Club 80-90 Forums

silverbullet wrote:This avo I finally got around to popping the Oetti case open, mostly to see where the tight clearances occur,

Very very tight behind the cam thrust face...

I am following this, out of idle curiosity, and would just like to say "bloody hell"

Clearance is clearance. Not much crank whip or flex by the look of it.
Must get a request in this morning for that chamfer to be ground on the new cams.

As part of preparing the new wbx "warm" cams and looking at rod clearances I took a closer look at the cam in this one. Its on a VAG cast blank but it has been reprofiled, so must be Oettinger's own grind from 1988.
30mm dia base circle (not 31 as per OEM) and with all lobes lifting 8.5mm i.e. the exhausts got an extra 0.5mm over the DJ profile but... its shot to bits so I probably can't even work out what the original timing could have been.
The front exhaust lobe has failed badly and has only 7.6mm lift!!!
That is what reprofiling a soft iron cam gets you after 200kkm....

After some real work for a customer this avo I hacked* the dead 2500E cam about to see what is required.
Ended up with this as a first attempt (thanks to Rocky Jennings in the USA for leading the way and publishing photos)

Then I used a single pulley hub (drill rivets out) and turned up a spigot adaptor to mount the timing wheel:

Ran out of time so still no idea if the Oetti cam timing, if I can work it out and find an unworn section on the profile...

*Bridgeport Interact 1 CNC mill and Haas 5C digital indexing head

Notching a new cam. Material is definitely harder than the originals.

I couldnt work out why I was getting persistant lowerback gip the last few weeks, despite avoiding any heavy lifting. Then it dawned on me that my engine stands were designed for persons of average stature and optimised for inline engines, not lanky types and flat 4's!
So cut the masts and added 200mm:

Just right

(I didnt have any 80x40x3 RHS so I sewed two bits if 40sq. together)

My engine stand's allright, but I've lifted all all my floor machines: mill, lathe, press stand, parts washer, etc. I'm not especially tall, 5'11", but these things are all built for dwarves or something.

I think it all causes a condition known as "Turner's Hunch" or "Miller's Stoop"

Or "Wrench's Wrench"

That is why I made my own elevating table. From pallet truck or customer's car boot to engine stand, solo and with no hernia. Its good as a mobile welding table too!

Not a great photo but you get the idea. It was made from leftovers and lifts from 300 to 850mm.

Found one of the frame before the top and handle was finished. The all ball-race castors came from some old hospital spares that we aquired:

That's a nice little rig there, I like it!

Thanks! It pretty well designed itself. I made it as big as I dared to squeeze through a std 700mm internal door.
40 x 40 x 3 or 4 tubes, 6mm top, M16 studding for the jack.
I wont break it.

Well the Oetti is still being used as a reference for clearancing.
I used the modified connecting rods (with their shoulders ground off to clear the camshaft...) as a try-out for ARP 3/8" BB Chevy bolts.
Unfortunately during fitting the caps developed a small split at the ground knife-edge under the bolt head, so they are now only good for R&D...ah well, they have done a lot of miles and one big end wasn't round anymore.
The ARP bolts clear best when fitted this way around( the heads are offset) I suspect not the usual way of fitting them but I can't see why not?

I should get back on to this in a week or two, now that Pete's engine is just about finished.
Chevy ARP bolts are a waste of time it would seem; the interference fit is just stupidly excessive, the caps need machining to get them to seat down and they dont even locate the cap on the rod properly, a right old bodge-up.

I now have a NOS set of rods c/w bolts and since the Omega pistons are so much lighter than DJ or even the Oettinger items I am not remotely concerned about bolt failures.