Making a TR6 more fun to drive....

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. 

https://youtu.be/z4IAupEOKPU