Tuesday, May 20, 2008

Interesting alloy welding stuff


No idea how well this works...

Might get me a 5 pack of rods to see.

Could be ideal for tacking up unimportant creations prior to TIG welding, doing small repairs, filling holes, leaks, filling up areas and sealing non structual gaps, panelwork.

Gearbox tunnel Part 3

Been messing with a load of ideas.

Here is a one test one made from plastic sheet (that came with some perspex).

Decided its poor idea.
I have come a better solution I think.

Having removed all material ready for some kind of tunnel I am left with a pretty big gap.

Well. Why not use the original radio frame to make the tunnel two piece?

The area from the radio frame to the bulkhead can be a pretty much perminant fitting.

If I have the top panel heading up as far as possible at the front to meet the sealing flange under the heater and heading down to meet the radioframe just under the radio slot, I can get the engine out without having to remove the front section and radio frame.

Also the radio frame can be bolted to the dash via a fabricated mount. This mount can also bolt to the top of the dash, the dash is MUCH stiffer than the normal one, so this would tie up the area and stiffen it.

To join the radio frame to the bulkhead I can get some 3/4" solid alloy box section and make a frame. This frame will run around the bulkhead area where the gearbox tunnel would normally seal to via the rubber seal. It can also run along the floorpan to meet the radioframe and seal to the body there. Then two more sections can run from the flange under the heater to the radio frame just below the radio slot. I can cross brace this with some box section. I can then bolt on some sheeting. To seal it up. This radioframe and new framework can be solidly mounted to the chassis via the radio frame, dash via the radioframe and also solidly mounted to the bulkhead via some M8 or 5/16th bolts. I can then just run a beed of sealant between the flanges when fitting. No rubber seal, no leaks and the front of tunnel ties the chassis/bulkhead/dash together in 6 planes.

That will just leave me with a rear section from the frame to the remains of the tunnel hump.

I am not that concerned by the amount of hump I have removed, as its floppy as playdough anyway.

Not quite sure how I am gonna execute this plan. Its gonna be a real pain taking it out and getting it welded elsewhere. So may involve alot of hassle. However it's the best plan I can formulate to add strength and give me a nice neat tunnel.

First task is to test how well new alloy can be welded to the cast alloy radioframe, lucky my cousin has some special welding rods. I will need to pickup another pair of radioframes as this one is not mine and test welding on it. I can bolt the frame together via a series of countersuck head hex bolts also.

The front face of the radio frame is currently arched to fit over the stock gearbox tunnel. Will need to fill that it with new metal and add a solid flange heading out @ 90deg to the frame for the rear tunnel section to mount to.

This has been doing my nut.

Saturday, May 17, 2008

Gearbox tunnel

Still pondering my options.

Maybe sometime :)

Kind of interested in something a bit more novel than normal...However struggling to find inspiration atm. Tempted to make something solid to stiffen up this end of the tub...However its quite complex.


Wednesday, May 14, 2008

Trick way to bolt down a gearbox tunnel.

Dzus fasteners :) 1/4" to release...No messing with screwdrivers or spanners...You can use big penny washers to spread load.

Tuesday, May 13, 2008

Gearbox tunnel

Well that time has come.

Being as I REALLY dislike filling, sanding and that nonsense, I may go for the original idea of making an alloy one from 2mm.

I can make a simply make one from 3 pieces of alloy and pop rivet it with 6 pop rivets and tangs to hold it together and get it seam welded by my cousin.So here is a scale model in cardboard.

I was hoping for a smooth and rounded look, however that means making the plug, then vac forming or making a fibreglass one, which could take a weeks work I reckon to get it right. This way I should just be able to get an alloy sheet and get going.
The flat area on the top also gives me room to add some kind of parcel shelf/glovebox on top. Once made I can sort out the steelwork at the back by the handbrake.

The flat area and legs at the bottom running back + vertical front surface can be made from one piece with 3 bends. The side panels can be welded in.

Just makes life easier, cheaper and less hassle. I can have absolute control over the object then too, so it will be quaranteed to fit. Where the vacuum forming may not go as planned.

I could round the back off to an arch but thats extra complication. I can add an inspection hatch for gearbox filling also.

Saturday, May 10, 2008

Water Waffle, redesign complete.

So the redesign is done bar the final welding.PRRT with its new hoses. 135 deg x 32mm and two 45deg x 32mm I/D.

If you want to neatly cut this stuff get some 32mm tube or the same I/D as the hose. Insert it, wrap some masking tape around at the cutting point. Cut around with a razor sharp knife using the masking tape line as a template. No nasty fluffy edges...Use a tiny bit of fairy liquid to get them on if tight...
All fits nicely. No stress on anything.
Ok thats the main bit done. Now the waffle.

With the EWP system or a normal system not the PRRT you could be quaranteed the swirl pot would flow outwards...However I read of some Caterham owners using the massive new bypass pipe as a heater return (to ensure all water goes via the PRRT (to quench any differentials before the engine = perfection (heater matrix cools fluid)...(bypass is the thing between the swirl pot and PRRT over the strut brace)...

This has made me paranoid about the pressure differential between depression and pressure and where this happens. As surely if these caterham owners are using the bypass as a place to return the heater water, then its either static (no flow pressure or not under a depression or suction from the pump (different to flow, I mean pressured flow, rammed or sucked...)...So its either niether suction or pressure and the Caterham owners are relying on the heater feed pipe pressure to blow coolant through the heater and its enough force to get it to return to the bypass or the bypass is under suction, or their heaters don't work?! System doesn't flow...Bypass could be pressured on the pump side, so the heater in and out are under pressure??...The heater is feed from the water rail, just before where my temp sender is, just after the kink out of the head. I will replicate the Caterham system.

Either their heaters as said rely on pressure from the water rail or the bypass is under mild suction or some combination of these factors or their heaters don't work well.

The heater is not my concern.

My concern is now having fitted the PRRT, the swirl pot MAY not be under constant pressure with coolant flow. So it may not always blow water out of the top outlet and into the airspace in the header tank. It would do with with the normal EWP or Thermostat, or with a remote thermostat as the radiator or small bypass acts as a restriction / centre of the system with the EWP alone and no stat. So the top hose is pressure, the bottom hose is suction.

They don't call it a "pressure relief stat" for nothing....It relieves pressure differentials also, flow pressure differentials...So it screws up my whole swirl pot plumbing.

I could bin the swirl pot...But I'd like to keep it as a 4 way union.

Same thing happens when you fit a remote stat in the top water hose, pressure and suction are placed on top and bottom hose...The small bypass creates a restriction so pressure will build up before the stat and small bypass, so swirl pot will flow out into a header tank with high pressure suction line in the base....

So in every situation bar the PRRT the swirl pot will act properly.

The swirl pot is the highest point of the system, which is not perfect as when the coolant contracts it will suck some air back into the pot as the swirl pot outlet/vent tube goes to air space in the header tanks and is above the water level...This will be immediately blow back out when you run the engine and any air quickly removed, alteast with EWP/EWP and remote stat, EWP and normal stat., stock pump and no stat, stock pump and normal stat, stock pump and remote stat. Under all these scenarios the swirl pot will be pressured and work fine.


With the PRRT (pressure relief remote thermostat) bypass being so big and used ALL the time bar when the engine is boiling 100C and the stat closes the bypass completely, there is NO assurance the swirl pot will not suck in air with the outlet line in airspace in the header tank.

I need to make some adjustments now.

The swirl pot outlet line must now go to below the water level in the header tank as its not assured the swirl pot is under pressure and may now flow out, and it will self prime, this way once primed it cannot suck air inward if the PRRT effects the differential this much.

I need to have a specific bleed and fill proceedure, where as before it would purge and prime the system even with the swirl pot above the coolant level in the header tank through its own action.

This is no longer the case (or may not be)...Worst case scenarios must be accounted for.

What will happen now is...

I will use the header tank to prime 95% of the water system. This will fill the head, rad and all pipes including the top hose....

However I cannot prime the very top of swirl pot as its above the water level. (problem generally this is, even with the header tank on the bulkhead.)

So I fill up the system up as much as possible with the header tank leaving the expansion space...Now I will stick the cap on the header tank, so it creates an enclosed atmosphere, remove the swirl pot outlet line and hold the feed line to the swirl pot (now taking off the header tank below the water level) upright so its higher than anything else.

I can then top of the swirl pot manually till full, the sealed header tank atmosphere will hold the added liquid in a hydraulic lock, so the water I am priming the swirl pot with cannot fall down and go back into the header tank cause its under its own atmosphere :) Once the swirl pot is full I will quickly duck the feed line to swirl pot downwards to below the level of the top of the swirl pot, till a little fluid comes out (bleeding the feed line)...Hold it up again and put the few drops of liquid back into the swirl pot to replace what dripped from the feed line...I then can replace/do up the swirl pot line.

Cause the swirl pot line is below the water level in the header tank and cap is on a hydraulic lock is created. I can then remove the header tank cap and like magic, the liquid that is above the level of the liquid in the header tank will stay inplace, the system is primed and under hydraulic/fluid lock...I can then run engine and sort out the final fluid level for the header tank.

I did some experiments yesterday evening on fluid dynamics and expansion. I calculated using my Alfa as a dummy that 8litres of coolant expanded to 8.3litres from ambient (16c) to 101c...

Each ML of liquid grew by 0.00040cc per degree of celcuis increase.

So basically there is not a fat lot of expansion happening. So I can run my header tank well over the level required to keep the head full. Also the Alfa test was done with the header tank cap off, so no pressure effect.

Thats important cause at the highest point of the head there is a outlet that goes to airspace in the header tank. However being as the coolant level in the tank will be well over the tapping on the engine, a hydraulic lock will keep all liquids in place. Also one could be concerned that during coolant contraction this line going to airspace could suck air into the head. However it will not as the tapping point on the engine will be below the coolant in the header at all times and there are 3 other lines going to the header tank all below liquid level, so when coolant contracts it will suck coolant from the header tank to replace it lost volume via contraction, not air, as air cannot purge back to this head tapping due to fluid level and fluid lock.

All quite simple, yet rather complex :)

Basically all this bullshit means:

The swirl pot with its outlet line below the level of the liquid (changed for PRRT) in the header tank will either do nothing under certain thermostat and bypass conditions and stay static, or flow outwards as intended and remove any air from the highest part of the system :) It cannot flow inwards, from the header to swirl pot cause where is the fluid going to go? The system is full and enclosed...you cannot force more water into the bled fluid lock.

So now there is nowt to worry about :)

Caterhams never use a swirl pot anyway, so I could just ditch it, as best it will work, at worst it won't do anything, either way its not really important...

Under fluid contraction after shutdown is the only time the liquid could flow backwards to the swirl pot, to replace volume lost in contraction :)

System has to bleed/fill in the manner above.

If you remove the header tank cap, no worries, liquid stays where it is, even though its above the header tank coolant level. However if you remove the header tank cap and take the connection off the swirl pot, the hydraulic lock is lost and air will rush in and allow the fluid that is normally locked over the header tank level in the top of the swirl pot to rush into and fill the header tank and be replaced by air... cause fluid lock is lost!

Simple physics.

Hope that helps ya understand cooling systems.

TVR use a similar system...The header tank is WELL below the engine and radiator, like 1 foot.

Proceedure for filling that is...

Fill the header tank to minimum line, place cap on.

The TVR has a swirl pot in the highest position on the system...So you then fill the cooling system via the swirl pot...Very much like mine, but mine is FAR less extreme...To get 100% fill on mine I need only add about 300ml of liquid into the very top of the swirl pot...so its near perfect with all the packing considerations its the best its gonna be. I have 100% faith in it.

So bar the heater/welding the new cooling arrangement is complete.

I should be able to fill the header tank 2/3rd's full cold. Well over the engine/head level and giving me 3x the expansion area needed from my test.

I can test the maximum the level by running the engine up 100C and topping it up leaving a bit of airspace in the tank.

I shall have the fan on at 90C anyways...

Happy with all that!

Thursday, May 08, 2008

Water Works Part 3.456

Dropped by another local company, AH Fabrications in Hereford. They make all the tanks you see @ demontweeks etc.Got them to make me a pair of tubes.
Which means tomorrow I can get some TIG welding done. The Extra pipe on the swirl pot and the water rail bracket.
PRRT Thermostat arrived. No sign of my hose...Awaiting a 135 bend from the radiator to the PRRT. And a 45 bend for the PRRT to the swirl pot tube.
Thats my final system. AS said before the PRRT uses a massive bypass to keep the coolant flow as great as possible and increase the fluid quanity used in the bypass system.
So just some welded and some hose cutting and that is done. Just have to adjust the header tank outlet and feed that into the alloy tube below the carbs.

Should be a reliable water system, better than a stock Caterham and they never blow headgaskets anyway. Temp should be pegged @ 82-83C.

Monday, May 05, 2008

More waffling about my waterworks

Okie. Few PRT options.

88°C Cream PCH001190 from LandRover
82°C Grey (lighter springs )PEL500110 from Landrover

Looked reading up the 82C Grey PEL500110 was the one to have.

It will fit more of less like this into the bottom hose. The pipe disappearing off to the passenger side will go to the adapted swirl pot.
Basically just have to weld this tube onto the swirl pot.
These two pipes will meet. Will get another length of alloy tube, bead the ends and run this tube between the PRRT and the swirl pot with two small sections of silicone hose on either end. This works out well looks I will only need to buy the alloy tube and get it beaded (£7.50) I can stuff I already for the rest. Ordered a few small bits to make the other adjustments few JIC blank caps and weld on adaptors.

Note to check the bypass pipe clears the top hose on the apollo tank!

Hopefully thats it then! I can easily plumb the heater in then, 1 outlet on the top water rail, one on the bottom. Blow and Suck.

Water system ramblings


Been racking my brains. The side circuits are all good. Its what I wish to do with the main circuit.

I got the Rover SD1 2000 thermostat, you can see it below in the top hose.

Problem is its an 88C stat.

Too hot. Especially when you counter in the length from the head to the stat, the fact the water rail is alloy, the swirl pot is alloy I predict a 2-3deg cooling from radiation of heat bar when at full bore on the pump. That means the engine will 90-91C before the stat opens...having tested the stat on the stove it closes @ 87C and is no full open till 90c.

So I am binning this idea.
Shame cause its a neat item. Rimmer's sell these, but this item, there are some other part numbers and superceeded parts. Can't be bothered with messing with this anymore.

Also I have decided to run the normal water pump. No real reason bar I am not worried about the 2hp-5hp gain it seems to give on a 1300 Triumph engine. Also the fragilty of the K head with regards to overheating, pump failure etc. I do not really see any point in using it now...I'll leave the wiring and the control box and it could tested later if needed. I am sure it would do the job afterall its doing the job on many cars.
I think I will run the special PRRT Pressure Relief Remote thermostat developed for the latest K fitments and backfitting to the Lotus and MGF.

This is a thermostat that reads both pressure of the system and heat, so will open in two ways.

This special thermostat has a massive bypass, the same size as the main coolant lines. It works in two ways also. When coolant is warming and the stat starts to open it blends coolant from both main pipes (from radiator and bypass). When the stat is full open it shuts off the bypass and sticks all the coolant through the radiator.

If will be fitted where the EWP was. Below images show a Caterham fitted with a PRRT. Its basically exactly as mine would be fitted. I may need to just adjust the alloy water rail over the suspension tower, by putting a kink in the end, but may just need some extra hosing.

You can see the irovy coloured PRRT basically where my water pump is now.
The bypass comes off the top hose. Cunning method to get this big bypass running in my system is weld another 32mm beaded alloy tube into the side or base of my swirl pot. I already have a piece of suitable tube. This leaves some minor considerations.

First one is will the bleed line from the top of the swirl pot blow or suck when the bypass system is in full operation. As the coolant will be coming out the head to the swirl pot, and being sucked out the swirl pot back to the pump...Which will dominate, important as the bleed line on the top of the swirl pot is vented (currently) to fresh air in the top of the header tank?

So will flow along the line from the head (pressure) or flow back to the pump (suction) dominate when the bypass is operating...As my swirl pot bleed line is currently attached to the air space in the top of the header tank that could cause a minor issue until the stat is open. It could suck air through the bleed line out the header tank into the swirl pot. As such I will weld another JIC 4 take off below the water level in the header tank, so the swirl pot is not effectived by any reverse flow from its intended direction (out the swirl pot), so it can flow either way during warm up...These things must be considered, no issue when the stat is open at full bore, the swirl pot will work 100% as intended. This added take off can be blanked.

I will tap a stud into the water pump shaft so I can run the pump on a drill. This means I can test the water system statically before adding the timing belt and commiting to it.

It also means I need to weld another -6 take off to the header tank and one to the water rail on the inlet side..To move the evacuation line for the header tank to a new location. Again the old lines can be left in place for future use and blanked off with -6 blanking caps. So all in all there no real mods and I can easily test a few systems if needed.

Sorry to technical? Opps...

I think would be the ultimate reliable water system. Hate to backpedal on my concepts but I think its worth while as the PRRT is a better system that the standard or remote thermostats it also comes in different temps...