The V8 Owners Forum -

Hi, have stubbled across this site and im after help if anyone can give me advise I would be very greatful:

Im running a rover v8 3.9 with stroker kit to 4.2, quad dellorto downdrafts and fast road cam, engine had been recently rebuilt b4 I purchased it, all I have done is fit the carbs and set it up, firstly engine runs fine, no problem there.

At cold I get about 3 bar oil pressure on gauge, once running it goes to about 2, sometimes in traffic down to 1, never below, i have had the cam covers modified, chevy conversions then had stock breathers fitted at about 3 1/2 inches above the top of the cam covers, this I thought would lower the pressure inside the engine a bit, hopefully like running with oil cap off! im finding when engine is opened up about 80-100 mph (private property obviously) oil is blowing out the valley gasket, it has a composite fitted, I have replaced this and gaskets so many times using different sealers, on cruise about 50mph no problem, oil pressure doesnt seem to rise at all, still about 2 bar, sometimes it even leaks out the big breathers ive fitted, 2 people I know had this problem and by fitting the large breathers it cured there fault, mine still seems to be there. Im running Castrol classic oil recommended for these engines, ive even tried having the cooling fans come in early so as oil doesnt get to hot and runny, fans cut in now at 60deg, and removed the thermostat, engine has never overheated, im lead to believe the rebuild was done by a guy who use to work for Landrover so I guess thats all done right,
Any ideas would be greatful, im about to strip the carbs off again fit new gasket and oil seals at both ends, anything else I should do?

Thankyou in anticipation.......

Hi welcome
Have you a crank case evacuation system on this engine after fitting the carbs? because the oil blowing out the valley sounds like the sump pressurising it generally is not enough just to ventalate to atmosphere.
I think you have a seperate issue with the oil pressure.
Best regards
Mike

Hi!
And welcome to the forum.

Firstly. Put the thermostat back in, or at least put one in that you know is working. If you have electric fan control I would fit an 82C thermostat, and set your fans to cut in around 88-90C. This will keep you plenty cool assuming the cooling system is clean. Running without a thermostat can cause lack of water flow to far reaching corners of the engine and leads to hot spots and more trouble.

Secondly! Where is the oil leaking from the valley gasket? At the rear maybe, and pooling on top of the bell housing. Or is it making a puddle near the dissy on the front cover??

Third!
As the engine is tweaked, has the block been decked or the heads skimmed? This is a common cause of oil leaks from the valley gasket.


And last!
Can you show us a picture of the rocker covers and breather setup please. This will give us an idea of how big your vent pipes are.
Get back to us with this info and we can help.
It doesnt sound like a major pproblem at the moment
The oil pressure isnt that bad by the sound of it. But I wouldnt want to push it above 45psi if using the dissy driven pump setup.

Perry

Thankyou for the welcome and the extremly quick replies so far,

1, No idea what a crank case evacuation system is, so no, i just took the injection system off and put the carbs on, re jetted and set up, if I need this how do I do it?
2 Its running a Mallory elec dizzy with the MSD multispark system
3 the standard water pump is working as orginal but also as water exits to rad the electric fan is wired so if this comes on so does an extra water pump that I have fitted between rad 1 and rad 2 . Oh forgot to say its in a kitcar mid engined
4 the oil is leaking from the bell housing end, and yes pools on top then runs round, I have no idea if any head work was done as engine came from a off roader that was breaking for spares, all info on engine was verbal, on fitting thou we removed the sump and rockers, engine was spotless
Unsure how to get the pics up here but heres some links to some pics of the setup

http://i601.photobucket.com/albums/tt95 ... ine003.jpg
http://i601.photobucket.com/albums/tt95 ... ine004.jpg
http://i601.photobucket.com/albums/tt95 ... ine005.jpg
http://i601.photobucket.com/albums/tt95 ... ine006.jpg
http://i601.photobucket.com/albums/tt95 ... ine007.jpg

forgot to say, prior to the big breather I tried hose to a catch tank with small breather on top, it didnt catch the oil and just blew oil out the small breather all over the engine

OK Mig!!
That gives us some better info.

Firstly the two K&N's are borderline for even an old smoker 3500...So they aint gonna do much on yours when you give it the beans.
You have 1/2 bore hoses which connect to filters with more like 10mm inlets.

Looks like you are also weeping at front right of the valley gasket.
leaking from the rear of the valley gasket does not really have to be related to a pressure build up. Have a look at your engine from the side! Does it lean back a bit?

Even engines with no breathing issues can still leak from the rear valley just because splashed oil in the valley collects and runs backwards where it gathers around the rear valley seal, just waiting and building up until it finds a way to seep out. How do I know?? I've got the T shirt on this one mate

Right, lets deal with the rubber seals on top of the valley gasket. They have a wedge at each end. This wedge is made to fit the odd gap between the head and the block which is a liitle Vee.
If the block and or heads have been skimmed this gap / vee shape will alter. Also most of the NEW valley gasket sealing rubbers you buy these days wont even fit an unmolested engine very well. So they need trimming to fit. As its already leaking, I'll assume we are going throught the process of fitting a new valley gasket and rubbers.

Once all the top stuff is off and you have a new gasket and a pair of rubbers to hand you will see what I mean.

I clean all the faces up with petrol or thinners first. Then I use electrical contact cleaner to make sure I get the little Vee's bone dry. Get a clean bit of rag and drag in forwards and backwars in the Vee to make sure its as clean as can be.

Now lay the rubber gasket on and you will find that you need to get a razor / stanley blade / scalpel to gently shave bits off the pointed section to get it to lay neatly in the Vee.
Its better to have the pointed bit just a tad smaller than the Vee so you can bond it with gasket seal.
Try to make sure the rubber are the newer type with the criss cross pattern on the underside. These are better than the original ones.

Now you need some "right stuff" gasket sealer from Real Steel. This is the best product I have found and I use it all the time. It aint cheap at around £18 for a small squirty can. But you wont regret the outlay. I've tried all the orange stuff etc but this gear is tops.

Now wipe both sides of the rubber with a cleaner and makes sure the rest of the metal surfaces are bones dry and oil free.

Lay a blob of sealer in each Vee, then lay a small bead 4-5mm along the top edge of the valley ridges.
Set the rubbers on top with light pressure.
Now squirt another bead on top of the rubbers.
Set the valley gasket on top and get the front and rear sealing plates / strips nipped down gently by hand.

This is where you only have 15 mins to play.

Lay the manifold on and get all your bolts in a few threads with your fingers. Give the manifold a wiggle to makes usre its as central as possible and then nip the front and rear sealing strips down a bit tighter with a socket. You should see a bit off excess goo oozing out
around the Vee's with a bit of luck

Now you can go for the first nip down on the manifold bolts to make sure thay are just touching the manifold. Now you can finally tighten the front and rear sealing strips before running through the tightening sequence on the manifold.

Sorry if this sounds a bit long winded and anal. But its what I've learnt by trial and error on my race engine. And I dont get any leaks on any RV8 that I build for mates using this process

For what its worth. I've used the twin K&N setup for ages now. This was ok on my 4.6 for nasp use. Under nitrous use it used to dribble oil from each K&N when i was using up to 150hp of gas (still with no leaks from the valley) and when i upped to 250hp of gas the dipstick started blowing out (but still no valley gasket leaks) so I converted the filler cap into a huge breather. The dipstick does not blow out anymore, and the gasket still does not leak.

I had to do an emergency rebuild two weeks ago and re used the valley gasket and rubbers. Its been on the dyno for 4 runs ans has done 8 passes on the drag strip. The valley gasket is still not leaking

The above is assuming you dont have any major underlying issue with blow by. But even if you do, you can overcome this with the filler cap mod I'm sure.

Perry

Migwell wrote:forgot to say, prior to the big breather I tried hose to a catch tank with small breather on top, it didnt catch the oil and just blew oil out the small breather all over the engine

Are you caling the two K&N's your big breather ??

The breathers , (u say K and N) I widened the inlet to match the alloy tube so I think the inlet to them is about 1 inch, maybe 3/4, cant get to car till morning to check,

Its possible it does lean slightly but have never noticed, the mount for gearbox and engine were already on chassis

I already have the gasket and rubbers with the criss cross as you say and the Right Stuff from Real Steal, just wondering if this will leak like all other attempts

If I use the gasket n Right Stuff as you say, should I do any other mods? is it possible oil is coming out of breathers? Looking throught this forum people seem to have a pipe back to carb, surely if your blowing oil it ill make the engine smoke alot?

All your help has been greatfully recieved, nice to speak to someone who seems to know the problem, thankyou again for your knowledge and spending the time to offer advice.

oh, by the way, the last 5 + gaskets ive attempted to fit ive never trimmed the rubber seal, always stood proud a bit but thought that would clamp down and it was as it should be, we learn !! does seem to be leaking further down the gasket thou

I think Perry has covered most of it but one extra tip is that the clamps for the valley gasket can tend to roll over the edges which deforms the seals, it help to put a larger washer on the clamping bolts which hold it flatter and ensures that the clamps are compressing the gasket and seals properly.

Oh another point you don't run it without air filters do you? if so your engine will not last very long.

Of course a positive crank case ventilation system (PCV system) would greatly reduce the internal pressure of the crancase and heads and thereby reduce the likelyhood of oil blowing past the gaskets.

It would be a bit more complex to set up with your induction system, but the rover engine was meant to have a PCV system.

Whats the car by the way?

Kevin.

Ive run this engine now summer drivin for 3 years, no air filters, just the trumpets, mainly to shows, and back.

I read a thread earlier re the washers , good point, will do this.

PCV system/ how do I fit one of these if needed?

Heres the car its in

http://i601.photobucket.com/albums/tt95 ... 6882-1.jpg

by the way, use to live in Sidcup Kevin !! brings back memories

Sweet ride Mig!!

It wont take long to solve the oil leaks dude.

Where do you live now eh???

Perry

Migwell,

Are you either a good welder or have Spanish associatons?

I think I might have noticed that flying around Sidcup, though there are a surprising number of hairy V8's that rumble past my abode.

A PCV system is basically a filter on one cover with a flame trap on the other then a PCV valve then a hose to a vacuum point, normally to a 4 barrel carb or a pair of SU's.

With one choke per cylinder it gets a bit more complicated, I think cobratone rigged up something for his throttle bodies on a similar inlet set up to yours so you could do a search for some recent posts and pictures.

On my engines I found it easier to trim off the end pieces and put a blob of high temp black silicone in the v's then smear a thin film over the seals then fit the seals and clamps, never had a leak problem, not saying it's a better method just something that works with engines that have had some machining to decks and heads.

If the engines been run without filters for some time it might have caused some bore/ring wear adding blow by which would add to the crankcase pressurisation, I would advise you to get some ASAP.

Kevin.

Kevin.

Thanks for all your advise and comments guy's, im amazed at the info on this forum, will definately recommend others.

Its amazing I can build a car but dont know much about engines internally.

Always been a lover of lambo's but way out of my fiances, easiest option was to build my own, took 2 years and 1000+ hrs, without lifting the engine cover its difficult to tell it from original so I know ive built it right, im a bit of a perfectionist there, still making changes as time goes on fitting orginal parts to give that finer detail.
I moved from Sidcup at early age, b4 driving, the car has been up that way on occasion when visiting relatives, but rare as dont like it left out of my eyes view. If the cars anywhere im not far!

Im in Folkestone now, less rush and slower way of life down here, if anyone fances a day out kettles always on.

On a side note, my old engine a 3.5 rover the bottom end started knocking and I took it out , while stripping odd parts off over time ive notice the push rods inside are adjustable and the valves have double springs, someone said that is rare and possible has big valve heads on, I havent taken the heads off and was going to scrap it, is this combination unusual? should I look into it further?

its worth investigating. It coud just be that someone could not get on with pre load settings and use the adjustables to make life easier. Thats what I do