Horizontal fan on a 911? LOLA PORSCHE

[911hillclimber]

I perhaps have a distinct advantage maybe: I'm an old guy. Daughter is 23 and nearly fully independant. Since she left Uni with a Music Degree she has NEVER asked me for money. A plus + I start work (in manufacturing, a dying trade) at 6.00 and get home for 6, so after tea straight to the garage alongside the house. Stay put till 10.00 no matter what except fri/sat/sun. Most of sat/sun in the garage! Having had a very terbulant affair with my Italian (welder) I am thinking of marriage to her (must be a she as she is so...moody[&:]) Fortunatly, my wife likes a Good Read, Spooks and such-like so I'm safe in the garage and never get any grief about time spent there. Also the house is quite modern, so not much maintenance! It's all in the circumstances! (sometimes contrived) [] Downside is at my age I can't remember page 1 let alone the one you refer to.. [] On the car front, I now have my discs for the March hubs, and I can't find the bloke who should be welding the one upright... []

 

[Alex Postan]

Look after your partners as you would have them look after you. I can remember magnesium welding back in the old days when FF1600 was the best racing in the world - (the winners were demoted to the procession of F1) You'd dismantle the completely buggered chassis from the remains of the the rear supension and gearbox, strip out the Hewland bits from the cracked case and strap it on to the pillion seat of the Honda 750 F2. Then whizz up from The Elephant & Castle to Hammersmith ((Racing gearbox centre) and a Kiwi would take the case, heat it up all over with a broad flat flame and proceed to flop great gobs of magnesium rod all over the broken bits. When finished it looked something like the worst bits of the elephant man but you were on your way back to Brandersnatch for next Saturday's qually...... Cost ? a fiver.

 

[911hillclimber]

It's gone up since then; £80 which I'm hoping will inc welding/machining.drilling. I was quoted for 2 new steel uprights to the March dimensions with bearings, drive hub/bolt-on wheels and outer CV with calipers and discs, all ready to bolt on. £3120 + VAT.....+ the weight + new wheels, so about £4K![:-] So far its £400 for the uprights, £80 for the one to be welded, £150 for the special 6 pin drive bells and discs. Need the calipers now, so about £500 and we are done. I get to keep the lightness and the March driveshafts and centre locks, and to use the Mag alloy 13'' x 12'' rims. I'm in for about £1200.[8D] Progress on the car will be slow now for a few weeks [:'(]

 

[911hillclimber]

Still sorting the drive train.... Anybody know the number of splines and the diameter of them for a 911 inner CV of the 100mm diameter type? Needs to go on the end of this:

 

[911hillclimber]

Got lucky twice tonight! [] Strangest things happen in the garage. The drivetrain that was in Terry's Nomad came with drive flanges in the 915 box with thick steel adaptors fitted. All nicely machined, but no good to me and the weird CV's from the March F2 rear shafts. Or so I thought... On removing the adaptor rings to see if I could use them again, I spotted under the murk 6 M8 holes all neatly filled in to plug the holes to prevent grease coming out. Low and behold, those 6 holes are exactly the right pcd for my wierd CV's! [8D] Some very carefull drilling and all the holes were open and the threads all ok. The flanges back in the box, the CV's bolted to the flanges and the whole lot fully lines up AND the driveshafts are the right length! Can you believe that the 1978 Lola rear end, fitted with 1974 March F2 rear suspension lines up perfectly with a 1985 915 Porsche box? [8|] It all does. The rear end originally was for a Hewland FT 200 box which was based on the humble VW box and we all know who did that design. This has saved me £540 for 2 shafts/CV's or £100 for making some new ring adaptors. Tha's paid for the HiTec brake calipers, or the Tilton clutch, or..... Neat or what? Thank you Terry and Crispin Manners for this surprise.[]

 

[jwhillracer]

ORIGINAL: 911hillclimber Got lucky twice tonight! []

Well done Graham! We'd better not ask about the second time then...........[8D] Cheers! JW

 

[Gary71]

I love it when a plan comes together!

 

[Alex Postan]

I'm not so sure that your CVs are weird. When we were Formula Fording back in the late 70's and early 80's, it was usual practice to turn down the outers of the CV so as to reduce the turning weight and also the overall weight. Yours look just like that; you could consider giving the outers the same treatment. We'd also take a rotary wheel to the inner CV grooves to make sure that they were as free and loose as possible. But then we were barmy in those days[]and even went as far as running the box on automatic transmission fluid rather than gear oil in the belief that it would reduce the friction losses in the transmission. Looking back, they were golden days - if you didn't win it wasn't because you didn't have the budget, it was because you weren't fast enough.........

 

[911hillclimber]

It has been a bit miserable on the car recently but this has made up for it. The CV's I'm told are Audi Quattro fronts from the early/mid 70's. They are 90mm dia with the 23 spline inner. Many F2/Atlantic set-ups used them. Nobody uses them today. Today they are mega rare. GKN Motorsport had not heard of them before... The options are usually 33 spline (FF) or 25 spline x 100mm dia. You then have wide/narrow and shallow/deep plunge. None of this lot would fit unless I could slip the F2 inner (23 spline) into the 100mm Lobro which would fit the 915 flanges. This quirk of luck and hidden discovery makes this project great fun overall. There are some big steps to make now over the next month plus making sure I've enough parts to keep me occupied over Xmas. The way things are at work, that Xmas break could be a 4 week one. (I am allied to the building industry...) Welding the rear chassis tight Finishing the rear upright (welding) Rear brake calipers/hoses Finishing the exhaust Oil cooler and dry sump tank/hoses Fuel system Electrics (hate electrics) I should be about 50% done by then! [&:]

 

[jwhillracer]

Hi Graham, I had gearbox output flanges made up by Bob Dayson, since the Porsche originals were 1/ VERY expensive 2/ Virtually unobtainable 3/ Nothing like as strong as Bob's units It may be cheaper to get Bob to make up flanges to suit whatever CV's are easily available. Cheers Jonathan

 

[911hillclimber]

When the F2 Cv's cry enough then I will be doing the full monty on the CV's. I hope with just 250 lbft at best belting through the drive train it will last 2009 and more, but I take your point. The Sierra CV's and shafts are huge by comparison and the same O/D as the 911 CV's and just £40 each. The killer are the shaft costs. Oddly, the splines in the upright CV's are huge on the F2 shafts compared to the gearbox side. You would think they would be the same? I came in from the garage early tonight as I've run out of 'big stuff' to do, so must spend more money to progress. I fancy doing the dry sump stuff now. Another £1000. Sometimes I wonder I should have done a 3.5 on my 3.2 on PMO's with a G50 box and Turbo brakes for my Bitza. What a nice thought, just so easy![8|]

 

[Gary71]

If you get stuck for anything drive shaft or CV based then give John at [link=http://www.davemacprops.com/index.html]Dave Mac Propshafts[/link] a ring. They are in the arse end of Coventry, but what they don't know about driveshaft, props, and CV joints isn't worth knowing! I used them for the CVs on my 911 after good experience with them making up custom prop and driveshafts for my old employer Prodrive.

 

[911hillclimber]

Thanks Gary. I'm hoping the lack of mass in the Lola will give the CV's an easy time as it is about 500Kg v the 911's 1000Kg ish. We will see at the first drop of the clutch!

 

[911hillclimber]

Some serious looking and thinking about the oil system today for this car. My Bitza (above) had some overheating this year in the rush of competition, something I do not want in the Lola. The plan is to have a dry sump tank of around 12 liters, a big cooler, about 3 litres and big hoses. The cooler will have a manually switched fan (might have it running permanently.) Pace do a nice big tank split in the middle to allow each half to be rotated. This neat trick allows much better alignment of the 2 major pipes, and also allows the fittings to be straight (cheaper and better flow) Bruce Anderson says the fittings should be -16 and -20 (ie huge) but the fittings used by Porsche are 30mm thread, and the brass pipes are quite small, even on the serpentine cooler tubes (which the bitza has). Anything with -20 is a custom built fabrication. The cooler can be big as I have the space, so 450mm long, 250mm high and a core thickness of 50mm will do. I've a good quote from Brise Fabrications for such a unit with -16's on one end. This again will make the alignment 'easy'. Paying £350 + vat is not so easy... I am using a snazzy filter adaptor again from Anderson instead of the engine cooler, and a -20 adaptor at the base of the engine there.(supply to the engine from the tank) Those of you actually paying attention to this drivvle will see a '?' mark on my sketch below. I seem to recal on impact bumper 911's there was a brass 30mm thread hose from the engine block to the front of the engine close to the belt pulley. Anyone have a picture of this hose? You remove it to fit SSI's etc to the later engines. If I can I will use one to keep this pipe away from the hot exhaust manifolds. Can anyone see any mistakes in my plan? It will all look a bit like this:

 

[911hillclimber]

You can relate the parts to this shot:

 

[jwhillracer]

I'm surprised your Bitza was overheating, our car only runs the standard 1972 S front serpentine cooler, and has never (yet!) overheated, even with double driving in the middle of summer. Why are you doing away with the engine oil cooler on the Lola? Is it not worth keeping? Try Concept Racing 01432 850889 for Dry sump tank and cooler. You make me feel guilty sitting here in the warm, and just going out to pump up the tyres and have a quick check over in the Spring.[8|] Cheers! JW

 

[911hillclimber]

The Bitza ran 212 F at one meeting but that was the day at Prescott Marshal's lunch Treat, 12 full bore runs one after the other...but sometimes 200 was seen. It has always done that. OK on the road mind. I'll check-out the contact!

 

[Alex Postan]

Graham, Keeping the oil cool is important for power and for reliability. I found that the serpentine was wholly inadequate for the track with a 2.7. Even a big mocal in the front wing is marginal - I have conidered changing to a front cooler or to have a second cooler in the LH wing with a crossover pipe system. If you run a fan on the cooler at the tail of the side pod, can I suggest that you make sure which way the air wants to flow and to run the fan in that direction? I have a sneaking feeling that it will pass from the higher pressure turbulent air within the engine bay/side pod to the lower pressure flow on the outside. Or is the fan to cool the oil after a run? Does the change to flat fan mean that you can't use the integral oil cooler as well as the external cooler? surely it is better to utilise the torrent of air that is produced by the fan and to reduce weight by using less oil and a smaller cooler? If you have 20 kilos of oil to warm up, would it be sensible to adapt a thermostat to your set up so that you can get the oil warm without subjecting the paddock to 20 minutes of fast tickover?[] I have had a look at the cutaway drawing of a 910 but that gives no clues - drawn by an artist and not an engineer. Keep at it, not only are you entertaining all of us but you are also creating a really intersting car.[]

 

[911hillclimber]

Thanks for the kind words. I had not thought about the direction of air flow! The engine came with the unusual flat fan, and the ducting to the engine cooler has 'gone', but the fabrication of the fan's shroud is too good to butcher. Terry ran this engine in the Nomad on the circuits with no probs, and a long hillclimb in the UK is about 55 secs (with me driving, 45 with JW driving [&:] ) You can find yourself with a running engine for ages at a hillclimb if there is a red flag and a major incident, so heat soak is a problem. My engine is about 250bhp tops, but then in 2010 who knows what will be squeezed in there..a 3.8? So; need to engineer for the future too. There is a stat in the block as usual, but a fan on the cooler matrix will help a lot. I think my layout will work ok.

 

[911hillclimber]

Back to basics... The Lola is right down to the tub abd fully welded frame. The pro welder has done a great job on the frame and the lower wishbones, so i can now do some wriggly-tin work. The underside of the tub is a bit second hand. Some rivits are worn off (!) a result of trailer and gravel-trap offs I think. Still, all repairable and I'm trying to keep as much as possible the original panels. The side pods are off now and must be the 3rd set on the car judging by the number of rivit holes in the floor... Some tin snips and some fresh folds will see to that and the floor can be painted satin silver. I'm planning to use Monel pop rivits for the areas I think are carrying stress. The rest will be large panhead pops. I can replace some of the Lola rivits with solid types where access is tight. This is where the build-up really starts, so quite good to be at this stage. The dry sump parts are sorted, just waiting on the price for a 14 litre system, 10L tanks, huge cooler @ 2 litres and some fat tubes, -20 would you believe. Hope this is not too much of a bore, but the easy bit has been done! (putting the engine and box/transmission in) Finally I have my magnesium upright welded and back, so soon the suspension can be loosed on and the brakes done too. Xmas break coming soon and short time working at work. My boss says I have to take a pay-cut of 4.5 hours a week but do the same hours and more. I officially do 37.5 hours, so about 12% drop, but actually do 6 till 5 so about 48 hours, but that does not count some how. Guess I'm not alone. []