Whats w this motor?

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AZ Landshaper
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Re: Whats w this motor?

Post by AZ Landshaper » Sun Apr 03, 2016 2:51 pm

Latest post of the previous page:

They hold fuel. Seals quite well actually but the valve is deff not straight in the seat and the adjustment screw on intake 1 is sticking out a good 2mm past the others. These heads have been stamped by three manufacturers. Probably pretty used up at this point.

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AZ Landshaper
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Re: Whats w this motor?

Post by AZ Landshaper » Sun Jun 05, 2016 4:10 pm

Back at work on the same van. Replaced heads w AMC heads and brought my compression up. Still runs hot (425+ on a small 2 mile long hill). A/f = 12-13 idle thru acceleration and timing is set to 28 WOT. Not sure what to make of it. Gonna check for vac leaks again this week but somehow I'm under the impression that the 12-13 a/f negates the need to look for vac leaks. In addition the motor is very responsive to any adjustments making me more confident that i dont have any vac leaks. But something must be contributing to the heat.
Any thoughts? Cooling flaps are open. Valves have been adjusted.

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Amskeptic
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Re: Whats w this motor?

Post by Amskeptic » Sun Jun 05, 2016 6:54 pm

AZ Landshaper wrote:Back at work on the same van. Replaced heads w AMC heads and brought my compression up. Still runs hot (425+ on a small 2 mile long hill). A/f = 12-13 idle thru acceleration and timing is set to 28 WOT. Not sure what to make of it. Gonna check for vac leaks again this week but somehow I'm under the impression that the 12-13 a/f negates the need to look for vac leaks. In addition the motor is very responsive to any adjustments making me more confident that i dont have any vac leaks. But something must be contributing to the heat.
Any thoughts? Cooling flaps are open. Valves have been adjusted.

What is your compression up to?

For fun, retard the timing to 26* BTDC at 3,400 rpm (no hoses) and see if it helps with temps.

Then use the wiper adjustment (trim with spring) to drop your full throttle 55-70mph mixture to 11.8 at 55, leaning out to about 12.3 at 70.
Keep notes of your starting points so you can always get back.

Always verify to yourself that the thermocouple ring under the plug is not leaking in any way. I commonly see that they like to stretch oval. Gas leaks cause skyrocketing CHT readings.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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airkooledchris
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Re: Whats w this motor?

Post by airkooledchris » Sun Jun 05, 2016 7:20 pm

Obviously, do what Colin says first. :p I'll still throw in my 2 cents:

Not every AFR gauge is equal nor accurate. I wouldn't worry too much about the actual number, just see if you can get your head temps where you want them and then deal with if/how rich is too rich.

My motor tends to run real hot as well, and according to my AF gauge it's also very rich when I adjust it to cool the heads where I want. My WOT is in the 10's when I set it up to run cool for highway driving.
1979 California Transporter

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Amskeptic
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Re: Whats w this motor?

Post by Amskeptic » Thu Jun 09, 2016 5:26 am

airkooledchris wrote:Obviously, do what Colin says first. :p I'll still throw in my 2 cents:

Not every AFR gauge is equal nor accurate. I wouldn't worry too much about the actual number, just see if you can get your head temps where you want them and then deal with if/how rich is too rich.

My motor tends to run real hot as well, and according to my AF gauge it's also very rich when I adjust it to cool the heads where I want. My WOT is in the 10's when I set it up to run cool for highway driving.
BobD is currently 10.9 under full throttle.
NaranjaWesty, on the other hand, lacking a CHT gauge, has currently unknown mixture readings, but the tailpipe is almost clear of carbon at 17 mpg. And exhaust #2 has shown some evidence of recession . . . . :blackeye:
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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Re: Whats w this motor?

Post by AZ Landshaper » Thu Jun 16, 2016 8:49 pm

Removed the CHT ring and it was way ovaled. Like way ovaled. Wicked bad. I pulled it and have been running w/out and my power is way up my temps are quite a bit lower and I'm quite a bit more satisfied w the situation.
By the way compression is 130 130 117 115. In order. Same pistons and rings that came w a the be but a used head from Chris and a new one from the AMC. Funny thing is the used head is I the 1,2 side where compression is highest. Maybe they lapped the valves. I did not.
Next month I have to deal w AZ emissions. Wish me luck.

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Re: Whats w this motor?

Post by Amskeptic » Mon Jun 20, 2016 4:47 pm

AZ Landshaper wrote:Removed the CHT ring and it was way ovaled. Like way ovaled. Wicked bad. I pulled it and have been running w/out and my power is way up my temps are quite a bit lower and I'm quite a bit more satisfied w the situation.
By the way compression is 130 130 117 115. In order. Same pistons and rings that came w a the be but a used head from Chris and a new one from the AMC. Funny thing is the used head is I the 1,2 side where compression is highest. Maybe they lapped the valves. I did not.
Next month I have to deal w AZ emissions. Wish me luck.
Good luck.
Achtung! Ve haff vays to pass ze emissions tests.
Kolin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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