[MrRocky]

i would upgrade the ignition system for lpg fuel such as these
http://www.rocky-road.com/zukmsd.html
and this may give you more insight to your timing issues
http://www.acl.com.au/web/acl00056.nsf/ ... enDocument
having the head skimmed to raise compression on a standard engine 3/4 of a point is about as far as you can go on 98 octane fuel without detonation (and pistons hitting valves) so you should be fine to do this on lpg which is a higher octane. The guy that did mine charged me $50 and is in bayswater. Gave a heaps bigger gain that fitting a webber ever did on mine.

[Che]

I think i'll do along the lines as you suggest Royce - but strip motor back to a bare block, get all the machining done, then order parts and rebuild from there as the new clearances are known and money trickles in. I won't touch the head, someone else can do all that - it's too tricky for me.

Believe me i've read, read, and read some more... then I discovered youtube has just as many good videos. Reading done was mainly on pulling apart and rebuilding US V8's, on youtube there's an MX-5 engine rebuild: a much better guide as it's a closer design to the motor i'll be rebuilding. I've now got a handle on how to ID upper, lower and thrust bearings, correct torquing procedures, and a heap of other things I didn't know this time last week. Cam bearings look like the trickiest thing to get right.



As for timing correction - Is that MSD thing somehow a dizzy replacement? I was looking for this type of thing the other day but came up empty.

[Che]

I got a problem... seems nobody can re-curve a dizzy in the west.

What are my options from here?

[MrRocky]

no-one can grind you a cam here either

[Teracis]

che_guitarra wrote:

I got a problem... seems nobody can re-curve a dizzy in the west.

What are my options from here?

I know it's a long shot but if you could find out what kind of advance you needed maybe something could be done by fitting some kind of restriction or jet in the vacuum line to the dizzy?

Or some kind of lever setup from the vacuum advance actuator?

Or maybe a stronger spring acting against the actuator?

I know if would be hard to get correct but how do they actually re-curve a dizzy? Maybe you could just look into how it's done and do what's needed yourself?

If it's a huge technical job that you need a dyno e.t.c for then I apologise for the silly ideas, I was only suggesting on the premise that you already knew the desired curve you were looking for.

[royce]

Parts and machining are difficult
You cant machine the bits without the parts, cant get the parts without knowing what size you need so it works like this

take block, crank, rods to engine guy, he measures and tells you what sizes will see you clear, for piston oversize and bearing undersize so all the machining is well into new material

then if you want to go get teh stuff you take them numbers and get some gear, dont worry its all standard incerements

get your gear and take it back, engine man will then measure it all with very precise gear, gear youll never afford or need again so him doing it is good value, then machine the bits to get the tolerances exact, to suit your gear, mass produced engines are done to a nominal tolerance but we want better than that (not really any dearer to do it this way)

Once the machining is done he will need to put some stuff together to triple check clearances so its worth having him do the assembly, gap the rings, fit the pistons to the rods, stick em in the bores, fit up the crank, fit the caps and torque it all up and recheck it, its the most simple yet critical part of an engine rebuild, without the right gear you jsut cant do it

we dont have cam bearing like a V8, same engine guy can likely do your head, give it a clean and skim and recut the valves and seats and so on

Ask Ben_Sierra about teh dizzy, youll need a dyno guy that does old engines, he is around speedway stuff so might know somebody

[Che]

Thanks for the help peeps. Royce, you're worth your weight in gold, I appreciate a decent answer - saves me asking the five next questions

I've seen a few vids on timing - this is probably the best http://www.youtube.com/watch?v=MyUwWUNJVpA It shows how to re-curve a dizzy right at the end... try it at your own risk

[JrZook]

Due to the difference in burn rates with LPG im pretty sure you need to dial in more low rpm advance and less high rpm. Zuk dizzy should have two springs in it, one high tension, one lower, corresponding to the advance given at high/low rpm respectively. You could play with these but without a dizzy graphing machine it will be a bit of trial and error

[MrRocky]

your welcome

shultz auto electicians can re graph dizzys i have it on good authority

they are in perth too

[royce]

with dizzy recurving its simple but something you need experience in to get jsut right

if you need less total advance, IE you want to run more at idle but same at higher revs or less at higher revs or whatever, there are stops in teh dizzy you adjust (normally weld shut a bit)

then to change the curve, IE how much it advances at a certain revs there are springs and centrifugal weights inside, the weights moving out make the plates advance and the springs resist how much they come out, so a stiffer spring will make the advance rate slower, softer spring brings it in faster

[Che]

Interesting... just pulled the rocker cover off my motor to rebuild

[Gwagensteve]

That's normal

Steve.

[Teracis]

Gwagensteve wrote:

That's normal

Steve.

To have a loose screw floating around in there?

I'm guessing that's what was being touted as interesting?

I should pull the other motor I have apart, I'm still trying to decide whether to rebuild the 1.3 and carby, or go the efi route.

[shep]

Gwagensteve wrote:

That's normal

Steve.

haha i have never seen one that didnt have at least one loose screw.

[Che]

Yeah - first looks I thought they had sheared off, glad that's not what's happened.

3 others were loose... coulda been a nice shebang if the whole bank came off.

[Damo]

shep wrote:

Gwagensteve wrote:

That's normal

Steve.

haha i have never seen one that didnt have at least one loose screw.

Yep, i'd be more suprised if all those screws were in place.

[Fatzook]

shep wrote:

Gwagensteve wrote:

That's normal

Steve.

haha i have never seen one that didnt have at least one loose screw.

Seen it 3 times now. I centrepunch the edge of the screws to stop that happeneing

[Che]

I got an alternator here on my rebuilder engine - looks in pretty good nic, just a bit grubby. Any maintenance I can do to it before it goes back in the engine bay?

[royce]

stick it on the shelf and use the one you already have, at least you know its ok and is one less new engine drama to chase down

[Che]

Good idea. I'll clean it up a little and sit it back on the shelf

[Che]

What dyer reckon a custom cam for a zook would cost? Just found the sweet link on rebuilding a donk for LPG http://www.gasresearch.com.au/epg.html it recommends I get a cam with longer exhaust durations.

I'll call around tomorrow anyway... just wondering if anyone knows how much in the meantime

[royce]

tighe cams in brisbane, ring em but they arent dear

[Che]

Now you see it


Now you don't


Now to source a 50mm throttle body from the wreckers, and build an adaptor plate.

[Teracis]

Good to see you're going the throttle body option! Surely this will remove some of your carb issues?

[Che]

We'll see

It'll certainly remove about a kilometre of vacuum and water hoses and simplify things that way, but it'll mean I need to sort out an upper and lower adaptor plate, and i'll probably need to mod the throttle cable.

Pulling it off is half the fun though

[shakes]

On my leyland p76 motor I went from running an mixer ring with 350holley to a TB from a VT 5 ltr with the same ring, didn't improve power a whole lot, but got rid of that "spongy" unresponsive feeling you can get with gas. then went to a better style of inline mixer and that increased power in a large way.

I cant find any photo's just quickly but making my gas adaptor dealy....

I found a mandrel 3" 90* bend, two bits of 10mm ally plate, cut the plate to the correct shapes using a holesaw trimmed them neat with a grinder. Welded the bend and flanges bolted up to the bench to minimise distortion.

Your local gas place that does gas research style stuff wil have a huge box of old throttle body's that they keep for spare parts. They may have an adaptor to suit a weber/holley flange to 90* to a TB of some sort. Which may save you some issues. or give you another option to confuse things more.

Hope all that made some sort of sense.

Simon

[Che]

Good one Shakes - totally forgot about those inline mixers

When I first got the install I wanted the Impco mixer from the Gotpropane.com zook kit, but old mate installer-man convinced me otherwise

A one piece solution is the way to go - the simpler I can get it the better... beats a sandwich of bits and pieces doing the same thing.

[shakes]

Doing it again, I would look seriously at gas research carbs. Last time I went the tightass option with 90% of the power, alot more dicking around but 1/4 of the cost.

They could of sold me a pre made bend to bolt to the holley intake mani.
a TB and mixer in one which cleaned up the engine bay heaps. and can be "jetted" to suit your motor. Was ending up somewhere around $600 before tuning. My option cost $180 plus a couple of days messing about.

Whether they make something that would be suitable for a 1.3 I have no idea as I've never really read up on gas tuning/sizing.

[Che]

shakes wrote:

Whether they make something that would be suitable for a 1.3 I have no idea as I've never really read up on gas tuning/sizing.

Nah, Gas Research is aimed at V8 solutions.

[shakes]

Thought as much. Could be worth removing absolutely everything from your carb and sealing it up. Or do you want to make a project of it all and make a new intake system for the new motor?