Viterbo

It's a common mod in Portugal, 3K pistons in a 4K (twin squish head)

Apparentely the oil issue is also solved...

Now everything is clear. Thank you to both of you! I'm running 95 octane gas. Tested the car on the road and it's flying!! Do you think the fact of the it being so retarded could be overheating my oil, about the problem I reported in another topic? My water thermostat is faulty and let the engine cool while running so I'm not getting excessive water temp. But I have no way of knowing that with the oil, and I know retarded advance causes overheating.

There are a few different hints you gave and I'm kinda lost here. Altezza you say the way it's working right now it's the way it's supposed to be so everything is alright? Banjo, I cannot praize you enough for taking so much time to explain everything the way you did, thank you. However I think you didn't fully understood my issue, maybe I expressed myself wrong. The car idles perfectly at 900 or so RPMs, the issue is, I think (I just think because I don't know if it is wrong or not) I'm running too much advance because I think I'm getting too much vacuum. With vacuum on I'm reading 20+ degrees at idle, with vacuum off and hose blocked I'm perfectly running the static advance of 8 degrees. I forgot to say I'm running a bit of compression, between 12 and 13 bar in all cylinders so I'm affraid of getting detonation with so much advance

I don't know, but there is no vacuum port there. I think it came from a flat front KP61

I'm running a 5K engine with a 4K engine carburetor from a Starlet. This carburetor doesn't have the vacuum exit on the bottom for the vacuum advance so I'm running the advance from the intake manifold. I usually use a timing gun to set the timing and usually run it at 8 degrees. A strange thing I noticed a long time ago was that if I unplug the vacuum hose from the dizzy the car shuts down. I'm taking mechanic and electronic classes and this week my teacher showed me how to set my static timing with a probe light. Basically I connect the probe light to the "-" side of the coil and to the ground of the car. Rotated the engine till the timing mark on the pulley sets at 8 degree. Then rotated the dizzy till the light turns on. Few things I noticed: the car starts much much better and revs like a maniac, so freely. But then comes the strange thing. At idle if I point the timing gun it gives me above the scale of the timing cover. It's around 25 degrees at idle!! If I take out and block the vacuum hose it reads 8 degrees as I have set! The hose is also pulling air very hard. What's wrong here? I'm affraid to suffer from detonation from such and advanced timing, but the engine now runs very well

I'm going to wait for the sensors and gauges to come and see what's happening inside the engine. With that I'll think about the oil. Maybe a 10W50 or 20W50. Mineral 15W40 do about 5000kms and it's my oil it's not far from that.

I'm using Total Q5000 15w40 (mineral). I'm tempted to change to a 20W50.

Today I drove the car with no highway road. Did a few pulls, today the idle was a bit lower than usual and the light didn't turned on. I assume it's temperature related (oil thickness) but still I think it shouldn't happen. In 3 or so weeks I'll have the gauges...

In that case, I should go to a 20W50? I guess it can be tested like that. The connection is tight, no problems there. But the light operation seems logic and how it's supposed to be. When the engine is off the light it's on, when I crank it the light turns off and stays that way when cold at any rpm and when hot appeared in that situation (idle after some kms). I didn't have the chance to drive the car again to see what happens now.

I got the tip here from Felix. Outer hydro body, top nut in the bottom and short pushrods (2K engine). Installed 4K solid cam also. Not going past 6000. What kind of checking can I do besides the basic? I think it must be working well, unless something in the switch itself.

Yes, not full but plenty of oil in it.

The only noise it has it's in the valvetrain, my valve clearance keeps untuning itself hehe. I have a kit of oil temp and pressure sensors and gauges coming but they won't be with me until 3 weeks or so.

I'm back to low oil pressure issues on my 5K. Last saturday I went on a trip and did about 60kms on highway. It was hot outside and since I have a short diff ratio I went the whole way at around 4000rpms. When I got to the tollgate, at idle, the oil pressure light started to blink slightly. If I let it idle for a bit the light turns off.I'm using a mineral 15W40 oil (Total Quartz 5000).I assume the oil got very hot and got thin. Engine background: 1 year ago crank was machined and 0,25mm oversize bearings (NDC brand) were installed. In january I did solid lifter conversion using the outer body of the original hydraulic lifters. I don't have (yet) oil temp and pressure gauges so I'm clueless about those values. Where can I be losing pressure?

Made the conversion this weekend and it works pretty well! A bit noisy when hot after idling for a bit, rev it and it goes quieter. Running on 15w40 mineral. No oil pressure issues so far, it warmed up to the fullest and no issues.

I think my hydraulics are going to give me a clue :lolcry:

I'm using Shell Helix H7 10w40 (semi-synthetic) and I'm gonna do an oil change soon, I'm gonna try Total Q5000 15w40 mineral.

I tried different advance settings and when set at around 15 degrees (with vac from manifold connected) the starter cannot start the car when hot. So I'm using around 12 degrees with vac on and that way it runs well. It's the second starter I use with exactly the same outcome (not new tho) I'm running around 12,5 bar in each cylinder which may be the cause of the hard cranking when hot.

The most similar I found runs through some weird valves I don't have. I'm going to install bike carbs in a few months, the vacuum will have to be connected to the manifold. Since that messes up timing, what people do to solve that when using bike carbs?

So this is the carb I have and I marked the two only ports it has. Both of them are at around the middle in height. Where should I connect it?

That's great news, thank you sir!

Top cap into the bottom with all the guts out and 2K or 3K short pushrods?

So I have it wrong by having it connected to the manifold?

Allow me to ask a question. I'm running the carb of a KP61 Starlet and since I don't know where to connect the dizzy vacuum advance tube on the carb I connected it directly to the manifold. When setting the timing, when I unplug the vacuum tube the engine stalls. Why does this happen? I just set the timing with vacuum on, I'm running around 12 degrees that way and it goes pretty well.

Yes it's the 3F engine lifters that fit in 5Ks. But I'm gonna give a go to Felix's conversion as I have all the parts needed. And those are the parts where my question about oil pressure comes in since they won't block the oil feed as the body of the lifter will still be the 5K hydraulic. I just can't contact Felix so he can give me a hint on this because he's offline since July and I need to go ahead with this soon...