Five Cylinder Radial With Ohc

Disaster Strikes.....
It seems that the interference I allowed was two large even after testing samples to see the amount of change .
Also it appears that placing a small part into large one, the heat mass immediately raises the temp of the small part before it can be pushed home.
So the two cages ended up being driven unmercifully into place with a big hammer the inlet cage ending up deeper than was intended causing distress to the area in the head where it sits, both cages broached out a sliver of material from the bores in the head. After the event I found no change to the length of the cage, or any evidence of distortion to the head apart from the inlet cage being .5 mm low in it's bore.
Deciding that the head was probably ruined anyway, I reprofiled the area of the head around the low cage with the flexy grinder and a diamond burr then continued to bore out the throat's and lightly cut the valve seat's , Just to prove to myself I had not got it all wrong .:confusion:

P1013241.JPG You can see the reprofiled area of the head around the cage nearest to the camera.
Now I have to rethink my method so I do not ruin another head. so it's time out on the valve work for the moment.

Live and learn, Brian.
 
Was wondering when Uncle Murphy (Murphy's Law) was gonna visit you... :grin:

He seems to come around me now and then... always at the WRONG time... :rolleyes:

Sounds like you have it under control... and yeah... new head. No telling what would happen when the engine got to operating temp.

GREAT thread... I am thoroughly enjoying reading it!

GA
 
You now have the "test part" for fit up and "let's see if this works" stuff...

Suggest next round of fitting just be into scrap.

Also question...

Test with oven to simulate operating temperature to confirm fit.

Does the aluminum expand greater rate than the seat?

If it does then the hole diameter will expand at a rate more than the seat and the seat could come loose.

Maybe add center punch dimples to fix in place?

Test with now test part before doing anything else as your plan may change post testing.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 
I think I have it sorted now time to continue with the replacement head.

Brian.
 
Brian;

Just a thought -- Is it possible to insert the cages into the heads partially machined? Then finish machine them in place. The heavier unfinished Brass will not heat up as fast. In theory anyway.

"Billy G"
 
Hi Billy G, on the ball as usual, that is my intention to install the cages with minimal interference & 620 Loctite then with suitable rests to allow the stresses to work out, cut the throat -seat and inlet tract.
Because in my design the springs do not act against the cage but on the head ,therefore constantly puling the cage into position I think it is unlikely that the cage will dislodge The lower spring location plate will also be made to act as a retainer around the guide part of the cage, using 620 to keep it in place, as this is a relatively cool area I doubt anything will move.
Thanks for your input Billy ,Always appreciated This is a big adventure for me so keep your fingers crossed.
By the way did you see my post in the Collchester lathes section.???? A blast from the past.
best regards Brian.
 
Hi All
No I have not been on holiday, Just slid down a set of marble stairs, hit the wall and bashed my head on the workshop door, The good news is that the wall and door are OK, I ended up a little fussy round the edges, just required a rest untill the head stopped spinning.
This is a drawing of the intended modification to the lower spring plate changing it from a flat washer to a top hat section .
the photograph is of the parts including the valve spring and cam follower.
Now waiting on delivery of the Loctite.
img181.jpg P1013252.JPG

I am intending to make a set of drill bushes to reduce the ports so i can open them a little at a time
Brian.
 
Hi Brian, Glad to here you are ok after taking that fall. This has been a great thread to follow. thomas s
 
Glad to hear that you are OK. I know falls down stairs can be bad. even without hitting a door. (broken bones) Again glad you are ok. The drawing reminds me of some that I have seen on some car engines
The only thing is setting the backlash looks like it could be a pain.
 
Hi Ken,
The lash will be set by trimming the end of the valve stem or putting a shim in the cam follower.
Along with cam timing--- ignition timing & keeping the belt centres correct, while not altering the compression ratio or any of the above. I think it will give me enough to keep me occupied for a while.
Brian.
 
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