Australian Belly Tank

[Dr Goggles]

Doc, add a little time on the dyno, it sounded like you might have been lean on top. If you are using ram air, it is harder to simulate on the dyno but set it fat.  Then when you run it keep adding fuel till you stop going faster.   Or get one of the air/fuel thingies and be at 12.2.

Now, we do have a scoop on top the car....however, the scoop is not sealed against the throttle body housing and behind it are the louvers in the cowl.....the idea of the scoop was to stop airflow across the top of the TB's..OK this ain't necessarily scientific but I didn't like the idea of smooth airflow across the top of the (vertical) TB's figuring it would hinder flow, whereas the arrangement of the scoop is such that airflow is forced downward, but I wouldn't call it ram air because less than 50% of the area at the base of the scoop is TB, the rest flows over the engine and leaves via the louvers ....below is a pic of the car on it's first day out, before the scoop, before the second throttle body was added


As you can see the bodyline is heading in at that point, so there is potential separation as well as the venturi effect I discussed above.....it may be as I say myself "bad science"....but we had no data to go on and my gut feeling was that we were better with than without.....now when I think about it I guess we are getting some ram air at that point when we're doing 193 and there is of course the possibility that the MAP sensor or something is creating a bit of "conflict".......that is a possibility .......here is the car last year, with the scoop.....



here's another shot from last year that shows the scoop and louvers behind it( for the nit-pickers, the cowl ain't buttoned up here), that's Frank Kletschkus  the guy who shot the pics mentioned on the previous page,former owner of a Brough and current owner of a 42 Scout...great photographer who deals up a pretty good coffee....

[fredvance]

I have a tire that is my dyno tire/wheel. That is its only use, dyno only.

[Dr Goggles]

I have a tire that is my dyno tire/wheel. That is its only use, dyno only.

engine dyno for us, that car is a nightmare ANYWHERE other than the salt....we coooooould take it to a chassis dyno in the nude but to be honest it's a whole lot easier to pull the donk and take the exhaust with it......

[hitz]

Dr G,
Read your post a couple of times about your runs and the engine seal leaking. I had troubles with the power falling off also at speed week 2009 and oil being pushed out of a crank seal. The last run the little Saturn pushed enough oil of more than a few places that I could smell hot oil in the cockpit. That put it on the trailer.

When I got home I pulled the engine apart and saw evidence of what looked like lack of oil. I'm sure the oil was aerated and causing most if not all of my problems. The pressure in the crankcase was probably from the piston ring seal breaking down and the power loss was probably from air in the hydraulic lifters. A few hrs in the pits would let the air out of the oil and things would be good to go. The last run was a turnaround and things got much worse quicker. Just a heads up.

Rev,
The lay out work on the tank turned out great and is one of the nicest looking tanks I've seen.

harv

[Dr Goggles]

Dr G,
Read your post a couple of times about your runs and the engine seal leaking. I had troubles with the power falling off also at speed week 2009 and oil being pushed out of a crank seal. The last run the little Saturn pushed enough oil of more than a few places that I could smell hot oil in the cockpit. That put it on the trailer.

When I got home I pulled the engine apart and saw evidence of what looked like lack of oil. I'm sure the oil was aerated and causing most if not all of my problems. The pressure in the crankcase was probably from the piston ring seal breaking down and the power loss was probably from air in the hydraulic lifters. A few hrs in the pits would let the air out of the oil and things would be good to go. The last run was a turnaround and things got much worse quicker. Just a heads up.
harv

The Colonel and I stood around out in the shed for a bit this afternoon and mulled over some of the results..the possible explanations we went through did not include that one but there is no reason why it might not be right.....we discussed using another vac-u-pan and putting a non return valve on the pcv fitting so it'll vent if it does get positive pressure... I'm going to speak to an engine builder in the next few weeks about sorting our heads, we're going to solid lifters  and roller rockers we'll probably also go for bigger valves which Chris ( the engine builder) suggested would be a good idea...........At the moment we still have a close eye on the cost, we have a decent bottom end , if we make it breathe better we might get some decent speeds out of it before we break something, the loose rocker this year was a lucky escape......

I took the tail off .....I emptied the fuel tank...nothing leaked down there, everything looked ship-shape, I emptied the first of the three extinguisher bottles..... cut myself on an exhaust gasket.........

It was interesting to see the car after this years meet more serious fretting and vibration wear in places where things touch.....The car did a lot more miles than last year ,thinking about it the short course runs would be about eight miles, the long course would be fourteen or so ....that means the car did about 45 miles during the week........ and some of them a lot faster than last year so obviously its copped more of a beating, the salt was a lot harder and didn't seem to grade as smooth...nothing was broken though but there's a lot of paint off the frame , it's looks old.........

time for a total tear-down.....

[Dr Goggles]

".....If a picture paints a thousand words....".....it really only needs to be four......this one says......."I think it's broken"....



it was taken by our good mate Dirty Dave , It's me , no not Al Jolson.

[bvillercr]

Clasic picture, that is worth a thousand words.

[wobblywalrus]

The breather problem might be a good one to investigate when the motor is on the engine dyno.  You can put a pressure gauge on your valve cover and measure crankcase pressure while under load.  Also, you can compare your breather fixes.

[Nexxussian]

If you are interested in measuring crankcase pressure or blowby, might I suggest a manometer.

If you are expecting enought blowby to have pressure, Cummins has a reference somewhere to hook one to the crankcase vent (without a vacuum pump or other crankcase evacuation setup) with a restricted outlet to read the flow of blowby.

If you are just trying to check for the pressure you could hook it up without the restricted outlet.

If it's beyond the pressure a manometer can practicaly register I would suggest it's too high regardless.

[Reverend Hedgash]

Is there any good oil on what the good oil is to use?

if aeration is a problem, can this be alleviated somewhat by a type of oil?

rH+

[grumm441]

If you are interested in measuring crankcase pressure or blowby, might I suggest a manometer.

That makes a lot of sense and it's not something I would have thought of
I used to use a manometer every day balancing bike carbs
Probably not that practical in the car, as Goggs said he couldn't even read the 5" tach
But certainly something to check on the dyno
G

[Nexxussian]

Yes, dyno use, should've mentioned that.



I would think a "lighter" weight oil would let loose of the "air" entrained therin more rapidly, but it would also likely reach a critical weakening of the film strength sooner (as I expect the film itself would be thinner).

If Blow by and Windage prove insurmountable, some of the dry sump manufacturers make a mechanical de-areator, I don't know that they sell them separately though.

Of course if there was room, a dry sump would be the ultimate fix for that.

Yeah, not in my budget this year either.

[Dr Goggles]

Here's some shots that have come in from Frank Kletschkus ( http://frankkletschkus.moonfruit.com/#/speed/4533837790 ) ....on his site are some absolute beauties....

these are all light-hearted....hey we can never be accused of taking this all too seriously.......

On the Sunday after a big downpour on the Saturday night , up to when the lake was dry as a witch's tit, lucky thing though was the salt was still as hard as concrete...at this point there was about 3/16ths of an inch of water running away from you in the picture.....


Packing the 'chute, the Rev, Nigel, the Colonel and ...hey if I hadn't them out you'd be able to see my tonsils.....



Laundry hung out to dry on the return road.....



Heading back to the pit , the Rev as beast of burden,Nigel Begg riding , Dr Goggles in undies on the push bike and Big Gaz( Aussie Jaguar build) in the DLRA top.



Next we're on the line , The Reverend tucking me in....That's Cled Davies our starter and new Pres and PJQ our immaculate transport and good friend...



On the way back on the return road from the eight mile, it's a long trip ( and, I have to tell you a darn sight more comfortable riding like this)and one tends to get a little peckish, those are barbecue shapes.



Next we have a moment in the pit when after driving back on the return road I was sure I could hear a clatter, when we started it again at the marshalling area she was missing badly, at that point the Colonel said "turn it off I can see something hitting the cover, right there!"....we waited til they closed the track for the day so at least we had a spot in the line then headed back to the pit.....here we have us all looking on while the Colonel does a little Zen thing with his eyes closed as we wait to see what was revealed ....turns out the rocker stud had just undone itself, no damage other than a little swarf.....phew

Looking straight down the gullet, not much room for anything else in that engine bay, striping by Ryan Ford..........



Thanks for the T-shirts Stainless,that's me the Colonel and the Rev'




The Rev may well have been nodding attentively at this point but I pretty sure whatever I was saying would have come out as "mmmmmmble oomph blllblllrdd "...just like anyone talking fast with a helmet on and the visor down...... the hand motions are critical.

[wobblywalrus]

The seal blow and excess crankcase pressure can be caused by a number of subtle problems related to engine tolerances.  The book "The Step-by Step Guide to Engine Blueprinting" by Rick Voegelin ISBN-13 978-1-884089-26-8 helps me a lot.  It does not go into the details of how to blueprint.  Instead, it tells the average person what blueprinting can do.  Cylinder distortion due to heat, excess ring end gap, poorly seated rings, and a number of topics discussed in this book might be your answer. 

[SPARKY]

The "lady" post a stylish pict. with her laundry out