Update June 7, 2009 - New entries will appear here on this page - See index
of older entries in right column.
INDIAN 741, 600cc Metanol-fueled, Supercharged, Bonneville Land Speed Record Special.
A Build Diary.
I know: I promised to tell about finishing the intake...but it's ain't finished yet, so I can't tell, can I. Sorry about that. The thing is still in this state, but it's a pretty engine...right?!!
Instead let's have a look at the engine and what's been done to it. Why not start from the top:
As you can see, the heads weren't too pretty. Now, one thing you want to avoid are sharp little edges creating 'hot-spots' which are are an invitation to pre-ignition thus creating further localised heat-buildup, and predictable total disaster. So first thing was to sand and polish using a variety of tools
Here's digging into the 'corners' of the head using a Dremel to remove some apparent ”original” cast-residue
Grinding and sanding with consecutively finer and finer abrasive paper and finishing off with polishing
Now that's more like it.... The spark-plug thread were long gone
...so inserts were fitted, and as you can see, the surface on which the head-bolts rest were machined for perfect 'flatness'.
...and at this point I glass-bead blasted the outside of the heads to clean them up perfectly and hell; they have to LOOK good as well... Here's the finished head shown with new James gasket and new head-bolts, ready for assembly.
As you may remember the pistons were a 'little' weird
. ..anyway, it really didn't matter, as the cylinders were to be bored up to a total of 600cc. Here's the new piston to suit the new bore.
All rings were taken off, inserted one by one in the cylinder and checked for correct end-gap, appropriately filed down and the 'outside' edges at the gaps deburred. The cylinders came back from Moen's machinist with bore axis angle in relation to the cylinder base gasket face checked, with new bores, new valve guides, fresh valve seats, and ports cleaned up. The exhaust valve ”holes” had been taken up to the same size as the intake. This was done as the engine, in its new configuration, will be force-fed a larger quantity of fuel/gas and there was a need for making it easier for exhaust gasses to be dispelled. I painted the cylinders with hi-temp spray-paint and baked them in the oven. Nothing like a table spread with nice new and re-conditioned parts!
Heads, cylinders, new pistons, new valves and new valve springs. Before assembling the valves, every spring was measured for pressure when set up at same length as when mounted in the cylinders.
This was done both for future reference (in case development work will indicate that there might be a problem with the springs; much easier to come up with an educated guess at solutions if you know what you start with!), and also to check if they were all equal, pressure-wise. That done; they were finally fitted in the cylinders
Next thing were the connecting rods. I must admit that first time I saw them I was quite baffled so see how flimsy they appeared.
I guess I was just fooled by the smallish dimensions, as I have only ever worked with aluminum rods that are considerably larger, and besides everyone assures me they are in fact rather sturdy items. There were a couple of things I could do to make sure they were OK and to considerably strengthen them.
After having casting flash etc ground off, and all sharp corners radiused (to avoid potential stress raisers, particularly - "blush" - in the "crotch" area of the "female" rod, which must be one the most highly stressed parts of the rod) and being blasted, first they were sent off to be Magnaflux tested for cracks. They came back with a clean bill of health, and next thing I wanted was to have them shot peened, but it turned out that such service just wasn't commercially available in this country.
After days of calling around, and through several detours, via a lot of helpful people, I finally found a company that imports shot-peening machinery. They were very helpful, and found a spring-manufacturing factory just half an hour from my workshop to whom they indeed had sold such a wonderful machine. I called them, and was lucky to be connected to the boss, who happened to be into motorcycles and who promptly invited me to the factory where they did the job, on the spot, for free and a with lots of good luck wishes, as I left the place with my now shot-peened rods. Wonderful!!
Off to Moen's place to put the engine together. It's quite handy, when assembling an INDIAN engine to be in a place with every conceivable INDAN part within hand's reach, and being in the company of a walking talking INDIAN encyclopedia, isn't too bad either.
The crankcase halves had been assembled with the new... everything! New main bearing housings, ground to correct OD after the case bores had been line honed round, straight and at right angles with the cylinder decks, internal diameter of the housings being line honed after fitting in the cases. The pinion side bearing housing is now the 1948 style "straight through" style (another IPE Special thing), which is both easier to line hone and to assemble. New cam bushings honed to size, and with "stick-out" determined to give the correct cam shaft end play with our chosen cam cover gasket, oversize valve-lifter shafts to match honed-round-again lifter pivot bores, new O/S pushrods in honed guides etc. New cylinder base studs had not been fitted yet in these photos.
...and the crank had been assembled with the freshly shot-peened rods. In addition to the treatment above, the rods were of course straightened and aligned, with new pin bushings and custom bearing races, rod big end eyes honed round and straight, IPE custom rod races ground to the correct outside diameter for the right press fit, fitted with the correct "stick-out" for play between the rods, and honed to size internally. The flywheels were balanced (stock balance factor as we didn't have any clue to what other factor might be better for this chassis and speed), trued and rebuilt with new crankpin and shafts etc.
Checked every single roller just to make sure that there were no wrong-size ones that had somehow go mixed in
The rollers were then placed in appropriate order
You might notice that the spacer betwen the two sets of rollers is slightly shorter than standard. That's to make space for the IPE modern lipped seal replacing the stock felt seal in the retaining nut at the outer end of the drive side bearing housing
Crank case halves put together and end float checked. Disassembled again to fit the right size shims (rubber band on pinion shaft holds the rollers in)
Of course I had to do it a couple of times to get it just right. Next thing was fitting the pinion-shaft pinion using this nifty Indian-tool (Yep, I know; embarasing. Hadn't cleaned the edges of the housing. Did it later)
Now, when you get to use the ”pinion-shaft pinion fitting tool” you also get to use the ”pinion-shaft pinion dis-fitting tool”!
...after a bit of fiddling with the spacer behind the pinion gear (this spacer is part of the new "straight-through" cam side bearing housing system, it isn't a stock part so don't let this confuse you if you are looking at your own 741 engine while reading this!) the whole assembly finally moved freely after another couple of rounds of disassembly and re-assembly. On went the valve-lifters (freshly rebuilt with new rivets and rollers, and their holes honed to fit new oversize pivot pins) and the cams lined up according to the markings on the wheels
...and finally the cam-case cover, with its little lipped oil seal to replace the stock felt here, too
You'll notice another IPE-modification there. One of Moen's standard lectures is on oil control for high speed engines... Well, "relatively high speed", in this case! Excess oil in the cases can cause a big drag on the flywheels. The usual oil-return sump valve has been repaced by a slightly massaged 1947 Chief scraper set-up to mimic the cast-in scraper of the1948 Daytona Scouts, and Chief engines 1948-up had. Where the old sump valve just picked up whatever oil had drained down to the bottom of the cases, the close-fitting scraper actually scrapes excess oil off the flywheels and funnels it to a single pickup point, to get as much oil as possible out of the cases to prevent it from dragging on the flywheels. Oil pickup point is at the threaded hole. It looks like this close up
...and like this seen from inside the engine
Next time: finishing the engine assembly and hopefully finishing the intake/blower setup.
Salt Cracker goes to Bonneville!
Links to Earlier Parts of the Story:
Indian Land Speed Racing Reading on the VI:
If you wish to support the endeavour and look flippin' cool doing it (I think that's what they call a pure win-win situation ...ha ha) please buy a "Salt Cracker Race Crew" T-shirt. Comes in two varieties: Red/Black: good quality 100% cotton, pre-shrunk.
-And Traditional Grey: 85% cotton, 15% Viscose. The fabric is not quite as thick as the Red/Black.
Both come in these sizes: Small / Medium / Large / XX-Large. They are on the smallish side, for their sizes.
Each can be yours for the modest sum of 20 Euros or $30US by PayPal. Air mail is 5 Euros (Europe) and $8US (rest of world).
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If you wish to support the Rockys Dream Catcher crew and looking flippin' cool doing that (again; that's gotta be a pure win-win situation) you can buy a Dream Catcher T-shirt for the modest sum of 20 Euros or $30US by PayPal. Good quality, 100% cotton, pre-shrunk, sizes from S to XXL. Comes in (salt-)white with (Bonneville sky-)blue sleves! Thanks to The James for modeling!
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Ordering, questions and PayPal: email@example.com
Apparently no-one knew the compression ratio on a 741 engine. so I checked it. Clear plastic glued to head + gasket. Filled it with water from syringe. Volume turned out to be 50cc.
Compression ratio, standard 500cc:
Compression ratio, 600cc big bore:
Another thing I couldn't find was the valve-overlap.
Why would anyone want to run a bike, fastlike, on a surface made of this stuff ???
Protective tin-foil head-gear to keep "I-give-up"-rays from outta-space from entering our minds
It's not ALL Indians; Kenneth messing with son's 85cc 2-stroke speedway bike.
Dear old Burt. T-shirt caption reads: "Dirty old men need love too". Indeeed!
Yours truly proudly showing off at one of numerous test-assembly occations