Project X

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madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Post by madforitkev »

Sorry mis comms there. I was referring to the BDK 'factory' bike not the TR750 which as you say had metal gaskets.

And yes larger transfers will follow and why not the 6 speed graft in!!

I am sure by the time I finish this I will be bored in a couple of weeks so might as well build a whole new engine using the lessons learned. :o

The O rings I am using are high temp viton and the biggest is only 3mm section. Its all about the groove tolerances for what are essentially static seals balanced against the shure hardness of viton Vs nitrile but with no exploding O ring grooves it should all be fine :lol:

Slight aside but I have been researching Cerakote engine coatings. They look pretty good and fairly easy to do (wife needed a new oven anyway).

Any experience?
Honest baby....this is probably the cheapest bike I have ever bought!!
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Alan H
Posts: 12104
Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: Project X

Post by Alan H »

I had a set of Cerakote (chrome-ish) spannies done about 4 years ago for the 550 and they still look good. www.camcoat.com recommend them - they do lots of colours too.
Proof that four strokes are over complicated
teazer
Posts: 1035
Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Project X

Post by teazer »

madforitkev wrote: Tue Mar 30, 2021 7:43 pm
The O rings I am using are high temp viton and the biggest is only 3mm section.
3mm cross section is H U G E for a head O ring. That's about the size of the outer O ring on a TZ that just seals water. the combustion chamber O rings are around 1.6-1.7mm but are hard to measure because they are so soft and squishy. Try to source some thinner O rings and cut the square shaped groove for them to suit the thin ring.
burgs
Posts: 70
Joined: Mon Feb 06, 2012 9:07 pm
Location: Hunter Valley NSW Australia

Re: Project X

Post by burgs »

Hi Kevin
I agree with Teaser 3mm to big, with the O-ring, keep it small, and go with the O-ring recommended groove specifications, don't try to make it any tighter, the O-ring needs to be touching the outside of the groove and clearance on the inside facing the pressure, when it is compressed it will fill the void.

1.6mm section should be fine and from memory is a standard size.

Regards
Burgs
madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Post by madforitkev »

Thanks for the info guys.

Its too late to cut a smaller groove and I know from the previous test runs that it did all sealed, its just this time the water jacket let go and must have been weak in a tiny area. I am sure cutting a larger groove didn't help but I am where I am and as far as I could see on the BDK one the groove was pretty large (I couldn't measure it).

I am using standard static seal tolerances and as Burgs pointed out, the groove is always larger than the ring section and it compresses to fit the space.

Backing rings are being made now so time will tell. I can't put metal back in because of the liner/block interface so hopefully the ring will work.

That's why they call it development!
Honest baby....this is probably the cheapest bike I have ever bought!!
madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Post by madforitkev »

Got the throttle body bits back today.

Bit of a jig saw......
throttle 1.jpg
All good and no screws or O rings left on the table!! Although Triumph dont make it easy with tamper proof Torx screws etc. :x

Inkedthrottle 2_LI.jpg
The red bits are where I have had to make extension pieces. Some of them are O ring sealed to that had to be mimicked on the extensions. The lever arm on the RHS side also had to have a fancy extension and the LHS butterfly arm had to be extended as well.

Fired it up through the controller and grip and it all works. GT750 fly by wire. :D Just gotta work out injector bits now when the modified reed bodies are done.

Just need to work out how to link to the oil pump now (although I am considering going premix after the strip down). If I extend the throttle position sensor linkage I can squeeze a lever arm in for the oil pump.
Honest baby....this is probably the cheapest bike I have ever bought!!
teazer
Posts: 1035
Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Project X

Post by teazer »

I expect that you will trim the butterfly screws and stake them in place.

What size are the throttle bodies? 38, 40mm?
madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Post by madforitkev »

Yep, need to tidy up the screws.

The bodies are actually 44mm internal diameter, so a little on the large. I was planning I can manage how open they go on WOT with the motor controller. Effectively throttling the air back if needed.
Honest baby....this is probably the cheapest bike I have ever bought!!
madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Post by madforitkev »

So while I am waiting for the barrels to get welded I have been looking at engine coatings and have decided on Cerakote.

Its basically ceramic paint. They do a range of options and colours and I have gone for the V series, higher temp option.

I am probably going to 2 tone the motor. Nothing too bling though.

Next problem is to get a full motor done it is about £1000!!! :o

So DIY is the order of the day.

Next I need a curing oven.

£22 on ebay and I have a nice Neff oven but it is a bit small, oh and it bits now......
oven 2.JPG
Quick trip to Ikea and shes all installed in a nice. cabinet.
oven1.jpg
Insulation slabs are on the way and I should probably make the wiring a bit safer but it all works. Fancy view window and lights installed!

It runs up to about 260C which is what Cerakote needs. Stay tuned for more tests..... ;)

Paint and Pizza! Whats not to like?

Just need to convert a dishwasher into a degreaser now (Wife caught me eyeing hers up :cry: )
Honest baby....this is probably the cheapest bike I have ever bought!!
madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Post by madforitkev »

Moving on.

Managed to repair the head damage. Machined off the rogue bits of ali around the liner and made some stainless steel backing rings for the O rings.
br2.jpg
They fit nicely in place and give the O ring the right compression.
br1.jpg
All running again with a few test rides. Cured the water loss which was a combination of the head failure pressuring the water jacket and some fancy hose clamps I though would be good that were crap. Back to faithful old jubilee bands! It was getting up to temp and the slight pressure increase squirted coolant out of the joints etc. etc.

So now running at around 65C which should be OK. I was worried about cooling with the rear radiator but it seems fine pending some power runs!!

Few other minor hiccups in the rebuild with timing and carb settings but getting there. I think its running a bit rich at the moment (180 mains currently on TM36-2's) so will play with that over the weekend.

Made some progress on the throttle body mounts. I wanted to be able to switch between carbs and bodies while I am still tuning so I made adapters for the reed bodies to take wither carbs or throttle bodies. The body adapter uses the triumph inlet rubbers.
tb11.jpg
tb12.jpg
Honest baby....this is probably the cheapest bike I have ever bought!!
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