BUILD PHOTO'S

[7spanner]

Here are some photo's of building the GT/TR engine by BDK

[750ynot]

[7spanner]

.... more.

[teazer]

Sweet. Those top end studs look familiar. I see you have their top end bolt kit too. Your sleeve nuts are silver color. Are they a an upgrade over the black anodized versions they used to sell?

Are you running total loss ignition or is there a thin permanent magnet alternator under that slim right cover? I was planning on fitting a GSXR outer magnet alternator but the rotational mass is too high I think for our skinny cranks to handle and they have a larger crank nose. The BDK unit is really nice - as are all their parts.

BDK do really nice work. I must get a set of those torroidal head domes to replace the old design I have now.

[gladders]

Looking great, what is the expected power output?

[badgereng]

Looks great. Nice job. What is the black finish on the casings? Likey like lots.

Pete

[teazer]

Looking great, what is the expected power output?

That's an interesting question.

But it's important to know what a stock GT750 makes so there's a basis for comparison. Back in the day, Suzuki used to advertise 60-67HP or more but where was that measured? At the crank probably. I have only seen a couple of rear wheel HP tests on a stock kettle and they were around 45-50HP on a dynojet. Auto engine dyno tests with back to back rolling road tests suggest that engine HP drops by around 20% at the rear wheels. So assume that say 100hp at the motor is around 80 at the rear wheels, maybe a little more. Cars and bikes are different and testing a bike on different dynos give different HP numbers, so it's all a bit subjective. My last bike made almost 5hp more on one dyno versus another that we started using, so comparisons are a bit apples and oranges.

Few of us have spent the cash on multiple dyno runs are in a great rush to share, but a ported motor with stock pipes can make around 60 and with chambers 70-80 depending on state of tune at the rear wheel (on street gas). I didn't ever test a stock motor with stock pipes or with chambers to see the difference, but someone published a dyno chart a few years ago with about 46hp stock and 54(ish) with Allspeeds on a dynojet.

Cycle magazine tested an M model back in 1975 on a Webco chassis dyno and reported that it made a very healthy 57hp at 6,500 RPM and 47 ft pounds of torque at 6,000. PB put Bill Calcutt's drag race bike on the dyno back in 88 and reported finding about 105 horses at 7500-7750 and that was probably also a chassis dyno.

[Kettletimes3]

I remember competing against bill many years ago,
That was a pretty quick bike.

[7spanner]

Thanks guys, lots of questions here.

The black colour is a sort of satin finish or semi gloss powder coat, all parts are powder coated.
I started with the BDK Ti or Al head bolts but they started breaking at UNDER minimum torque, so I went to Ian at Astrax who custom made me 304SS - BTW BDK would not warranty them, although they admitted a fault - I dont use them now.
The slim alternator is actually a generator modified from a T305/350 to work - the associated wiring I'll post next week.
Ignition is the German Accent ignition modified to work with the narrow crankcase. Uwe there has been excellent help!
I'm looking to clear 80+HP at the crank with JL expansion chambers and Mikuni flat slides.
More later
Chris

[teazer]

That news on the BDK bolts and nuts came as a shock. I spent a small (or not so small) fortune on the complete set. Did the studs and bolts yield or the sleeve nuts or both?
Ian is good people.

I like the small alternator idea. For a race bike, total loss is fine, but for the street you need to keep the battery or cap charged so that's a smart move.

Accent are probably the best fixed timing ignition system for our bikes. No quick shift function or timing table, but for a mild bike they are perfect.

Thanks for sharing

BTW, the top radiator hose looks to be higher than the filler on the radiator and will trap air. I had a similar issue with a modified stock radiator. Make sure that air isn't trapped there or it will blow coolant out.