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Old 04-05-2017, 05:14 PM   #1
Old Radio Tech
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Trying to decide what I have

1960 283 with iron 1960 heads. measured valve diameters at approximately .34" Trying to decide if it has a cam and solids. Doesn't make noise like solids but I can't compress the lifter manually pushing down on the pushrod after removing rocker, even after sitting all night. Has intake valve stem seals I'm unfamiliar with. Rubber cylinders with round metal band at the top and flat wider band at the bottom. If I rotate the engine around and check the lash, all pushrods will turn with slight pressure and have no sideways movement. Runs very rich. Timing, vacuum checked. new fluids. very rough at idle but smooths out just off idle. Rebuilt carb, new distributor, hoses, etc. Timing set at 4 deg BTDC. Quadrajet. Idle screws almost all the way in. compression 140-152. Could be high because of carbon buildup?
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Old 04-05-2017, 05:44 PM   #2
andyh1956
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Re: Trying to decide what I have

I got lost at "measured valve diameters at approximately .34". that's less than half an inch. You have the heads off???
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Old 04-05-2017, 05:52 PM   #3
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Re: Trying to decide what I have

Sorry, stem diameters. Heads on
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Old 04-05-2017, 06:36 PM   #4
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Re: Trying to decide what I have

I assume that he is referring to the valve stem diameter?
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Old 04-05-2017, 07:30 PM   #5
jayoldschool
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Re: Trying to decide what I have

1. Look at the end of the head to figure out what head you have. See below.
2. Take the intake off to see what lifters you have.

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Old 04-05-2017, 09:32 PM   #6
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Re: Trying to decide what I have

C/N 460
3774682
D270 - Apr 27.1960

I think this engine was heavily modified in the early 80's, but have no way to find out what was done. Was hoping to answer the lifter issue without taking the intake off. My understanding was that once the oil was out of a hydraulic lifter all that remained was a spring that could be easily compressed. So I set to #1 TDC, removed the rockers and tried to compress the lifters. no luck.
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Old 04-05-2017, 09:51 PM   #7
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Re: Trying to decide what I have

Man, the descriptions of the different heads was awesome! I new of a couple of them but never knew of all of them, THANKS for that!
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Old 04-10-2017, 10:49 AM   #8
andyh1956
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Re: Trying to decide what I have

Yeah you won't be able to compress the lifters by hand once they get oil in them, the oil don't drain outta them. You can use a lever of some type & it may take a few min to push the oil out but not really necessary for what you're trying to do. If you have a solid cam there should be lash when the rockers are at TDC compression. The old Duntov 283 cam lashed at .030" I & E, spose that's why it was called the "30-30" cam.
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Old 04-10-2017, 12:45 PM   #9
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Re: Trying to decide what I have

Just for info---the first solid cams lashed at around 12 and 18 like the 097 cam the 30-30 (356) did lash at 30-30 and was a 327 cam. You would hear the valve lash with either.
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Old 04-10-2017, 02:08 PM   #10
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Re: Trying to decide what I have

Bump up the timing to around 10-12 degrees BTDC and try that. You'll probably have to bring your idle speed down a bit after advancing the timing. Off chance it has a snotty cam in it.

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Old 04-10-2017, 02:13 PM   #11
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Re: Trying to decide what I have

Quote:
Originally Posted by Old Radio Tech View Post
1960 283 with iron 1960 heads. measured valve diameters at approximately .34" Trying to decide if it has a cam and solids. Doesn't make noise like solids but I can't compress the lifter manually pushing down on the pushrod after removing rocker, even after sitting all night. Has intake valve stem seals I'm unfamiliar with. Rubber cylinders with round metal band at the top and flat wider band at the bottom. If I rotate the engine around and check the lash, all pushrods will turn with slight pressure and have no sideways movement. Runs very rich. Timing, vacuum checked. new fluids. very rough at idle but smooths out just off idle. Rebuilt carb, new distributor, hoses, etc. Timing set at 4 deg BTDC. Quadrajet. Idle screws almost all the way in. compression 140-152. Could be high because of carbon buildup?

Put some timing in it.
Try 14 initial.
THen close your primary throttle back down and adjust the mix screws.
It's running rich because you're idling on the power circuit.
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