Getting Very Close Now

guy851

How it all started

I came across a couple pictures that Helen had taken and I was reminded of the day last summer when it all started.

My Tricolore, tho much loved was sold to makeway (and fund) something even more special.

I had also purchased the other 888 with the notion of using it as a doner for parts but in the end I did not have the heart. A bitsa for sure but still a belting good ride.

Just taking off the corse/23mm swinging arm that sadly stayed behind.

And I am still buying parts, where will it end😯

Guy851

guy851

Almost there and then 4 steps backwards

🙁 🙁

Having had a brilliant day with the family yesterday I have a moment by myself before the next wave arrive later for another beast feast.

Progress has been snail slow for a while and the pressure was on to meet the "home for Christmas" deadline

Plan 13b was for the final heatcycles/running in on the dyno to be finished last week and then the long awaited setting up and power runs on the dyno at loooong last.

And then, heat cycle number three, motor loosening up nicely and everything setting down and ******* **** she develops a mild mechanical noise😡

The alternator side was first suspect as this and all the starter gear/motor side is all fresh and newly fitted...but all fine in there.

A little more detailed examination traces the noise, not huge but there to the rear cylinder at TDC

So all in mothballs for a week to let the dust settle and then its time to check out the clearances back there and dig out the files.

It will have to come off and fingers crossed its not any deeper down in the belly of the beast

On the bright side im easy going and its too cold to ride anyway but its still a right bummer as I was poised to fit up up the bodywork and tidy a few odds and ends.

Any kind words of
Oh its only the cam pully rubbing on the cover
Or its just vibration and some external parts are rubbing together
Or its just the loose mounted Ohlins remote buzzing against the frame are most welcome

Otherwise all in fine and dandy in the wilds of Wales, sun is out and I got a new Dremel set and a folding bike ramp for Christmas and I will be off to seek out a new road helmet in the sales soon

More as it comes

Guy851....888 soon

Henrik

guy851 wrote🙁 🙁 she develops a mild mechanical noise😡 More as it comes Guy851....888 soon

A mild noice from a Duc, something is for sure wrong😉
Don't give up Guy, spring is coming to fast (is that possible)? when the bike is not in order.

Brgds
Henrik

griff851

Is it a whirr or a ticking noise?

Griff

Mr.R

griff851 wroteIs it a whirr or a ticking noise? Griff

If it's a ticking noise my money's on it being piston to head or piston to valve contact.
Who built this motor for you Guy?
Did they dry build it and check out all of the clearences, were the valve pockets in the piston crowns big enough for the valve sizes/deep enough for the valve lift?
I'd be looking for at least a 30 thou clearence in every direction (with a cold motor) for the valve pockets and at least 0.9mm at the squish to avoid any contact when the motor warms up.

Steve R

tbunnell@mac.com

Looks Great!

Looks really good Guy!

tbunnell@mac.com

Nice Job!

It looks really good Guy!

guy851

depressing but true it must have been me

😡

Something...small has entered the rear inlet valves during dyno runin No.3

Inlet valve bent and head/piston are marked and the "object" is in small schrapnel pieces on top of the piston.

Piston and head are marked but OK😄

Valve guide check in the morning.

Did i forget to locktite something???????

Everso dissapointed in myself as I was soo soo carefull

But these early Corse bikes with open/closed intakes are a nightmare

Do i continue to run an open airbox with a basic "no big stones" filter or move to an ITG 916 fugyerair job over my carbon intakes?

The pure sound of the open airfilter is just the best ever

Tone it down with a filter?

I dunno

Comments ?

Guy851

griff851

Damn and bugger on that one mate. Are the throttle plate screws still there?
A piece of sponge like a UNI filter change naff all on the air flow front and stop a lot of stuff being ingested. If you are going to ride it on the road you will need something in the air filter dept.

Griff

guy851

dam and bugger indeed

Everything is still there but I am thinking a an ITG over the trumpets might be good

But the induction noise will be sacrificed, will it ?

Guy851

griff851 wroteDamn and bugger on that one mate. Are the throttle plate screws still there? A piece of sponge like a UNI filter change naff all on the air flow front and stop a lot of stuff being ingested. If you are going to ride it on the road you will need something in the air filter dept. Griff

Jasper

Gutted for you mate.This is what i did.

adie851

That looks like a neat mod Jasper,assuming that's a corse type airbox,what actually does the filter element consist of.Fraid I don't know much about the race bikes,just the SP's,having had one for nineteen years.What actually is your bike,or what did it evolve from ?

I saw Guy's bike last time I was down at Tony's place last year.Looks good..Would like to know what sort of horses it's chucking out at the back wheel when it's sorted.

Cheers,adie 851

Jasper

I have an SP5 with a few Corsa bits thrown at it(no engine work other than light flywheel and PCIII).

I milled the filter housing out of aluminium plate,put wire mesh over it and got a sheet of pipercross air filter to fasten to it.

Mr.R

guy851 wroteEverything is still there but I am thinking a an ITG over the trumpets might be good But the induction noise will be sacrificed, will it ? Guy851

Hi Guy,
If you're using an open airbox with one of the lozenge shaped ITG/JHP filters that fit over both bellmouths, you'd have to be a bat or dog to be able to hear the difference.
At the moment I'm using an open topped standard 851/888SP4 airbox with a screen type ITG filter on my 851/916cc bike and it sounds no different to my ears than a completely open airbox, or the 888/926 I rode last year with the lozenge filter fitted.

I've got a nice new 748/916/996 lozenge shapped ITG/JHP filter waiting to slot over the bellmouths when I fit my 3 piece carbon open airbox, unless you're going for the last 2 or 3 rwbhp these filters are the way to go IMO, especially on a track bike because if you do take a dive into the gravel trap and the tank flies off there's very little chance of the filter being ripped off and your motor gulping down lots of nasty kitty litter.

Jasper's solution looks good apart from what I've said above.

It's (in the real world) only when you fit a completely sealed/pressurised airbox system that they (the Lozenge type filters) restrict the motor over running no filter at all, as they upset the pressure waves.

Steve R

Henrik

guy851 wrote😡 Comments ? Guy851

I really feel sorry for you. Bad luck!

I am running with the standard airbox on a testa engine. The box is only modyfied in the bottom to fit the engine plus larger airducts from a vacuumcleaner and a KN-filter. With this simple solution I get no absolutely no effect at all in the Dyno when the lid is taken off. So I guess in my case a corsa box would be a vaste of time and money. But, they look very trick and might save some grams.
If it was my choice I would keep it simple, life is full of obstacles anyway.

Keep up the spirit, you have had your share of bad luck.
Brgds
Henrik

guy851

The bad and the good in my engine Questions on Spec

Thanks all for your comments and I will certainly be going down the Mr R road of the 916 type ITG over the inlets I think, just for piece of mind if nothing else.
The air inlet and airbox is actually very well sealed as its a one piece airbox, removable top brace type with a full lid section so no messy three piece and trying to seal under the tank. There is a mesh filter in between the Y runners and the airbox so I was really surprized that "something" had managed to get lost in there and sucked into the motor.

BUT...now the head is stripped it is all much clearer.

A valve guide has let go causing the mayhem and distress its bits of guide on the piston top.

Phew...small cast iron fragments and its all looking good again.

Questions questions questions and what shall I do now??

The heads are 851 with guides taken out to 33/29 SP3 spec. I have always intended to run her as she was and then move closer to Corse spec valves when I could afford it.

What shall I do now?

Options:

Assume that the guide failure was a one off, replace and get her running as quickly and cheaply as pos with a simple replace as was?

Assume the worst and the cast guides are just too old and I should replace them all?

If I replace them all then take them out to 34? But leave the exhausts as they should be fine?

Fit 33/29 valves with wasted stems?

Or just bugger it and purchase some heads or rebuild mine to 36/31

Money is tight....Purchased another bike on a bit of a whim a couple of weeks ago..

Parts?

I may well be influenced by forum members coming to the rescue with offers of valves, heads etc that simply are too tempting

So it may well all turn out for the best in the end

What thoughts?

Guy851

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