The Triumph Dolomite Club - Discussion Forum

Tonight's job was to do a leakdown test. I have to admit that I haven't done this before and despite doing a lot of reading up on the subject I'm not 100% familiar with it so I'll go through what I did, followed the instructions of course and let Jeroen or anyone comment.

I removed the cam cover so I could easily see when each cylinder was at TDC on the compression stroke, I also removed the expansion tank cap, dipstick and air cleaner. The reason I did this was so I can hear for any air leaking past the inlet valves (through the carbs), exhaust valves (from the pipe), rings (dipstick) and the head gasket (bubbles in the expansion tank).

Everything looks ok under there, a bit dirty but the cam is in good condition.



Set the engine to TDC on number 1 cylinder on its compression stroke.

I set the air pressure on the compressor to 60 psi (the instructions said anywhere between 7-100 psi).

Screwed the adaptor hose into number 1 cylinder

Connected the unit to the air supply and set the cylinder leakage to 0

Connected the adaptor hose to the measuring unit, noted the results.

I did the same for each cylinder in the firing order 1-3-4-2

These are the results.

Cylinder 1



Cylinder 3



Cylinder 4



Cylinder 2



If I have done everything correctly the the readings look very good indeed and show that the internal condition of the engine is sound. I did this twice and got the same readings, the inlet pressure looks consistent as well. Jeroen, what do you think. Have I done this correctly?

I would try it at operating temp and a different pressure again. 4 bar you can try. The results look ok. When they are consistent at different temps and test pressures I think you have a good engine.

Jeroen

Thanks Jeroen, I'll give it a go tomorrow.

Hit it with a hammer he said, well he actually may have said 'give it a tap' erm... Now the front silencer joint has a crack in it and the exhaust is properly blowing now!

To be fair, I didn't hit it hard and a speedbump could have done the same thing, so I need to order a new exhaust.

I was fed up with deliberating over electronic ignitions and just went and bought the Lumenition system as I have always got on well with them in the past.



I wont be installing it before I am happy that the power issue is sorted out.

On that note I did another test with the engine up to temperature as per Jeroens advice and the results were exactly the same, if anything marginally better. I upped the pressure and the results were the same. Double checked everything was working properly and it is so I think I can safely say that I have a good engine.

I didn't bother taking photos when I increased the pressure.

Cylinder 1



Cylinder 3



Cylinder 4



Cylinder 2



The next thing to do is get the new exhaust on there and see what difference that makes.

In the meantime the top end was a bit noisy so I have left the car to cool so I can check the valve clearances.

James467 wrote: ↑Tue May 23, 2017 2:14 pm I was fed up with deliberating over electronic ignitions and just went and bought the Lumenition system as I have always got on well with them in the past.

I wont be installing it before I am happy that the power issue is sorted out.
In the meantime the top end was a bit noisy so I have left the car to cool so I can check the valve clearances.

Great choice ! You won't have many problems with that one.
Tony.

I lost a Magnetronic unit because of the ign coil I had, does this apply to the Optronic units ?

Mahesh wrote: I lost a Magnetronic unit because of the ign coil I had, does this apply to the Optronic units ?

I don't think so, I cant see how the coil could kill it unless it was wired up wrong. They do a coil for it but as long as the coils good I think it's OK.

Technical question for everyone, I'm looking to swap out the mechanical fan and fit an electric one, once everything's working of course. There looks to be a point on the rear of the head on the jacket/plate where I could mount a temperature sender for the fan and just wire it through a relay. Is this a good place to put it? Or how about this, as this is the hottest part of the head should I move the temperature sender there (as it's probably always going to be submerged) and put a fan sensor where the temperature sensor would normally be.

Or is the best place for the fan sender in the top hose?

I'd buy one of the Revotec pipes which as the sender in, you then clamp your top hose to either end. Won't leak like the Kenlowe bulb design. You want to cool more efficiently than the mechanical fan but you must be careful not to over-cool it either. I would imagine the top hose is a good place to start.

We sell the Revotec things at work but are widely available. Here's the link so you know what it looks like

https://www.bighealey.co.uk/Austin-Heal ... ng/CHT142A

Given how long the car has remained unused I imagine the cooling system must be pretty crudded up?

James467 wrote: ↑Wed May 24, 2017 3:12 pm

Mahesh wrote: I lost a Magnetronic unit because of the ign coil I had, does this apply to the Optronic units ?

I don't think so, I cant see how the coil could kill it unless it was wired up wrong. They do a coil for it but as long as the coils good I think it's OK.

Technical question for everyone, I'm looking to swap out the mechanical fan and fit an electric one, once everything's working of course. There looks to be a point on the rear of the head on the jacket/plate where I could mount a temperature sender for the fan and just wire it through a relay. Is this a good place to put it? Or how about this, as this is the hottest part of the head should I move the temperature sender there (as it's probably always going to be submerged) and put a fan sensor where the temperature sensor would normally be.

Or is the best place for the fan sender in the top hose?

On the sprint i made a new plate to go at the back of the head,which im going to fit a hose tail to have water going in the back of the head, also use a capillary tube for the temp gauge,there's no reason why you couldnt do the same on the 1850, stags have the same water transfer housing

Dave

The lumenition optronic cannot switch a wrong type coil and does fry itself. It does need a blue bosch or a red bosch with ballast resistor.

You can ofcourse use an inferior coil of your own choice but make sure the resistance is ok and around 3 Ohm or more in total.

In other words, a ballasted type coil without the ballast resistor does damage the optronic module.

All is mention in the fitting manual.

You can fit a 4 or 5 amp fuse in the purple wire to coil minus to protect the module for too much current but then you have to be sure your chinese manufactered spade or glass fuse does blow at those amps. Most chinese blade fuses are the same amps but only differ in colour....

Jeroen

Well that's sorted that out then!

Good idea with the fuse, I'll do that.

Jeroen, what's the part number for the red coil? I know you told me on Facebook once but I don't have access to that group anymore!

Is it one of these?

http://www.burtonpower.com/hp-coil-bosc ... 19030.html

Yes. But the best is to use it with a seperate ballast resistor which you can measure properly.

When all fitted you can even measure the amps going through the coil and resistor with a multimeter before connecting to the module.

Jeroen.

Thanks Jeroen, yes I am using a separate ballast resister already, actually the one I'm using is a Lumenition one so should be fine.

I'll get that coil ordered.

Oh and thanks @Mahesh for pointing that out!

Magnetronic module lost because of Lucas sports coil.
Lumenition MS3 coil lost due to contacts and condenser
(possibly just faulty coil)

Now on Magnetronic with MS4 coil.