Wet race tyres

[COLIN STUBBS]

i think weve hit the nail on the head here. denis needs a standard oil pump. i had similar problems using a big flow pump in an essex. iv been paranoid about oil pressure for years[as it shows] and spent far too long sorting it. its amazing how you need to go back to basics to get a solution sometimes.trouble is denis it dont matter what you do-you will still beat me!! see you at silverstone? hope my new lsd dont give me terminal oil surge cos after all iv said i havnt got an oil pressure gauge in the rover!!

[Al Weyman]

And as the yanks say 'If it ain't broke, don't fix it' and I have read that many times or words to that effect in relation to chevy oil pumps. I think we sometimes forget that the factory builds engines to do what 150,000 miles plus and all we are asking them to do is hold together for a few hundred laps at most before a rebuild.

Do you have a 25psi idiot light fitted Colin. :-)

[greenamex2]

The reason I have an external oil pump is because my original engine builder blamed a blowup on the standard oil pump cavitating. Subsequent investigations/engine builders have proved that this probably wasn't the case and the problem was simply oil surge due to poor sump baffling/no accusump.

Maybe we need to investigate re-commisioning the original pump?

Certainly my old spare engine never had ANY problems in that area and that was running a standard pump. But that only revved to 8500RPM and produced 168BHP.

The comments re the accusump are correct. It is even worse than that. even when it isn't helping it is consuming about 10psi out of the oil system just pushing the plunger back. And when it does 'help' you now have an extra litre or so of oil floatig around inside your engine!!!

On the subject of oil pressure, I am beginning to come to the same conclusion, especially with modern synthetic race oils (I use Royal Purple). Due to oil leakage and insufficient oil cooling I have regularly run pressures down to 45psi and temperatures upto 120 degrees C. We checked the big ends and they were all fine.

I'll be at Silverstone. Don't know why I wasn't on the final instructions, my entry was in on time. Not if it's wet I won't beat you!!! If you want an oil pressure guage cheap let me know, I think I have an old Racetech oil pressure/water temperature guage lying around somewhere.

[COLIN STUBBS]

Al my car is one of the old 216gti cup cars and is bog standardish at the min,even down to the instruments. the honda motor seems to be nearly unmoddable and nigh on bullet proof. cant live without a gauge though. think you better bring it denis. my race spec ecu should be ready any day now,the honda fireblade throttle bodies are nearly ready to fit and.......... here we go again!!!!

[greenamex2]

Once you've got your race ecu your engine will be very moddable. Just depends how big your wallet is!!

If you want the oil pressure guage working for Silverstone you'll need to sort out the plumbing beforehand (it's capillary not electric). Do you need any details from me?

[graham bahr]

Originally Posted by Denis Bassom

Certainly my old spare engine never had ANY problems in that area and that was running a standard pump. But that only revved to 8500RPM and produced 168BHP.
.

i dont really revs as an issue with oil pumps, imps happily rev to 10,000 on std pumps, my mate had a rally car back in the 70's with a 1300 x/flow with A8 cam and all the works, that also reved to 10,000 on a std oil pump, on its last meeting a threw a rod, but the bearings were in perfect condition still, i know i've still got them,

anyone want 3 lightened, polished, truftrided 1300 x/flow rods?

[graham bahr]

[QUOTE=Denis Bassom]
On the subject of oil pressure, I am beginning to come to the same conclusion, especially with modern synthetic race oils (I use Royal Purple). Due to oil leakage and insufficient oil cooling I have regularly run pressures down to 45psi and temperatures upto 120 degrees C. We checked the big ends and they were all fine.

QUOTE]

my old atmo car never had high oil pressure 50psi max. one day i had an electric waterpump seize whilst leading a race, i finished with a watertemp of 130.C oil pressure was down to 20psi at seriously high revs, when cooled off normal oil pressure returned so i just finished the season, when i stripped the engine at the end of the season, the bearing faces were in perfect condition! although you could see the back faces of them had been fretting in the rods but thats no suprise 20psi at 8,000rpm, it seems at even that low pressure there was sufficeint oil to lubricate the bearing, if not hold it a tight to the rod as it should be.

at very high revs rods deform and are no longer round, the low oil pressure was insuffient to keep the bearing properly in contact with the rod, i dont recoment that you run such low pressure as i ended up changing the rods, although the crank was reused without even needed a grind!

[graham bahr]

[QUOTE=Denis Bassom]

Certainly my old spare engine never had ANY problems in that area and that was running a standard pump. But that only revved to 8500RPM and produced 168BHP.

QUOTE]

from memory thats not THAT much higher than the std Toyota engine reved to anyway

[dtype38]

Originally Posted by Al Weyman

And as the yanks say 'If it ain't broke, don't fix it' and I have read that many times or words to that effect in relation to chevy oil pumps. I think we sometimes forget that the factory builds engines to do what 150,000 miles plus and all we are asking them to do is hold together for a few hundred laps at most before a rebuild.

Do you have a 25psi idiot light fitted Colin. :-)

I'm not Colin, but I just thought I'd mention that I threw my 25psi idiot light away. I've got a standard oil pump and an unbaffled sump, so every time I hit the brakes during a race the light would come on. Going downhill it came on for quite a while. It made me worry a lot, but I kept racing. At the end of the season I stripped the engine and all the bearings were perfect. I've now fitted a 7psi switch for the idiot light and it doesn't come on at all, and I've stopped worrying about oil pressure

[graham bahr]

Originally Posted by dtype38

I'm not Colin, but I just thought I'd mention that I threw my 25psi idiot light away. I've got a standard oil pump and an unbaffled sump, so every time I hit the brakes during a race the light would come on. Going downhill it came on for quite a while. It made me worry a lot, but I kept racing. At the end of the season I stripped the engine and all the bearings were perfect. I've now fitted a 7psi switch for the idiot light and it doesn't come on at all, and I've stopped worrying about oil pressure

err yes i can see your point, obviously your engine still had sufficeint oil pressure to lubricate the bearings, and it generally wont do any harm if your on the brakes rather than the throttle, however if i were you i would baffle the sump as you know the pump IS being starved of oil, just in case, you never know, but one day your engine might leak or burn a bit of oil, or maybe you go out with a slightly low oil level, and do some damage that would of been other wise prevented by a few baffles

for the record i use a 7psi switch

[COLIN STUBBS]

cheers denis bring the gauge and ill fit it later. thanks mate. on the subject of a light coming on whilst braking-maybe the engines off load at the time and oil pressure is restored by the time you get your power back on. trouble is when your lights on theres air going thru the system.under load one bubble of air can be enough to spin a bearing. guess some folks are born lucky!! iv never seen the standard oil light flicker on at all this season and seeing as how the cars been thrashed round since 1991 on slicks and im mostly on toyos now its not a problem,but if we get a bit more power out of it/spend some money on it/do some lma next year i might not sleep without some gauges and a light.

[greenamex2]

Having just seen how much a set of Dunlop R's cost Al (650 quid), I am going to stop complaining about my cars lack of wet weather ability and replace my wet weather tyres every year, and have a holiday.

Maybe.

[dtype38]

Graham... I'd love a baffled sump. I've been quoted £500. It's on the shopping list with three Webber48DCOEs, new cams, outboard rear discs, a new diff, new rear wishbones, new dampers all round, a bonnet, a new steering column, adjustable anti-roll bars...... all I need now is one of them sponsor thingies! :-)

[greenamex2]

£500 sounds a bit dear, it it a custom gold plated item?

I would have though a decent welder (ie not me) could fabricate one in his lunch time given an appropriate pattern!

[graham bahr]

Originally Posted by Denis Bassom

£500 sounds a bit dear, it it a custom gold plated item?
!

does seem more than a little expensive!!!! why not fabricate a bolt in one?

[dtype38]

If it was a simple case of welding some plates in I'd probably use the money towards a tig welder and do it myself. Unfortunately... or so I'm told... its not that easy. My sump has a deep rear resevoir about 1/3rd the length of the engine. The rest is very shallow, not much clear of the crank. Putting in some cross webs would stop oil from the front of the engine getting back to the resevoir. The only one I've actually seen had a complicated series of shallow serrated plates and wears along the whole length to allow the oil to flow back to the resevoir, but not surge forward under braking. I don't know of a commerically available one (the qoute I had was a make-to-order one-off). I think that's cos most serious (ie rich) Jag racers go dry sump... and that's a great deal more expensive. :-(

[greenamex2]

Just copy an existing design. American V8 sites (eg Moroso) are littered with piccies of designs.

What do you have at the moment?

[Al Weyman]

I bought a 3 stage weaver pump, a dry sump pan, all the lines (braided) fittings, MoonEyes tank, Aircraft screen filter, gears, belt, fittings the whole monty for £650 off eBay a while back and had it shipped from the USA.

[dtype38]

My current sump is from a standard S-type XK3.8 saloon. It has a bolted in plate with an internal baffle over the rear resevoir and a hole in the top where the pickup pipe goes in. As an aside... just to venture even more off topic! at the last rebuild I discovered that my dip stick was the wrong one for my engine and I was overfilling with oil by about 1/2"-3/4". I decided to lower the oil level and was pleasantly surprised that not only did this reduce the oil spat out into my breather tank (about 1/2 a cupful per race) but also seemed to improve the oil pressure. I can only surmise that the overfill was spending time being worked by the crank (ie dipping in the sump) and that this was increasing the overall oil temperature....??

Anyway.. Al, I think you got a real bargain there. Most setups I've looked at start at £2k mark. In my case, though, I don't think the extra weight and complication are needed for now. I don't do endurance racing and my engine is already as low as it can be mounted in the chassis, so the benefits would be few. :-)

[greenamex2]

You are correct about the reduction in oil temperature theory. If I could ever get my dad to listen to me we would benefit from the same thing!

Your lucky, my engine is chucking out over two litres into the catch tank during a race. We know it is OVER two litres because we only have a two litre catch tank, and a very smoky engine bay! I fitted a drain back to the sump so we can at least reclaim some of the oil.

Talking to people over the weekend, it seems most of our competitors either want or are not adverse too dry sumping so I think there may be a rule change or two over the winter. 10,000RPM here we come!

[graham bahr]

[QUOTE=dtype38]
I decided to lower the oil level and was pleasantly surprised that not only did this reduce the oil spat out into my breather tank (about 1/2 a cupful per race) but also seemed to improve the oil pressure. I can only surmise that the overfill was spending time being worked by the crank (ie dipping in the sump)
QUOTE]

could be temperature, but more likely is suspect is the oil wasn't getting as airated by having the crank wisking the sump contents like a food blender

[greenamex2]

True, you'd need an oil temperature guage to know for sure. But if it is fixed, who cares!

[greenamex2]

PACE are so fed up with my constant phone calls etc that they are going to look over my car and make some recommendations. Top blokes.

[COLIN STUBBS]

hi dennis pleased to hear you ok after looking in the marshals section. hope it wasnt an oil related problem you had. would have been there but had to take gf,s daughter to uni.10000 rpm,dry sumps,wotever next! when will we get to know whats happening with the toyos for next year?

[greenamex2]

I am going to phone Gerry today to arrange a get together at Silverstone.

And get a new door square to de-Peugot my car. Nothing serious, just a difference in cornering style between FWD and RWD.

The dry sump came about because our cars keep going quicker and quicker as we get used to the Toyo T1R's and some cars can't cope with a baffled sump and accusump alone. Unknown to me several others are suffering the same problems as me. One guy has done SIX engines in the last two years, hardly cheap racing!!! It will of course be discussed and agreed with all existing participants.

There were some other ideas discussed around a cheaper entry point for the series which will no doubt reappear at the official get together.

My car may started revving past it's existing 9500RPM, but it still won't make any torque or go round corners (especially in the wet).

You have a mail by the way.