham,
 
Reckon I'll have to use an angle grinder as well as a die grinder and a Dremel too but not until it's warm enough to do it outside on a piece of land alongside my garage.
It's a pity the direction some of these grinding tools run in can't be reversed. I'm right handed, when I use my die grinder or Dremel the dust always goes all over me and my face.
I was thinking that if the valve chests and cylinder were painted with Matt black HT paint the discrepancies might not be noticeable but now it's assembled I don't think so.
Andy

[Alyn Foundry]

Hello Andy.

In the past I was rather lucky being ambidextrous, I was at home with either hand, sadly an old injury has now added arthritis to my left hand making the use very painful, ah old age eh? 

I was looking at the print Jason posted on the previous page, do you know I had never spotted the " Stirrup " on the exhaust valve before ? Are you going to try it ? A lot of early gas engines used this practice as compression springs were quite weak and prone to losing their tension particularly on the exhaust side that gets hot.

I would also like to suggest that you study the Horizontal engine governor assembly as it appears Gardner's used the same method on the vertical engine.

Kind regards, Graham.

[Chipmaster]

Hi Graham,
 is the stirrup arrangement for the exhaust valve spring just the same as the Gardner O type that I built  from your castings almost 20 years ago.
I thought the inertia governor as set out in your plans is similar to the horizontal "O type governor. The O type governor has a light bias coil spring to adjust the trigger opening the gas valve whereas the Retlas appears to use a weight that is moved along an arm for speed adjustment. If only we could see that sort of detail in pictures of those two survivors you told us about.

Andy

[Alyn Foundry]

Hi Andy.

Yes it is the very same, only slightly larger.

The governor used on the vertical engine is exactly the same as the size " 1 " horizontal, in fact the vertical was just a size " 1 " turned through 90 deg.  There may have been bigger sizes made, Geoff recently told me of a size " 9 " horizontal appearing, it's massive !! As a BTW I have some copies of AE & H Robinson sales brochures they were advertising a 10 HP oblique engine !!     Imagine that !

Few people know that the Gardner size " 0 " was an afterthought,  sizes 1 to 10 were on offer but there was a market for 3/4, 1 HP engines so the figure 0 was used, hence the Gas bag and exhaust bottles fitted were a bit larger, actually being intended for use with the size " 1 " engine.

Kind regards, Graham.

[zeeprogrammer]

the pictures aren't interesting

Not so. I'm learning from them.

[Alyn Foundry]

Good evening Andy.

I spoke with Geoff today and he's taken some close ups of the enclosed crank verticals that directly followed as a result of poor cylinder lubrication.

I hope you find them useful?

Kind regards, Graham.

[Chipmaster]

Thank you very much for adding those pictures Graham, the family resemblance and development of the governor from the horizontal engines is there to see, my thanks to Geoff.
Is the engine featured fuelled with petrol? I reckon that is the case because it doesn't have two valves on the inlet side?
I can't increase the size of the image of the open crank vertical enough to see the detail of the governor for those earlier engines which have the trigger block positioned 'outboard' whereas the trigger block is inboard between the inlet and exhaust valves in these latest photos. I'll certainly consider whether I can use a spring to control the trigger (not sure of the correct terminology) but it might have to be a hybrid depending on how the essential components can be mounted on the Retlas castings. Perhaps I'll complete the engine as per the plans and get it running before I try enhancements that copy the original engines.
I will make the stirrup and tension spring for the exhaust valve, that will look good.
Andy

[Alyn Foundry]

Thank you very much for adding those pictures Graham, the family resemblance and development of the governor from the horizontal engines is there to see, my thanks to Geoff.
Is the engine featured fuelled with petrol? I reckon that is the case because it doesn't have two valves on the inlet side?
I can't increase the size of the image of the open crank vertical enough to see the detail of the governor for those earlier engines which have the trigger block positioned 'outboard' whereas the trigger block is inboard between the inlet and exhaust valves in these latest photos. I'll certainly consider whether I can use a spring to control the trigger (not sure of the correct terminology) but it might have to be a hybrid depending on how the essential components can be mounted on the Retlas castings. Perhaps I'll complete the engine as per the plans and get it running before I try enhancements that copy the original engines.
I will make the stirrup and tension spring for the exhaust valve, that will look good.
Andy

Hello Andy.

Yes those are both " Spirit " engines as Gardner's called them.

What isn't shown in the photos is the auxiliary atmospheric air valve " Snifter " in the top of the cylinder head. This allowed the engine to decelerate quietly rather than dynamically as some other hit and miss two valve engines did.

I have to admit I'm really looking forward to the conclusion of your Retlas, as we now know more information than we did nearly thirty years ago !!

Kind regards, Graham.

[Chipmaster]

Hi Graham, after yet another look at the photos of the original Gardner vertical inlet valve chest, I reckon the positions of the gas and inlet valves are reversed on the Retlas, what do you think? 

The big end bearing also looks different to me, the original appears to be steel throughout probably with bronze shells rather than the large bronze block used in the Retlas plans, could that be due to the National Gas Engine influence as per the studs going through the rebate in the main bearing caps? Reckon I'll make a con rod with a steel cap and bronze shells like the Gardner '0' type model.

Andy

[Alyn Foundry]

Hi Graham, after yet another look at the photos of the original Gardner vertical inlet valve chest, I reckon the positions of the gas and inlet valves are reversed on the Retlas, what do you think? 

The big end bearing also looks different to me, the original appears to be steel throughout probably with bronze shells rather than the large bronze block used in the Retlas plans, could that be due to the National Gas Engine influence as per the studs going through the rebate in the main bearing caps? Reckon I'll make a con rod with a steel cap and bronze shells like the Gardner '0' type model.

Andy

Hi Andy.

Ah, dear Vincent, he loved his National " K " type. Did I tell you about him having to make a lathe to restore his engine? His father wouldn't let him buy one so he built his own from scrap metal !!

As we now know the Con rod would be all Steel with bearing shells so that's probably your best direction.

Kind regards, Graham.

[Jasonb]

Yes steel conrod with separate shells , fitted bolts on the big end with nuts and lock nuts at the top and cross drilled for wire/pins. Gudgeon pin cross drilled and in from each end for oiling to the bearing. Should be two bolts to stop the pin moving rather then end pads. There is a sq headed screw and locknut in the end of the little end which I think must be to stop the bearing rotating.

CI bearing caps with oil pockets, separate split bearings. Not studs but fitted bolts passed up from below close to bearing hole but not cutting into it. Straight split on the caps not the legs going down the side of the bearings. good radius on the insides of the bearings to clear fillet on crank and a decorative 1/4 circle concave cut to the outside edge

Air valve on top of cylinder

[Jasonb]

Also big end does not have the greaser but a little "bucket" to catch the oil from the glass oiler on the side of the main body