Jump to content

Engine re-build and backfire


Recommended Posts

Jim

Believe me it matters not a jot where the drive dog is, or what Haynes or any other book says. PROVIDING: when #1 is at TDC on firing stroke the rotor arm must point to the contact inside the disy cap that holds the lead to #1 cylinder. And then leads to 53624 follow around the cap anti-clockwise looking down.

Do that and it will fire fine unless the 123 is not doing what's on the box.

MU timing is not critical.

Peter

Link to post
Share on other sites

[quote name='Peter Cobbold' timestamp='1307998925' post='21849

MU timing is not critical.

Peter

 

 

It is vital to correct running end of chat. I will play no more part your call from here Peter

Link to post
Share on other sites

It is vital to correct running end of chat. I will play no more part your call from here Peter

 

Neil

The original Haynes manual - which I stll have - printed the diagram on the MU timing upside down! - so many TRs were 'miss-timed' without anyone noticing.

The reason it does not matter is that, particularly at cruise, the volume of air taken is fraction of the volume of the inlet manifold supplying a cylinder. So each squirt serves merely to contribute to an average mixture in the inlet duct. Nor does all the fuel evaporate in the air, some evaporates more slowly off the walls, further negating the importance of MU timing.

MU timing is not what's causing flame in the inlets on Jim's engine.

Peter

Link to post
Share on other sites

Hey Peter,

 

Going to sign off on this now and it's off to TR Enterprises (plan z). Anyway final update is that this evening I did change the drive to exactly like the Brown book and guess what ... didn't make a jot of a difference so you were spot on.

 

Once again many thanks to you and everyone for their advice. I think we're all lucky to have TR Register especially us new Guys just getting into the joys of Triumph. All the best :)

Link to post
Share on other sites

Hey Peter,

 

Going to sign off on this now and it's off to TR Enterprises (plan z). Anyway final update is that this evening I did change the drive to exactly like the Brown book and guess what ... didn't make a jot of a difference so you were spot on.

 

Once again many thanks to you and everyone for their advice. I think we're all lucky to have TR Register especially us new Guys just getting into the joys of Triumph. All the best :)

 

 

Same to you Jim ;) the Mu will be out :( hey your money good luck

Link to post
Share on other sites

It is vital to correct running end of chat. I will play no more part your call from here Peter

 

 

Interesting this diversity of view. When I had a 6 I was passionate about timing the MU, then I saw Page L22 on the Technicalities CD which opines in support of Peter's assertion. Indeed it makes the further point that some more modern (than the Lucas system) injection systems use non-phased injection to no detrimental effect - Jaguar V12 for example.

Link to post
Share on other sites

Interesting this diversity of view. When I had a 6 I was passionate about timing the MU, then I saw Page L22 on the Technicalities CD which opines in support of Peter's assertion. Indeed it makes the further point that some more modern (than the Lucas system) injection systems use non-phased injection to no detrimental effect - Jaguar V12 for example.

 

 

One can be a small amount out not both :D

Link to post
Share on other sites

If you've got your old distributor why don't you put it back on & see if it runs?

Likewise with your old coil.

 

At least then you will have ruled out the new dizzy.

 

Is the fuel return from the metering unit blocked?

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.