Considering engine swap in the Brum

Silverbullet · Post by **Silverbullet** » Sat Mar 30, 2013 3:39 pm

Thank you Jonno! That was the problem, the positive power was the black wire

Now going through the resistor then to positive side and I figured out the other wires judging by the plastic caps on them

She runs!!!

First crank and it fired right up. A bit off since the timing was about 10 degrees ATDC so out with the timing light. Don't want to get it up to op temperature just yet as all the gasket goo is still quite fresh but I'm pretty happy with how it's going so far

And no petrol, fumes or coolant sprayed out! Bonus!

steptoe · Post by **steptoe** » Sat Mar 30, 2013 3:48 pm

woo hoo , didn't have fingers crossed for you - didn't need to eh ?

New points and condensor in the dizzy or just an old set?

Silverbullet · Post by **Silverbullet** » Sat Mar 30, 2013 3:50 pm

I did test the rest of the wires too, there's no more circuits between them apart from the power wire.

Points and condenser are quite new, dizzy cap is new but leads aren't. I think I'll replace them next.

Silverbullet · Post by **Silverbullet** » Sat Mar 30, 2013 6:26 pm

Just went for a drive, it's so much better. And the only issue is the temperature gauge doesn't come up; a switch/sensor issue as the engine definitely get's up to operating temperature. It drives so so so much better than before and actually has some get up and go with absolutely no flat spots or carbie issues like before. Got it onto an 80 zone to make sure the secondary opens up and it does, still makes 65 easy in 2nd gear. Also most of the vibration is gone and it no longer shakes under load, there's still a little shuddering some times I think that's the drive shaft/hub problem poking through.

So relieved, I now have a much more driveable car and don't need to spend the rest of the weekend fiddling with it! yipppeeee!

steptoe · Post by **steptoe** » Sun Mar 31, 2013 7:40 am

GREAT STUFF - now, what sort of mods - a weber ?
Saw a weber on a tidy Brumby the other day with an electric choke mechanism - the ECM was squished up against one lead terminal insulator boot of the dizzy cap.The adaptor plate had some aluminium saving design with the carby to adaptor threads in a boss cast on the ends rather than a larger overall adaptor plate.

Silverbullet · Post by **Silverbullet** » Sun Mar 31, 2013 12:25 pm

A Weber one day maybe, not any time soon though

There's still something not quite right with my ballast resistor wiring, it works fine but gets far too hot for my liking. I think there's a wire the wrong way round somewhere. *Edit* so I just checked and the positive power changes depending on if the engine is running or when first starting up. I think I read somewhere the ballast resistor is only supposed to be used when first starting up? Then when it's running the power switches to a different circuit...well I tried swapping them over and it still starts up, but there is still power going through the resistor when running

It doesn't seem to get hot though. It seems to idle alot worse too.
*double edit* Scratch that, the resistor is supposed to be active when engine running, inactive at first startup to give the coil more juice. So I had it right yesterday but my resistor still gets too hot to touch. Hmmmm, dodgy old resistor? It is pretty old, I'm kinda worried about it failing on the way to/from work one day since it would leave me totally stranded.

And does anyone know which sensor controls the temp gauge? Is it the one next to the thermostat housing or the one at bottom of radiator, just hoping I don't have to drain the rad again.

steptoe · Post by **steptoe** » Sun Mar 31, 2013 4:18 pm

think it is something like " the points system is to run on ~9V, and due to starting voltage drops (with the starter load causing that drop) the coil still sends out nice healthy spark when starting, not a weak spark supposed to work on 12V. Think you will be surprised the heat the resistor gives off - hence the ceramic surround ! Doesn't explain why the resistor does not drop voltage further though does it ?

littlewhiteute · Post by **littlewhiteute** » Mon Apr 01, 2013 6:37 am

tambox wrote:Valve clearances quiet = small valve clearance = good compression = crap power.

A small clearance is still a clearance. Even 4 thou hot.
A tight or riding valve gives low power AND a poor compression reading.
Good compression does not equal crap power.

tambox wrote:Valve faces and valve seats wear, closing the valve clearances.

That is true to a point.
The rest of the valvetrain is also wearing: cam lobe, lifter face, pushrod end and cups, rocker arms, valve stem tip etc.

By the time it all adds up, technically the clearance should remain fairly constant between scheduled valve clearance check intervals.

Clearances that need constant adjustment proves abnormal wear is occurring at some point in the valvetrain.

Clearances that go tight would be valve recession, clearances that go loose would be lifter/cam lobe, and/or rocker/valve stem etc.

Silverbullet · Post by **Silverbullet** » Tue Apr 02, 2013 8:16 pm

4 thou hot, hmm that translates to .1mm...that's sounds like alot to me but I guess I'm used to playing with .01 at work

Well, it happened. I wasn't convinced with the "they should be hot" talk about ballast resistors and I was right. Broke down about an hour ago on a steep up-hill narrow winding road in the dark

Going up the hill with high-ish revs she started to miss, big time. It was exactly the same symptom I got before I replaced my coil but 10 times worse. Eventually it just crapped out and would not start again. To nobodies surprise the resistor was red hot and while I was poking around under there on the side of the road a very nice man who lived on the other side who admitted he knew nothing about cars but offered to let me use his driveway to get off the road. A few minutes later the resistor had cooled off and it started and got over no problem at all. Another 10 minutes later Dad arrives with jumper leads and a spare battery (I originally thought the battery was flat because it wouldn't even turn over) not needed in the end as the resistor was cold again, start her up and got home 5 minutes later.

So a new resistor is first on the list of things to get tomorrow, god forbid if this had happened on the way to work when there's nobody home and with me on the other side of the city, could have been alot worse. And after meeting Peter a piece of my faith in humanity is restored

Anyone know how many Ohms they are? 1.4?

steptoe · Post by **steptoe** » Tue Apr 02, 2013 9:27 pm

what is an ohm ? I know stuff all about electrical things on cars

OK, I have felt them hot, even seen them glowing red too and recall nothing else though
I think I read you were using a points coil ? Does not say use with igniter does it ?
Or is it aftermarket coil?

Once had old Jap on points that kept ashing up yellow - all that stopped when I fitted a second ceramic resistor from a wreck, can't recall if I got success running it in series or parallel - but screamed for six years after

Sorry if I was the one responsible for giving you a bum steer on hot resistors

steptoe · Post by **steptoe** » Tue Apr 02, 2013 9:33 pm

my cammed EA81's were set at 4 thou hot and could still clatter a bit when cold, maybe their new profile allowed 4 thou, factory 10 and 12 cold made it sound like a chaff cutter from the early 1900's !

Silverbullet · Post by **Silverbullet** » Tue Apr 02, 2013 10:13 pm

Hehe nah it's not your fault Jonno, pretty much everywhere I looked said it's normal. But this resistor is untold number of years old and although there isn't much to go wrong it's the only thing that hasn't been replaced out of the ignition system since I've had this symptom (misfiring) No igniter required, just resistor.

Silverbullet · Post by **Silverbullet** » Wed Apr 03, 2013 9:59 am

I'm beginning to believe something else is going on here, maybe I should just give up and go to electronic ignition with no resistor...

So I got the replacement today, a universal type with spade connections. Hooked it up and started the car...runs fine. A few seconds later there is quite a bit of smoke emanating from the resistor coils underneath...this doesn't look good

I had nothing to lose so I left it running. Smoke coming off for a good few minutes and the resistor getting as hot as the old one. The car never hiccuped though and the smoke stopped eventually, the coils underneath were pretty much black by now. The old one never hiccuped either until I was going up a hill so this wasn't a very good test.

Out with the multimeter and there's 14V going into the resistor, 10V coming out. 14V at the alt too, which I think is normal? Urrrgh, I'm getting sick of this. It's a problem that's followed this engine from the bullet and still hasn't found a resolution. Having rebuild the carb, replaced the coil, leads, cap, rotor, condenser, points and plugs it still persists. Then the new resistor is smoking and getting hot I don't trust it one bit.

tambox · Post by **tambox** » Wed Apr 03, 2013 11:11 am

When you say 14v is that at idle?
If you rev it, does it go past 14.4?

Silverbullet · Post by **Silverbullet** » Wed Apr 03, 2013 12:07 pm

14.15 at idle, max 14.2 when revving, measured at the resistor input. This is the alternator originally out of the ute, had this same problem with a different alternator.

steptoe · Post by **steptoe** » Wed Apr 03, 2013 4:10 pm

two resistors in series ? smokin' and getting hot almost says a short somewhere ? - like putting a bike spoke across a batterys' terminals, can melt them to white hot or DANGER WILL ROBINSON - blow the battery casing spitting eye burning acid in your eyes or someone elses, blinding you and burning skin.

Just how is the wiring in the dizzy of the points and condensor, nothing just lighlt touching somewhere? Is there a bad earthing nut to dizzy body with a wire rope lead on it needing attention ? Subtle little errors can happen in the old points dizies somethimes. check in there with multi meter from points to body etc ?

Silverbullet · Post by **Silverbullet** » Wed Apr 03, 2013 5:37 pm

Just tried 2 resistors in series, and it sure dropped it down to 9V alright, and perfectly replicated my misfire symptom, straight away no hills needed. So that idea is out the window. With the new resistor 14V goes in and pretty well 11V comes out

maybe too low resistance?
There aren't any short circuits anywhere from what i can tell, all wiring in the dizzy is good.

I'm just about fed up with this, if it still shows the symptoms over the next 2 days I'm putting the electronic dizzy in Saturday morning with electronic coil, and no bloody resistor. For now I just bolted the new next to the old and left a screw driver in the glove box so I can swap the leads over if I'm stranded again.

I give up

Subydoug · Post by **Subydoug** » Wed Apr 03, 2013 7:57 pm

So your engine is missing when the coil voltage is above 12v? Double check all the lead connections to the plugs. I replaced my stock coil in my wagon, but the coil packs too much punch and its arking out somewhere it shouldnt. Best to have a look at night. Mine is better now that I have the correct ballast resistor but it still misses every now and then. New leads, cap and rotor button would probably help out. You could also try plugs with a smaller gap.

Opps, realise you replaced all that already. I would just wire up the essentials. Power to ballast resistor, from resistor to coil +. Points to the other -ive side and thats it. Coils can draw a bit of current, something like 3 amps from memory. That shouldnt fry that resistor.

Regards

Doug

Silverbullet · Post by **Silverbullet** » Wed Apr 03, 2013 8:35 pm

I think it's more like it misses when the coil voltage is below that, at 9V it misfired heaps. Then I've read a full 12V fries the points, and there's 11V coming out of my new resistor which gets too hot to touch (still don't know if this is normal) and emitted smoke on first usage.

Does a resistors "resistance" increase the hotter it gets? One theory is during higher revving i.e up hills mostly the ballast gets hotter, increases resistance and delivers less than the required voltage to the coil causing my misfire. Last night when I pulled over and let it cool down it started up again and didn't misfire all the way home (down hill) And if any of my fiddling about or this misfire has caused damage to the coil then it could be a combination of the two

phantomD · Post by **phantomD** » Wed Apr 03, 2013 9:05 pm

No way that resistor should be getting that hot.

The resistor getting that hot would not normally be an indication of failure of the resistor but of an overly large amount of amperage (never mind voltage) going through it. It's like you have some sort of short happening on the other side of the resistor that's also causing poor ignition.

Definitely have a look at night and see if you can see any sparks flying in the dark. Also check all wiring and ground connections VERY carefully.

Make no mistake this is probably not a problem with the resistor.