Well, the break in has not gone well. On start up, the engine sounds like I dropped a wrench into it. To say that the lifters are loud is a gross understatement. To add to that, only a few of them are spinning, which indicates to me that the lifter and lobe is ruined. And on top of all of that, when I check the oil, there are metal particles on the dipstick.
When it warms up, it runs like a bat outta hell. It has more pull and harder acceleration than any TR I've ever driven.
I'm going to put 200 more miles on it and then pull the valve gear to then measure the lift on each lobe. If any measure low, then I'll pull the head to see what the lifters look like.
I need to know why it's now eating a second cam.
In reply to oppositelocksmith :
Does this engine have cam bearings installed? When I had mine done, one wasn't completely clear of the tappet hole and dragged on the tappet. Otherwise, I wonder if the new tappets may be slightly larger than stock or your block has some wear that may be causing the tappets to bind. With the higher lift cam, it's also possible to need some pushrod length adjustment. But I'm far from being an expert here.
I hope this can be resolved without another teardown. But yes, pulling the head may be the best move.
Thanks Joe. No cam bearings installed, so no interference issue there.
I talked with another 6'er yesterday who went through a similar cam issue over the past few years. His thoughts were that the cam grinder I bought the cam from may not have been a good choice - he bought several from this grinder before effectively deciding that they were part of his problem and moving on (no issues since moving on to a new mfg).
He also commented that I may have the wrong valve springs installed. What I have installed are suggested by another cam mfg for their cam, however, I've found that other mfgs suggest stock springs for similar cams.
In then end, I pulled the head last night and pulled the tappets. Good news is that they all have been spinning, they all were in relatively good condition. The lobe with the worst wear does in fact have a tappet with an odd pattern on it, but not like anything I've ever seen before. All the other tappets and lobes look great.
Basically, there is no real smoking gun from pulling the head.
I'm heading to Road America today, and going to take my tappets with me to see if anyone there sees anything they think sticks out.
In reply to oppositelocksmith :
I absolutely feel your pain! I have a '74 TR6 that over the winter of '21-'22 I pulled and rebuilt the engine. Also use a lot of Richard Good's parts (including roller rockers) as well as shaving the head to bump compression to 9.2 to 1. On initial start up I followed what I thought was a proper break in but I did have trouble keeping it running consistently at 2,500 rpm. Carbs were flooding and ignition misbehaving so there were some stall- start- stall- start instances.
I carefully put the first 500 mi on the car. No hard acceleration and kept it below 3k. One warm summer day I hit the interstate and pushed it harder. That did not go well. Engine overheated and stalled at the bottom of the exit ramp. Had to let it sit for a while before it would restart. When it did, I had a lot of valve clatter that wasn't there before. Nursing it back home I began to hear what I thought was rod bearing noise as well.
I got pretty disgusted and just stuck it in the garage and walked away. This weekend, almost a year later, I'm going to drop the pan and take a look at the cam lobes and rod bearings. The whole thing got pretty confusing as I did send an oil sample off to Blackstone and they said everything looked OK to them. When this happened I changed the oil and cut open the oil filter (cannister type). I ran the drained oil through a spray gun paint filter and got nothing. There was some glitter in the filter but I understood that this was normal for break in of a rebuilt engine. The fact that there was nothing in the sump told me the filter was doing it's job.
I don't think this failure had anything to do with Richard Good and the engine parts I'd gotten from him. My strongest suspicion is toward the oil that the engine machine shop strongly recommended I use during break in. They wanted me to use "Honda GN4 10w - 40". Only available at a Honda dealer. This machine shop does a lot of Triumph engines including those in vintage racers, so I followed that advice. After my problems began, I researched this Honda oil a bit and read some disturbing things.
I'll have a better idea of what I'm looking at this weekend. If I do replace the cam, I'll use the Goodparts GP2 again, but this time get it cryogenically treated first and leave the inner valve springs off until broken in.
I just got home from the Weathertech Challenge/Kastner Cup up at Road America.
While I was there, I spent a ton of time talking to different engine builders about what they think went wrong with my recent engine build and start up. Three different theories were the most common.
- First was a suggestion that I have the wrong springs for the job in the car- likely too stiff. Since the vendor won't tell me the seat pressures, I cannot tell for sure, but this is a possibility. Easy one to remedy by using a specific set suggested by the vendor I pick for the next cam.
- Next up is a theory that the cam and tappets possibly were not ground correctly- likely the cam did not have the correct grind/slope on it to provide proper spin on the tappets. I'll measure the grind this weekend when I pull the cam.
- Final is that I did not break it in right. Pretty high likelyhood this was a factor. When I was starting the car, the distributor gear was 1 tooth off, causing it to start up running rough. I had to shut down and install it correctly for it to then start up right and run great. All the engine builders indicated this was really bad for breaking in that cam.
From one Triumph specialist, I got a recipe (very complete) that I've written down and plan to follow for the next build. It will take me some time to pull the engine and clean and rebuild it this time. I really don't want to do this again.
GopherBroke, I hope some of what I just typed maybe is useful for what you went through. You'll get it running!
After several discussions with the cam supplier, I've reassembled the engine. I also found the source of the metal in the pan- the oil slinger was rubbing on the timing chain. I fixed that issue.
oppositelocksmith said:
I just got home from the Weathertech Challenge/Kastner Cup up at Road America.
While I was there, I spent a ton of time talking to different engine builders about what they think went wrong with my recent engine build and start up. Three different theories were the most common.
- First was a suggestion that I have the wrong springs for the job in the car- likely too stiff. Since the vendor won't tell me the seat pressures, I cannot tell for sure, but this is a possibility. Easy one to remedy by using a specific set suggested by the vendor I pick for the next cam.
- Next up is a theory that the cam and tappets possibly were not ground correctly- likely the cam did not have the correct grind/slope on it to provide proper spin on the tappets. I'll measure the grind this weekend when I pull the cam.
- Final is that I did not break it in right. Pretty high likelyhood this was a factor. When I was starting the car, the distributor gear was 1 tooth off, causing it to start up running rough. I had to shut down and install it correctly for it to then start up right and run great. All the engine builders indicated this was really bad for breaking in that cam.
From one Triumph specialist, I got a recipe (very complete) that I've written down and plan to follow for the next build. It will take me some time to pull the engine and clean and rebuild it this time. I really don't want to do this again.
GopherBroke, I hope some of what I just typed maybe is useful for what you went through. You'll get it running!
One other possibility. I don't know if this has been checked.
When Catalytic converters happened the oil companies removed zinc and ? (ZDDP) from oil to prevent them from clogging the converters.
That's why all modern cars went to roller cams. The lifter sliding across the cam lobe quickly ruined the cams that ZDDP originally protected.
In reply to frenchyd :
Thanks Frenchy. Yeah, more than aware of the flat tappet/ZDDP issue- common talking subject in all the LBC forums. For the previous break-in, I used Driven brand High ZDDP break-in oil and cam lube.
I'm trying Brad-Penn break-in oil this time per a builder that suggested it (high-ZDDP) and Isky cam lube.
It looks like the oil slinger may also be the source of your metallic noises. With that fixed and a properly setup cam, you should be back in business.
She runs! We did the break-in this afternoon after work.
Fired on the first turn and ran well from the start. AFR did not work, so I need to figure that out, but everything else went well.
https://youtu.be/eI3T_TEpxvk?si=jB-uXmw9ybO3i7oC
outstanding! man, what a beautiful car. i need a TR6.
Beautiful car indeed! The TR6 was one of those inexpensive factory restyle efforts where it was done right and Karman did an excellent job of taking the TR4A/250 chassis and central body section and making it into a new model with a completely different look. It all looks right and these were one of the first Triumphs that caught my eye and got me into these cars.
Angry, you do need one at some point in your life!
Thanks much Dherr! Agreed completely on the Karmann stuff as well!
My buddy Pete cam over to help me drop the bonnet in place yesterday after I re-installed the interior. Afterwards, we took it for a spin.
It revs so easily with the Fidanza alu flywheel. The engine feels much smoother to me as well- I'm guessing as a result of dropping 60% of the weight off the flywheel and better balancing.
Cam sounds great in the engine. No tappet sounds this time, and it sounds great overall. You can really feel the powerband hit as well.
The past two days have been excellent.
I really like the process of dialing something in- making it perfect. So, over the past two days, I've driven about 150 miles, and stopped periodically to adjust different things.
I started off by getting the adjustment on the heater cable right. Not a lot of fun driving along in 90 degree heat with the heater on. Adjusted, much better!
Then, I realized I was definitely not getting full throttle and heel/toeing was not quite right, so a minute in the parking lot got full throttle (not that I'm using it) and made heel/toeing the car much much more accurate.
Next up, I did not think I had the timing just right. I broke the engine in with a conservative static timing, so throwing a timing light on it showed that I could advance it another 5 degrees. Doing that unfortunately got the distributor and tachometer cable at a really odd angle, so I re-clocked the distributor to fit much more nicely. That really woke up the engine as well!
She runs very nicely now. So smooth, very rev-happy and eager to go.
I'm glad it worked out. Just wait until you no longer need to worry about holding back.
The Fidanza flywheel works great in my TR6 too. Someday, I'll drive it down closer to sea level, but it's pretty fun at 7100 feet with around 20% less power.
In reply to oppositelocksmith :
OMG that car is just lovely. berkeleyin' A man, congrats.
The cam and lifters have 500 miles on them now, along with a 45 minute break-in. Everything is running right, head has been re-torqued, lash re-adjusted and she's running great. Rest of the motor has about 9k miles on it.
With that, I'm going to hit an autocross tomorrow. I've missed the entire season, but should be able to get this one and one in November. I'm excited and nervous.
This will be my first time running with the new front sway bar, as well as the new cam. I run by myself in HCS, but it's still fun to improve each time and see what I can do in overall PAX.
dherr (Forum Supporter) said:
Angry, you do need one at some point in your life!
someday maybe I can commission a dherr build!
In reply to oppositelocksmith :
Have fun, good luck, ask someone to take pix of you on course!
Today went great. Honestly, the course was not great gearing-wise for the car, but it really did well overall anyway. I like the new anti-roll bars, the car felt very balanced overall with just a little push. I'll try a little more tire pressure differential next time to get the rear end to rotate better.
Engine had wayyyy more than enough power, but 1st was just a hair too short for a couple of the straighter parts, and 2nd was wayyy too tall.
I ended up 10th of 18 on PAX against much more modern machinery and guys who've been driving every event this year.
Video of my two fastest runs from today. Seeing the vid - I know I was leaving time out there. :)
https://youtu.be/hQzDqUF0sYo
Last Autocross of the year. Had a good day. Really tough course, bumpy, tough layout. I experimented with tire pressures and was sneaking up on a better setup when the day ended. I hit a lot of cones today (first run was fast, but hit two cones - bleep). If you're not hitting cones, you're not trying hard enough!
Car is really pretty balanced, but to get more out of it, I need to learn to drive better, and need to go ahead and shell out for some 200tw tires.
https://youtu.be/fQjz9sXajUQ?si=iRpX62RPAJ6ctL3E
Hi Oppositelocksmith, I have been reading your TR6 adventures with interest, I found this page when I was searching for good alignment specs for a TR250/6. I didn't find any, but good reading nonetheless.
I regularly autocross my TR250. What tires are you running? I have Bridgestone Potenza RE760, 195/65-15s, which I think is like a 330 tread wear. I did have Vredstein Sportracs 205/60s, but they wore out and can't find them anymore. I think I was faster on the Vredsteins.
I kind of wish now I had gone to a 16" wheel for better tire choices. Anyway, good reading about you adventures, keep them coming.
250Man, your car is gorgeous! I understand completely regarding the tires. I'm running some Firehawks right now. 205-65/15's. They work well, but I could really step it up with some 200TW's.
I got a nice surprise this week- a full Autocross schedule for the year, and my car on the digital flyer!
It rained all weekend, so I used the downtime to do a bunch of necessary maintenance. Lotsa fluid changing, and then resealed the windshield. The fluid changes went great, the sealing, not so much....
