3.5 Litre Dipstick in a 4.6 Litre.

[Richard Kaye]

I have just built a 4.6 for my 1988 RRC, got oil pressure with a drill and installed it into the car. Used the sump off the old 3.5 on the new motor, I bent the front section of the sump for the 4.6 crank to clear.

While I was building the 4.6, I measured the length of the dipstick below the level of the sump mounting bolts. I was convinced the measurement was the same on both motors with the 3.5 dipstick and dipstick tube.

Problem I have run into is it has taken 7 litres of oil to get the oil level halfway on the dipstick, a 3.5 sump should take 5.7 litres to reach full on the dipstick.

I cranked the motor over today and still have oil pressure, so all the galleries and filter are full of oil.

So why has it taken so much oil to get to half on the dipstick? Anyone ran into this problem before?

[V8Ian]

Is the seal/stopper on the dipstick the same distance above the sump gasket on both blocks?

[Slunnie]

I just did a really quick bit of reading, it sounds like there are 2 dipstick tube lengths, so 2 dipstick lengths to match. It seems that irrespective of what sump you have on it, you run the same dipstick that came with the block so the oil fills to the correct height within the engine rather than filling by oil volume.

dip stick length - The V8 Owners Forum - (https://www.v8forum.co.uk/forum/viewtopic.php't=14945)
Sumps - The V8 Owners Forum - (https://www.v8forum.co.uk/forum/viewtopic.php't=2933)

[Richard Kaye]

The 4.6 I bought didn't come with a dipstick or dipstick tube.

I also don't have the 3.5 anymore to check the measurement.

[PLR]

G`day , it sounds like you have a later tube and an early stick , the length from the block into the sump is the same distance , the lengths the other way are very different and the stick lengths are very different also , get back later .

[Richard Kaye]

Both the stick and tube I took from the 3.5.

When it was in the 3.5 the reading on the stick was correct for the volume of oil added e.g. 5.7 litres took it to full on the dipstick.

[PLR]

G`day only approx in cm

23.5 block ring to base , tube

28.5 overall , tube

39 stick end to top of hat , stick

Straight tube loop on end of stick rounded .

Later type

23.5 block ring to base , tube

43.5 overall , tube

57 stick end to top of hat , stick

tube bent last quarter , end of stick d shaped.

Have a 4.0 crossbolt , 3.5 sump , stick and tube reads as it should also a 4.6 crossbolt , 3.9 sump , stick and tube reads as it should .

If you have the shorter tube/stick , i would check that the tube is sitting home on the block the ring hits the block . The tube should go into a hole with nothing else there .

The other thing is you mention work on the sump normally a 3.5 and/or 3.9 sump should just bolt up as is .

[Richard Kaye]

I put some plasticine on the inside of the front of the sump (the highest part, not the lowest) and bolted it to the motor. The crank and conrod bolts hit the sump and left large marks in the plasticine when I turned the motor over.

I knocked out where it hit for clearance.

Today I will measure the length of my dipstick and the length of the tube from the block up to the top of the tube and see what I have.

[Richard Kaye]

Drained the oil from the sump this morning and got a total of 5.2 litres out of it.

I definitely put 7 litres into it. Say the filter takes 0.8 litres I am still missing 1 litre, have no idea where it’s gone.

With the 5.2 litres in the sump, I get a reading of half on the dipstick.

[Slunnie]

Drained the oil from the sump this morning and got a total of 5.2 litres out of it.

I definitely put 7 litres into it. Say the filter takes 0.8 litres I am still missing 1 litre, have no idea where it’s gone.

With the 5.2 litres in the sump, I get a reading of half on the dipstick.

It might be ok.

The Disco2 V8 is 7 litres from dry, 6.27 with oil and filter change, less with just oil.

[Richard Kaye]

I have ended up putting 5.8 litres in the sump and that has taken it to full on the dipstick.

Haven't had any oil leaks or blown out any seals. The oil pressure is still good too.

[DoubleChevron]

I dont think the dipstick tube sits flush in the block on the 3.9 in my classic. I haven't been overly concerned. so long as its not full enough the cranskshaft splashes in the oil, it'll be fine :)