More oil questions

[teebee67]

Having rebuilt the motor after it threw a rod it is now up and running. On start up I checked the oil return and was pleased to see it returning ok. Several start ups and running on the stand for 10 minutes at a time and all seemed well. Went for a 10 minute ride and, on returning, checked the oil return to find nothing coming back. I revved the engine to about 2000 rpm for about 10 seconds and still no return. At this point I panicked and turned the engine off. As I was going to re torque the head bolts and redo tappets I let the engine cool and did this, when I did the tappets it looks like oil was getting up there ok and, on removing the timing cover, everything seemed well lubed. I know the return pump pumps faster then the circulation pump but is it usual to have no return after a run or is this wishful thinking?
Also I have been told these motors can be run without the engine oil filter (seems dubious to me), can anyone tell me if this is true or not?
Any help/info much appreciated.

[1608]

If the oil is still refusing to return to the tank you need to check the sump and measure how much has accumulated in there. You can run the engine without the filter, but why would you want to. I did for a short while and decided that it did not improve oil pressure and was no advantage.

[teebee67]

Thanks for the quick reply, I will drop the sump tomorrow and measure the amount. It's not that I'm wanting to run without the filter it's just I am using 1961 crankcases replacing the 1959 ones which were badly damaged when the rod broke. The filter arrangements are different, I have blanked off the hole at the rear of the 61 filter housing and am using my 59 filter but I am unsure of how these filters work so am not sure this is ok.

[Ib-Denmark]

Having rebuilt the motor after it threw a rod it is now up and running. On start up I checked the oil return and was pleased to see it returning ok. Several start ups and running on the stand for 10 minutes at a time and all seemed well. Went for a 10 minute ride and, on returning, checked the oil return to find nothing coming back. I revved the engine to about 2000 rpm for about 10 seconds and still no return. At this point I panicked and turned the engine off. As I was going to re torque the head bolts and redo tappets I let the engine cool and did this, when I did the tappets it looks like oil was getting up there ok and, on removing the timing cover, everything seemed well lubed. I know the return pump pumps faster then the circulation pump but is it usual to have no return after a run or is this wishful thinking?
Also I have been told these motors can be run without the engine oil filter (seems dubious to me), can anyone tell me if this is true or not?
Any help/info much appreciated.

Dont want to scare you, but this pic. show how the inlet looked in the return pump in my G12
Just after a rebuild.
The lumps, blocking the channal are liquid gasked left somewhere in the engine by another mechanic (not me)
It resulted in exact the same symptoms as you mentioned.
regards Ib

return pump.jpg

[teebee67]

It was silicon gasket (again not by me) clogging the crankcase filter that caused the oil starvation and broke the con rod in the 1st place. We have been careful not to use it on this rebuild just a very small amount of wellseal on the timing cover.
I have now drained the crankcase and there was only a shade over 100 ml in there which would appear to say the oil was being returned. I am going to double check the crankcase filter to ensure it hasn't blocked again but I would be very surprised if it has.

[ajsph]

You have blanked the hole in the rear of the filter tunnel, are you talking about the hole for the oil pressure relief valve.
Poul

[teebee67]

Yes, because mine is the earlier type filter. I was told this is correct if using the earlier type filter?

[clive]

How did you blank the oil pressure relief valve hole off? If the blanking failed you would immediately loose oil pressure. (But this would fill your sump pretty quickly)
Logic says if the oil is not returning AND there is no excess in the sump then either the failed return happened just when you checked or more likely the supply side failed. I wonder if your oil pump on the supply side is blocked? This is what Ib is suggesting.

[dave16mct]

Why not fit the later one piece filter assembly and keep the pressure relief valve?
Dave.

[teebee67]

Hi, thanks again for the replies

The blanking was done by a custom made interference fit alloy plug, we also added some hard setting Locktite. I have checked and it is still in place. It does still have a pressure relief valve but the older felt filter type that exits at the front. I have examined the filter and top end and oil seems to be getting there. There was only just over 100ml in the sump. I have run the engine again several times and oil is returning. Went for another gentle run and, on return, found oil was not returning but after a short while (about 1.5 to 2 mins) gave the engine a little throttle and oil started to return well.

I have bought an oil pressure gauge but need the old type filter housing nut (part number 016179) in order to fit it and the club parts department says no stock. I tried AMC classic parts but they are closed until Monday and I am on holiday then (complicated isn't it - lol). I will try to order the correct part at the back end of next week or, failing that, will drill and tap my filter housing nut.

Meanwhile any further info/suggestions would be very welcome, what a great club this is - glad I joined.