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TR4 -v- 4A engine


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I'm looking to buy a Tr4A engine, and have been speaking to a couple of chaps,  but I'm not absolutely sure of what is the difference between the two models.

On Friday I might be going to look at what is supposed to be a US import TR4A one (it is to be rebuilt) . . . 

This is what I gleaned :

  • 4A cyl head is slightly reworked to breather better with the later manifold, but this is not apparent from the outside.   Likewise the engine bore / capacity, compression ratio and camshaft profile are is not outwardly apparent.
  • TR4 has steel push-rod tubes,  whereas the 4A has aluminium ones.  ( is this correct ? )
  • starting handle dogs on the TR4, deleted on the 4A. (B.Piggot)
  • the breather of the 4A is a closed system via a tube from the rocker cover to a PCV valve.  The TR4 has a pipe in the side of the crankcase, below the petrol pump. Later TR4 from CT14234 has a tube from the rocker cover to the air filters.  However a TR4 engine might have been fitted with a core plug - in which case you can't tell from that.
  • TR4A inlet manifold (if original) has the triangles cast into the balance pipe, and the vacuum takeoff is not on such a large raised boss.  
  • Exhaust manifold on the 4A went to 4 into 2 down-pipes.  TR4 has a single downpipe.  (B.Piggot)
  • Stromberg carbs were standard on the 4A until CT62191. thereafter SU were used.  Fuel pipe and throttle linkages changed with the carbs.  (B.Piggot)
  • Flywheel is slimmer / lighter on the TR4
  • clutch on TR4  is dry plate spring type, whereas the 4A has a diaphram clutch. (B.Piggot)  The clutch splines however are the same size.
  • there is some difference (?) between how the camshaft or its seal is retained. 
  • engine plates are the same on TR4 and 4A.  ?
  • commissioning numbers : TR4 from CT1 to CT40304 (06/01/65).   and 4A were CTC 5001 to CTC78684 (10/06/67).  Were the engine numbers the same ?

Any other visual indicators as to what is from which engine would be greatly appreciated. 

Many Thanks.  Pete.

 

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Pete

this web site should be useful to tell the head difference  

http://www.tr3a.info/FAQ_heads.htm

I have a 4a head and inlet manifold on a 3a engine so they can be mix and match. 

H

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I spy with my little eye...The tropical cooling fan - worth getting the engine just to sell that on. plus as you also say the sidescreen car rocker cover.

..and I see they took the rear lifting eye off (including head stud and nut) to remove the exhaust manifold.

Looks like a 4A head - The inlet ports are smaller than the TR3A-4. which is not a bad thing.

Cheers

Peter W

As Hamish has said these things mix and match OK.  My 3A has 4A head and inlet manifold.

 

Edited by BlueTR3A-5EKT
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8 hours ago, Bfg said:

59654680890__70ACFF36-4283-4ABA-8F43-D1A44AE2E2EC.thumb.JPG.1aae7062c55876fc41cdb678c4099020.JPG

This is the engine I'm looking to buy tomorrow, as a 4A engine. Seemingly with a hot climate six blade fan, and a side-screen car rocker cover ?

59654682257__CDEBEC1B-C60B-432A-90EC-C478E3A31CE6b.thumb.jpg.0ec3af2fbce97ee006276dc36b2a987f.jpg

59654689455__C56BFE93-F6F0-4948-80D7-E2124A6960C4.JPG.0f72df9768ca151b63ceb19167d291ca.JPG

59654690671__914BEC42-51EC-4051-87B6-8669CA410113.thumb.JPG.10f9e0b401aa0e802194e97f22f57c52.JPG

 

Pete

you don’t want that one. It’s dirty. 

Let me have it and you can find a nice shiny one. 

 

Mr jealous of Cheshire 

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.

Successfully viewed, purchased and collected today.

P1320794.thumb.JPG.ab66861ac28ecb43763a0844f01b7963.JPG

engine number is  near to CT56400E  so that would be a 4A  from mid-1965 (..I'm guessing).

..all I need to do now is to figure out how to get it out of the back of my Chrysler Voyager. :wacko:

Pete.

Edited by Bfg
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1 hour ago, Bfg said:

.

Successfully viewed, purchased and collected today.

P1320794.thumb.JPG.ab66861ac28ecb43763a0844f01b7963.JPG

engine number is  near to CT56400E  so that would be a 4A  from mid-1965 (..I'm guessing).

..all I need to do now is to figure out how to get it out of the back of my Chrysler Voyager. :wacko:

Pete.

Re Engine number,  577 * * is July 65 so yours is probably May/June.

Chris

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When we moved house, four of us, with a couple of scaffold poles into the bottom of a pallet, managed to get my spare engine into a Transit van.  I had laid the engine on its side as it was more stable that way.

Ian Cornish

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^ Sounds like a plan, thanks Ian.

I asked the seller and he thought the engine was not drained of oil before being pulled, hence the reason it's wrapped in cling film for transport but strapping it to the pallet (rather than the Chrysler's rear seat fixings, as it presently is)  and pulling it out en-mass does make sense.   Cheers. 

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I had drained the engine of oil before laying it on its side and securing it firmly to the pallet.  Because of the considerable weight, it would help removal from your car if you had a strong support, almost the height of your car's boot floor, situated behind your car, so that you could move the pallet onto that as step 1.

For step 2, we had an old kitchen worktop inclined downwards from the support to the ground, and we slid the pallet down to ground level.

For step 3, to get the pallet into the shed, we adopted the technique used in moving the huge stones to Stonehenge - 3 rollers to go beneath the pallet as we moved it forward slowly.

Ian Cornish

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.

After the frost had gone this morning, I decided to tackle this.  My being on me own like - it went like this .  . .

P1320801s.jpg.e6456785210126be090359cece1b94a1.jpg

^ Just because it would have been too easy on the flat n' level, let's at least make it an uphill struggle :P

P1320797s.jpg.b02fc4256070cdf57d1d94ded77fe698.jpg

^ Then move the straps from being tied to the floor to being tied to the pallet.  Theory was that it would be more stable.  :wacko: Whose idea was that ! ?

With blocks and lever the motor ascended to dizzie heights.  ..I'm not sure if Tutankhamun would have been proud of me or be turning in his Saatchi Gallery !

P1320800s.jpg.068e1f739a6f9ab915ae86e05f2419de.jpg

^ Part B of the plan was to move the engine onto my home adapted motorcycle lift.  That should take the weight shouldn't it    . . . .  shouldn't it ?? :huh:

P1320802s.jpg.6db3ea6f2829f6e1cdc688b6a1b5a07d.jpg

Shuffle., shuffle. 

P1320805s.jpg.402164ab9d9702285dd1177724b2dcbf.jpg

Shuffle., shuffle.  some more.  

                            *Crack*  ..what was that ! ?

..can't go back now. 

P1320809s.thumb.jpg.e6f0db596cc02763e561a26d2ec02e70.jpg

Shuffle., shuffle.  some more.    Yeah !  Balance point :lol:

^  duhh.,  that pallet is bending quite a bit .  .  .

P1320810s.thumb.jpg.b29ce80781554523cf9a72c5fe6bbc62.jpg

^   Raving Success !!! :D

 

P1320811s.thumb.jpg.555354997bdc155b73eea13beec78ba0.jpg

The bike lift, now with this heavyweight TR4A engine, is on rollers, so easily moved to under the block n' tackle I use as an aide when removing my Sunbeam (motorcycle) engines. With that tensioned (as a safety steady for the engine) the side blocks and straps could be removed. And it's now at a decent height to work on.

I thought I could do get the engine out of the car on my own ..but of course one can never be 110% sure., and I'm darn sure it would hurt if I dropped it on my toe. !

 

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.

Because this engine is intended for Chance, the TR4A I'm still trying to buy in the US,  I'm proceeding with its cleaning, dismantling and investigation < here > on its  ' That was a year that was ' thread.

But many THANKS  to those who contributed, helped and supported me here,  as I tried to identify what was the difference in engines.  And a special  BIG THANKS  to Rich Crewe-Read < rcreweread > whose off-line wisdom, help and advice has been truly invaluable, and again to others of the all excellent East-Saxons Group.

Cheers, Pete.

 

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Hi Pete,

would you like to tell us what you payed for it?

I'm also looking fir one since some time, but they are very expencive if they are complete,

or still expensive when they are just a rusty block.

This is always the moment I wish I would own a TR6 (this is just for a twinkle of an eye).

Ciao, Marco

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  • 3 weeks later...
On ‎11‎/‎27‎/‎2019 at 10:17 PM, Hamish said:

Pete

this web site should be useful to tell the head difference  

http://www.tr3a.info/FAQ_heads.htm

I have a 4a head and inlet manifold on a 3a engine so they can be mix and match. 

H

Hi Hamish,

thank you for this link,

the head on the engine in my 4A has aluminium push rod tubes.

The head on the currently bought 4A engine is also a 4A head with (rusty) steel tubes.

Both have the flat area with a stamped number - both the same!?! The number is 511695

Ciao, Marco

 

Edited by Z320
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