Compression Ratio, Will I be able to tell the difference? Options

[Jack Standz]

It's a good idea to fill the oil filter with oil before installing it.

[sdoolin]

I have confused myself. It happens.

Having re-installed the distributor in roughly the same orientation as before this rebuild (the engine ran well), with the plug wires in the same orientation, I notice that the rotor is aligned with the wire that is for cylinder #2 when the engine is at known TDC for #1.

Rotor turns in a clockwise direction when engine is turned.

A pic...

[Superhawk996]

Follow the Haynes or factory manual to instill the dizzy drive and distributor

If what you have said is correct the dizzy drive is mis-installed. Each tooth is about 30 degrees of rotor rotation. Sounds like you are off by two or three teeth.

[sdoolin]

Follow the Haynes or factory manual to instill the dizzy drive and distributor

If what you have said is correct the dizzy drive is mis-installed. Each tooth is about 30 degrees of rotor rotation. Sounds like you are off by two or three teeth.

Thank you superhawk. I'm a little embarrassed I didn't figure that out myself. Dizzy drive was mis-installed by a tooth or so. All good now.

[sdoolin]

Engine went in on Friday. Easy peasy. After I poured a celebratory Bourbon, I realized I had installed the moustache bar incorrectly. Easy enough to fix. Attempted to start her up today. No go. Triple checked everything. No vacuum leaks. Fuel pump is working, carbs are getting gas, plenty of air, so it must be spark. Yep, dizzy driveshaft installed 180 degrees out.

My 40 years old Haynes manual (for a bus) says to install the dizzy driveshaft such that the "small" side of the slot is on the left hand side. Well, the left hand side, to me, is the drivers side of the engine. The Haynes manual should say to install the dizzy driveshaft such that the small side of the slot is on the left hand side of the engine when approaching the engine from the fan side. Anyway. I fixed that and she starts and runs. Not well. but the carbs need to be synched.

The worst bit is that my oil pressure light goes out for a short bit, then comes back on. It has done that about three times so I have shut it down and commenced heavy drinking.

I'll find a way to put a proper oil pressure gauge on it before I start it again. Sheesh. She is really putting up a fight.

[sdoolin]

Could this be a faulty oil pressure sending switch? Green ight goes out (indicating good pressure), then comes back on after a few moments?

[VaccaRabite]

Could this be a faulty oil pressure sending switch? Green ight goes out (indicating good pressure), then comes back on after a few moments?

Maybe. Or you are loosing pressure on warmup.
There is usually a spike of oil pressure on start up that fades as the oil comes to temp.
If you have an oil pressure gauge, what does it say?
Are you using a stock idiot light switch? Stock one is supposed to light up at 3-4 psi. But you can find plenty of switches that light up a lot higher then that. The dual pole switches light at close to 10 psi. Which STILL should not be an issue on a fresh engine.

Do the basic electric checks too. Make sure leads are tight and grounds are clean.

If this was first start, the light may have come on while it pumped oil to other systems, especially if you have an external oil cooler.

Zach

[Superhawk996]

If it were me I would not be starting the engine just relying on the idiot light.

Get a real gauge on it.

[sdoolin]

Installed my brand new oil pressure test gauge (Harbor Freight) in the location of the OE pressure switch (which is remote from the normal case mounting location (you can see it in the pic a few posts back)). The line on the gauge is long enough that I can sit in the car and start/run it and see the gauge.

I am seeing 76 -78 psi of oil pressure at 2200 rpm. I'm not sure what is "normal", but for now I am going to call success and move on to fine tuning. I actually found a brand new OE oil pressure switch in one of my many boxes of spares, I'll install that. Previous owner installed an oil pressure gauge into the center console, but it has never worked so I imagine I'll finally fix that too. I will have questions because I'm no good with things that need wires to operate.

Let it run for about 5 mins. Oil pressure stayed at 70+ psi. The passenger side carb "leads" the drivers' side quite a bit, so I need to synch things up, and spend some time with a timing light to verify ignition timing.

I also noticed a small oil leak at the oil pressure relief valve, so I need to replace that crush washer.

Thanks everyone as always for the assistance. Should have her on the road again in a week's time. Then I have a 1990 Honda RC30 to restore...

[VaccaRabite]

Your pressure is high because the oil is cold and you are likely using a 20w50 oil. It will drop into a normal range as it warms up.

"normal" will be 10psi for every 1000 rpm, or somewhere around there.

Having a real oil pressure gauge in the car is a good idea.

Zach

[rfinegan]

Woohoo
glad you get the pressure...sounds like the wrong or bad sensor

[sdoolin]

Yep, cold oil and running (expensive) Brad Penn 20W50. And yes, I think a bad oil pressure switch. I replaced it and all is good (green light goes out).

[sdoolin]

She's alive, and running well(ish). Drove about 10 miles yesterday. Carbs are well synched, she idles well and takes throttle without drama. I think the timing is a little too advanced, I got a little spark knock on full throttle uphill climbing. I can fix that easy enough.

She doesn't feel quite as perky as she did before this build, but I haven't driven her in over a year, and I have new rings and bearings to break-in. I'm hoping after break-in she perks up a little more, hard for me to believe I can feel the difference between 9:1 and 8.8:1 compression ratio.

Found a pretty significant oil leak at both valve covers, which I hate. Just hate. I've ordered new bales and have fresh gaskets on-hand.

Thanks as always for all of the helpful responses to my questions. I'm sure I'll have more...

[friethmiller]

@sdoolin ,

Congrats! Glad the build was successful. My build is coming soon. Still waiting on the machined/balanced parts. (IMG:style_emoticons/default/dry.gif)

[930cabman]

She's alive, and running well(ish). Drove about 10 miles yesterday. Carbs are well synched, she idles well and takes throttle without drama. I think the timing is a little too advanced, I got a little spark knock on full throttle uphill climbing. I can fix that easy enough.

She doesn't feel quite as perky as she did before this build, but I haven't driven her in over a year, and I have new rings and bearings to break-in. I'm hoping after break-in she perks up a little more, hard for me to believe I can feel the difference between 9:1 and 8.8:1 compression ratio.

Found a pretty significant oil leak at both valve covers, which I hate. Just hate. I've ordered new bales and have fresh gaskets on-hand.

Thanks as always for all of the helpful responses to my questions. I'm sure I'll have more...

congrats, running/driving is great. I can't imagine a seat of the pants could "feel" a .2 change in compression. Having things broken in will help slightly.

[sdoolin]

Moving on to some other fiddly projects. Oil pressure gauge in the cabin now functions (woulda been helpful 6 months ago). Oil temp gauge on this car has never worked. I discovered the fairly specific wire that connects the sending unit in the taco plate to the rest of the harness under the battery tray. Woulda been nice to know I had this before the engine went all back together, but I just found it in a box, inside of a box of spares that came with the car. That wire, which is very OE, will not connect to the sending unit. See pic below...



Seeing as I'm going to have to fabricate a wire anyway, what kind of connector attaches to that sending unit? Do I get a different sending unit?

I also found the cover plate for the taco plate that routes the wire up the front of the engine, so may employ that with my custom wire(ing).