SENC Posted May 31 Share Posted May 31 Here is a picture of my old and replacement pumps, to the extent it may help you. Link to comment Share on other sites More sharing options...
TEM Posted May 31 Author Share Posted May 31 Mine looks like the one on the right. Are the new after market pumps better? If I'm going to change the pump I want to best one I can fit. Link to comment Share on other sites More sharing options...
jbcollier Posted May 31 Share Posted May 31 Measure the clearance between the impeller fins and the pump body. It should be no more than 1 mm. Link to comment Share on other sites More sharing options...
TEM Posted May 31 Author Share Posted May 31 These things are pretty simple. Just can't see what could cause this pump not to pump. Shaft is intact, seals are good, no damaged vanes. I'll pull the pump again and take another look. It's much easier when the radiator is not in the car 1 Link to comment Share on other sites More sharing options...
SENC Posted May 31 Share Posted May 31 18 minutes ago, jbcollier said: Measure the clearance between the impeller fins and the pump body. It should be no more than 1 mm. .03", or .77 mm to be exact Link to comment Share on other sites More sharing options...
TEM Posted May 31 Author Share Posted May 31 My largest feeler gauge .75mm can just squeeze in. There is no slippage of the vanes to pulley. No bearing movement in any direction. Just can't see any issue with the pump. Link to comment Share on other sites More sharing options...
jbcollier Posted June 1 Share Posted June 1 Can you show us a picture of your radiator? And where the hoses run? Link to comment Share on other sites More sharing options...
jbcollier Posted June 1 Share Posted June 1 You have a had a look at everything. Your water pump looked fine. If the block is hot and hose is cold, there are only two possibilities: 1) coolant level is low 2) there's a blockage in the system Link to comment Share on other sites More sharing options...
SENC Posted June 1 Share Posted June 1 The perplexing thing is you were seeing flow into thw swirl pot at higher rpms (though higher than expected), so there must be at keast some flow. You mentioned that on disconnecting everything you discovered the radiator was empty. I'm sure youve double checked the top hose for blockage and thag water flows through the radiator well. The other thing that comes to mind is an airlock within the engine - that expands when it gets hot and fully blocks circulation. In the Elan I learned to be sure to always make sure it is nose up when draining/refilling coolant. Apparently these engines are known for getting air pockets in the back of the block when nose down or even level. Perhaps park it nose up overnight then refill from the swirl pot - or better yet remove the top hose from the swirl pot and add water through the radiator until you see it (hopefully) rise up into the swirl pot. Link to comment Share on other sites More sharing options...
TEM Posted June 1 Author Share Posted June 1 Unfortunately, I can't remove and fill from the top hose. My spacing from radiator to swirl pot is very short with an 8" flex hose. So I have to remove the swirl pot to remove the top hose. The last time I filled the system that is what I did. Removed the top hose (and swirl pot) and filled the from the radiator until water cam out the thermostat opening. Put the swirl pot and top hose on and topped off the swirl pot. Made no difference. Swirl pot water cold, cylinder head water very hot. I think the pump doesn't have enough oomph to overcome the head pressure to reach the swirl pot. Pushes the water around the cylinders but not up into the swirl pot. I'll put the pump back on tomorrow and try the nose up filling. Link to comment Share on other sites More sharing options...
SENC Posted June 1 Share Posted June 1 Yeah I didn't think about that but you're right, I couldn't do what I suggested either. Maybe you can get a hose into the swirl pot and directed towards the outlet. Something to see that you can force water up through the engine and to the swirl pot. Link to comment Share on other sites More sharing options...
MV8 Posted June 1 Share Posted June 1 (edited) I still think you have abnormal restriction through the head gasket. Also, the crank pulley should be bigger than the water pump pulley which is most critical for lower rpm. Here is a pic I found (happens to be a xflow). Note the crank pulley is bigger. Looks like it should be 4.75-5 inch od if the water pump is 4.25. Senc may have an aftermarket smaller crank pulley too. It sounds like the crank pulley is undersized, slowing the water pump: https://www.burtonpower.com/v-pulley-crankshaft-4-steel-fp224.html "Pulley is also smaller, reducing speed of water pump..." This place offers many pulley options. May want to ask how big the standard pulley they offer is: https://anemboengineering.co.uk/x-flow/ Edited June 1 by MV8 Link to comment Share on other sites More sharing options...
SENC Posted June 1 Share Posted June 1 (edited) Agree with MV8 on the relative sizes - I didn't notice your measurements before. Mine is similar to the picture MV8 posted - I can grab some actual measurements if you'd like. I believe the crankshaft pulley is 4" diameter and the water pump pulley slightly smaller. EDIT: my memory was right and wrong! My Elan has a 4" diameter crankshaft pulley, but my Seven is 4.75", as MV8 estimated. My water pump pulley on both is 4.25" If you have the 4" crankshaft pulley you're definitely losing some efficiency at the pump. Edited June 1 by SENC Link to comment Share on other sites More sharing options...
TEM Posted June 1 Author Share Posted June 1 Now that makes more sense. I doubled checked the measurements now that the water pump and V-belt are off the car. I can't get a caliper into the space to measure the crank pulley so that one is eye balled with a tape measure. Both numbers are confirmed with water pump pulley at 4.25" and crank at 4.0". And that crank measurement is generous. It might be a 100mm metric (3.94"). SENC, from the pictures of your engine it looks like your crank pulley overlaps your timing marks. Do you have any trouble timing the engine? My pulley has the timing notch on the outside of the pulley which, given the angle I have to hold the timing light, would make it difficult to see both marks. Link to comment Share on other sites More sharing options...
TEM Posted June 1 Author Share Posted June 1 If my math is correct there is a 353rpm difference at the water pump between the 4.0" and 4.75" pulleys at 2000rpm on the tach. This would explain the higher rpm's I'm seeing regarding water flow in the swirl pot but should eventually move water through the radiator which I'm not seeing. So, I may have a combination of issues. This smaller crank pulley aligns with what the previous (2nd owner) told me, and some of the other things I'm noticing about the car, related to the car being used for racing by the first owner. - First gear is very different from a normal road going car, it's more for speed - hard to start from stopped and picks up speed quickly. I may need to address this later. - The lack of wiring for high beam, front running lights, and turn signals all around. - Windshield wipers but no motor or drive cable. - Seat back was cut in half so only seating for the driver. Link to comment Share on other sites More sharing options...
7Westfield Posted June 1 Share Posted June 1 I dug out the stock pulley I took off my 1600---it's 4.75 OD I'm running the smaller one from Burton Link to comment Share on other sites More sharing options...
TEM Posted June 1 Author Share Posted June 1 Found a spare pump and 4.75" pulley from my local club member. Will pick up tonight. How hard is it to pull the crank pulley off with the engine int he car? Near impossible I assume. Link to comment Share on other sites More sharing options...
TEM Posted June 1 Author Share Posted June 1 I was able to get the crank pulley off. It came off surprisingly easy. The pulley only measures 3.8". I would need 2500rpm's to match the speed of the water pump with a 4.75" pulley at 2000rpm. Fingers crossed a new pump and pulley will resolve my issues. Otherwise, I'll be left with the head gasket and port cleaning, which doesn't excite me. Link to comment Share on other sites More sharing options...
SENC Posted June 1 Share Posted June 1 Smaller crankshaft pulleys were used frequently by racers to reduce wear in the water pump - and as they were almost always above 3k rpm it would pump just fine. Here is a closer shot of my crankshaft pulley and timing marks. I'm not with it right now, but it appears they are roughly on the same plane. Link to comment Share on other sites More sharing options...
TEM Posted June 1 Author Share Posted June 1 Larger pulley and new (used) pump installed and same result. Under 5 minutes from cold engine to over 200F water temp while driving at 25-30mph, nose cone on, fan running. After engine shutdown, lower hose was very hot, upper hose was cool. Swirl pot was cool to the touch. There was some heat in the radiator but not much Before driving I noted no flow in the swirl pot, just some surge when lifting off the throttle. 2000-3000rpm, no flow in the swirl pot. I'm out of ideas. Link to comment Share on other sites More sharing options...
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