TR4/4A TR4 build

[wannatr4a]

Hello to all here,
Preparing to build my dream car, and could use a lot of advice,
It will begin with a TR4,(love the E-brake placement), with a IRS chassis now I'm stuck at the hard part, which engine would be best for a daily driver?,(4 or 6), really concered with reliabiliy, I do a lot of long distance commuting,(Los Angeles to Sacramento). Which means crossing the grapevine. Any and all advice will be deeply appreciated, nothing but manuals have been purchased as of current, I will be doing most of the mechanicals my self, and farming out the body and paint.
Thanks in advance for the advice.

 

[roofman]

If originality is important, go with the 4, if more power is desired go 6, but with either make sure you have overdrive for highway usage.

 

[TR3driver]

Hmm, IRS means at least a TR4A. The TR4 was never offered with IRS, and doing a major conversion like that would NOT be the route to long-term reliability. I assume you are aware that you can get a TR4A (with the center hand brake) with a solid rear axle if you want (which IMO is less troublesome than the IRS).

Reliability is rather a matter of opinion. Mine is that the 'big' TR 4-banger is one of the most reliable, abuse-tolerant engines ever; while the TR6 motor is slightly less so. You'll never ever hear of a TR4 motor losing it's thrust washers, while it happens all the time to TR6 owners. And that long, 'stroker' crank in the 2.5L flops around at high rpm (the 2.0 version found in the GT6 is much stiffer). The TR6 is still a fine, strong motor (especially in de-tuned US form), just not quite as much so as the TR4 motor IMO. (We don't call em TRactor motors just because they were used in tractors!)

I didn't make a habit of going over the Grapevine in my TR3A, but it's been there many times and never had a problem. I did put maybe 200,000 miles on it, mostly doing battle in LA freeway traffic (literally my daily driver from 1984 until it got rear-ended on the 91 freeway in 2005). I've even limped home without a fan belt!

But for day-to-day driving, I would suggest (for any TR2-6) converting to a high output alternator and as big an electric radiator fan as will fit (eliminating the mechanical fan). I also opted (eventually) for a "high tech" gear-drive starter, and Nylatron suspension bushings; both for better reliability.

And I do agree with Roofman about OD. Probably for drop-dead reliability, you should go with a Toyota 5-speed conversion; but I have to say I prefer the original A-type OD, and in all those miles it never kept me from getting home (although there were a few times I came home in 4th direct). I also feel the TR2-4 clutch is more reliable on the street (TR6 are famous for having clutch problems), and the Toyota conversion requires the later clutch (so I'm told).

 

[sail]

keep the 4 in it.

 

[SCguy]

If you had any illusions of keeping up with traffic on I-5 be forewarned that even with overdrive you will be struggling. Anyone who says otherwise just hasn't driven I-5 recently. Personally I'm not a fan of semis at 80 miles an hour. I live just off I-80 and modern traffic speed was the major reason I choose to buy a TR8.

PS I love the ride and engine in my TR4.

 

[TR3driver]

Personally I'm not a fan of semis at 80 miles an hour.

Me neither, they slow me down!

Seriously, my only slightly modified TR3A would cruise all day at over 90 mph. Last time I got clocked, it was at 96 on the 405. However after some discussion (officer almost ran off the road trying to follow me when I pulled over, but it was hard to claim I was trying to evade him when I stopped behind the traffic on the off-ramp), he only wrote me up for 84 in a 65. Just speeding, not reckless driving.

 

[TonyPanchot]

same happed to me on the 101 "interesting"
go for the 6 w/ od

 

[4aKen]

I went to college in the early seventies up at San Jose State and made the run home to Southern Cal once or twice a month. Used to have this thing about cars passing me on hwy 5...rarely under 90mph all the way down to the grapevine, as long as I did not bogg down behind traffic the 4a cruised up the vine in 4th.
At the end of many of these trips the 4 seemed refreshed and invigorated having escaped the traffic of the 101 bay area commute.
Them there big fours need the open road. (Fan belt and points, maybe a spare water pump, couple of plugs wouldn't hurt either....) Of course I would not put the TR or myself through these paces now...we have both reached the age of reason.

 

[TR6oldtimer]

Back in the day, I regularly cruised at 80 mph in a TR4 (no OD). Leave Vallejo CA, fuel up in Bakersfield, then on to San Diego. Even with the top up, you could not hear the radio.

 

[vagt6]

Lots of good advice here, but maybe we're looking at the problem from the wrong perspective . . .

Triumph TR4s are not 90 MPH cruisers, by any stretch, without extensive modifications to every system on the car. But, a well-sorted TR4 with OD should be able to keep up with interstate traffic at the posted speed limit anywhere. However, I tend to avoid Interstate highways like the plague in antique cars, or on my motorcycle. Too fast and the car is too lightweight in the wind/traffic. But each to his own, YMMV.

Bottom line: few, if any 30+ year old LBCs should be driven at sustained speeds of 80 or 90 MPH++. The cars simply are not up to it in anything near their stock form. In fact, to do so is downright dangerous.

Having said all that, clearly a well-sorted TR, GT6, Spit and other Triumphs are relatively happy to cruise all day long at 70 MPH with stock or period-correct (restored) systems, but <span style="text-decoration: underline">NOT</span> at 80 or 90 MPH.

If you want to cruise that fast in ANY car, join the SCCA and take it to the race track.

Back to my hole now . . .

 

[SCguy]

Of course I would not put the TR or myself through these paces now...we have both reached the age of reason.

I guess this is how I feel... I drove my TR6 to the University of Southern California from CT in 75. Then up and down the coast for years. Thing is the speed limit was 55. If you felt dangerous perhaps you took it up to 70! Now everyone drives 80 and faster on I-5.

A couple of thoughts, my TR4 doesn't have overdrive and my six can be a little squirrelly at high speed. That having been said, I see old MGs and Triumphs (even a 74 Pinto) all the time on I-80 and always in the slow lane.

It's your call, these are just my thoughts. I'm sure what every you buy and build you will have a car that you won't regret owning!

 

[Geo Hahn]

...Bottom line: few, if any 30+ year old LBCs should be driven at sustained speeds of 80 or 90 MPH++. The cars simply are not up to it in anything near their stock form. In fact, to do so is downright dangerous...

When the situation calls for it I certainly don't hesitate driving 80 on an interstate. It doesn't come up often as I usually plan routes on 2-lane blue highways but there are only a couple of reasonable ways to get from Southern California into Arizona and all 3 of them are interstates with 75 mph speed limits.

The car is a TR4 with OD and it certainly doesn't seem to mind such treatment nor does it feel unsafe provided I avoid congested traffic and leave a lot of room around me (good idea in any car).

 

[TR3driver]

Triumph TR4s are not 90 MPH cruisers, by any stretch, without extensive modifications to every system on the car.

Exactly which systems do you feel are inadequate? The stock brakes are larger than most modern cars (especially compared to the car's weight) and very effective when in good condition, so no issues there. With overdrive the engine is turning under 4000 rpm, which is between peak torque and peak power, clearly within the engine's intended operating band. (Mine actually seems happier above 3500 rpm.) At speed there is no need for a fan at all, so the stock fan is entirely adequate. (The problems arise when you stop suddenly, which is why I recommend an electric fan for driving in traffic.)

Yeah, sure, you're going to want modern tires and wider wheels. Pretty minor modification, IMO.

Granted, my experience is with a TR3A, which is just a smidgeon lighter and just a little less frontal area than a TR4; but I have literally driven for hours at speeds close to 100 mph with no problems.

Sure, it's not like driving a Volvo. But that's kind of the point. And you'll be just as dead doing 65 in the slow lane, after that semi runs over you. I've had two serious accidents in my TR3A (last one totaled it); both times I was completely stopped. It ain't the speed that kills.

 

[4aKen]

I don't think anyone posting here is suggesting taking 40yr.+ drive trains out for sustained high speed driving. I do think the early TRs with the passing of years have been badly remembered as to their real road potential. I remember reading articles with the canned statement, "can cruise all day at 90 miles per hour." In 66 the 4a irs were 1,2, and 3 in class at the Sebring 12 hour..some modifications, yes, but not much the average weekend racer couldn't accomplish.
Posted Freeways in California in the 50's and 60's was 75mph and the cars of the day were more than capable.
A couple of years ago I was reading an interview by a TR6 club with Kastner. The interviewer asked him what was the fastest TR's he'd been associated with, he thought about it and much to my delight mentioned "some very fast 4a's."
Group 44 cut it up in TR4's in 60's.
It doesn't take a highly modified TR3/TR4 to kick it with modern traffic.

https://www.kaskastner.com/roadtrack2.pdf

 

[vagt6]

Randall, if YOU want to cruise around at 90 MPH in a TR3, be my guest. Not for me, tho'.

And, please don't cruise on Interstate at 90 MPH in my neighborhood 'cause if I see you, I'll call the cops on you, immediately.

With 50,000 deaths each year on U.S. roads, responsible folks tend to observe traffic laws. Ninety MPH on public roads in <span style="text-decoration: underline">any</span> vehicle is unacceptable, especially an antique vehicle.

Again, if you've got to speed join the SCCA and do it safely on a race track, under supervison, with EMT services available.

Sheesh, some folks . . .

 

[TR3driver]

Randall, if YOU want to cruise around at 90 MPH in a TR3, be my guest. Not for me, tho'.

That's fine, I never said you <span style="font-weight: bold">should </span>drive that fast. But you said the cars are not capable, and I disagree.

Since you still have not answered my question, I assume you realize how silly your previous statement was. Reasonable/prudent/legal is a different question entirely.

Sheesh, some folks . . .

 

[tomshobby]

If you guys only want to go 90 I guess that is up to you!

 

[TR6oldtimer]

Again, the question was one of reliability. A properly maintained or restored TR4 is more then capable of sustained high speed driving, if that is your desire. The early stock car would do 110 mph at 5,500 rpm. Later versions of the car would do 120 mph, and with larger tires could hit a little over 130 mph (at least mine would).

Would I drive one at that speed today? No, but then I am three times as old now then when I did. Unfortunately, unlike the car, I cannot be rebuilt to what I once was.

https://www.flickr.com/photos/brizzlebornandbred/2114885508/in/set-72157615122321275/

 

[wannatr4a]

Everyone thank you for your opinions, they are deeply appreciated.
The posted speed limits will be fine, since I am a truck driver and cannot afford traffic violations.
I love the e-brake being in the floor on the passenger side and thaat they are closer to my age,(born 1961), which is my main reason for looking at the 4 rather than the 4a.
The main goal is to put together a Micholetti body using as much of the later technology as possible, while also keeping some of the early ideas,( mainly the e-brake).
So after having read Roger Williams How To for the TR6,( still waiting on the one for TR4A), and speaking with the gentelman from Ratco,( he suggest using the later rack in pinion).
That I would start with a complete TR4, and build from there using the Ratco frame with the modifications needed to accommodate later changes along with the modificaion recommended by those with the experience that comes with ownership.
I actually picked up the Kaster book and throughly enjoyed it.
Again, Thanks to eeryone for the advice and shared adventures, hopefully in a year from now I'll be sharing some of my own.
P.S,
Promise to post my progress. :}

 

[TR6oldtimer]

Having owned a TR4(the first car I bought) and now own a TR6, IMO. The non-IRS TR4 was a much better handling car then the 4A or the six. Either way you will enjoy it.

I have shown this picture before, but here it is again. Taken in 1967 in Balson Spa upstate NY. The same car I drove from Vallejo to San Diego many times, then from San Diego to NY, a winter in NY, then back to San Diego. It went on for several more years until I launched it over a center divide.

Oh, I expanded the rims on that car from 4.5 to 5.5 and had nice big Dunlaps and never used chains.