Jump to content

TR4 Bonnet hits carbureteur


Recommended Posts

Early TR4's had the same manifold as TR3B's which, as far as I can see were the same as TR3/3A but with a vacuum take off. (which yours has)

so you definitly have an early TR4 manifold.

So, were the early cars fitted with H6, HS6 (which are shorter) or perhaps Stomberg carbs ? (which may be lower.)

Bob.

Edited by Lebro
Link to post
Share on other sites
15 hours ago, Z320 said:

I layed a straight wooden lath across the wings and measured for you to compare:

I have just tried the same thing with very different results!

The top of the valve cover is more or less the same as your measurement at around 50mm

But the top of carbs is above the line across the wings by about 30mm.

So that would indeed seem to suggest the engine is mounted more or less correctly but there is an issue with the inlet manifold or wrong carbs fitted?

 

IMG_3884.jpg

IMG_3883.jpg

Edited by solaise
Link to post
Share on other sites

Looking again at your carb pics earlier in the post, they are not 4/4A carbs...the left one has the float chamber on the 'wrong side'...who knows what else is wrong..by the look of the dents in your bonnet the manifold (or carb body) is too short by 20-50mm....and your latest message indicates too high also...suggest get on ebay and look for the unfashionable Strombergs which are functionally identical/superior and cheap.

Link to post
Share on other sites

Hi,

please note I own a TR4A with HS6 carbs and the unique TR4A manifold,

and all the other guys also seam not to own a TR4, all TR4 guys seam to be out for holiday....:lol:

Some more photos for you, the top of the carb is about 34 cm from the wing on my TR4A

DMVU554KzRwrYXnIrJqEsVsg9EEq3wyV4ZxhoyYv

aYWgrDWVN81KVXtqRWlAe7-lK8y-yejPvCziNOHx

This is about exactly in the middle of the bulb

EstV0CILt2ayjgpMmgwOSk1wT4vd0hN0wgCyVf-Q

This flat look back from the front on the carbs may help you, the inlet maifold is horizontal, the carbs are going silghtly up

Ls2kpIlJd3baGysuDg7dnDw64Iq2YBnQ2MZrTkIy

Ciao, Marco

Link to post
Share on other sites

Solais,

you have the incorrect inlet, change to a TR4 or 4A.

 

 

IMG_3878.jpg.1786500e9ede7b3b860754911555f5d6.jpg.137290d2386ea62fa9717e69b4b23cf3.jpg

This is yours, TR3/3A

 

 

 

710539941_IMG_4055(2020_03_0509_55_05UTC).thumb.JPG.797626e62485579bfa55adf7775c804c.JPG.bbcd3830c3e5b6307ab0ce64580c3d06.JPG

This is a TR4A look at where the carbs are in relation to the valve cover

 

The correct inlet will put the tops of your carbs. in the 'Crown' of the dome, and solve your issue.

 

John.

 

 

 

Link to post
Share on other sites
44 minutes ago, Z320 said:

the top of the carb is about 34 cm from the wing on my TR4A

I measure mine to be 37cm which along with the extra 3cm up brings it into contact with the inner part of the bulge.

I am wondering if I change my current inlet manifold (part 2 in image) to be the long neck version (part 3) if that will bring it more into the centre of the bulge, which even with the extra height should accommodate it. Although I have no idea if that would mean changing the exhaust manifold as well...

 

tr24_20_03_05.jpeg

Link to post
Share on other sites

This is a 4A special, it goes to the "positiv crankcase valve" (PCV) for an active ventilation of the engine.

You see that on my photo above.

Edited by Z320
Link to post
Share on other sites

Early TR4's had the same manifold as TR3B's which, as far as I can see were the same as TR3/3A but with a vacuum take off. (which yours has)

so you definitely have an early TR4 manifold.

So, were the early cars fitted with H6, HS6 (which are shorter) or perhaps Stomberg carbs ? (which may be lower.)

20210321_174445.thumb.jpg.01cc92caa1774d97f54629ebec148da0.jpg  20210321_174532.thumb.jpg.2923ef65131124062b704628007c581e.jpg

Taken from Triumph TR4 parts book.

Bob.

Link to post
Share on other sites
5 minutes ago, Quicksilver said:

there is one on ebay;

I think that is the one that I have at the moment and is not long enough.

The engine number is CT9366

Moss lists 
305744 MANIFOLD, inlet - TR4 to (c) CT21470 

307455 MANIFOLD, inlet - TR4-4A from (c) CT21471

https://www.moss-europe.co.uk/inlet-exhaust-manifolds-tr2-4a-1953-67.html

There are a couple of these I can see on ebay, with the 307455 being more easily available in the UK, the exact 305744 all being in the States.

Could I use either of these? 

Link to post
Share on other sites

Heres an overhead shot with the tape measure starting at the edge of the bonnet.

Tom

(btw thanks for all the input from everyone so far - it really is very much appreciated - I didnt anticipate all the help the forum would generate.)

IMG_3887.jpg

Link to post
Share on other sites

What I dont fully understand about this problem is exactly where the dashpot top is hitting the bonnet - at the very start of the thread, there is a photo of the underneath of the bonnet which appears to show the "rubbing point" being on the very nearside edge of the bonnet ie towards the middle. 

The early Tr4s had H6 carbs and the stubbier manifold, but the carbs had longer bodies than later ones, hence why the later and improved manifold had longer inlet tracts, but shorter bodies in the 175 CD Strombergs and later still the HS6 SUs - this later manifold is to all intents and purposes the same as the later TR4A manifold, the only difference being a triangular "bump" on the balance pipe of the ealier one compared the 2 smaller "ears" on the 4A one - see attached photos of the two types.

I think the issue in this instance is that the H6 carbs may be the wrong ones and do not have the correct angle of inclination of the correct ones and this is kicking the whole fitment too high up, and combined with the shorter earlier inlet manifold ends up rubbing against the bonnet.

If you don't seat the inlet manifold properly against the head, ( and it's easy not to) you can tighten it up but at completely the wrong angle - this happened to me and at least one other person I know about, and it would have hit the bonnet if I hadn't noticed it but I don't think that is the issue here because the engine has been in use.

Unfortunately I haven't got a set of H6's I can compare against at the moment to be definitive but hopefully the above may help a little!

Cheers Rich

IMG_3645.jpg - Resized.jpg

IMG_3646.jpg - Resized.jpg

IMG_3823.JPG - Resized.JPG

IMG_3648.jpg - Resized.jpg

IMG_3822.JPG - Resized.JPG

IMG_3821.JPG - Resized.JPG

IMG_3651.jpg - Resized.jpg

Link to post
Share on other sites

Interesting to see on the photos above (TR4A) are the 2 different inlet manifolds with SU HS6 (like on my 4A) and with Strombergs,

both with 13 cm probably too long for Tom's H6, as you can see on Quicksilver's "modified" air filter on the front carb....

68vSMsLq5QxbOhr8Lcb9lmXITrNVZhsY5nDbu6Ux

 

Edited by Z320
Link to post
Share on other sites
3 hours ago, solaise said:

I think that is the one that I have at the moment and is not long enough.

The engine number is CT9366

Moss lists 
305744 MANIFOLD, inlet - TR4 to (c) CT21470 

307455 MANIFOLD, inlet - TR4-4A from (c) CT21471

https://www.moss-europe.co.uk/inlet-exhaust-manifolds-tr2-4a-1953-67.html

There are a couple of these I can see on ebay, with the 307455 being more easily available in the UK, the exact 305744 all being in the States.

Could I use either of these? 

Tom,

 

yes you could use either of these inlets.

 

I have sent you  a PM, (Personal Message) click on the envelope top Right to open.

John.

Link to post
Share on other sites
18 hours ago, John Morrison said:

 

 

 

 

 

 

 

 

 

710539941_IMG_4055(2020_03_0509_55_05UTC).thumb.JPG.797626e62485579bfa55adf7775c804c.JPG.bbcd3830c3e5b6307ab0ce64580c3d06.JPG

This is a TR4A look at where the carbs are in relation to the valve cover

 

The correct inlet will put the tops of your carbs. in the 'Crown' of the dome, and solve your issue.

 

John.

 

 

 

No its not John thats a Peerless.

Stuart.

Edited by stuart
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.