Flippin heck! - who nicked the pump!

[Paul Thompson 'Hooligan']

Hi all -

Was working over at Roys today on the 40 - still in bits but much progress has been made and gearbox has been fully refurbed, with new seals/gaskets thoughout - ATB Diff reworked - and we now have a 5th gear with teeth again! /ubbthreads/images/graemlins/grin.gif Talking of which - if anyone has a 'long-set' for 5th on the UN1 they want to sell - please let me know (gonna make the 200 or bust this time!)

On another note -
WHO NICKED THE WATER PUMP? : /ubbthreads/images/graemlins/smile.gif

 

[Trevor Booth]

I hope the (presumably) electric pump has plenty of grunt.

 

[Paul Thompson 'Hooligan']

Hi Trevor -
You assume correct, and time will tell. We know a number of people using the Davies Craig pump who have been very pleased with the results but I'm sure there will be a learning curve. The alloy Clevor block is fed from front and water flow through the head is controlled by a head gasket that incorporates graduated hole sizes to ensure water flows to rear of head ok. The water exits through the front of the heads through removed core plugs.

We will be logging the engine water temp as it leaves the heads using the Motec system and may use the ECU to control the Rad Fans and possibly water pump. I may add a few additional sensors elsewhere in the system as it might help us devise a better cooling control solution.

Finally, the gearbox is being fitted with an external electric oil pump and cooling rad (+ filtration) in an attempt to get the Crown and Pinion to last longer - we feel we are beginning to overstress these components. (on 3rd or 4th? set now) A specific oil feed may additionally be added to further lubricate 5th gear but the crown and pinion might not be fed also, as doing so robs power and we suspect that getting the gearbox oil temp down will help anyway.

Should make for an interesting season if we ever get finished. /ubbthreads/images/graemlins/grin.gif

 

[Jools]

Roy said his water-works needed attention , now I see what he ment /ubbthreads/images/graemlins/grin.gif
You two just can't ever do things the easy way can you !!
I'm waiting to see the "portable waste atomic fusion re-acter " that I'm sure you've got planned to fit next season /ubbthreads/images/graemlins/shocked.gif When you finally get that thing to fly / or the whole world starts to rotate beneath its tyres I'm not playing with you any more /ubbthreads/images/graemlins/grin.gif

 

[Trevor Booth]

Paul,
you could do a lot to the external plumbing to make it easier for the pump. Mandrel bent smooth radius bends will make a huge difference. The transition from the two head outlets to a single is critical as you may preferentially serve one over the other. Monitor temp at each head outlet will show this up (if a problem and all other things are equal) On high HP marine engines I have run two smaller pumps rather than one large one. (belt driven two stage) Not tried in car but same theory applies.

On the subject of gearbox lube. Pressure fed system uses less power than splash system and is more effective in putting the oil where it is needed. You could run a small pump off the front of the camshaft or off the drive shaft at rear and add external oil feed lines to each gear set. The HP required to drive the pump is far less than gears running in an oil bath.
Or you could put a ZF in the car.

have fun
Trevor

 

[Russ Noble]

[ QUOTE ]
On the subject of gearbox lube. Pressure fed system uses less power than splash system and is more effective in putting the oil where it is needed. You could run a small pump off the front of the camshaft or off the drive shaft at rear and add external oil feed lines to each gear set. The HP required to drive the pump is far less than gears running in an oil bath.

[/ QUOTE ]

Trevor, this is interesting, you are obviously talking about a "dry sump" type system here, presumably with a seperate scavenge and pressure system and oil tank? Is this the usual way of enhancing the oil feed and cooling, or just the best way? Is there sufficient oil splashed around to lubricate the bearings or does oil have to be directed to those as well?
I have observed several oilfeed/cooling mods which appear to be merely an additional pump to circulate oil through a cooler and direct it back onto the gears as an enhancement to the original "wet sump" setup. Although I might have got it wrong.
The dry sump system seems to be a better system. I take it that it's a common racing application? Do you feel it is worth the extra weight and complication?

Regards,

 

[Trevor Booth]

Russ,
A pressure fed system is the better way to lubricate the trans. What you have probably seen is a circulating system to cool the oil. This is commonly used in racing car trans. The lubrication is still the splash system. For a pressure fed system you would need a scavenge and pressure pump. The oil tank can be common with engine dry sump tank (if trans can run engine oil). Generally the bearings would be lubricated at the same time as the gears but this depends on the trans.
If you were searching for the ultimate in power or trying to save an overstressed trans (as in Pauls case) the complexity is worth it. For normal use probably not.

 

[Paul Thompson 'Hooligan']

Hi again -

Initially we will be using a pump to circulate gearbox oil through a filter and cooler in an attempt to aid the oil maintain a better working temp (any suggestions on such a temp???) After that, a pressure feed to at least 5th and the crown/pinion + possibly all later.

We have made lot's of changes - with more to be done so its going to be a busy time. I have sorted the adapters required now to fit the replacement 59lb injectors so a re-map is going to be on the cards although we will probably wait until we have test run the new plumbing arrangements first.

Asking again for opinion - what is the maximum temp would you like to see in the transmission?? /ubbthreads/images/graemlins/smile.gif

 

[Trevor Booth]

Paul,
Your max temp will depend on the ability of the oil you are using to maintain its viscosity at elevated temperature. Ask them for a viscosity/temp chart. You will see a point where viscosity drops off sharply, stay below that point.

I would be getting nervous if the operating temp is at or near the drop off point. For your situation where the trans is working hard I would be aiming for around 65ºC to 85ºC but I would consult with the Oil Coy.

Oil breaks down due to viscous shear and temp is the enemy.

I have for a number of years used a heavy duty Automatic Transmission Fluid that can cope with elevated temps. Most gearboxes should be OK with ATF but I have never used it in a high HP transaxle set up. Discussion with oil company may indicate that it will cope with the CW & Pinion but I have not done this.

The other aspect is what the trans itself can cope with and that is probably a process of experimentation. It is probable that the trans will cope with a higher temp than the oil.

Why dont you divide the return line and let it return to the trans above the gear sets incl CW&P

How are you going to know if the cooling system is as efficient (or better) than it was before if you have changed injectors and re map.

Cheers

 

[Paul Thompson 'Hooligan']

Hi again Trevor

Thanks for the comment - I will check with Silkolene and Shell to see what they say re temperature as you suggest.

Re the re-map, as I said we will run the car 'as was' initially as we are familiar with its temperature signature and can check logged data too. With the addition of extra sensors in the water system, I would look to log their readings and ensure all is well with the system before the new injectors and remap.

The problem with the existing injectors is we are running out of time to inject at higher rpm. Was not a problem when they were batch fired in pairs with the Accell as we often pulled to 7500+rpm, however, since moving to 347ci with Motec, I switched to fully sequential and the injectors need to be bigger. Max revs recently has been a little over 6K, say 6200?

Also - re the trans, we have considered splitting the return and feeding both c&P and 5th and may well do so in time.

Thanks for the input... /ubbthreads/images/graemlins/smile.gif

 

[Trevor Booth]

Paul,
My translation from english to Oz was mala. I read that you were installing the 59Lbs and re-map later.

I am not an EFI guru but I am of the understanding that you can vary the open and close set points with a Motec to counter the lack of time issue.
Cheers

 

[Paul Thompson 'Hooligan']

Correct - but our base pulse width with the existing injectors is now too big. A function of bigger capacity engine and being used sequentially.

The larger injectors will enable us to reduce the base pulse width, as they will flow more fuel in a shorter period of time and hence we should be able to rev higher.

The injectors we will be using are low impedance (1ohm) Bosch items, which have been proven to be good for up to 800+ HP on other V8s.

 

[Trevor Booth]

I know the Bosch units, they are very good. 59lbs is a big injector. The trend in Oz is not to get too big in injector rated flow for better atomisation at the actual flow rate. The good guys with mega dollars are getting 650-700 FWHP from 302 on unleaded fuel. I have cranked near 200FWHP out of a 1600 4cyl with set points that far apart it was almost a constant flow!! Admittedly it ran concentric above butterfly injectors and offset crank trigger.
As we all know it just takes time and money