'63 Super Seven Cooling

[SENC]

3 hours ago, TEM said:

JB, I'm not saying that the inlet and outlet of the swirl pot are reversed, I'm saying that the outlet of the swirl pot should be higher than the inlet of the radiator.  Yes, swirl pots remove air but in our application they also are the means to fill the system with water.  When the tube to the radiator is below the top of the radiator, an air pocket will remain. 

 

I want to say that there is a very slight incline from my swirlpot outlet to radiator inlet, but it isn't much.  Without looking at it in person, I'd guess the incline is less than the ID of the outlet - and that any rise in water to/above the outlet inside the pot results in flow to the radiator.  I'll post a couple of pictures for comparison.

 

 

 

I've been trying to think through whether/how that is contributing to your circulation problem.  Presumably it worked at some point so I'd think it would be ok - but perhaps minor efficiency losses due to restricted water paths, pump wear, etc. are combining with a marginal design to result in your outcome?

 

Considering the water level in the swirlpot during your video - can you estimate where that is in relation to the high point in the connection between the swirlpot outlet and radiator inlet?  Ie., is that high point above the water level in the pot?

 

If so, I could see that being an issue.  The water pump pushes what it can through the engine and to the pot until it reaches that level, but if (at that level) gravity doesn't force water back to the radiator the pump would quickly run out of water to push.  Perhaps the post-rev gurgle you're seeing is the result of a little vacuum created upstream of the pump through the radiator trying to suck some water through?  Or opposite, a release of some air from the radiator due to back pressure?  I'll be interested to hear today whether your radiator appears to have very little water in it today as it did yesterday.

Edited June 2 by SENC

[SENC]

Was at my shop some today so took the opportunity to take some measurements - maybe something here will help you in evaluating your system.

 

The bottom of my swirl pot is roughly 1" below the bottom of the radiator inlet pipe.  My swirlpot outlet is about 1/4-1/2" above the bottom of the pot - so overall rise from the bottom of the outlet inside the swirlpot to the bottom of the radiator inlet pipe is roughly 3/4-1".  As the cold level of water in the swirlpot is about 1/2", it requires a rise of roughly 3/4-1" before unpressured water would flow to the radiator.  My swirl pot is about 4" diameter, so if my math is correct it only needs about 7 ounces or less of water to get enough rise to start unpressured flow.  Our cooling system holds about 12 pints, just under 200 ounces - so thermal expansion takes care of most/all of that rise at 200F (93C).  Ie., it wouldn't take a lot of pressure on the downstream side of the pump or suction on the upstream side of the pump to get and keep circulation flowing.

 

I'm still confused why you don't get visible inflow into the swirlpot at higher than idle rpms.  Perhaps measure the level when cold and observe the flow immediately upon start-up.  Is the pump pushing up water to the pot (with rpms) when cold but not getting high enough in the pot to flow to the radiator.  Is the pump eventually sucking air from the radiator and "running out" of water to push?

 

Other measurements - my swirlpot inlet is about 2" higher than the swirlpot outlet.  That puts it an inch above the radiator inlet.  The top of my swirlpot is about 1/2" above the top of the cam cover.  The design of my swirlpot would naturally flow water from the inlet pipe around the opposite side of the pot, and directly towards the outlet pipe, so even before a rise in water level would send a good bit of water to the radiator.

 

If your rise from swirlpot outlet to radiator inlet is larger than mine and you determine the swirlpot needs to be elevated, it shouldn't be difficult to machine an aluminum or brass spacer/riser to fit between the head and the swirlpot inlet flange.

[TEM]

Senc, your swirl pot to radiator angle is much better than mine.  I'll shoot another picture so you can see what I'm talking about.

 

Where did you get that lovely flex hose by the way?  The one I found (Amazon) is too stiff and my local auto parts don't have anything I can use.

[SENC]

12 minutes ago, TEM said:

 

Where did you get that lovely flex hose by the way?  The one I found (Amazon) is too stiff and my local auto parts don't have anything I can use.

The top hose?  I can't remember off the top of my head - seems like I searched for a bit for what it came off and found another British car of that era and then found a NOS hose.  If that's the one you're talking about I'll see if I can get lucky and find an invoice for it.

 

This might be it...

https://bpnorthwest.com/triumph/radiator-hose-upper-spitfire-62-to-78-gt6/?gad_source=1&gclid=Cj0KCQjwsPCyBhD4ARIsAPaaRf1OLe4nEubif6utMAYrZo2ME68CRHeaZytA6J2t7LO76VPTHoiuCZkaAlTIEALw_wcB

 

Or this...

https://www.ebay.com/itm/190848712318?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=190848712318&targetid=&device=m&mktype=pla&googleloc=9010076&poi=&campaignid=20394324446&mkgroupid=&rlsatarget=&abcId=9317262&merchantid=6365194&gad_source=1&gclid=Cj0KCQjwsPCyBhD4ARIsAPaaRf1qfqrAFgZSJzYmNR7t0s9bnBvLJ_864xc6cmZ23RW0cWvJruxYgL0aAk_6EALw_wcB

Edited June 2 by SENC

[TEM]

Thanks and yes, I was referring to the top hose.

[TEM]

Pictures of my swirl pot to radiator inlet.  Hope these are clear.

 

The top of my swirl pot outlet tube is about 1/2" below the bottom of the radiator inlet tube.  I will fill the system from the swirl pot then pull the top hose to see how much water is in the radiator.

[SENC]

So your rise is about 1.5", roughly double mine.

 

The pictures may be deceiving, but the top of your radiator looks to be higher than the top of your cam cover.  The top of my cam cover is a bit (maybe 1/2-1") higher than my radiator.  Is your radiator sitting down in the chassis mounting holes (with top hat style bushings)?

Edited June 2 by SENC

[TEM]

Good observation.  I made sure the posts went into the top hat bushings but I recall the bushings being more proud than expected.  I assumed that when i pressed the radiator down into the bushings that the bushings would fit back down into the chassis.  I will check.

[TEM]

Problem solved!

Time for me to fall on the stupid sword.  When I put in the new pump and pulley, I also made a new gasket for the swirl pot.  In my rush, I failed to cut out the center hole

With proper hole cut in the gasket the car ran well for the 2 mile loop and temps stayed below 140 (short drive).  I will take it for a longer run but first I need to make it a little more civilized - lot's of back firing on throttle lift.

 

 

[TEM]

I also tested manual VS swirl pot fill, with proper gasket.  I filled the radiator from the top till it started drooling out and then filled the engine from the swirl pot, finger over the swirl pot exit port.  Bottom hose connected.  I then drained the system from the radiator drain port and measured the amount of water drained.  I then connected the upper hose and filled the system only from the swirl pot.  Significantly less water was drained.  My swirl pot outlet port to radiator inlet port relationship is leaving a large air pocket at the top of the radiator.  Perhaps the top hat bushings are preventing the radiator from sitting further down on the chassis.

[TEM]

One other interesting observation is that the 4.75" pulley has the timing mark about 10-15deg further clockwise than the 4" pulley.  I don't know which is correct.  Time to buy a piston stop to verify TDC on the pulley.  Perhaps this is why the car runs so unruly.

[TEM]

Thank you everyone for your help and ideas.  Now on to the next problem.

[SENC]

14 minutes ago, TEM said:

One other interesting observation is that the 4.75" pulley has the timing mark about 10-15deg further clockwise than the 4" pulley.  I don't know which is correct.  Time to buy a piston stop to verify TDC on the pulley.  Perhaps this is why the car runs so unruly.

When the timing mark is at the pointer, you should be 10°BTDC.  The mark on the smaller wheel my be for TDC?  Pretty sure that's the case on the Elan.

[TEM]

Good to know.  I played with the timing and the best seat-of-the-pants setting is with the timing mark right in the middle of the two prongs of the pointer.

[MV8]

I suggest rotating the crank key slot to the top center (0 degrees/tdc for #1), place a small piece of tan, masking tape over the pulley face adjacent to the timing tab, then using a sharpie or ballpoint, mark the pulley where tdc is indicated by the tab. Align #1 cap post to the rotor. Starting should be easier. Sort out any idle speed problems, then adjust the timing based on the pulley to 10btdc and appropriate idle speed.

It looks like you have room to run an 8-10 inch electric fan behind the radiator with the nylon rod mounts through the core. They have foam pads so the core is not rubbed by the nylon and are easy to remove but one-time use. Use a relay with power from the alternator and controlled by the existing fan circuit and/or a toggle. I'd also remove the oil cooler to eliminate the oil pressure drop, cooling when you want to heat the oil quickly to running temp (engine wear), and the short life of most rubber hoses with hot oil.

In general if the engine while cranking doesn't rotate smoothly/near constant rpm with the starter, the timing is probably way off.

 

Imho, while not ideal, I don't see a significant issue with the custom filler tank.

[TEM]

Timing is predicated on knowing where TDC is on the pulley.  I'll work on that next but I do believe that I'm currently way off.  I'll turn the advance back down until I figure it all out.

I agree there's plenty of room for a suction fan.  I'll get to that but it's not my first issue to solve.  I'm having issues disengaging the clutch - trouble getting into gear with the engine running and stays in gear when pressing the clutch peddle all the way in.  I rebuilt the master and slave, bled air from the system and adjusted the clutch per the manual.  I'll be checking for air again but this may become another topic because I really don't want to pull the engine to replace the clutch.

[SENC]

You may or may not find you need a bigger fan - I have an original small fan on mine and it seems to do the trick when idling in traffic as long as I keep water flowing periodically.  That said  I don't have the oil cooler you have restricting airflow when driving so yours may have different needs.

 

 

Re clutch bleeding, like our Elans the rotational angle of the slave cylinder and location of the bleed screw can cause issues with air in the slave itself.  On my Elan I added a length of brake hose and fitting and effectively raised the bleed screw to near the master - which made for much easier bleeding and ensured air from the slave reached a higher point.  The Seven is open enough I haven't felt the need to do that.  I also found that the pumping action when bleeding agitates the fluid and introduces air throughout, that then finds its high point and stays there.  My solution to that has been to use a board to hold the clutch (or brake) pedal fully down overnight after changing fluids.  This seems to give the air a path out to the master cylinder.  A top off in the morning and I've yet to have a problem.  If your problem is air in the system, perhaps this will help.

Edited June 3 by SENC

[TEM]

Since I rebuilt the mater and slave, before re-installing the slave I raised the slave above the master and oriented the bleeder upwards.  I clamped the piston so it wouldn't shoot across the garage and bled as usual.  I have not had any issues with this process on my Elan.

 

As for cooling, after I resolved the "blocking" gasket I moved to carb tuning which meant removing the nose cone and tuning off the fan.  I did periodically blip the throttle during the process but the car did eventually over heat.  This time everything was hot including the radiator.  So a bigger fan may help.  But first I want to get everything else working correctly and see how the car behaves on the road.

Edited June 3 by TEM

[IamScotticus]

I was going to suggest a coolant hose inner liner or winding layer may have separated and formed a flap blocking flow.

I didn't know they could do this until I was talking hoses with a man at an auto psrts store (a man who knew a Pinto bell housing when he saw mine).  He mentioned the older wound hoses would unravel inside.

 

Is that chassis grey Lotus original?

Edited June 4 by IamScotticus

[TEM]

I have seen them col;lapse but not internal unwinding.  My new hoses have a removable steel wire that prevents them from collapsing under suction or sharp bends.