Another T rebuild: left cylinder compression

[Testarossa]

My suggestion would be to run a flex hone through the bore and not worry too much about the marks , replace the rings, run it in and re check the comp.

Dusty and Chuck:  What do you think of Phil's encouraging words?  I have new rings in hand. Can't hurt to try?

[oldbike54]

 Seth , it might be ok for a bit , but for how long ?

 Dusty

[chuck peterson]

Hot soapy water bath before install, too

[lucky phil]

Hot soapy water bath before install, too

Agreed, good point, after a run through with the flex hone hot soapy water and completely dry it off then rub the cylinder with engine oil and wipe out with a paper towel and you're ready to fit it up.
Ciao

[lucky phil]

Seth , it might be ok for a bit , but for how long ?

 Dusty

For the life of the engine. The deciding factor will be the comp and oil consumption.
Nikasil is super durable stuff. I've seen race motors re ringed and the nikasil cylinders hand finished with 400 wet and dry to knock any glaze off and ensure the rings seated. It was fine and never gave any issues.
Sometimes you need to add lib a bit at the track.
Ciao

[lucky phil]

You sure 130psi is ok? My v7 shows around 230 psi

Have you checked valve seats for damage? If water and silt got in to the cylinder it must have gone in via an open inlet or exhaust valve

Corrosion or a small body hammered into the seat may well cause low readings

Did you turn the engine and hydro lock it before finding the jug full of water, you could have bent a rod or damaged a big end shell causing lower compression reading

230psi!!!! On a V7, I'd be checking your compression tester
Ciao

[Chuck in Indiana]

230psi!!!! On a V7, I'd be checking your compression tester
Ciao

  Yeah, really.

[oldbike54]

 Tbjs isn' t a race motor .

 Dusty I

[Testarossa]

Bad rod bearing. I'm going to drop the engine and pull the crank. Time availability is an issue. This project may take a couple of months.

Thanks to all who offered advice!

[bmc5733946]

As I was typing this Seth posted about the bad rod bearing. I'll post it anyway.

It is really hard to tell from a photograph just exactly how deep those vertical scrape marks are.  I think Phil's experience is telling and may be the way to proceed.  If I couldn't snag a fingernail on those vertical marks I would definitely consider going in that direction.  In race conditions I have done many things I would never do in other circumstances as, have many others.  A good look by someone with experience with Nigusil would be a good thing.  All this boils down to Seth's effort and time and what he deems them to be worth.  The engine disassembly and reassembly is not difficult work but it is time consuming, for a retired guy like me, no problem.  We are also at the start of riding season in the northern hemisphere and I am sure that Seth would like to ride soon.  Sooooooo long story short I just might take the expedient route and slap that sucker together with some new rings and pray it goes the season and take another look at the end of riding season.  It is after all a mechanical beast and not flesh and blood, it is repairable in any count.  Best of luck to Seth whichever ways he goes.

Brian

[Testarossa]

Brian:  Thanks for your concern.  As it happens I am retired, and while I have part-time consulting work, my time is very flexible. And this lovely old beast is not my only motorcycle: the dependable daily rider now is a BMW (Aprilia) F650, also perfectly adequate for day-touring, and we'll certainly put 3,000 miles on it this summer.

The time constraints are a pending wedding (mine), home renovation, travel for honeymoon, to visit daughter and elderly parents, and even the 50th high school reunion (yikes!). Rebuild of the T -- third in five years -- will proceed at a leisurely pace.

And while I'm frustrated with my own slovenly neglect at the post-flood rebuild (obviously leaving some grit in the intake tract), I have passionately fond memories of the sweet way this machine used to run and handle. Will be happy to have it back on the road before the snow flies.

[oldbike54]

 Congratulations Seth .

 Dusty

[twowings]

Brian:  Thanks for your concern.  As it happens I am retired, and while I have part-time consulting work, my time is very flexible. And this lovely old beast is not my only motorcycle: the dependable daily rider now is a BMW (Aprilia) F650, also perfectly adequate for day-touring, and we'll certainly put 3,000 miles on it this summer.

The time constraints are a pending wedding (mine), home renovation, travel for honeymoon, to visit daughter and elderly parents, and even the 50th high school reunion (yikes!). Rebuild of the T -- third in five years -- will proceed at a leisurely pace.

And while I'm frustrated with my own slovenly neglect at the post-flood rebuild (obviously leaving some grit in the intake tract), I have passionately fond memories of the sweet way this machine used to run and handle. Will be happy to have it back on the road before the snow flies.

Since you are of retirement age (like me  ), if you spend the time and scratch to rebuild it right now most likely you will not have to touch the motor again until you're riding in the clouds....

[lucky phil]

Tbjs isn' t a race motor .

 Dusty I

Thanks, I do believe I'm aware of that.
Ciao

[oldbike54]

Thanks, I do believe I'm aware of that.
Ciao

 Well , you seemed to be making .a recommdation based on race bike practice , just checking

 Dusty,

[lucky phil]

Well , you seemed to be making .a recommdation based on race bike practice , just checking

 Dusty,

I'm giving a recommendation based on my experience with nikasil cylinders from engines I have worked on and built that competed in world F1, F2 and WSB plus my own road and race engines.
Thought it might be usefull and interesting to give an example of the robust nature of this type of cylinder coating.
Ciao

[Chuck in Indiana]

Well, just my honest opinion here. The first cylinder's rings were worn out from abrasive material. I'm betting ring gap on the second will be too big, too. Bad rod bearing. All this points to abrasives. They'll still be in the galleries, etc. if new parts are installed, and the cycle will continue.
I would completely tear it down and start from square one. Flush the galleries, take a *serious* look at the oil pump. It'll be cheaper in the long run, and leave some money for some red gaiters, Phil. 

[Testarossa]

I didn't mean to start an argument.  After seeing the bad rod bearing, I am going to tear the whole thing down, look at the oil pump and cam surfaces, and blow out the passages. Will report on right side ring gap today.

[Testarossa]

Ring gap on the right side within spec, but . . .  the middle ring was broken.

[Chuck in Indiana]

Check your rocker arm shafts & bushings, too. Do it once, do it right, and it will treat you well for the rest of your life. 

[lucky phil]

Well, just my honest opinion here. The first cylinder's rings were worn out from abrasive material. I'm betting ring gap on the second will be too big, too. Bad rod bearing. All this points to abrasives. They'll still be in the galleries, etc. if new parts are installed, and the cycle will continue.
I would completely tear it down and start from square one. Flush the galleries, take a *serious* look at the oil pump. It'll be cheaper in the long run, and leave some money for some red gaiters, Phil. 

My opinion here Chuck is directed specifically at the cylinder the assumption that it and the replacement ring gaps is still within spec. Nikasil is a very durable material and as someone earlier pointed out its not unusual to still see the hone marks after many klms.
It wouldn't surprise me to find the rings shot but the cylinder still useable.
I've actually just had a set of Daytona cylinders re nikasiled locally but haven't used them as yet. I'll be interested to see how they compare to the factory cylinders when it's up and running.
Ciao

[Chuck in Indiana]

I didn't mean to start an argument.  After seeing the bad rod bearing, I am going to tear the whole thing down, look at the oil pump and cam surfaces, and blow out the passages. Will report on right side ring gap today.

Actually, there isn't any argument.  I respect Phil's knowledge, and agree that the cylinder *might* be usable. It will take more than a picture to tell, though.
You are totally right in tearing it down, IMHO. Look at *everything* critically that goes round and round and up and down.
As an aside, Pat Cowden is the only guy I know that successfully salvaged his money creek flood bike. He completely took it apart and cleaned it, including all of the electrical system. Everything. No doubt, it was much more labor than the bike was worth, but.. he liked it. <shrug>

[Testarossa]

Chuck, I'm in Pat's position. I've stubbornly spent far more on this bike than it's worth.  I replaced the entire electric system after the flood except for the coils, and I'll replace them this time. Tore the gearbox down and replaced the timing chain and all the carb internals. I thought I'd got all the grit out but no, and since this bike has no oil filter . . .    Well.

I also lost a Subaru in the flood, but I wasn't in love with it so had no trouble donating the hulk to NPR.