TR2/3/3A Tr3 Gas Additives

[mountainman]

Got my license plate today for the TR3 . Ready to do some driving At last. I have read many articles on gas additives that I am comfused and would like the forum opinion on what you use. Also what octane do you recommend?
Thanks
Greg

 

[NutmegCT]

Greg - congrats on the license plate. Feels good, eh?

So, if you feel you're ready to hit the road ...

I use many brands of fuel, all at 87 octane. No additives, and I drive the car every month of the year (when the weather is dry). Been driving it for three years here in New England, mostly on our rural roads, with some Interstate here and there.

No problems yet, altho' I'm sure there's always something "better".

Higher octane won't hurt, but it usually doesn't do you any real good. Most additives won't hurt either ... but the same "usually" applies. Same for "lead substitute"; I've heard many guys here say that unless you're racing or putting lots of miles on every year, the lead-free we have now won't cause harm.

Tom

 

[Andrew Mace]

Octane rating depends on the car. Most of the "small" Triumphs until at least the early 1970s had to run on "premium" gas...and still do. I'm surprised you get away with 87 octane in a TR3A; I remember having to use "premium" in mine back in the early 1970s.

I'm pretty sure that the engine in my '62 Herald has never been apart. I bought it in 2002 with 50k on it; I'm near 90k now. Some years it's gone easily 7-8k solely on lead-free gas, and now pretty much solely on 10% ethanol gas. I've check valve clearances several times over the years, and I've yet to see any signs of valve recession. In fact, the last couple of times I've checked, I've only had to reset one or two, and then by only the very slightest amount.

In my mind, most of the additives belong at the carnival midway behind the games, right next to the magic steak knives and other miracles of modern living. :laugh:

 

[hondo402000]

if you dont drive it often might want to use gas stabilizer with every fill up

Hondo

 

[newguy]

great question! I drive my TR3A 12 months a year here in Florida. Completely stock engine. I have always used 93 octane and since it usually comes from Shell Oil, it has (up to 10% ethanol). I use a small amount of a product called Startron. I'm not sure it really does anything. It really would be great to know if we need an additive or not.

 

[Moseso]

My TR3 had the "go ahead and use unleaded fuel job" done to the head as part of it's recent rebuild.
I use no additives in the fuel I use -- which has been unleaded 90 w/ 10% ethanol, or unleaded 92 w/ no ethanol.

 

[angelfj1]

Tom: You run 87 octane? Do you have the timing retarded from book spec.? I'm really surprised. I recall owning my first TR in 1966, a 4A, and it didn't like to drink anything but Amoco super.

Cheers

 

[TR3driver]

I have a feeling that the correct answer is "it depends".

The original valve seats were not hardened from the factory and hence may be subject to increased valve seat recession from running unleaded fuel. But such effects are generally only seen when running under sustained high load, and I'm guessing that most people don't drive their TRs at 80+ mph for any length of time. (I mostly don't anymore, as my hat blows off

) In addition, the protection of leaded fuel seems to extend long after switching to unleaded, as long as the valve seats are not resurfaced. More at https://www.vtr.org/maintain/valve-seats.shtml

So, the smart course here seems to be to not use an additive; and if you do run into problems with VSR, have hardened seats installed in the head.

Ironically, the only time I've had trouble with VSR, it was on a head that already had hardened seats! Not sure what the explanation is, perhaps the seats weren't really hardened, or perhaps it was due to the 'racing' valve springs I used. Or it might have had something to do with how far the head was shaved (I had to run premium plus lots of octane booster with that head).

However, there is another consideration :

Steve Hedke (of British Pacific ) has reported a new problem that he feels is caused by ethanol : Rapid piston ring wear after a rebuild. He says they have seen this happen on several widely different motors (TR4, Land Rover, vintage Ford flathead, etc.) where the rings simply wear out (huge end gaps) within the first 10-15,000 miles. He now recommends using an upper cylinder lubricant (also recommended in the TR3 owner's manual I believe).

Steve likes Marvel Mystery Oil, but based on some other information making the rounds, I'm trying synthetic 2-cycle oil (TCW3 spec) instead (which is a bunch cheaper than MMO). https://www.ls1.com/forums/showthread.php?t=91206

Too early for me to say if it works or not, but I sure am pleased with the way my TR3 is running at the moment.

 

[NutmegCT]

Hi Frank - yep, been running 87 for over three years. I think I *once* had a "ping" when I floored it going up a long hill in high gear. Other than that, smooth as a kitten.

I actually learned about using 87 (regular gas) from a long-time member here. Also, I just did a search on "octane" and "additive", and found several long detailed topics, with opinions all over the ballpark. Interesting comment from one of those discussions (paraphrased): You'll actually get slightly less power with higher octane fuel (on an engine designed for lower octane), as "higher octane" actually means the fuel burns slower. (or something like that).

Tom

 

[MGTF1250Dave]

Aloha All,

Like Tom I use regular unleaded E10 fuel which is 87 octane. My current TR3A is my daily driver and I drive it about 6000 miles a year. I been driven TR3As for the last fifteen years or so and always used unleaded regular fuel. I did use a lead additive for a short period of time in a TR3A I used to own. I haven't used any additives in the fuel and I know I haven't added hardened valve seats or stellite valves, so the head could be stock in my current car. So far I have not had any significant loss of compression. I set the engine timing using the static timing procedure described by Ken Gillanders as an initial starting point. Final adjustments are made using the vernier knob on the distributor after road testing the car.

 

[Don Elliott]

In Canada, we never know if there is any ethanol in any give brand or not. But I used unleaded Shell 91 octane for 43,000 miles in my 1958 TR3A after my engine re-build in 1990. After about 5 years, I was re-gapping the valves every 1000 miles because 8 of the 0.010" gap had disappeared because of valve seat recession in the original cast iron head. I had 4 inserts installed for the exhaust valves. I had not been using any lead additives. The seating edges of the original valves with 123,000 miles on them from new had become razor thin. Along with the 4 new inserts, I put in 8 new valves and 8 new valve guides. Since then, I've driven another 82,000 miles. I always have used Shell 91 octane when I could find it because it works and therefore, I believe that they don't add any ethanol. My timing is adjusted for 91 octane. My engine is 1991 cc and completely stock.

I had trouble in USA in 2007 with ethanol so I changed the hoses and banjo fittings which feed my float bowls. At the same time I started to add 4 oz. of Marvel Mystery Oil to every tankful of gas. The ethanol (if there is some) has not been a problem and the car runs great.

We can't get Marvel Mystery Oil here in Canada so when I was last in Vermont, I bought 4 quarts at Walmart - good enough for about the next three years or so.

 

[angelfj1]

Tom: So did you retard the ignition from spec?

 

[RJS]

I use Shell 91 octane and drop 3 oz MMO in every fill up. Engine rebuilt ~8K miles ago. Valve seats not replaced with hardened ones. No clue how many miles were on the original head (odo reads 31K miles and rolling?). But, have excellent 180psi compression across all 4 cylinders.

Oh, and every 3K miles I add some Techron to the tank.

Bob

 

[prb51]

Redline Lead Substitute was one of only a few additives that actually reduced seat recession in an extensive British Auto test. 1 ounce per 10 gallons.

This stuff https://www.bndautomotive.com/page/page/931760.htm is extremely expensive but has proven itself in independent tests by multiple sources to reduce cylinder wear in a huge way (like 600% less than an engine using straight gas). I use it in my HotRod as I drive that very hard.
It also raise 87 Octane to around 96 Octane if you use the amount advertised but I cut that in half on the recommendation of Vizard after his test of the product so it goes a very long way.
Most octane raisers advertise they raise octane 3 points but they don't tell you they mean .3 points.

 

[TR3driver]

Most octane raisers advertise they raise octane 3 points but they don't tell you they mean .3 points.

Actually, the industry definition of "point" seems to be 1/10 octane number.

IOW if your improver adds "3 points" and you put it in 87 octane fuel, the result should be 87.3 octane.

 

[prb51]

Randal,
That's what I meant about most all oct boosters...otoh the Ace raises 87 to 96 Octane if you use the manufacturers rec amount, he states that on his product and indep testers have verified the results ...I cut it in half because Vizards test showed (he used 3 identical motors he'd jsut built)that cutting it in half didn't noticebly reduce effectiveness and the stuff is dear.

 

[angelfj1]

Why not "roll your own"

Following from SOL web site


How to make your own octane booster (this is the basic formula of one of the popular octane booster
products). To make eight 16 ounce bottles (128 oz = 1 gal):

100 oz of toulene for octane boost
25 oz of mineral spirits (cleaning agent)
3 oz of transmission fluid (lubricating agent)
This product is advertised as "octane booster with cleaning agent *and* lubricating agent!". Diesel fuel or
kerosene can be substituted for mineral spirits and light turbine oil can be substituted for transmission fluid.
Color can be added with petroleum dyes.

 

[NutmegCT]

OK, maybe I missed something so far ...

what octane (and its modern USA equivalent) was recommended by Standard Triumph for the engines of the TR3, TR3b, TR4, TR6, etc.

Tom

 

[TR3driver]

Why not "roll your own"

Because at least in my case it took a huge proportion of that concoction to make any significant difference. A quart of 'improver' to 5 gallons of Premium was noticeably better than just the Premium, but still not good enough. And I just wasn't interested in having to carry around a gallon of it, just to fill the tank.

What I found was that only boosters containing MMT would keep my engine happy; and even then there was a fine line between enough and too much (which would foul plugs with a funny orange colored deposit). Unfortunately there has been a lot of legal wrangling over MMT (apparently mostly because it does work and isn't made from petroleum), which may have been the reason that the product I found worked best for me was dropped from the market. The name got sold to a different company, who revived the name but their product didn't work nearly as well.

 

[TR3driver]

what octane (and its modern USA equivalent) was recommended by Standard Triumph for the engines of the TR3, TR3b, TR4, TR6, etc.

Factory recommendation was 95 octane for TR2-3, 97 for TR4A, 91 for (US-spec) 72 TR6.

But these numbers are all "research" octane, it's not clear to me exactly how they compare to the method used in the USA today (average of "research" and "motor" octane), except that our numbers are definitely lower for the same fuel. According to the venerable Gasoline FAQ https://www.faqs.org/faqs/autos/gasoline-faq/part3/, our numbers should be about 5 lower, but it does not seem to have been updated for RFG2 or E10.