Orient Express drag bike resurrection.

[zed1015]

As posted in discussion board i've been asked to rebuild the engine / engines of the famous Orient Express funny bike.
Originally built by Jack o'malley (founder of Orient express performance) this bike was imported from the states by the late Steve Tong and is thought to possibly be the first of its type to be brought over.
Here's a pic of the machine as it should be.


And here as it has been for nigh on 30 years since it blew over the line at long marsden




I have now got the engine and spares on the bench for inspection


Pulling the barrels reveals the the cause of the engine failure .
Both center pistons suffering from detonation and the excesssive heat that running 30psi of boost will create.



A little mystery for now is how this lump of sump got ejected from its moorings ?


Initially i thought the the camchain had snapped,wrapped around the crank and had destroyed the main bearing cap with shrapnel exiting through the sump, but a quick inspection revealed the chain is untouched and peering through the hole shows the cap intact and everything turns freely
It should all become clearer once i get the sump off


A couple of gems were revealed whilst sorting the good spares from the bad
"New" welded crank from Chris Applebee still in the kawasaki box soon to be woken from it's slumber.




And belt and braces approach to clutch slip .
Who need steroids

[Ginger Bear]

Rob, this looks like another one of your masterpieces I'm gonna be 'glued too'.

[Is Vic There]

Another thread of your's I'll be watching
You do know your stuff.

[zed1015]

Well! i pulled the sump this morning and found nothing wrong downstairs that could cause the sump damage.
Nothing unexpected but more interestingly nothing i expected either.
Oil pump is std, no rear pick-up, not even a gate and the black sludge is only clean oil and assembly lube.
Everthing is in excellent condition so far and if you didn't know it could have come straight from the track yesterday.


Crank is just a welded std one, nowt special or lightened and no cap support or hd crankcase studs.


Same for the gearbox .
Apart from evidence of freehand undercutting it's std z900.


My theory now is that the area around the sump plug was already damaged and weakened previously by maybe jacking up the bike on the sump pan etc and when the engine blew, the cases were pressurised enough by the turbo to simply pop out the fractured piece.

[Crofty]

I thought the same about the sump plug when you said the camchain was intact Rob. The bike is very low, maybe it got rolled over something getting loaded into a van or over a kerb and the sump plug got hit?

[ADRIAN H]

Not much wrong then, a bit of a result in a way.

[Big Fluff]

I had some pistons just like that 2 years ago
TBH they look like standard pistons to me (forgive me, could be wrong), but they certainly don't look forged either.
I would imagine that 30 years ago, the bike wasn't running any automated retard function, hence the detonation. Is he looking to upgrade to plenum pressure switch activated Dyna 2000 Rob ? Would help it an awful lot... I know

Great project Rob, it'll be great to see it back ont the strip too.

Will

[neilbarrett]

the ignition has a boost retard facility,via minifold pressure,weather it was plumbed in is another matter

[zed1015]

Pistons are forged wiseco's.
Look like 10.25 to 1's with thick head gasket to compensate.
Distributer ign has retard facility and was connected.
Rebuild needs to stick with original appearance for accurate historic record so can improve on internals but pretty fixed with the rest.
Boost won't be 30 psi so that should help reliability

[zed1015]

Bit of an update.
After very close inspection most of the engine parts are either worn out , unsuitable or just plain buggered and all the usable parts that don't need any major work are in this pic and are mainly from the spare engine.



This thing is fighting me all the way and both heads need everything re-newing, the seats are pocketed and all the correct cam caps need sorting as they were all mixed up in a box with some others.

Burnt valves,sagged springs,odd retainers and old style square keepers.
All this needs replacing.


Have chose to use the spare crankcases as the others have been bored out for a big block and as a result will be more prone to flexing and will be weaker around the barrel studs.
On the upside these cases have had the groove for the bearing retainers machined on the inside of the case in BOTH case halves for a more robust construction so it's just a matter of flipping the bearing 180 deg to fit and they will also help reduce the halves moving independantly


Groove in lower half which the std cases don't have.


All this means is that there are now several large boxes of tasty parts currently winging their way from Pitstop Performance in the US to help fill in the (large) gaps.
Not so much of a rebuild now ,more like start from scratch

[Al]

Thats a pitiful pile of useable stuff remaining.

Is that the original engine the bike was built with that has blown or just a runner for testing etc.

Keep the info coming together with the pictures its' pure gold.
It is also on dragbike.com? Not been there for a good while.

AL

P.S. the output shaft bearing i fitted recently came with a full circle snap ring.
Any use??

[zed1015]

Thats a pitiful pile of useable stuff remaining.

Is that the original engine the bike was built with that has blown or just a runner for testing etc.

The blown engine is the original but it's as original as a woodsmans chopper, Had 3 new heads and four new handles in its life

The original cases are the bored out ones and so is the bare alloy head as far as i know.
Most other parts , barrels ,cranks, gearbox etc have all been blown and replaced one or more times.
I'm trying to use as many original motor parts as i can but the spare cases are better, of a similar age and due to the amount of parts needed it's only right to use the best of what's here as a basis.

As for Dragbike.com it is very quiet on there and you get very little response regarding the old Zeds so i don't post much but it is good for the archive stuff.

[mikeyoz1]

I lived 20 minutes away from Orient Express .
there engine work is running on tracks today .
34 years later . Check out there record runs in the 70 tees and up

[zed1015]

Postie finally delivered a big box of goodies from the US .
Almost every internal part is being replaced .



Even bought a complete refurbed undercut gear cluster.
It's a joke that this item shipped from the states cost nearly half the price delivered than the cheapest quote we got for labour to undercut our own.


While we were waiting for the parts to arrive the cases etc have had a trip to the aqua blasters so i could make an immediate start on the re-assembly.
A few hours work saw the Oil pan gate, HD case studs, valve guides , oilseals and gear selector fitted


The barrels are now away getting bored for the 72mm MTC turbo pistons so this gives a few days to sort out the head.
The seats were pocketed and even tipping the std size valves left no clearance with the thinnest shim so fitting oversize valves gets everything back in usable range.
Now just have to open up the throats to match and take full advantage of the larger valves.

[Pigford]

Was that lot from Joe