gerg

Engines with short rods/long stroke have very little piston dwell time so ignition timing is critical in that short window you have to play with. What fuel is he running? Some engines can actually go backwards with power before even starting to ping, I've had that on my LPG Corty, when you could hardly tell the difference between too advanced and too retarded (never pinged, ever). It's a very subtle difference but with too advanced, the engine feels a bit rough in the car, like you can feel the power pulses much more. Retarded feels smooth and doughy, and exhaust note gets a bit louder. So the age-old method of "bump it up till she pings, then knock it back a bit" doesn't apply necessarily for all engines and fuels. Sounds like you're pretty chuffed at the performance thus far, and I would be too... And you still have more to come!

351 2V closed chamber never existed! All 351 2Vs were open chamber. The 2V closed chamber head was created for use only on 302 Clevos, exclusive to Australia and were sought after in the states for obvious reasons. Sounds like that 351 had those 2V heads fitted by someone some time in its life. All 351C closed chambers were 4V from factory, but not all 4Vs were closed... Post-'71 US 4V Clevos went to open due to emissions, etc, Confused yet? 2V heads fitted with 4V valves were a very common sight back in the day, and Clevo120Y I think might have tested a set. Seem to recall that he found that increase over 2V valves was ok but not spectacular. without some serious blend work in the bowl, etc I think it's not worth doing. If they're already done, then no dramas.

Top work mate, always interested in your latest mad scientist creations. Have you thought of taking a mould of the prototype in body filler and then making a few from epoxy/glass?

Just on the subject of idle adjustments: not many people are aware of this but ALL 4-barrel Holleys have secondary idle circuits, even the non-adjustable and emissions models. As the secondaries don't get used anywhere near as often, the fuel in that bowl can go stale very quickly, particularly in a hot engine bay. To keep the fuel fresh and flowing at a light trickle, very small idle ports are drilled below the transfer slots. When doing up a carby, these have to be cleaned out as they can easily carbon up being so small.<br /><br />The primary throttle blades need to be adjusted with the carby off so that the transfer slot shows as a little square from underneath the carby. This is to ensure that there is vac signal in that circuit ready to pull fuel in as soon as you touch the throttle. Otherwise if there's no slot showing, you'll get a stumble off idle.<br /><br />If your cam is too lumpy at that idle setting for the engine to run and you need more idle air, don't simply open up the throttle more, as ando76 said, you will lose your idle mixture adjustment because your fuel will be drawn more from the transfer slot, which is a non-adjustable circuit. Instead, try adjusting the secondary blades to get more air in, and if desparate, drill 3mm holes in the throttle blades. An old hot-rodder's trick is to drill through the bottom of the air cleaner stud hole, which opens out into a cavity under the carby that sees manifold vacuum. BG carbies actually came with an idle air screw already in there for this reason.

Make sure it's got "extra zinc" noted on the label. Flat-tappet motors need it.

That thing will be off it's tits

Factory Ford manual says ATF DIII with lubrizol additive. I would use Nulon G70 as a substitute.

Even satan himself runs a mile from them

Sounds like your pilot bearing isn't spinning freely enough, causing your input shaft to turn with the engine, even though the clutch is disengaged. Try this: when crawling along , pop it into neutral then back into 1st. If it goes into gear nicely, then that eliminates bent shift forks or rails. Try the other gears at rest as well.

It's a constant supply (not through acc or ign) so maybe things like radio memory tee off? Normally the courtesy lamp itself gets constant power and the door switches earth it out. Try the wiring from the fuse to the light. Could be a screw or something through it up inside the a-pillar. Has someone taken power for something else like a hands-free kit off it? We used to get shit like that all the time with what contractors had done to our fleet vehicles, like scotch-locks and twist-and tape jobs.

We're all on here mate... As crossy fans, we're dinosaurs and you'll struggle to find a shop that specialises in them. Any mob that can screw together a hot SB Chev or Clevo should apply the same rules to your weapon of choice and get good results.

I'd say the one to suit their alloys has revised port placement (maybe higher?) and/or shape.

Locked dizzies are most suited to alcohol or race-oriented engines like Slydog's with big cams that bleed off lots of low-rpm compression. It just so happens that this allows low-rpm timing to be advanced to the point that it matches (roughly) the high-rpm requirement, so the timing is simply locked at this figure for the whole rpm range and the engine is reasonably happy with that. On anything resembling a daily driver, many more variations must be factored in, like part-throttle response and fuel economy (vac advance), ease of cranking (base timing), and higher-rpm performance (mechanical). All of these parameters are catered for in a factory setup but as you chase more power using cams and compression, etc you find that the factory tune is inadequate. We're not saying all this so you'll reach into your pocket and fork out for a whiz-bang setup that you don't really need. We all have personally seen definite advantages using the various systems we keep harping on about. I like my MSD not because I want to justify to myself that spending 450-odd bucks was worth it, but because I know I can tune that fucker exactly how my engine wants it. It starts and idles like it has no right to, barely needs any choke and I can actually jet the carby down for a bit leaner cruise. The flow-on effect of having a kick-arse ignition is not realised until you actually use one.

Wow what a fucking mess. Hope it's not too worn out or corroded inside. Hope you've got access to new jets, might be worth your while to get a jet kit. I know it's half full of shitty little ones that you'll never use, but with the ones that you can use it still works out much cheaper than buying individual pairs. You could start with the sizes we suggested and go from there.

A mate had himself chasing his tail with an EB XR8 cutting out intermittently. Turned out it was an earth screw terminal next to the ECU that was a bit corroded.<br /><br />I had an EF that cranked but had no injector pulse. Turns out it was the back of the fuse panel being a bit corroded. Sparky gave it a bit of a jiggle and a spray and it came good.

If you're bolting a 4-barrel on, you're not going for economy... Am I right? I should imagine that you'd need something like 64/70 jetting, the reason why so big is that smaller motors don't pull enough fuel through the boosters with standard jetting. Use the lightest secondary spring (white) to get them to open. They probably come with a yellow or purple. Slydog will tell you to turn the carby around 90 degrees so the barrels feed the ports evenly. I think it's well worth the effort of re-drilling the bolt holes and re-routing the cable to suit. Run the spacer if you can fit it. I'd run a 4-hole rather than an open one but I like torque. 570 is pretty big even for a moderately worked engine. You'd have to have it screaming pretty hard before that became your limitation.

here's a little more on them: http://www.ozfalcon.com.au/index.php?/topic/1708-msd-6al-2-programmable-anyone-running-them/

Another wacky idea... Use the sump plug as a banjo fitting? I did it on my corty as the block was out of a Falcon and hadn't been drilled for the Corty dipstick, so i made a banjo bolt, my own dipstick and tube.

Nachos rule..... They RULE! Huhuhuh

Hey folks, seems to be a bit of interest in carbys of late, so here's a tech thread where you can ask about them. Note to mod: is there a better choice of section to put this under, or should we create a new one? This thread would apply to all carby-fed engines, not just Clevos.

Ok easy one that... Your stock dizzy advances the spark timing in relation to both rpm and vacuum. As you modify your engine, the timing requirements change drastically. You could either "recurve" your dizzy to suit (trial and error) or use a programmable ignition unit like those you mentioned. It's still trial and error but the difference is instead of pulling your dizzy apart for every little change you want to make, you can tailor the curves exactly to what your engine wants at the click of a mouse. The ignition unit cannot predict when the spark will happen, so in order to get the spark timed correctly, it retards it back from the maximum you set the timing at. Say the absolute most timing your engine will need is 45 deg. You would set the locked dizzy at that and the computer will hold back the spark to the preset value you've put in. This is why the MSD program only ever mentions "retard" and not "advance" because that's all the computer is doing. The graphs on the MSD program show this too, with a maximum of 30 deg total able to be adjusted. The reason why only 30 is allowed is not because the computer has such a small range of adjustment, but because your distributor cap has only so much distance between terminals. Any more timing variation would cause problems like cross firing between cylinders and spark degradation from having to jump such a large gap between rotor and terminal. So my example is 45 total, and you program your dizzy at a particular point to knock it back by 15 degrees. That makes it 30. Another point might need less again (say when cranking) so you take it back a full 30 deg, that would then be at 15. Are you catching my drift? What I did was go to the MSD site and download the software for free. It's their way of marketing it in a way but it got me familiar with it before buying the product. See what you think.

If by Holley you mean BG or Quickfuel with the screw-in ones?

No probs, helps me understand it better when I explain it to someone else

Ok some teminology: • Advertised duration - the actual length of time (in crank degrees) the cam lobe raises the lifter off the base circle. It is for reference only, and is not the hard-and-fast rule for determining a cam's characteristics. • Duration at 0.050" - the one you should really look at. It's measured when the valve is actually off its seat by 0.050", which is the industry-accepted standard at which air flow is enough to be measurable for this purpose. It also allows for all flex and clearance in the valve train to be taken up so you're actually measuring the end result. • Lift - how far the valve is lifted off its seat. A general rule for crossies and Clevos, anything much over 0.500" lift needs roller rockers and good valvesprings/retainers. If you go heavier with valvesprings, then your flat tappet cam and lifters will wear out more quickly. This is why we say plan your engine well from the start so you don't build it twice. • Overlap - on an engine with good breathing ability (ie bigger carb and extractors) there is more scope for the cylinder to be "scavenged" by using the inertia of the exhaust gas rushing out to create a vacuum in the cylinder to pull in more inlet air/fuel. This happens when both valves are slightly open at the same time, due to a longer duration of each cam lobe. This is called "valve overlap". It is most beneficial at higher rpm when there is less time for things to happen. A larger overlap at lower rpm gives over-scavenging, where under load, inlet charge can be pulled straight out the exhaust, unburnt. Also kills idle vacuum because exhaust gas is being sucked back in to the inlet manifold with both valves being open for so long. So less overlap = more tame street manners • Lobe Separation Angle - drawing an imaginary line at the halfway point of each lobe, and measuring the included angle of these lines between inlet and exhaust gives you this number. It can alter the "personality" of your engine as much as any other aspect. For a given duration, a narrow angle gives a lopey idle and narrow rpm band, lots of overlap, is more "racey". Needs more compression as some cylinder pressure is bled off. A wider angle gives more sedate low-rpm behaviour and a wider torque curve, but needs less compression as cylinder pressure is higher (less bleed-off). A narrow LSA would be 106 deg, a wide one would be 112 deg. This is not necessarily a way of determining overlap but is an indication of where the "meat" of the valve openings occur. • Advance/Retard - adjustable via multiple keyways on your cam sprocket, this aspect will raise or lower the rpm at which your cam will work in its optimum torque band. Advancing brings it on earlier, retarding brings it later. Sprockets are mostly made with +4, 0 and -4 deg keyways. Most cams should be installed "straight up" (0 deg) unless you're looking for a particular characteristic not available with any other choice in cam profile. They've done the homework for you so it's best go with their advice. • Hydraulic/solid - cams are ground with different lobe shapes. Solids have a gentler ramp up than hydraulics to ease the shock on the other components. Hyd/solid cams are not interchangeable. • Flat tappet - not quite flat but the lobes are actually ground with a slight (2.5 deg) taper to match the convex shape on the lifter face. The lobes also don't sit square to the lifter bores, but rather to one side. All this is to ensure that the lifter rotates, and so it and the lobe get even wear throughout their lives. Cams are made from heat-treated iron. Always use high-zinc engine oil with flat-tappet cams. They took a lot of zinc out of engine oils as it damages cats over time. You can get additives instead • Roller cams - sit square in the lifter bore to line up with the roller on the lifter. Made from billet heat-treated steel. Lots of OEM manufacturers went with them since unleaded came about, not because of their "high performance" image, but because oils can no longer have the required additives that they used to have to prevent wear on high pressure areas like with flat-tappet cams/lifters.

YES! Roooock! Huhuhhuh