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Update time! This is a short version as the first reply got lost in the ether somewhere. I've been working on the pipework for the oil system. This includes a fine mesh filter for inside the sump, for the pickup pipe, and an adjustable pressure regulator for the oil return pipe. This...

OK the points ignition system is in and working. It's a bit crude at the moment as I wanted to see if it works ok, and indeed it does. I can't believe all the time I've wasted with the 2 electronic crapnition systems so far. Now I know it works I need to source some smaller points and fit 2...

Hi Diesel. So can I assume that the rc carbs would run fairly well if a new needle was made with the same small and large diameters, but the middle was fattened out a bit to lean out the midrange? Or doesn't it work like that?

Luc, you're just confusing people again. Maybe you could start your own thread for your engineering theories? 5250rpm isn't a magic number, it's just where the hp and torque curves cross each other on an engine printout. It will be the same for a lawn mower and an F1 engine, but nothing to do...

Thank you all. I would like to use this Walbro type carb if I can, although once I'd sorted out the electrics the small rc carb seemed to rev well. It got to about 6000 rpm when the Chevy ignition module expired. I will get the Walbro stripped and see if I can identify the spring in question. It...

Luc, Sage, I didn't know what you meant about an O ring, but now the penny's dropped. At the moment there is no groove in the liner, just a 15 thou' step. The white ptfe washer is 20 thou' thick, so gives 5 thou' of crush. I never considered using an ordinary, Viton?, o ring in a full groove in...

Oh, forgot to mention, this morning I suddenly got loads of smoke out the back. Turned out to be a head gasket ptfe ring had gone. I replaced it and carried on but this needs a different material too.

Well, some mixed success. I figured out the revving problem. Just a stupid electrical fault of my own making. I was just getting the mixture right at higher rpm when it stopped suddenly. Turns out the HEI ignition module has bit the dust. I've had it now with electronic ignition systems. I'm...

Thanks again for replies. I'm having a bit more luck getting it started, still with the small rc carb, but it won't rev over 2000 even at wide open. I think I need a rethink on the spark plugs first. I have kept the ptfe in place by crimping over the top of the plug, but it doesn't seem to work...

Sage, there is a number on the carb, but I suspect it isn't a genuine Walbro number, not at the price I paid. The no. is NFI35286. Luc, the carb is like you said, and needs some positive,(or negative?) pressure pulses to pump fuel. Unfortunately my crankcase isn't sealed yet so that won't work...

So how about this carb? I bought it a few months ago purely for testing purposes. It's a Walbro 'type' carb according to the ebay description, but again no instructions. I've no idea if it needs pressurised fuel feed, or what the screws do. The bore is just under 11mm. I tried to start the...

Well finally I got it running. I had to cobble the insides of the HEI dizzy to the font of the engine to get some decent sparks. I bought a simple small rc type carb to try. It has a 5mm venturi. After another week of trying with this setup I started to get some signs of life, and eventually...

Sage, thanks for that. Don't think I've seen your V8 anywhere before, looks nice. I did think about those cdi ignitions early on, but couldn't figure out where the coil went, so discounted them. Seems like the coil is built into the unit then. I will have a look and see how much these are in...

I want to keep the 2 x distributors, at least on the final engine. For now though anything goes. The twin dizzys aren't a problem for the Powerspark, as it will fire each one in turn, so hopefully it will turn out to be the coils which are the problem and not the Powerspark. If the Powerspark is...

Thanks all. Some good points raised. Funnily enough I was lying in bed last night after saying I'd file off 4 of the pointy things and thought 'hang on a minute, that might not produce enough voltage'. Then I thought even if it did work, how am I going to split the sparks between 2 x dizzys. My...

Yes, good point. I'll file 4 of the points off the ring and the inner wheel, not shown in pic. Cheers.

Well, it seems there's nothing wrong with the plugs. I wired the Chevy dizzy up and tested my plug. It showed a really fat spark. So then I put the plug in the pressure tester and wound the pressure up.Got up to full pressure with still a nice fat spark. This is the guts of the sender...

Thanks for replies. It all gets absorbed into the brain-box, even if I forget to reply to specific points. I certainly will try the standard plug under pressure, when I can sort a suitable tap out. My current thinking is that the coils are crap. They were no-name ones of ebay, a bit cheaper than...

Thanks Steve, I forgot about that stuff. I'll try and ebay a chunk. Jeff, Thinking about it the timing light does go off when the spark dies. I need to try some different coils maybe? My mate's coming round tonite with a Chevy HEi dizzy. Going to see if I can pirate that for bits. Keith.

Lakc, the insulator material in the plug is plain PTFE. The plug bore is 3.5mm and the centre electrode is 1mm, so that gives 1.25mm, or .050" of insulation inside the plug. I have wondered myself if the spark energy is going through the ptfe inside the plug, out of site. I have had the ignition...