My dip stick rises with hard acceleration

camprofile · Post by **camprofile** » Sun Aug 26, 2007 6:32 am

When i am in second gear and put my foot down hard, the dip stick on my SD1 rover V8 rises by about an inch. The engine never seemed to do this before i but the webber 500 on (when it was on the standard SU's). Another curious thing is, ever since i bought the car the oil level was always about half full which is fine but i recently topped the engine up to the full mark. This would naturally create more pressure due to more oil. Is the rising dipstick a feature of this engine or do i have a problem Houston ?!

sidecar · Post by **sidecar** » Sun Aug 26, 2007 7:07 am

Have you connected the engine breather to the non-timed vac port on the carb? If not then the sump pressure could build up high enough to push the dip stick up.

Filling the sump up the max mark with oil should not make the pressure any higher in the sump.

Maybe because the engine is breathing better with the weber you are getting a bit more blow by passed the pistons now and that has just pushed the pressure up a bit?

If you've just fitted the weber with the jetting as it comes "out of the box" then you should consider leaning off all the ciruits (apart from the idle mixture screws) as they over fuel most RV8's and this will cause bore wash and then loads of blow-by.

HTH,

Pete

Post by **katanaman** » Sun Aug 26, 2007 9:34 am

do you mean the actual dipstick or the dipstick and outer tube it sits in?

camprofile · Post by **camprofile** » Sun Aug 26, 2007 12:05 pm

I mean the actual dipstick itself not the tube that it sits in. Listening to the engine the tappets sound slightly noisey on the left hand side compared to the right , the right bank do not make any noise at all. I have never done an oil change since i bought the car and the car was sat for two years prior to my purchase. I think that the oil filter may be partially blocked and as such i think that i will do an oil change and change the filter, then see what happens. I hope to find that the left bank of tappets will quieten down and that the dip stick will stop lifting. The mixture screws are locked either siezed or have has some kind of thread sealer applied i am inclined not to adjust them as the engine runs fine.

Paul B · Post by **Paul B** » Sun Aug 26, 2007 2:10 pm

camprofile wrote:I mean the actual dipstick itself not the tube that it sits in. Listening to the engine the tappets sound slightly noisey on the left hand side compared to the right , the right bank do not make any noise at all. I have never done an oil change since i bought the car and the car was sat for two years prior to my purchase. I think that the oil filter may be partially blocked and as such i think that i will do an oil change and change the filter, then see what happens. I hope to find that the left bank of tappets will quieten down and that the dip stick will stop lifting. The mixture screws are locked either siezed or have has some kind of thread sealer applied i am inclined not to adjust them as the engine runs fine.

The engine oil pressure has nothing to do with the dipstick or whether it rises, but it might be a good idea to change it if it has sat festering for so long. Use a good 20/50, not some modern synthetic tosh.

mgbv8 · Post by **mgbv8** » Sun Aug 26, 2007 9:03 pm

With the carb upgrade you are probably getting more air into the engine. I would make sure all your crank / rocker cover breather pipes are clear. Mine recently blew the dipstick up about an inch, but that was 3/4 track on the drag strip when I holed pistons 1 and 2 during a run with a 200 shot of gas. I have my rocker breather pipes run full bore via flame traps out to the inner wings.

mgbv8 · Post by **mgbv8** » Sun Aug 26, 2007 9:04 pm

Or you may have some strange vibration issue going on?

camprofile · Post by **camprofile** » Tue Aug 28, 2007 1:20 pm

The specified oil for my Rover V8 engine is 10W/40, 10W/50, 15W/50 etc but a 20W/50 is not specified. Am i right in thinking that because my engine is an older engine with probable high milage the 20W/50 is thicker and thus affords more protection, and thus is what most people tend to use instaed ?

Post by **katanaman** » Tue Aug 28, 2007 2:44 pm

the thinner oils are for 4.0 and 4.6 engines, 3.5, 3.9 and 4.2 use 20/50 oil.

JC. · Post by **JC.** » Thu Aug 30, 2007 1:44 am

Oil technology has moved on since the 50's.
Certainly an old engine always run on 20/50 mineral oil should continue to be filled with mineral oil. The use of synth oil with its detergent properties in an older engine might dislodge oil sludge accumulated over the years leading to said sludge blocking oil galleries and subsequently oil starvation.

However, on a new build, after appropriate running in, of course, it is perfectly acceptable to use a fully synthetic oil. Additive packages used in such oils have vastly superior additive packages to cheap mineral oil.

Its a bit like points versus EDIS in that on a new build its a bit of a no-brainer.

ChrisJC · Post by **ChrisJC** » Thu Aug 30, 2007 6:58 am

I ran my new-build 3.5 on 15/40 as I had some. The oil light stayed on when the engine was very hot and idling.

I switched to 20/50 (as per the manufacturers instructions!), and the light stays out at all times.

Chris.

dicky · Post by **dicky** » Sat Oct 27, 2007 6:32 am

10W/50 is proberbly a better compromise then if you can find it in mineral oil.

I will be using Silkoline Ester based 10w/50 in my RV8 when I finish rebuilding it and running it in.

kiwicar · Post by **kiwicar** » Sat Oct 27, 2007 1:50 pm

10/50. . . . your tappets will rattle on start up.
Mike

Post by **Coops** » Sun Oct 28, 2007 9:41 am

i use a fully synthetic 20w/50 in my 3.9 from lucas oils.

mgbv8 · Post by **mgbv8** » Sun Oct 28, 2007 7:03 pm

I use Halfords finest 20/50 classic in the 3500 and their 15/40 in the 4.6