Heat shed, what am I missing to cool her down?, *Update - 1st Test Run after cleanup - still HOT |
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Heat shed, what am I missing to cool her down?, *Update - 1st Test Run after cleanup - still HOT |
nditiz1 |
Jul 5 2020, 09:41 AM
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#1
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Senior Member Group: Members Posts: 1,191 Joined: 26-May 15 From: Mount Airy, Maryland Member No.: 18,763 Region Association: MidAtlantic Region |
Update - pass side tin removed. Signs of leakage.
*Update* - Webers were successful in scooting the teener down the road, but head temps still reached 400, engine drop to follow shortly. Stock 2.0 Engine Converted to carbs - (Dual 40 Dells - 60 Idle jet) Engine tin in place - needs seal on the passenger side Thermostat - dead/expanded - flaps auto spring to full open Valves set .006/.008 Timing 28 - New Pertronix SVDA - vac plugged when timed to 28 No AFR setup - want to say rich not lean New plugs NGK B6ES gapped to .028 *Updated info based on comments* Oil pressure when hot 40 PSI at 4k - so looks ok Oil currently in the block unknown - dark lol, but within the min and max marks Targa was on during test run Deflection flaps present Cooling fan has 1 broken fin CHT gauge is Dakota Digital under cyl#3 spark plug Engine lid is currently off - Dealer installed AC - Box and grate still in place - is this robbing the cool air from under the car at speed? Running oil temp 240/250F 85F ambient temp Head temps in 4th on flat cruising at 65 mph at 4k RPM - *400 and climbing if going up a hill Head temps in 3rd up and down hills *395, but can hit 400 if I get on it just a little Compression test was Cyl #1 - 135 Cyl #2 - 135 Cyl #3 - 130 - CHT temp sensor Cyl #4 - 135 Assuming the carbs are not lean (went 3 turns out, and now went to 4) what should I check next? I thought maybe I needed a rebuild since the compression numbers cold were around 125 with with a 12 psi gap between 2 of the cylinders, but this warm compression check looks healthy. The plugs do look a little white, but the last run I did was in the garage with it running at idle and some briefs to 3500 RPM to ensure the timing was correct. I know this is not to preferred method to check plugs as they should be done driving regularly and then shut off the engine and not let it idle to get a true reading. I have a gas tester I can maybe hook up to check the CO2 at the tail pipe (yes, I should have an AFR to get better readings) In the garage I was running at 350 head temp just at idle ambient temps 82. I know sitting has no air flow. I feel like when I rebuilt my last 2056, I could idle in the garage all day long at 300 or under. Let's assume the carbs are rich enough in the mixture so as to not be lean, will the engine seals being tattered and 1 missing (most crucial side (IMG:style_emoticons/default/dry.gif) ) be enough to make even back road driving push cyl 3 head temps to 400 and above? Plugs - less than 50 miles - maybe not enough time Cyl 1 and 2 (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-18763-1593964487.1.jpg) Cyl 3 and 4 (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-18763-1593964488.2.jpg) |
Superhawk996 |
Jul 6 2020, 06:59 AM
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#2
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914 Guru Group: Members Posts: 5,899 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
I'm going to stir the pot a little here. (IMG:style_emoticons/default/stirthepot.gif) 240F to 250F is not too hot for oil. I know there is this mythology that 180F is the sweet spot for oil. Not so. 240F oil is OK but it should just be changed every 3000 miles or so.
Your head temps are hot (assuming gauge is correct). Check calibration as suggested by Barefoot. Your head temps are hot because you're missing an engine seal. These engine seals are not optional. Without that seal you're pulling hot air from under the engine right back up into the fan and recirculating that already heated air across the engine and heads. Recall that VW sealed the front fan tin between the two pieces of tin with caulk. This sealing of the tin was done to prevent that crack/gap between the tin from sucking in hot air under the engine. You're missing way more sealing that that! You mention that you may have other "tattered" seals. Fix those too. The other items mentioned (timing, carb tuning, etc.) are all fine but you've got to replace that seal before you make any further conclusions about your temps. The other issue you'll have is the A/C. I have yet to see an A/C install that doesn't completely butcher the passenger side engine tin and the associated sealing. It sort of "works" assuming the A/C compressor is there and largely filling the hole opened up by the butchery but even at it's best, the A/C conversion creates a lack of CRITICAL sealing between the bottom of the engine (where the hot air is) and the top side where the cooling fan is supposed to be bringing in COOL air. FYI - don't sweat the loss of one blade from a cooling fan. It isn't going to affect your temperature in any meaninful way. To address your quote "In the garage I was running at 350 head temp just at idle ambient temps 82. I know sitting has no air flow. I feel like when I rebuilt my last 2056, I could idle in the garage all day long at 300 or under." You are right -- 350 is too hot for just idling. You are incorrect in stating that there is no air flow. There is plenty of airflow coming from the cooling fan at idle to keep the engine cool at idle but again that assumes a proper state of tune and most importantly that the engine seals are in place and that the hot air under the engine isn't able to rise up from convection and re-enter the engine compartment. With respect to cylinder 3&4 those plugs look too lean. That surely isn't helping. Make sure that you don't have air leaks. Sometimes you need to double up on gaskets between the cylinder head and the carb manifolds to get a good seal. Did you use head gaskets with the rebuild? Hopefully no. Even if you didn't use gaskets - are you sure your heads are seated properly and not leaking? A leak at the head can cause a lean condition. Make sure the carb jets are clean on cylinder 3&4 side. Measure the idle jets with a wire size #drill bit if necessary to ensure size is the same on 1/2 side and 3/4 side. Both Dell's and Webers run on the idle jet and progression circuit way more than you might think they do before tranistioning to the main jet circuit. |
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