The Rocket Eight
Conceived way back in the late '80s, this is the slowest-gestating project I ever undertook! Bought the engine in 1990 and made most of the gearbox a year later. Its been put on the back-burner so many times, it ought to be burnt to a crisp!
|If you'd asked me why (as some did) back then I'd
have answered 'because somebody has to'.|
Back in 1988 a customer at megacycles called Tino was enthusing about a rover-powered bike in a magazine. It was horrible and I said so. Tino said 'why dont you do one then?' pointing at a buggered old Chrysler small-block I had in the corner.
There had been very few V8 bikes done at that stage, none were much good, So I thought I'd grasp this nettle. A rover all-ally V8 was far too obvious a choice, besides its pig-ugly when viewed from side-on.
Whereas the 2.5L Daimler lump was pretty as a picture and had good motorcycle heritage behind it - it was designed in the late '50s by Edward Turner (whose portfolio included the Triumph speed twin and the Ariel square-4) while he was managing-director of the BSA group which owned the Daimler brand at that time.
Various parts were made in the early '90s, and Zit from the Leicester NCC supplied a Z1300 swingarm, bevel box & wheel. But I didn't get much else done till we moved to Norfolk in '98. There was a burst of activity then as I made the frame, wheels, forks, exhaust, seat, rear fender, radiator and handlebars and got it rolling as seen here.
The tank came later, after a frustrating & abortive attempt to get a certain tank shop in Dumfries to make me one. Dont ask.
"If you want something done right, you have to do it yourself" So I bought a small wheeling machine along with sandbag & mallets and set about making the tank myself. Not perfect, but not bad for a first attempt.
In January 2010 I got back into it with the intention of getting it done no matter what.
A list was drawn up of stuff to do.
I got the front fender done, the front calipers mounted properly and most of the electrics mounted. Then the footrests & rear master cylinder mounted the ally side panels.
I decided those bars had to go. They're comfortable enough, but dont look right. Something resembling drag bars on kicked back risers are what I had in mind.
I spent half my time retracing my own footsteps, not having touched it for so long. I got properly back in the groove with it and made plenty progress
Got those side panels done. Getting quicker with all that sandbag / wheeling stuff.
First one took 2.5 hrs. Quite pleased; kind of a bulbous shape which suits this fat bastard of a bike.
Another week saw all the remaining fabrication work done .
By the end of January the frame was finished and off to Aerocoat .
Early March saw the Frame powdercoated by Aerocoat
Building a Daimler V8 for fun & profit
Cambridge rebores bored the block and skimmed the decks .050" to compensate for the shorter Triumph T140 pistons. They ground the crank -.030" and skimmed .010" off the heads to clean them up. I took the guides out and turned them to accept harley evo stem seals.
Happiness is a freshly machined block - Hers me demonstrating how light the Daimler iron block is, only Bee was taking her time taking the pic & my grin was slipping a bit!
There was one last job to do before assembly; Ol' Edward Turner whilst a great designer, was never (as we all know) much of a one for ensuring oil-tightness! I guess he thought oil-seals were boring or something.
So the poor old Daimler lump ended up with a crude rope seal / scroll machined-into-crank setup at the back and just a scroll in a steel sleeve at the front.
Whilst rope seals can stop most of the oil coming out(!), I wanted an absence of puddles under this bike, so I did this one-piece rear seal conversion.
The rear crank flange had 2 scallops machined into it, so I filled these with weld, rough-turned it and had Cambridge Rebores finish-grind it as seen here.
For the actual seal housing, I did it in 3 parts; a 2-piece backing plate that bolts to the block & rear main-cap, and the seal holder itself which bolts to the backing plate. Had to do it like this as the available area on the block was smaller than the OD of the crank flange.
I clamped a turned mandrel in the rear main housing and used this to locate the backing plate holes. The block is too long to get under the mill, but the ol' floor standing pillar drill accomodated it just fine.
Finished job. No oil leaks. Fingers crossed.
Ready for a good clean of the block, crank etc and start of assembly.
Early April. After some interruptions progress is resumed....
Heres the bottom end assembled; Replaced the turned main bolts with some 180000 psi allen bolts. Had to shorten the oil pump pickup as the sump is shallower than stock. Luckily the pump was in good shape, as replacements are megabucks.
I bought a set of 8 Triumph T140 8.5:1 pistons from MCS in Leytonstone back in '92. A bit of a savings then- about £200 compared to £300 odd for replacement Daimler ones.Use of T140 Triumph pistons is common in these.
Heres a Triumph / Daimler comparo
You can see they're a bit shorter, a bit higher domed and a bit sturdier. Checked valve clearance - Loads.
And heres the top view of the completed short block. All clearances were good and it all rotates freely. Had to file-fit all the rings though.
I never got a stock crank damper with this engine, but I did have one off a 283 Chevy. So I turned the crank to take it. This allowed me to shave an inch or two off the length of the crank shout. There was enough room between it and the timing cover to fit a v-pulley for the alternator, further shaving length.
The real breakthrough in keeping it all short was discovering the Davies-Craig electric water pump. Its a remote unit and so I modified the front of the sump so it could mount under it and made these water manifolds to plumb it all.
I made each manifold out of 2 thicknesses of 1/2" ally plate. The water passages were milled into mirror-image (almost) faces and welded them together.
The water pump bolts to the lower flange of the lower one.
Heres a mod that all Daimler V8s need; stem seals. Even a brand new Daimler was expected to use a pint of oil every 600 miles or so! Imagine trying to sell such a vehicle today! I used aftermarket Harley evo type seals.
Theres the top end on. The valve covers will be polished, but I had to move the location of the breathers first and couldn't do that till it was back in the frame.
The stock Daimler one is a bit antediluvian, its about a foot tall and parts are stupid money - £60 for a cap!
Its the same basic setup as on Rolls-Royces. HRH can afford it but I'm buggered if I'm going to!
Enter ol' Henry. I got one off a 302 Ford for a tenner. Its electronic and parts are peanuts - £8.50 for a cap and £16 for a electronic pickup, which it didn't really need, but daft not to while its apart.
I turned the body down to accept an ally mounting boss and made a bit to go on the shaft with a tang to engage with the daimler cam skew-gear
Also made a pair of rocker oil-feed manifolds. Stock setup is a rusty steel pipe with banjo fittings brazed on. OK in a car where you cant really see it there behind the heads, but its in yer face here. Made them out of ally which will get anodised blue. A bit of braided hose will feed them.
One thing about Daimler V8s I always disliked were those hand-tightened valve cover retaining nuts
So I turned up some nice stainless ones which will accept Chrysler hemi plug-wire boots. Engine is now wearing its nicely polished valve covers
With the engine taken care of it was now time to deal with the transmission.
Much of this was done way back in 1991
Its based on a Borg-Warner 35 box which is what was stock on a Daimler. My donor came from a mk 1 escort though. This had the advantage of having a smaller torque converter and therefore a higher stall speed which will reduce creep whilst in Drive. I also scored one from a Rover V8 for parts because some internals are beefier and has the parts to allow an external fluid cooler.
Heres the innards laid out. Fluid to actuate the front clutch enters thru the rear end of the shaft.
The output shaft is turned up out of an old Z1100 gearbox shaft; the spline where the sprocket would have gone now carries the driveshaft flange. I ground the teeth off one of the Z's gears so there was just a boss with a spline, turned it and pressed & welded it into the output sprocket. Chain is 1/2" pitch triplex.
Driveshaft is Z1300 shortened 5"
Heres the modified case. I made casting patterns, cut the stock case down and welded the new casting to it
By the 3rd week of April I got the tranny assembled
Although much of the work was done yonks ago, I hadn't tackled the hydraulics side of things. And what I had figured out, I'd forgotten. Luckily, the Daimler manual has detailed diagrams of the fluid passages and what goes where in each gear.
Rather than get all fancy, I just modified the stock valve body so that it just has one fluid outlet. I decided to have the shifting done electrically from a couple of handlebar push-buttons.
First I tried using using a left-over solenoid from a Chevy 4L80E Tranny
but this proved inadequate, so a Ford door-lock solenoid was used internally to mechanically shift from neutral to drive.
The wires exit thru an existing boss and is sealed (hopefully) by a rubber compression joint.
After another break to do proper work, assembly resumed at the beginning of June
Shorter, wider, braced Z1300 swingarm - bearings are 2 taper-rollers each side.
Above: Electric water pump; Right - electric fan in place.
I took a couple of days in mid July to prepare parts for going off for paintwork. First job was to finish the tank & do the dash.
Had to go for chrome because the sides are a different alloy to the top, the welds would show as different colours when polished.
Got the front end on. Finally able to roll it about. Had all the ally repolished as 10 years had made it a bit scabby.
First I had to get the rad mounted and the alternator; used a dinky little Mitsubishi one with internal regulator.
Gap in the grille is where the trans cooler will go.
November. Got the Paint back from Darren at AirFX. Nice job.
Autumn and Winter are busy times at CCD, so further work had to wait till April. Took a whole month off to wire it and get ready for fireup.
Most complicated bike wiring job I've ever done (theres 8 relays here!) 5 metres of solder used.
Miraculously it seems to work OK
Pleased that little Varley battery turns it over easily. Nice big fat spark from the ignition system (Ford Dizzy, Mopar module & MSD coil)
Finally acheived fireup on 28 April.
After carb & ignition tuning, it settled into a nice smooth idle. First test ride was made about a month later. SVA booked for June 16th.
Got thru SVA at second attempt after some trivial fail points were sorted. Still waiting for DVLA to sort out the registration after 3 weeks. But its done, apart from some transmission teething bugs.
Actually took DVLA 7 weeks in the end!