Some great pics from my friend Jane Absolom. Taken at the autocross a last weekend.
Some great pics from my friend Jane Absolom. Taken at the autocross a last weekend.
Two updates.
First up, I did an oil change back in July. As part of that, I sent in a sample of the oil to Blackstone labs. Interesting to see the results. Seems like the engine is fine on bearings, and possibly getting wear on the cylinder walls. Report says its wear from the hard running in the autocrosses I'm doing. That makes some sense as that is the majority of the driving I'm doing right now. I was also pleased to see that there was no fuel dilution going on.
Second up, I ran another autocross this past weekend. This one went really well overall. 15th on PAX with a doggone old car (and while PAX does help me, it does not help me as much as say being a novice). I did not forget much heading to the event (except my Gopro) and managed to drive the car fairly well. There is still more capability in the car than in my driving skill.
I'm considering a different tune in the Webers to get more bottom end where I really need it on an Autocross course. Its so easy to create two different setups in these carbs- Why not?
You could be seeing some extra wear from the cam as well if you have a higher-lift cam and didn't install cam bearings. We ran the autocross car in Virginia quite hard for around 18 years and only rebuilt the engine once, so I wouldn't think you have anything to worry about. Just keep checking the oil for gasoline. I think that's what ate our cam and killed the engine. That and the high lift cam and roller rockers with no cam bearings.
The car looks great.
I've researched fitting roller cam bearings to Triumph 4 & 6 cylinder motors.
Many of the Triumph motors run the cam directly in the iron block without any bearings.
Like many domestic V-8, the the stock oil distribution system has a design weakness, worn cam journal clearances
rob vital oil flow from the main and rod bearings.
Oil flow restrictors can help, at the expense of even greater cam journal wear.
Many modern V-8 use roller cam bearings, which do not require any pressurized oil flow.
To fit Triumph plain cam bearings requires the cam tunnel to be bored, and the bearings pressed in.
Roller cam bearings can be done, not much more machine work needed than fitting the plain cam bearings.
Thanks for the input Joe. No roller rockers at this input. Motor is built with the 150bhp PI cam from the UK, so not terribly radical either. I had the valve train rebuilt by a reputable rebuilder when I did the rebuild 2 yrs ago, and of course used new lifters and pushrods with the new cam. Put a lot of attention in on the break-in as well. Hopefully all those helped. - Your comments on fuel in the oil were part of what prompted me to have this oil analysis done.
Shore, that would be a pretty interesting improvement to the car in a definite weak area.
Going forward, I'm looking at two areas of improvement - I'm considering making a change to the ignition system - one that will improve total combustion and give me a rev limiter of sorts (Joe, yet another thing from you and from Ed Chan) and also considering a different anti roll bar for the front.
Joe, if I remember correctly, you had a crank triggered ignition system that you ran on the autox car? I've found some good notes on other cars prepped to the same level as mine that ran the MSD 6245AL (the digital with the programmable rev limiter).
I have no experience with MSD but know people that have run it successfully. When Ed and I ran Webers, we used an Electromotive HPV-1 that was crank fired. Today, there are more modern alternatives, but that setup worked well. The wasted spark probably helped burn some extra fuel. The best thing that we did was install a wide-band O2 sensor after the rebuild but before the EFI conversion. That really dialed in the Webers and leaned out the mixture.
I'm fairly certain that the rev limiter saved our engine on many occasions. It's just too easy to focus on the upcoming brake point and overshoot the revs.
Thanks for the Joe. Good to know on the wasted spark.
I've got a wideband installed - don't think I could have dialed in my setup without that!
Well, this update is about 4 weeks late...
I had my last autocross of the season. For this event, I spent extra time walking the course beforehand and time talking it through with one of the local hotshoes. This was definitely worth it. The car ran great all day and I drove better than I have all year - walking the course and thinking it through definitely helped so much!
In the end, I placed middle of the entire field overall. For a 50 year old car on allseason street tires, I don't think that is bad at all. Of the cars in front of me, two thirds of them were autocross prepared cars on 200tw tires, driven by much more experienced drivers than myself. So, I'm really happy with that.
I also did some work on the car prior to the event. Installed an MSD ignition box on the car with a rev limiter((not scared of over-revving). This gave me some confidence in the car, and it seemed to help the bottom end power somewhat.
Here's a vid of two runs from the day. Cam died before my fastest run.
Have not posted anything in a while. Have done some cool things to the car, but unfortunately I've got a problem here in the meantime.
First, the problem is that we've basically lost our autocross venue - actually both at once. I've been out looking at all of our old sites, and still no luck. Nothing new has been built in many years that would be of any use. I'm hoping some of my friends will be more successful than I've been.
In the meantime, I've built a custom stainless mesh grill for the car, along with a stainless insert for the lower intake as well. I think they look great.
Nice! Where did you get the mesh and what size etc?
TurboFource said:Nice! Where did you get the mesh and what size etc?
This! Hopefully in black too....
I picked up the mesh from a fleabay vendor called CustomCarGrills. They sell pre-cut stuff for modern cars and blanks in many sizes as well. Good quality stuff.
I like that grill.
Having helped start and run an autocross club in DC, I know how it goes with venues. It certainly hasn't gotten easier. My days of running events is probably over, but I hope to drive a little more before it's too late.
Since my last post, I've gotten some good news and picked up some parts to improve the car's handling a little.
The good news came through in the form of 4 autocross dates. I'm looking forward to them.
On the parts side, I got my hands on a set of 7/8 front and rear fully adjustable sway bars. Got them used, but in great condition.
I'm also about to head out to Road Atlanta for the Mitty in the next couple weeks. I plan on hitting a bunch of good mountain roads on the way, so I hope to install everything in the next couple days.
Finished the installation of the new anti-sway bars.
Removing both old bars was easy. For the front, I got out the old cutting wheel and sliced the u-bolts that held it in. The ne bar bolted into the stock holes, and was a quick job.
The rear was another matter entirely. It mounts very similarly to the skinny aftermarket bar it was replacing. Unfortunately, the dimensions of the new bar put it right through the middle of my exhaust system. To that end, I spent a good two hours reworking my muffler hanger to raise the routing of my exhaust to allow the bar to clear the exhaust.
The results are great. I used the settings a buddy gave me from his car and the difference is substantial. Such a huge reduction in body roll.
Here are a couple pics of the old skinny bars with their replacements, and the final installations.
Well, I had absolutely the best time at Road Atlanta a few weeks ago. The weather was great, racing was great, seeing friends was great- Ok, the weather sucked on the first and last day. My car ended up like a bathtub. I removed my footwell carpets when I got there and water did not just drip from them, it streamed out of them for the first 15 mins. Yikes. You would thinks that folks that live in a country that rains as much as it does could make a car that was more weather proof than a Triumph is. That car is like screen doors on a submarine.
Moving forward-
Long Post- Sorry in advance
(TLDR version - I wiped a cam lobe).
I drove my 6 to/from work the other day. Had a very noisy lifter during the drive. After the car cooled, I measured the lash, and all were good except #4, which was 22 thou out. On starting the car, the valvetrain sounded normal again.
I had just set the valve lash about 2k miles ago, so either I had an adjuster creep on me, or something wore down fast.
This morning, I elected to pull the valve gear off, and all arms, adjusters and the shaft are in great shape - all were rebuilt back when I built this motor in 2020.
At this point, I got out a dial indicator and measured the lift on each lobe. All measured within tolerances (total lift .250) of spec except #4, which shows total lift of .227.
Add the amount I had to adjust (.022) plus the total lift I measured (.227) and I get what should have been the lift of this cam-
I wiped a lobe. And it is now making metal.
Everything else on the engine is in great shape - oil pressure good, no compression issues. I believe I've caught this before the free metal from the cam had a chance to eat up any of the rest of the engine.
My plan is to now do an in-chassis cam change. Pop the head and front cover, install new cam, lifters, etc and go from there.
The cam that failed is a BP Northwest '150bhp' cam from the UK spec car. The cam absolutely runs great in the car, but I feel like putting the same cam back and expecting a different result would be silly.
My car is built to a high spec for running the backroads, autocrossing (did 8 events last year) and an occasional track day. Everything else in the engine and chassis are built to support this.
Considering the stuff above, I now need to decide what cam to put in the car and need to order soon.
As for the water, I'm convinced they put holes with rubber plugs in the floorpans to act as drains.
The radiator and grill will need to come out, but replacing the cam isn't too hard. Ed and I had a Crane cam degrade from lots of autocrossing. It took out the oil pump, but the bearings were fine. I'd plan on replacing all of the tappets with the cam. I like the Richard Good GP2 cam for street use, but his GP3 has higher lift and more duration, bumping the power band up 500 rpm. If you have roller rockers that increase lifter ratio, the GP3 cam will give a lot of lift but need careful consideration of pushrod length. That setup has worked well in Ed's autocross car, but the idle is fairly high and lumpy.
It may be worth giving Ted Schumacher a call as well.
Thanks much for that Joe.
I pulled the head and lifters Sunday and the destruction is pretty bad.
I will likely pull the engine this weekend to start a partial rebuild.
The good news is that the compression, cyl bores, oil pressure and cyl head are all in great shape.
This past weekend, my buddy Pete and I pulled the engine and transmission from the car. We broke down the engine, and I had more good and bad news.
The good news was/is that the block is in great shape. Bores are as good as I thought, and crank journals are in great shape- representative of the good oil pressure the car had.
Bad news is that the oil pump definitely ate the chunks that the tappets shed. I could have re-used the bearings, but that would have just been silly- new sets are on the way.
So a new cam and tappets just arrived from Racetorations in England, and the rest of the parts will arrive early next week.
I spent the remainder of the holiday weekend scrubbing out the block to get any metal contamination out of it. It's shiny!
Here's something I've thought about as an improvement for these engines. Oil slingers. It should theoretically be possible to cut a notch on the conn rod big ends so as to throw oil onto the cam from below. You could also weaken the rods doing so. Since I'm considering adding roller rockers with increased lift, the concern of wiping a cam has been on my mind lately.
I hope this goes back together smoothly.
2 weeks later, and the motor is back on the wooden stand ready to be installed.
I've been working a couple hours every evening to get it done. New rod and main bearings. De-coked the piston tops. I'm putting a new harmonic balancer, oil pump, along with ARP rod bolts.
The cam is a fast road cam from Racetorations. I spent time on the phone with the cam designer and he picked a cam profile from his catalog for me. I think it will do well based on the specs (I've run this engine with a fairly similar cam years ago). The phone conversation was fun!
With a little luck, tomorrow, I'll have the engine back in the car.
Photo dump
Curious your thoughts on the "skinny" rear bar for a street driven TR6. I put TSI's upgraded springs in during the restoration, but still have the stock front, and no rear bar. It's just a sunny evening cruiser, but there is more lean than I'd like in anything close to a twisty road.
wake74 said:Curious your thoughts on the "skinny" rear bar for a street driven TR6. I put TSI's upgraded springs in during the restoration, but still have the stock front, and no rear bar. It's just a sunny evening cruiser, but there is more lean than I'd like in anything close to a twisty road.
I had the skinny 5/8" bar in my car for many years (a friend designed that bar and I got one of the first run). It definitely improved the overall handling of the car by making the rear end stay more settled. I think it was a great improvement.
This weekend, I was able to get the engine installed and ready for a run-in. Will be breaking in the cam hopefully tomorrow afternoon.
I had one significant issue I found after the engine was in the car - the oil pump internals were not to spec, so it was locked solid. I ended up linishing about 5-6 thou off of the rotating parts to get them to clear. That was pretty disappointing and required pulling the pan and pump after the engine was in the car- not fun (but I should have checked it).
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