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Discussion Starter #61
Hi All, Only took 38 turns! Here’s the cam timing. TDC tool in crank.
Can’t see crank pinion Mark, but I know it’s TDC.
Oil pump & gears look perfect. Had good pressure with gauge test recently. Drive block clearance .006”.
Will get new block. Plunger cross heads very good. Will reinstall pump.
Feel no play in right bearing. We’ll see when crank is out. Of course will replace.
 

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Keep the posts and Photo's coming Don,, All very informative and right where I'm up to myself...

Col
 

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A little trick to try, is to measure both lobes, sometimes there is tolerance in the grind that you can’t do much about, but if you find one lobe is advanced on both opening and closing compared to the other lobe, you can twist the tappet guide block in the barrel slightly, this will move one cam follower forward and the other back, the moved forward follower will engage the cam sooner and the moved back follower later. So correcting (improving) small imbalances in cam timing between the two cylinders.
VERY Interesting!

I've been around "a while" and have never heard of this trick. Sounds sensible.
 

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VERY Interesting!

I've been around "a while" and have never heard of this trick. Sounds sensible.
Funnily enough, I just built an engine that had a difference in cam timing left to right and hoped it could be the tappet block alignment - unfortunately it wasn't! I have never had this problem with a genuine Triumph camshaft, but this was a new "Triumph" pattern one - we are talking 4 degrees different here.
 

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Discussion Starter #65
Hi All, After verifying cam timing, moved on to removing gears. Cam & crank nuts were very tight. Especially crank nut. Oil pump was in very, very good shape. Will get new drive block only. Gears looked perfect.

Having special tools makes disassembly easy & damage free. Made the cam gear puller. 650 cam gear set has exhaust cam taper protector. Using spacer tubes the 650 tool installs cam gears easily as well. The oil feed of crank must be protected at all costs. I made a protector for pinion puller to press on. Pinion was tight, but not bad. The 750 case & gear gives easy full access for puller jaws. Cam gears tight, but not a very hard pull.
Right main bearing feels very smooth. We’ll see
End play of cams I .010”, E .011”.
Next I’ll take out trans, then pull cylinders, pistons.
Don
 

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Hi All, Only took 38 turns! Here’s the cam timing. TDC tool in crank.
Can’t see crank pinion Mark, but I know it’s TDC.
Oil pump & gears look perfect. Had good pressure with gauge test recently. Drive block clearance .006”.
Will get new block. Plunger cross heads very good. Will reinstall pump.
Feel no play in right bearing. We’ll see when crank is out. Of course will replace.
AAARRRGGGG !

This has to be done at TDC ?

No wonder my scrambler won't start

My book said to just line the marks up , nothin about TDC

Ah well thanks to you I can start again with fresh info


Sent from my SM-J250G using Tapatalk
 

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Discussion Starter #67
Hi Rossmick62, I'm talking Triumph.... If you line up marks like in manual, motor will automatically be at TDC or very close to it. Point is with nut on crank pinion 90% of the time you can't see the dot on pinion. So I use TDC to guarantee crank pinion is lined up. No guess work.

I don't know about BSA.... Looks like BSA idler gear is offset, so the marks are different. If you lined up marks like it shows in BSA manual, it should be correct I'd think.
Don
 

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Hey Don, any news to share , I'm interested in your sludge trap findings 😉
I am going to guess its under half full as mine was at about 40,000 miles with no oil filter. This is an interesting one as Don gives a lot of information and pictures. I am also waiting for more.
 

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Discussion Starter #71
Hi All, Thanks for the interest. Not done much for nearly 4 weeks. Sister in law passed unexpectedly, yet had been ill for some years. So not surprising really. Thank God the suffering is over. My wife was overlooking her needs, she was in board & care. Lots to do in making arrangements & all that goes along with passing. Plus working on home improvement projects. When I had time for bike I couldn’t properly focus on the work. Bike is a hobby so it waits.
Things have settled down for now so I am back to it today finally!!
I’d like to split cases & tear down crank next week. My life is still unsettled so who knows? I’ll certainly post detailed photos. I still have 100 photos to transfer to PC.
I got all my micrometers calibrated last night & the .075” rod alignment check bar fit. I seem to have lost my 4” micrometer so ordered a nice vintage one on eBay. The nice vintage ones are not too costly & still work perfectly. No batteries! I got a set of USA made standards 1-5”. I knew I was not perfect on my larger mics. The measurements weren’t adding up for “L” grade original pistons. Fitting pistons & rod bearings I split hairs.
Don
 

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Discussion Starter #75
Hi All, Moving onto bikes, I got cylinder mostly prepped for boring today. Did a little video on how to remove tappet blocks. Only 3:16 minutes, but too long to email. But it will text. I'll have to learn how to edit it into 2 parts. But that's how easy it is.

Tappets & cams look really good for 36k miles. Practically zero wear on stems or tappet blocks. I'll take some more photos tomorrow if time permits.

I noticed tappets running slightly offset side ways. I'll not worry about that. I don't see step wearing on cam lobes. I didn't used to pay such close attention to the tiny details.... It may be normal?

I aligned tappet blocks very carefully at 12k miles during reseal. The wear pattern on block is dead even, no signs of twisting at all. I've seen blocks not quite aligned & the wear was offset like tappet was being twisted in block by cam lobes bucking it trying to run straight. Cam center lobe testing spot on one cam. within 1/4 degree on the other, so the straight edge in tappet block measured to outside of cyl method proved good in this case. I did it pretty much within .001". Not that hard to do. I'll video that on assembly.

I did little video on checking top of cyl block for flatness. Has dip of about .00075" or so. Using Starrett straight edge .0005" feeler is free to move under it at center. .001" strongly drags the straight edge. I don't don't know what I'm going to do yet. The metal in dip is burnt to a degree also. There are a few high spots by less than .0005" around some bolt holes. I may have it skimmed. I don't want to split hairs, but don't want further head gasket problems either... Depends what machine shop has to say. They are very skilled.

I haven't checked head yet. Hope to tomorrow.

I still need to photo the center head studs also.

Transmission had some interesting wear.... Didn't expect that. Plus rust never sleeps... 60 more photos to send to PC on that so it'll have to wait.

I'll also do a little photo shoot & vid on how to practice fitting pistons with ring compressor using old pistons, rings, bores. It's good to have a feel for this when time to assemble with new parts.

Will be in attic part of day looking into new furnace-A/C unit. I don't mind our heat, wife doesn't like it so much. So we're moving forward with HVAC in attic it looks like.... And we thought Triumphs were costly....

Still have to learn to post vids on YouTube as well. My PC is junk. Using wife's for last few years. So new PC is in the works. Lots to do!
Don
 

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Just a word of caution, like Don, I set up the tappet blocks using a straight edge, but found a difference in cam timing between the two sides on new aftermarket camshafts, I had to set up as a compromise.
 

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Anytime you can detect perceptible uneven wear, it becomes even more critical to ensure all the followers go back in their original bores, oriented as they were; or else the new wear rate will be higher than before, and even more uneven (possibly to the point of excessive to failure)
 

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Discussion Starter #78
Hi, Thanks guys. I carefully marked & photoed the position of tappets to insure that.

These days on tear down I like to check things carefully for damage or oddities. I made a little test bar. .0005" smaller that wrist pins which are spot on .750". Close enough for what I need to know. Bar passes evenly & the rods feel in good alignment. Bores/pistons were worn evenly. So bores appear perpendicular to crank.
Don
 

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Hi Don,

Just as a matter of interest, are you planning to check rod lengths and big-end ovality against spec.?

Regards,
 

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Geez, I hate checking the rod big ends because they almost always borderline.... On my 79 T140D showing 15k miles on an inop speedo when I bought it, the rods were within .0005. Reused the same rods, I flog the bike often....Healy says no more than .001 on a moderately ridden street bike...But JH was a dealer so he is always conservative with recommendations...Me, I have zero faith in old aluminum rods if the all the engine performance will be used often...
 
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