dry sump

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Discussion

cerberus 1

Original Poster:

73 posts

272 months

Monday 11th February 2002
quotequote all
the speed six engine is a dry sump , i think but am not sure that the tuscan race cars are also dry sump ,what are the benefits of this and has anyone converted a 4.2 or 4.5 to a dry sump.....sorry i am not mechanically minded and my limited knowledge of engines stops at they are usually but not always shoved in under the bonnet

dannylt

1,906 posts

285 months

Tuesday 12th February 2002
quotequote all
The benefits are slightly increased power due to removing cranking case pumping losses (imagine the pistons & crank sploshing through air & oil), removing a risk of oil surge (oil moving away from pickup under sustained forces), and also making the engine less tall so that you can potentially mount it lower to reduce centre of gravity.

Disadvantages are just added complexity, hoses and space. And you generally need several scavenge oil pumps instead of just the one. Oh, and you can only measure the oil level after having run the engine to warm on a dry sump... which always struck me as a bit dangerous if it was really low in the first place!

There is NO point converting a 4.2 or 4.5 AJP8 to dry sump since :-

a) It will be expensive!
b) You won't be able to mount the engine any lower for better handling without reengineering the whole drivetrain, so you lose that benefit anyway
c) The extra power you get will probably be negligible, and would be more easily gained more cheaply in other ways.

I think the only "road" cars that generally get converted are Caterham things, e.g. the K-series to get up beyond 190bhp. You can kits quite cheaply for these type of applications.

cheers,

danny

RobM

392 posts

285 months

Tuesday 12th February 2002
quotequote all
ajp8 4.2 & 4.5 are dry sump anyway

cerberus 1

Original Poster:

73 posts

272 months

Tuesday 12th February 2002
quotequote all
well mines not ....er i think

RobM

392 posts

285 months

Tuesday 12th February 2002
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Maybe you have a chim What makes you think its not ?

tvradict

3,829 posts

275 months

Tuesday 12th February 2002
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Whats the physical differences between a Dry Sump and (what I would assume is called) a Wet Sump engine???

bennno

11,659 posts

270 months

Tuesday 12th February 2002
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nope, ajp is wet sump.

basically wet sump is oil in the bottom of the engine with everything sloshing through it, dry sump is oil being pumped around the engine with no excess in the engine but in a seperate container.

no major advantage on the road as per an earlier mail, main reason for it is to combat oil surge (from high g's) in racing use / on slicks etc.

Bennno

tvradict

3,829 posts

275 months

Tuesday 12th February 2002
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ahhh! You learn sumink new every day!

RUF 3

240 posts

268 months

Tuesday 12th February 2002
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RobM,
ajp8 engines are NOT dry sump. If they were why would they need a dipstick in the engine ? If you don't have sufficient knowledge you should not post replies on factual matters.
TVRaddict,
A dry sump engine has a much shallower sump, an externally mounted oil pump on the side of the sump pan and a remote oil tank. To check the oil level you run the engine for a couple of minutes to allow the oil to circulate round the engine, and check the level in the tank (thus no engine dipstick). A common mistake by those unfamiliar with checking the oil level on a dry sump system is to dip the tank with the engine off. Without the oil circulating, quite a bit of it drains back from the tank and lies in the sump, thus the level in the tank appears low. If you were then to top it up to the level and start the engine, there would be too much oil in the system and it would be blown out the tank. This is seen most often in Porsche 911's and makes a hell of a mess of the engine bay !

GreenV8S

30,208 posts

285 months

Tuesday 12th February 2002
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quote:
ajp8 engines are NOT dry sump
Don't be too hard on the guy, as you know the V8 AJP is wet sump but the straight six IS dry sump and so there is obvious scope for being told the wrong way round/forgetting/generally being confused. The thing for the owner to remember is the method of checking the oil is quite different on a dry sump engine so you really do need to know. For the rest of us, its academic.

Cheers,
Peter Humphries (and a green V8S)

RobM

392 posts

285 months

Tuesday 12th February 2002
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Ah, It appears I was wrong. I was sure I had some tvr postcard with ajp8 spec saying it was ?? never mind, you learn something new and all that, But for what Its worth mr RUF, Something I do know is I dont need you to tell me what I can and cant post.

>> Edited by RobM on Tuesday 12th February 23:14

Martin Hunt

301 posts

269 months

Saturday 16th February 2002
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RobM, many thanks for asking this question, as the answers have helped me out.

As for RUF, you are a Pretentious w$$$$$r the same as the lecturters at uni, who I had to deal with while I was studying. Whom now answer to me, how dare you comment on another fellow PHs knowledge.

If you ask a question about maths, physics, or geography, I only hope I am there to shoot you down in flames.

Having looked through your profile and the comments you have made on certain threads, you are obviously an elitist!!!!!

I have more to say, but will bite my tongue until we meet.

>> Edited by Martin Hunt on Sunday 17th February 00:08

oliverkelly

116 posts

271 months

Sunday 17th February 2002
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Hope your camshafts didn't cost as much as mine. Have they been done yet ?

mags

1,131 posts

280 months

Monday 18th February 2002
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quote:

The benefits are slightly increased power due to removing cranking case pumping losses (imagine the pistons & crank sploshing through air & oil),



Err hold on...
Your crank shouldn't be doing that, that causes the oil to foam and break down more easily I think?
That is caused by overfilling.

Mags