 Obtaining CAM shaft specs without disassembling the engine? |
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| GGerg1186 |
 Dec 27 2020, 05:21 PM
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Newbie  Group: Members Posts: 15 Joined: 28-September 20 From: Dubuque IA Member No.: 24,724 Region Association: Upper MidWest  |
I purchased a used 1.7L engine out of an autocross 914 car. Seller said it had a "performance cam" in it which could mean anything. Planning to pop a valve cover off with a dial indicator and the degree wheel on the front of the engine "spec" my cam. Should be able to get open, close, lift, and calculate duration. Should I put the dial indicator on the push rod side or the valve side of the rocker? Anyone had any success with identifying their cam without engine disassembly?
Next question, any way to determine compression ratio without removing the cylinder head? I am leaning towards removing the cylinder head just to see if I have cast or forged pistons & connecting rods. Ultimately, I want to know whether I can run regular pump gas, what max engine speed should be, and an appropriate carburation system to match the cam. Let me know your thoughts. |
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| barefoot |
Dec 28 2020, 08:36 AM
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Senior Member Group: Members Posts: 1,279 Joined: 19-March 13 From: Charleston SC Member No.: 15,673 Region Association: South East States 
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Cam makers specify valve lift, not lobe lift, so indicate on valve retainer.
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| Mark Henry |
Dec 29 2020, 07:37 AM
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
QUOTE(barefoot @ Dec 28 2020, 09:36 AM)  Cam makers specify valve lift, not lobe lift, so indicate on valve retainer. Or times by 1.3 the rocker ratio. |
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Posts in this topic
GGerg1186 Obtaining CAM shaft specs without disassembling the engine? Dec 27 2020, 05:21 PM
Mark Henry Pop the oil pump off, most aftermarket cams are st... Dec 28 2020, 07:35 AM mlindner I like Marks idea. but if you want to measure like... Dec 28 2020, 07:54 AM
bbrock I don't want to hijack but I'm getting rea... Dec 29 2020, 09:13 AM GGerg1186
Am I correct that I need to multiply the CAM Lift... Dec 29 2020, 12:24 PM |
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