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Did I lose my CAM?

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Did I lose my CAM?
#1
  This topic is about my 1969 Triumph Spitfire MkIII
brucejon Avatar
brucejon Bruce Jones
Santa Cruz, CA, USA   USA
1962 Triumph TR3B
1963 Triumph TR3B "Tupperware TR3"
1969 Triumph Spitfire MkIII
1972 Triumph TR6
Hi all,

I am in the first 100 miles of my 500 mile CAM break in and I am sweating bullets here. I have already done the 20 minute break in, and the oil change/retorque head. I swapped the old Delco Remy for a rebuilt Lucas from Advanced Distributor. It was running great on the Lucas before this happened. I rechecked the timing and the vacuum connections, they are good. I checked each cylinder for steady fire with the light, that is good.

My power all of a sudden, within seconds, just dropped off and the engine sounds rough. My first thought based on many threads on this forum was I just lost a CAM or followers. I've never had that happen, so I don't know if it happens that fast or not.

So I just checked all my valve clearances, and I have one tight, the rest between .022 and .028 hot. They are supposed to be .017 cold. I need to go pick up a base for my dial indicator to measure total drop in the valve rockers.

My plan is to let it cool overnight, reset the valves hoping this is because of that tight valve, retorque it, check the drop. If that all checks out, do a compression check, then fire it up again. If all is otherwise good and it is still rough, swap back in the Delco Distributor. Any thoughts?

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clshore Carter Shore
Beverly Hills, FL, USA   USA
Cam/lifter is unlikely to have failed so suddenly.
Revert back to the last thing you changed.
Put the old dizzy back, and see how it runs.
Still bad?

Do you have a magnetic drain plug?
No? Do you have strong magnet?
Put the magnet into a Ziploc baggie, pressout all the air, and seal it.
Drain the oil into a clean container.
Now take the magnet in the baggie and swish it gently around in the drained oil for 2-3 minutes.
See anything sticking to the magnet?
If no, then the cam/lifter is probably OK
If so, then maybe an issue.
Pull the head, pull the lifters (keep track of their positions.), and examine the faces.
Damage will be obvious if the cam is failing.

brucejon Avatar
brucejon Bruce Jones
Santa Cruz, CA, USA   USA
1962 Triumph TR3B
1963 Triumph TR3B "Tupperware TR3"
1969 Triumph Spitfire MkIII
1972 Triumph TR6
The good news is that there is no metal in the oil! Now I need to figure out what happened.

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SpiTazz72 Avatar
SpiTazz72 Bryan H
Magnolia, TX, USA   USA
If you didn't properly tighten the distributor clamp the timing could have changed from the dizzy rotating.

Lizzard d id
san jose, CA, USA   USA
In reply to # 1533644 by brucejon My power all of a sudden, within seconds, just dropped off and the engine sounds rough. My first thought based on many threads on this forum was I just lost a CAM or followers. I've never had that happen, so I don't know if it happens that fast or not.

So I just checked all my valve clearances, and I have one tight, the rest between .022 and .028 hot. They are supposed to be .017 cold. I need to go pick up a base for my dial indicator to measure total drop in the valve rockers.
A screwed up cam / followers has "wide" gaps . As the cam and or followers get worn away the gap opens up . Your measurements don't point towards a screwed cam or followers . The suddenness also doesn't point towards cam / follower damage . Cams / followers don't fail all at once , a cam bump , a cam follower , might go south slowly . It would be odd for all the bumps and or all the followers to go bad all at once .

In reply to # 1533644 by brucejon My plan is to let it cool overnight, reset the valves hoping this is because of that tight valve, retorque it, check the drop. If that all checks out, do a compression check, then fire it up again. If all is otherwise good and it is still rough, swap back in the Delco Distributor. Any thoughts?
Because the hp drop was sudden I'd look at crank to cam timing and parts . Did the cam come from adjustment . did the chain jump a tooth . I'd also look for a leak in the intake that might cause the mixture to go way lean , a clogged up exhaust pipe / muffler , exc .

brucejon Avatar
brucejon Bruce Jones
Santa Cruz, CA, USA   USA
1962 Triumph TR3B
1963 Triumph TR3B "Tupperware TR3"
1969 Triumph Spitfire MkIII
1972 Triumph TR6
In reply to # 1533664 by SpiTazz72 If you didn't properly tighten the distributor clamp the timing could have changed from the dizzy rotating.

Thx for the suggestion. I did check timing both statically and with a light, hasn't moved.

GeorgeOhr Nonya Business
Yes, confused, USA   USA
Check carb/fuel. Ya need that too ya know...winking smiley

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Wolfcreek Steve Steve P
Central, WI, USA   USA
Stop wasting time and energy chasing the "bad cam" idea.I'll pretty much guarantee it isn't the cam. Are you running points, are they closing up? bad condenser? Vacuum hose fall off somewhere? Lots of things can make a quick change in performance, but unless the cam breaks, they take thousands of miles before they become noticeably bad.

Spity Avatar
Spity John Biek
Fresno, CA, USA   USA
Like Steve said, bad condenser is a possibility. I had similar symptoms after replacing my old lucas condenser with a modern Lucas condenser. Get a different brand if that is what you have. Most likely all the current Lucas brand are faulty.

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brucejon Avatar
brucejon Bruce Jones
Santa Cruz, CA, USA   USA
1962 Triumph TR3B
1963 Triumph TR3B "Tupperware TR3"
1969 Triumph Spitfire MkIII
1972 Triumph TR6
Will check all these tomorrow. Thanks all. You know how it is, our minds tend to sweat the disaster. I've never had a cam go bad so didnt know if that was in play.

carChips Avatar
carChips Victor Harnish
Kelowna, BC, Canada   CAN
1933 MG Magnette
1973 Triumph Spitfire 1500 "Chip"
1989 GMC Sierra 1500 "Bush Truck"
It's most likely electrical, but pull the float bowl lids and check the needle and seat area for any kind of blockage.



'S all for now
Vic

Lizzard d id
san jose, CA, USA   USA
In reply to # 1533691 by brucejon Thx for the suggestion. I did check timing both statically and with a light, hasn't moved.
If the spark timing hasn't changed then the cam timing hasn't changed . My suggestion of crank to cam timing and parts can be tossed .

SpiTazz72 Avatar
SpiTazz72 Bryan H
Magnolia, TX, USA   USA
Does it idle smoothly or seem ok at low rpm?
I'm thinking about fuel starvation.

brucejon Avatar
brucejon Bruce Jones
Santa Cruz, CA, USA   USA
1962 Triumph TR3B
1963 Triumph TR3B "Tupperware TR3"
1969 Triumph Spitfire MkIII
1972 Triumph TR6
So all I had time for today was to check compression. 160 on all but one at 170. Waiing on new points and condenser.

brucejon Avatar
brucejon Bruce Jones
Santa Cruz, CA, USA   USA
1962 Triumph TR3B
1963 Triumph TR3B "Tupperware TR3"
1969 Triumph Spitfire MkIII
1972 Triumph TR6
In reply to # 1533805 by SpiTazz72 Does it idle smoothly or seem ok at low rpm?
I'm thinking about fuel starvation.

Thx. Was struggling at low and mid rpm. I changed out the coil and it was a little better. Waiting on a condenser, and tomorrow will look into fuel as well.

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