• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A TR3B Engine Authenticity

Share this page

Brooklands

Brooklands

Yoda
Silver
Country flag
Offline
I have a question on trying to get the engine compartment in my TR3B to be closer to its original configuration. My car, which is commision number TCF120L should have engine number TCF141E. Instead, when I received it, it contained engine CT39529E which includes Zenith Strombergs and emission plumbing in the air cleaners. I am not sure of the source of this engine, but it seems to be a later one than my 1962 build date.
I have access to engine TS 79189 E which I believe is a late TR3A engine. It has the SU H6 carbs and such. Would a swapping from this engine get me a closer to original configuration that would be close to authenic?
Thanks for any resources which will let me know how to make this car closer to original without a complete restoration or engine swap...
 
ZS's on a TR-BLOODY-THREE!?!?!

Whoa!

Yep, the late TR3 engine would be WAAAY closer than that smog controlled lump you have in it now. Check about transmission compatability before you "jump" tho. I don't have the data here to know just what you've got now as a unit (engine/gearbox) but I think someone else here will chime in soon. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

If you went through the "TS 79189 E" engine before making the change, you would have a VERY authentic, fresh rebuild car... and FAR be it from ME to suggest anything nefarious, but: a Dremel and a set of appropriate steel stamps may get you back the original engine with a bit of judicious knobblin'... /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif
 
That engine (CT39xxxE) would be a very late TR4, possibly a late-1964 build date.

Certainly the TR3 engine would look correct or at least more correct.

I see no issues with mating that TR3 engine with the gearbox you have in there now, be it the original TR3B gearbox or the one that was originally mated to the TR4 engine.

BTW -- the TR4 engine you have is scarcely a 'smog controlled lump'. We automatically think that way when we see 'pollution' equipment on one of our engines but the minor bit of plumbing on those TR4 engines really had little or no effect on performance (or pollution for that matter).
 
Yes Doc...
Most of the TR3B's ended up in the US of A. Two stories of why they were built after the 3A, simultaneously with the TR4.
Version one is that the American dealers felt that the new "modern" body of the 4 would not sell in the US, so they requested more 3's. The other version states that the factory had a few over 3000 bodies left so they used them up in the 3B's. The first run was the TSF commission series with the 3A engine and TR4 tranny, then the TCF assembly started with the larger engine and the synchro transmission from the 4 as well. My car should be the second version.
Now you know the rest of the story. They are hard to get much info on. The Triumph history books just gloss over them due to the very limited numbers. All help on getting this closer to correct is appreciated.
 
Geo Hahn said:
That engine (CT39xxxE) would be a very late TR4, possibly a late-1964 build date.

Certainly the TR3 engine would look correct or at least more correct.

I see no issues with mating that TR3 engine with the gearbox you have in there now, be it the original TR3B gearbox or the one that was originally mated to the TR4 engine.

BTW -- the TR4 engine you have is scarcely a 'smog controlled lump'. We automatically think that way when we see 'pollution' equipment on one of our engines but the minor bit of plumbing on those TR4 engines really had little or no effect on performance (or pollution for that matter).
Click to expand...

I don't really want to replace the engine, just the carbs, etc. which I believe look wrong for the 3B. Or were there 3B's with Zeniths?
 
No way. All 3's were SU's.
 
DrEntropy said:
No way. All 3's were SU's.
Click to expand...
/bcforum/images/%%GRAEMLIN_URL%%/iagree.gifEven early TR4s had SU H6 carbs. However, the 3A/B intake manifold will bolt right up; no need to change the whole motor.

SU's will even fit the ZS manifold, but I'm not sure if it would have the linkage pivot.

Either way, you'll probably want to change the rocker cover, and definitely pry out the plug to put back the road draft tube (near the fuel pump).
 
Brooklands, as far as authenticity...close only counts in horseshoes and hand grenades. Keep the TR4 engine..2138 vs 1991cc and swap the carbs/manifold/valve cover. If it is not block vented,the put the block vent in. Assuming the orifice is still there.



orifice????? almost didn't use that word......
 
Brooklands said:
The other version states that the factory had a few over 3000 bodies left
Click to expand...
That version is a myth, though. Rather than having bodies left over, they had to tool up at a different plant to build them. 3A bodies were built at Mulliners; while 3B bodies were built at Forward Radiator (who also assembled the cars). Another tidbit : 3Bs were only built in LHS versions; unlike the earlier cars, the bodies had no provisions for the steering wheel and hydraulics to be on the right.
 
I agree that the TR4 engine actually makes for a more nearly authentic TR3B, at least a TCF series. Originally, that would've had a TCF serial number on the engine, which would denote it's being the 2138cc. So in terms of displacement (which is difficult to determine except via tear-down and measurement, I'll grant you), you're there! Add a road draft tube, find the correct TR3B valve cover (<s>usually still </s>with<s> the front-mounted oil filler and</s> a brass plug in the top center), get yourself some late TR3A or early TR4 SU H6s and manifold (if necessary), put a couple extra coats of black over the area of the block serial number, and you're done.;)

Oh, and Randall's right about Forward Radiator, which actually (in the always confusing world of subsidiary companies) was a subsidiary of Mulliners, which in turn was a subsidiary of Standard-Triumph!
 
Andrew Mace said:
...the correct TR3B valve cover (usually still with the front-mounted oil filler and a brass plug in the top center...
Click to expand...

Verdad? I've seen the brass plug on the covers with rear-mounted breather caps and no plug on front mounted caps but never the filler cap up front with the plug.

BTW -- It is possible to remove the plug in the side of the block and install a breather tube with the engine in place.
 
Geo Hahn said:
Andrew Mace said:
...the correct TR3B valve cover (usually still with the front-mounted oil filler and a brass plug in the top center...
Click to expand...

Verdad? I've seen the brass plug on the covers with rear-mounted breather caps and no plug on front mounted caps but never the filler cap up front with the plug...
Click to expand...
My apologies; you are absolutely right. I was relying on ever-fading memory of the TR3B I used to own. Here, in all its "glory," is a picture of the car as it resided in my barn and showing the original valve cover as you describe (rear-mounted old-style breather cap and brass plug in the center).

tr3b-engine-3x.jpg
 
When did the oil fill move from the back to the front of the valve cover? My '59 has a front fill with no vent tube.
 
Basically at the start of TR4 production. ISTR there might have even been a very few TR4 with the TR3 cover. But by the time TR3B production started in 62, almost a full year after TR4 production started, there were only covers with the rear fill.

And the vent tube didn't happen until some time after that, 1963 as I recall offhand.
 
'63 sounds about right for what I think was one of the earliest Federal government regulations on emissions: positive crankcase ventilation. It might even have been a bit earlier in California?

Anyone ever seen a genuine early TR4 with the optional 1991cc engine? I wonder what they had for a valve cover. For that matter, I wonder if any cars equipped that way even made it to North America....
 
I may have it wrong, but ISTR California was where recycling of crankcase fumes first became a requirement (in 1963). I don't think the Feds followed suit until 64 or 65. However, Triumph (like many other foreign car makers) didn't want to bother with building "49 state" cars, so all their cars met the California standards (until the late 70s when they had to start using EFI to meet the tougher CA standards).

BTW, although they met the requirements of the day, I wouldn't call those early crankcase vent systems "positive". For positive ventilation, there needs to also be a fresh air intake to the crankcase. Otherwise the blow-by fumes accumulate, even if the crankcase pressure is slightly negative (as the later Triumph systems did).
 
Andrew Mace said:
...a picture of the car as it resided in my barn...
Click to expand...

Geez Andy, could you post a warning before you show pictures like that? Something like 'May be too intense for some TR owners'.

I'm still shaking.
 
/bcforum/images/%%GRAEMLIN_URL%%/lol.gif

You 'rumphy guys are a sensitive lot. /bcforum/images/%%GRAEMLIN_URL%%/jester.gif
 
Back
Top