Dip Stick Tube Length

[EricB]

Another question about my Burton Water Pump conversion. I was assuming that I would insert the tube into the Burton front casting so the same length is sticking out of the casting to hold the dipstick as the OEM one which in my case is 2 1/2 inches.

However, I saw a previous note from englishmaninwales (5th Mar'19) that said that the dipstick angle is different in the Burton vs the Original.

What is the forum experience? Does that affect the oil level reading significantly? What is the length of tube left outside of the casting? Is 2 1/2" correct?

I am assuming that I will have to heat up the casting in that area (with a hot air gun) and then
gently tap in the tube (which has been chilled in my freezer). Will have a bolt in the top of the tube to take the hits. My Burton tube is chrome plated by the way.

[rgh0]

The casting detail in this area where the tube is inserted varies between OEM versions ( Lotus has 2 versions of this casting) and the after market versions and the Burtons cartridge versions so you should not use the projection length of the tube but the height of the tube lip above the bottom face of the front cover casting. There is some debate about that dimension as Lotus had 2 versions for early and later engines and also change the dip stick version, there was a recent discussion on all of this. I use the "B" dipstick and six bolt sump and 105 mm to the lower lip on the angled tube above the bottom flange of the cover, which works for me

The tube supplied by Burtions with the kit I got a few years ago also had a small step part way along where the extrenal machining to tolerance stopped. This step may prevent the tube going in further depending on how much heating and chilling you do and even if it goes in it may crack the casing if the interference is to great. If you cant get it in far enough. You may want to check this before inserting the tube and if you cant get it in far enough need to cut the tube shorter.

I dont believe any angle difference with the burton casting for the tube is signficant.

cheers
Rohan

[englishmaninwales]

On my Burton front cover the resultant entry angle was slightly shallower compared to the original. As it was a fresh engine build, I simply recalibrated the dipstick with a dry engine oil fill. This resulted in a small change, probably not worth the trouble on a road car.
Malcolm

[Donels]

Brian Buckland says “The pipe top should be 4.1 inches from the bottom flange where the sump goes”. When I did mine I recall that the tube bottom went to the end of the casting to get the above dimension. Which makes sense as it is independent of casting and and tube length and assumes a standard sump.

I put the casting in boiling water and the tube in the freezer and it slid in ok, but you don’t have long before it grips.

[fatboyoz]

Hi Eric,
Have just fitted a Burton front cover. Filled the oil filter, oil galleries and sump with the book fill for my S4. 7.5 imperial pints (book says, or 4 litres, which is incorrect, should be 4.25 litres) total fill.
I then tapped the dip stick tube further into the cover until the full mark on the dipstick read full.
The resultant measurement is 60mm from the end of the tube to where the tube enters the front cover.
My dipstick tube is brass, so may be slightly different to your chrome tube.
Cheers,
Colin.

Another question about my Burton Water Pump conversion. I was assuming that I would insert the tube into the Burton front casting so the same length is sticking out of the casting to hold the dipstick as the OEM one which in my case is 2 1/2 inches.

However, I saw a previous note from englishmaninwales (5th Mar'19) that said that the dipstick angle is different in the Burton vs the Original.

What is the forum experience? Does that affect the oil level reading significantly? What is the length of tube left outside of the casting? Is 2 1/2" correct?

I am assuming that I will have to heat up the casting in that area (with a hot air gun) and then
gently tap in the tube (which has been chilled in my freezer). Will have a bolt in the top of the tube to take the hits. My Burton tube is chrome plated by the way.

[EricB]

Hi Colin, my measurements agree with your value of 60 mm exposed length of the tube. As the casings are already in place on the engine, I took a 3/8 OD length of wooden dowel and shaved off enough so I could get the dowel into the tube opening right down to the bottom of the sump.

Interesting how the angle of the dowel shows both an angle as viewed from the front of the engine as well as another angle viewed from the side of the engine.. Will need someone to sight the front angle as I tap in the tube from the side.

Again as the new castings are already mounted on the front of the engine, I am a little nervous about applying too much heat to the area of the tube hole. Wonder if anyone has just used the freezer chilled tube and tapped it into room temperature casting? Even thought of getting some liquid nitrogen to chill the tube even further but difficult to get..

I'll start another topic just about that. Thanks.