SOHC or OHC, how to identify?


tinkering
07-14-2014, 12:07 AM
1998 Explorer XL 4L

The 8th digit 'X' of the VIN suggests that it is an OHV but when I did a couple of those VIN Decodes online, it says it is a SOHC. Is there an easy way to ID the difference rather than relying on the VIN, since the motor could have been changed out somewhere along the way? :screwy:I need to know which one it is so I can get the correct Idle Air Control valve.

Stealthee
07-14-2014, 07:28 AM
SOHC and OHC should be the same thing.

In case you didn't know SOHC means single overhead cam. Obviously then, OHC would just be referenced as overhead cam.

shorod
07-14-2014, 07:45 AM
As stated above, you're talking the same thing. The other engine option is OHV for OverHead Valve.

On the SOHC/OHC Explorer engines I've seen, the engine cover has the acronym "SOHC" molded in to it. If your Explorer still has the engine cover, take a look at it and see if it confirms SOHC.

-Rod

tinkering
07-14-2014, 10:15 AM
SOHC and OHC should be the same thing.

In case you didn't know SOHC means single overhead cam. Obviously then, OHC would just be referenced as overhead cam.

Sorry about that; I was confused. I should have been saying OHV rather than OHC.

tinkering
07-14-2014, 10:35 AM
As stated above, you're talking the same thing. The other engine option is OHV for OverHead Valve.

On the SOHC/OHC Explorer engines I've seen, the engine cover has the acronym "SOHC" molded in to it. If your Explorer still has the engine cover, take a look at it and see if it confirms SOHC.

-Rod

You are right, Thanks, the SOHC engines have 'SOHC' molded into the engine/intake cover but the OHV engines have nothing molded into the engine/intake cover.

Another thing I came across:
Oil filler cap on right/passenger side bank = OHV
Oil filler cap on left/driver side bank = SOHC

tinkering
07-14-2014, 11:54 AM
I have screwed up here; The two engines are SOHC and OHV not OHC. Sorryhttp://www.explorerforum.com/forums/images/smilies/eek.gif
I removed all the convoluted information I had posted.

The bottom line is:
Single OverHead Cam has one cam on top of each bank.
SOHC means one cam opens the inlet valves and the exhaust valves.

Double OverHead Cam would have 2 cams per bank, one for the inlets and one for the exhausts. A V engine would then have 4 cams in all.

I have an OverHead Valve engine, with pushrods and one cam. OHV.

tinkering
07-14-2014, 12:27 PM
My apologies again for the confusion, and my thanks for your answers.

It was interesting though, for me to discover that some over head cam engine designs (I do not know the manufacturers) used wee push rods above the cylinder heads.

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