19 replies to this topic

[Ricester]

Hey again, A quick summary of whats happened so far: Fresh rebuilt engine by myself. CSI electronic distributor. HS4 carb. 998cc with 12g295 head, Swiftune SW5 cam. Engine hasnt been ran in yet owing to overheating and timing issue. CSI distributor states to install and set static timing at TDC. Instructions state rotate distributor anti clockwise until flashing LED, then slowly clockwise until solid LED then lock down. Distributor rotor arm is pointing to cylinder one. Done. Cylinder one is on its firing stroke, rockers are loose and cylinder 4 rockers tight. distributor drive dog is right way round. Distributor drive spindle is right way round and also pointing to 2/8. Engine labours on starting and revs climb and fall, uneven running. Will only continue to run when choke is out/above 1,400 rpm. Any lower and revs dip themselves until cut out. If car is ran for 5 minutes or more, car will quickly overheat, temp goes to "Hot" on Dial (88 degrees thermo I think) and I turn it off. Good spark, fuel getting through carb no problem now. As previously advised Ive been assuming and investigating timing. Ive got a Sealey strobe. I am unable to have the car sit at 1000rpm idle as it cuts out if it dips lower than 1,400 or so rpm. My Sealey strobe is also able to tell me my degrees of advance, I have no idea how it does this (!) but it can. When the car is at around 2,000rpm (Will move around a few hundred rpm) or at any rpm, I cannot see my timing marks on the pulley. I was initially doing it outside but just to be sure, I done it in the dark in my garage and they arent there. This is presumably as timing is miles out. My strobe, at 2,000 or so rpm tells me my degrees of advance is 67!!! I suspect the overheating issue is a result of the timing problem so in trying to solve that first I have two issues; 1) why is my timing so wildly out, I believe Ive done everything exactly as I should have, what have I missed? and 2) how do I fix this. Thanks for your help, happy to take some pictures if someone can spend the time helping me. Ive been struggling with this issue for over 4 weeks now and really need to get this car on the road and some load through the pistons before the next issue.

[nichmoss]

If you suspect the timing with the new electronic distributor, have you considered refitting the original distributor? At least this might give some pointers to the issue. If all is well with the original, then you can set the car up and afterwards retry the CSI.

Good luck, Chris

[Ricester]

If you suspect the timing with the new electronic distributor, have you considered refitting the original distributor? At least this might give some pointers to the issue. If all is well with the original, then you can set the car up and afterwards retry the CSI.

Good luck, Chris

Thanks Chris, I have no original though. The car was a non runner when I bought it 5 years ago. 

[nichmoss]

Ah, fair enough, that's unfortunate.

You say the CSI distributor is set up correctly but you feel there is 60+ degrees of advance as shown by the Sealey strobe. If so, then why not just loosen the pinch bolt and rotate the distributor by hand when the engine is running? This should let you get to a point where the advance has been tamed.

The distributor supplies four pulses (each cylinder) for one revolution which corresponds to two revolutions of the engine. So, you'd expect to turn it half the amount you want. If you want to reduce the timing by 40 degrees, you'd turn the dissie some 20 degrees. The rotor turns anti clockwise so to reduce advance, you'd turn the body anti-clockwise which will delay the point when the rotor arm reaches the post. I think that's right but certainly it will be obvious when you start to rotate it and see what the strobe shows. When we were young and lazy, we'd get the engine going like this - have someone turning the engine over while the distributor was being gradually turned until the engine fired.

Hope this helps and good luck, Chris

[GraemeC]

How have you established and set the engine at TDC before installing the distributor?

[Ricester]

Ah, fair enough, that's unfortunate.

You say the CSI distributor is set up correctly but you feel there is 60+ degrees of advance as shown by the Sealey strobe. If so, then why not just loosen the pinch bolt and rotate the distributor by hand when the engine is running? This should let you get to a point where the advance has been tamed.

The distributor supplies four pulses (each cylinder) for one revolution which corresponds to two revolutions of the engine. So, you'd expect to turn it half the amount you want. If you want to reduce the timing by 40 degrees, you'd turn the dissie some 20 degrees. The rotor turns anti clockwise so to reduce advance, you'd turn the body anti-clockwise which will delay the point when the rotor arm reaches the post. I think that's right but certainly it will be obvious when you start to rotate it and see what the strobe shows. When we were young and lazy, we'd get the engine going like this - have someone turning the engine over while the distributor was being gradually turned until the engine fired.

Hope this helps and good luck, Chris

Thanks for this. I had hoped it could be as simple as firing up and turning the dizzy. Ill do that and see what I get. 

[Ricester]

How have you established and set the engine at TDC before installing the distributor?

Hey,

 

By all the methods, literally. A screwdriver down cylinder 1, wedged one wheel while the car was jacked up, had the car in gear and rotated the other wheel until I could see the screwdriver sitting proud and not going any higher. I watched the rockers and saw cylinder 4s were moving while doing this and cylinder 1 were not. I then checked the rockers and felt rockers for cylinder 1 were loose while 4 were tight. I then checked the pulley and saw the mark on it indicating TDC and it was slightly off. I rotated the wheel slightly again until I got TDC on my timing marks on my timing cover. I then checked the flywheel which Id installed and could see the notch indicating TDC. 

[GraemeC]

OK that sounds good.

 

I've just looked at the Swiftune instructions for the CSI and it says to set the engine at 10 degrees BTDC before installing the dizzy, wonder why they say to do it differently/

Could it be you have the CSI set on a strange curve?

Edited by GraemeC, 19 April 2023 - 04:05 PM.

[Ricester]

OK that sounds good.

 

I've just looked at the Swiftune instructions for the CSI and it says to set the engine at 10 degrees BTDC before installing the dizzy, wonder why they say to do it differently/

Could it be you have the CSI set on a strange curve?

That is interesting. I know CSI make "switune specific" distributors, but I wasnt sure if that was maybe just a marketing thing to get you to buy a swiftune one (cost slightly more than minispares). The instructions I have say set it at TDC for installation and 10 degrees BTDC at idle (600-1000rpm). 

 

I selected curve 1, which seems to be the most unoffensive curve with a max advance of 30 degrees. 

 

I have since gone back to the car with the strobe and my reading was wrong (67 of advance), I was actually miles after TDC. I only became aware of this when I began rotating the dizzy clock wise and could see the markers coming back the way. As I rotate the dizzy clockwise to advance it, when I get anywhere near TDC with the strobe on the pulley marker, there is some knocking. When I get the pulley marker to go before TDC, the engine labours extremely, with knocking, and will cut out. Still with the overheating. It also looked like I was getting two readings with the strobe. Again this is the first time Ive used this so bear with me, but the marker on the pulley was jumping from two different places. Sometimes it was before TDC and sometimes it was after, despite the revs not changing. 

 

Im really at a loss now. 

[GraemeC]

Just to check the obvious, and in no way questioning your ability, you are using the cylinder nearest the radiator as cyl 1 and this is also the lead your strobe is clamped around?

[Ricester]

Just to check the obvious, and in no way questioning your ability, you are using the cylinder nearest the radiator as cyl 1 and this is also the lead your strobe is clamped around?

Thanks, no I appreciate it as my ability does repeatedly need questioned! Yes, Cylinder 1, the one closest to the radiator. Thats the lead the strobe was clamped around. 

[nichmoss]

I'm not aware of the CSI distributor but it looks like a similar idea to the 123 design. I use one of those on a sixties Jaguar and there are different models (some Jaguar specific). As I recall, some are set at TDC with the LED and some at 10 degrees BTDC so, it may be that the Swiftune Mini one has a different setup. We get a bit blinded by these things but really, it is just replacing the points and the springs/weights that control the advance - in all other respects, it's just a dissie.

I would check that the leads are in the correct order (I know, seems obvious but we've all done daft things). Try the strobe on each lead in turn and see if it flashes as that will confirm that all cylinders are getting a spark. Check the rotor arm is on properly as well and that the cap is correctly fitted.

Forgetting the strobe, can you just turn the dissie until it runs smoothly - either direction just so it runs. It's been thirty years since I built an A series so I don't know if you can get the distributor drive out by some varying degrees or something? Is it possible that due to a build error, you should be timing on another cylinder? Someone on here will know.

If you can borrow another dissie, try that. In the end, if you can't get it to run then it would be worth checking the cam timing I suppose and so on...

Good luck, sure you'll get there, Chris

[nichmoss]

Sorry, I meant to say that your timing light may be the issue. It can't tell you the advance unless you are setting it to the TDC mark so it can't tell you the advance is 67 degrees when "I cannot see my timing marks on the pulley"

Usually, there is a knob on the back which you turn when the strobe shows the flash at exactly TDC. Then you read off the back of the strobe how much the advance is. If you have turned the knob then it may be that your strobe is applying its own advance/retard to the flash - obviously not to the engine. Do you know the model of the strobe?

Not sure if that's clear. You don't have a simple strobe as well do you?

Cheers, Chris

[sonscar]

Set the strobe to zero and read the timing off the pulley.As mentioned the TDC mark is always illuminated by the strobe and the advance read off the dial when more advanced readings are needed.Steve..

[Ricester]

Set the strobe to zero and read the timing off the pulley.As mentioned the TDC mark is always illuminated by the strobe and the advance read off the dial when more advanced readings are needed.Steve..

"set the strobe to zero"... such an innocuous unassuming line.... 

 

So Id had the strobe set at full advance, hence I wasnt seeing my pulley marks when the strobe triggered. You live and learn - thanks for the advice. 

 

SO Ive now been able to time it in. However I have the same issues as follows:

 

1) I cant put the choke fully in or the car dies. Itll sit at around 1400 rpm with the timing being 12 degrees btdc but any lower and it slowly cuts out. 

2) Its still overheating. Within 5 minutes of idle running at the above, temp gauge goes to "hot". Engine doesnt feel overly hot but the radiator top feels fairly hot. 

 

I presume these are now two separate issues.

 

Issue 1) Can anyone advise what to check here? Ive already fully stripped my carb twice now. The needle is straight and seats properly, the carb has had a service with new jet and gaskets etc, dash pot oil is the SU oil and fully filled up. 

 

Issue 2) this is a complete newbuild. New temp gauge, sensor, indicator, loom etc. New water pump, hoses. Could I have created an air lock and how do I test for that? Would it result in the engine gauge going from cold to hot in 5 minutes of running? 

 

Thanks again for your help,