Heat shed, what am I missing to cool her down?, *Update - 1st Test Run after cleanup - still HOT Options

[nditiz1]

@Superhawk996 - Excellent points. To address the flaps, the thermostat is expanded and dead. The wire is no longer connected. I have a new one ordered, just waiting for delivery.

I will clean up the oil residue best I can. My fear is one of your other points - LEAKS - While I did do a compression and they seemed good the leak down was not so favorable even warm and worse when cool (20 - 30%) The leaks between the block and the jugs and the jugs and the heads are probably all attributing to the lean cyl 3.

Maybe I will rebuild this into a 2056.

I will clean everything up and add seals where missing and button it back up. Hopefully temps stay down and I can drive a long distance to make the east coast meetup. Otherwise engine rebuild is in order.

[Superhawk996]

@Superhawk996 - Excellent points. To address the flaps, the thermostat is expanded and dead. The wire is no longer connected. I have a new one ordered, just waiting for delivery.

I will clean up the oil residue best I can. My fear is one of your other points - LEAKS - While I did do a compression and they seemed good the leak down was not so favorable even warm and worse when cool (20 - 30%) The leaks between the block and the jugs and the jugs and the heads are probably all attributing to the lean cyl 3.

Maybe I will rebuild this into a 2056.

I will clean everything up and add seals where missing and button it back up. Hopefully temps stay down and I can drive a long distance to make the east coast meetup. Otherwise engine rebuild is in order.

30% leakdown is quite a lot. For relative comparison my Miata engine at 220K miles had a leakdown rate of 15%.

While you have the tin off you may want to take the opportunity to retorque the cylinder head bolts while you have access to the upper fasteners. That might help seal up cylinder 3/4 leaks a little bit.

If you're going to do attempt that - soak with penetrating oil for a day or two. Then loosen them 1st and then retorque up to spec. Obviously there is some risk to trying this - stud may loosen in case 1st or you could break a stud.

[barefoot]

One thing I noticed when I was first cleaning up the 2L heads I'd acquired with a complete 2L motor is that there was a LOT of casting flash mostly blocking cooling fin passages near where the exhaust ports pass by. With accumulated junk, these passages were completely blocked. So after cleaning I had to go into these passages with drills to clean out the aluminum flash.

[type2man]

Buy some 62 idles, and then get all your gauges, throw them in the trash and just drive it.

[VaccaRabite]

What were your head temps with the Webers bolted on?

Pulling the tin was smart, you have a lot of crap built up in there.

Superhawk is right about the leaks. Before you pull it apart, just check the torque on your head bolts. And maybe put a tad more torque on the bolts that are on the leaking jug and check leak again.

Its very possible that you have slightly warped heads, and its very possible that you have collapsed registers on the case (which was the problem with my engine ages ago when I had good pressure but bad leak down numbers).

Zach

[nditiz1]

Zach the head temps were about the same with the Webers.

Just got done cleaning a bunch of the muck out. I'll try to bolt it back together in the next day or so and retest. This is make or break for the east coast meetup on Friday.

I think this fall an engine top-end rebuild is in order. The new garage will be built so it will be plenty of clean space to get it done.

[nditiz1]

*Will need a drop and rebuild

Not sure what else I can do.
-I have cleaned out most if not all the gunk on the 3/4 side
-sealed up every hole and crack
-jetted the idles up to 55 from 50 on a set of webers
-set timing to 27 degrees

Tonight I performed another test run and things seemed like they were doing better than last time. Ambient temps 70. Engine temps stayed under 400 in 5th on the highway. After a 20 minute drive I got on it a little from rest back onto the highway. Temps started creeping up as they did on the way to the city. I could no longer keep the temps under 400 while going up a long slow incline. Dropped it to 4th helped a little, but never brought them back under 400 until I was at the crest of the hill. Mashing the pedal in 4th and winding it out for a few seconds actually helped in bringing the temp down. I can only assume this was due to the large burst of air and the accelerator pump on the carb dropping some much needed fuel into a leaning out cylinder. I'm already running 135 mains. I feel like this engine should be running 120 mains with 50 idles, but i was trying to throw more fuel just to see if that would keep the temps under control (I have several jets for tuning so it wasn't any additional cost to test) At one point when I was really stressing the engine 415 degrees or so the oil pressure light kicked on. I let off the gas and it went out after a few seconds. I checked the oil pressure gauge and it still looked good around 30psi so I'm not sure what that was about.

So I feel like only an engine tear down can tell me where I am failing to keep the cylinder rich.

[Superhawk996]

Arghh . . . .

Only last suggestion - sorry if I've missed it earlier in thread. Did you check temp sensor calibration against boiling water or maybe IR temp gauge just to be sure the error isn't in the gauge?

Given that the oil light flashed on when hot I'm concerned for you. Definately don't want to drop a valve if it really is running that hot.

Out of curiosity . . . not meant to imply anything . . . are you sure you're not lugging it? Especially on grades. No harm at all running 3000-4000 rpms even if that means 4th gear. scratch that. see you were running 4K rpm in OP.

Sorry about this situation. It really does suck. Going to have to figure out why 3/4 is running lean.

[nditiz1]

I did not check the accuracy of the CHT. I can do that today.

No lugging was happening. On the highway in 5th I was at or a little above 3000 RPM. When I saw the oil light flick on briefly I was in 4th I think at 4000 RPM.

I think its like you said the leaking of the cylinders is too great and leaning out the cylinder. I think this shows why compression tests do not always mean a healthy engine. The leakdown from the start was suspect.

[Superhawk996]

I did not check the accuracy of the CHT. I can do that today.

No lugging was happening. On the highway in 5th I was at or a little above 3000 RPM. When I saw the oil light flick on briefly I was in 4th I think at 4000 RPM.

I think its like you said the leaking of the cylinders is too great and leaning out the cylinder. I think this shows why compression tests do not always mean a healthy engine. The leakdown from the start was suspect.

Out of curiosity . . . were you able to retorque the cylinder heads a bit? And, after all these test runs are the plugs on 3/4 still that white?