Concave sump base possibly reducing oil capacity

[Cullystvr]

Is anyone familiar with the sump on the TVR S2 2.9, is it normal for the sump to be concave on the bottom. This looks to be deliberate to accommodate the exhaust however oil capacity would surely be reduced. I’ve read that the sump is standard Granada/Sierra and pics don’t show it to concave. Anybody got any info on this,

[phillpot]

Yours is bent, should be flat.


Got a nice cast alluminium sump if you're interested

[v8s4me]

Blimey! It would have to be one hell of a dent to reduce the oil capacity by any amount that would matter.

EG. if your dent was hemispherical and say 1" across and 1/2" deep it would displace approx
0.0043 of a litre, ie 4.3cc *

Time to get out a straight edge, a ruler and a calculator.

• volume of a 1" sphere divided by 2

Simples

[Cullystvr]

How’s a piece of wood, top of stick to depth of dent 8mm tapering to full width/length of sump base, base of sump approx 200mm, rough calc 150,000 mm3 equates to approx 1/6ltr big dent but not much reduction in oil capacity, does that sound about right 👍

[v8s4me]

So about 150cc then? That's not much out of the capacity of the sump. Just top it up a bit above the full mark on the dip-stick.
So long as the crank is not touching the top of the dent there's nothing to worry about.

[GreenV8S]

Cullystvr said:

Anybody got any info on this,

I suspect you'll find that at some point in the past somebody grounded the exhaust so hard it smacked into the sump.

[mentall]

v8s4me said:

So long as the crank is not touching the top of the dent there's nothing to worry about.

Oh yes there is!

If the crank or big-ends touch the surface of the oil they can beat it to a froth (oil-air emulsion), which the pump can't pump.

I can't find a cite, but I recall in the '60's a manufacturer having to alter its dipstick so that 'over-enthusiastic' filling wouldn't wreck the engine.

I expect that by the time our Fords and Rovers came along, manufacturers were making an allowance for over-filling. But by how much?

[phillpot]

You'll hear it if the crank is hitting tthe oil!

That is the well of the sump, the crank is no where near that but the oil pump pick up could now be squidged against the bottom


If this is a continuation of your "it only took 3 litres of oil" post that little dent is not the issue ...... imho

Not a Ford V6 but you get the idea

[Cullystvr]

Thanks for the comments, the main reason for the post was that I used a Sealy vacuum pump to extract the oil as it’s much quicker and less mess. Looked at the dipstick which was full so expected to get about 4ltrs out but got 2 3/4 ltrs out, had a few goes to make sure sump was empty. So thinking I must have misread the dipstick and it was actually on the lower level I put the new oil in but only got the same back in. Before I take the new oil out and waste it using the sump plug I was trying to eliminate any reasons why I only got 2 3/4 ltrs out ie wrong dipstick (found to be right) dent in sump which looks deliberate as it appears shaped (rather than bashed) to enable the exhaust to sit higher which only reduces the capacity by 150cc or there is maybe a baffle or restriction in the sump preventing the vacuum pipe going all the way down to the bottom of the sump which would mean there’s 2ltrs of old oil still in so I’ve got a mixture of old and new so will have to drop it all and replace. I now think it’s probably the latter and wondering if anyone can confirm this 👍

[v8s4me]

If it was me I'd just take the sump plug out and do it the old fashioned way then you know you're getting all the old oil out and you can measure what the new oil as it goes in. That way, once you've added the correct volume of oil you can mark the dipstick with the correct level for your engine.

It's a PIA + knees + back + anything else that's worn out but you know the job's done.

Just do it

[Cullystvr]

That’s a great diagram, looks like the dipstick is above the oil pickup, I’ve either hit the top of the pick up or the other diagonal part with the vacuum pump pipe. Yes it looks like it will be another morning crawling round on the floor, worst thing is should have gone traditional method in the first place as had to crawl around to get the oil filter off. Thanks for the help I will post an update probably Wednesday to confirm I get 4ltrs out. At least everyone knows now that you can’t vacuum the oil out 😃👍

[Cullystvr]

Cut out pic of the Ford 2.9 V6 showing oil pick up in line with the dipstick 👍

[phillpot]

Curiosity got the better of me so I've just slipped the sump off my engine, do you think that baffle plate could be the issue?

Can you measure how much tube is going into the engine then hold against outside of engine to get a rough idea if reaching the bottom?

[Cullystvr]

Thanks for going to this extreme (engine out and sump off) that is commitment to the cause and that’s a very clean sump 😃. Yes definitely, the baffle is the problem I can tell by looking at it, the angle of the dipstick tube would take the vacuum tube right into the corner of that baffle and this would explain approx 1ltr left in the sump. Thanks for the photo it’s much appreciated always good to get the answer to the problem, could have just drained the oil but that wouldn’t have given an answer to the problem 👍

[magpies]

phillpot said:

Curiosity got the better of me so I've just slipped the sump off my engine, do you think that baffle plate could be the issue?

Can you measure how much tube is going into the engine then hold against outside of engine to get a rough idea if reaching the bottom?

I presume while it is off you will now make a polished stainless steel version

[Cullystvr]

Update on oil capacity, dropped the oil today via sump plug and dropped just under 4lts which accounting for filter and concave sump is about right. So anyone with a 2.9 S you can’t oil change using the dipstick vacuum method due to an internal baffle (only takes out 3lts with full dipstick level) it has to be via sump plug, possibly the same for the 2.8 but can’t confirm. If you get 2 washers with a new sump plug use the nylon one for tin sumps and the metal with rubber seal for alloy sumps, not both. Thanks to all who posted comments and pics, job done, every days a school day with TVR 😬

[phillpot]

magpies said:

I presume while it is off you will now make a polished stainless steel version

Settled for alluminium , guess your Cozzie engine would have had one of these Mick?